← All changes | includes/class-cache.php +9612 -219 1.0.6 → 1.4.1 View file →

		@@ -11,8 +11,64 @@
11	11
12	12	class Cache {
13	13
14	14	/**
	15	+ * Response header the generated server rules stamp themselves with, so a
	16	+ * cache hit says which version of the rules served it. See
	17	+ * rules_marker_expected() for what the value means.
	18	+ */
	19	+ public const RULES_HEADER = 'X-XSpeed-Rules';
	20	+
	21	+ /**
	22	+ * Response header carrying the unix time the served HTML was generated.
	23	+ *
	24	+ * Free owns it on every path where PHP runs, and emits it from the same
	25	+ * `filemtime()` of the file it is about to send: the drop-in stamps it in
	26	+ * advanced-cache.php, and the template_redirect serve path stamps it in
	27	+ * serve_not_modified(). The nginx and Apache static paths never emit it —
	28	+ * no PHP runs there, so a consumer reads their `Last-Modified` instead.
	29	+ *
	30	+ * An add-on cannot supply this value, and edge_headers_for() strips it
	31	+ * from the `xspeed_edge_cache_headers` result in every context rather
	32	+ * than asking add-ons not to try. Nothing on the filter's side of the
	33	+ * seam knows which file is being served: mark() resolves the filter with
	34	+ * no file and no mtime, so an add-on has only time(), which is when the
	35	+ * page was SERVED. A downstream purge verifier compares this stamp with
	36	+ * the moment it asked for the purge, and a stamp that is always "now"
	37	+ * makes every purge look like it worked — worse than sending nothing.
	38	+ */
	39	+ public const BUILT_HEADER = 'X-XSpeed-Built';
	40	+
	41	+ /**
	42	+ * The headers that can grant an edge a lifetime: `Cache-Control`,
	43	+ * `CDN-Cache-Control`, `Cloudflare-CDN-Cache-Control`,
	44	+ * `Surrogate-Control`, `Edge-Control`. Matched on the header NAME.
	45	+ *
	46	+ * advanced-cache.php carries a copy of this and of the pattern below,
	47	+ * because the class is not loaded when the drop-in runs. Change all four
	48	+ * together; EdgeLifetimeEntryCapTest compares them.
	49	+ */
	50	+ public const EDGE_LIFETIME_HEADER = '/(?:^|-)control$/i';
	51	+
	52	+ /**
	53	+ * A lifetime directive inside one of those headers, and its seconds.
	54	+ * See cap_edge_lifetime().
	55	+ */
	56	+ public const EDGE_LIFETIME_DIRECTIVE = '/(?<![\w-])(max-age|s-maxage)\s*=\s*"?(\d+)"?/i';
	57	+
	58	+ /** Map of rules hash => the settings fingerprint that produced it. */
	59	+ public const RULES_INPUTS_OPTION = 'xspeed_rules_inputs';
	60	+
	61	+ /**
	62	+ * User meta holding {hash, at}: the rules version this admin says they
	63	+ * pasted into the server config. See rules_copied().
	64	+ */
	65	+ public const RULES_COPIED_META = 'xspeed_nginx_rules_copied';
	66	+
	67	+ /** How many rules versions the map above remembers. */
	68	+ private const RULES_INPUTS_KEPT = 10;
	69	+
	70	+ /**
15	71	* Output-buffer nesting level at which we opened our cache buffer, so
16	72	* `close_buffer()` can flush ONLY our buffer and never disturb a buffer
17	73	* another plugin pushed on top of (or below) ours.
18	74	*
		@@ -19,11 +75,181 @@
19	75	* @var int|null
20	76	*/
21	77	private static $buffer_level = null;
22	78
	79	+ /**
	80	+ * Bytes freed by the current sweep, accumulated by sweep_delete().
	81	+ *
	82	+ * A counter rather than a return value because the two sweeps that free
	83	+ * the bytes — the flat glob loop and the recursive static walk — already
	84	+ * report a FILE count, and `wp xspeed purge` needs both numbers from a
	85	+ * single pass. Re-walking the tree to size it would double the I/O on
	86	+ * exactly the caches large enough for the number to matter.
	87	+ *
	88	+ * @var int
	89	+ */
	90	+ private static $sweep_bytes = 0;
	91	+
	92	+ /**
	93	+ * The `X-XSpeed-Cache` value decided for this request, and — when the
	94	+ * decision was BYPASS — the slug of the gate that made it.
	95	+ *
	96	+ * Recorded as well as sent so unit tests (CLI SAPI, where header() is a
	97	+ * no-op and headers_sent() is meaningless) can assert on the decision.
	98	+ *
	99	+ * @var string
	100	+ */
	101	+ private static $status_header = '';
	102	+ private static $bypass_reason = '';
	103	+
	104	+ /**
	105	+ * Edge/CDN headers decided for this request, after sanitising.
	106	+ *
	107	+ * Same reason as $status_header: header() cannot be observed from the CLI
	108	+ * SAPI, so the pairs we sent are recorded here too.
	109	+ *
	110	+ * @var array<string,string>
	111	+ */
	112	+ private static $edge_headers = array();
	113	+
	114	+ /**
	115	+ * This entry's edge headers when they differ from the site-wide bake,
	116	+ * resolved once per store. Null until asked.
	117	+ *
	118	+ * @var array<string,string>|null
	119	+ */
	120	+ private static $per_entry_edge = null;
	121	+
	122	+ /**
	123	+ * Cache key whose write was deferred to shutdown because a render-time
	124	+ * translation plugin's buffer wraps ours. Null on every ordinary request.
	125	+ *
	126	+ * @var string|null
	127	+ */
	128	+ private static $deferred_key = null;
	129	+
	130	+ /**
	131	+ * Translated page HTML captured by the outer buffer, for the deferred
	132	+ * write. Only populated when a translation plugin is active.
	133	+ *
	134	+ * @var string
	135	+ */
	136	+ private static $translated_output = '';
	137	+
	138	+ /**
	139	+ * Did finalize_buffer() run to completion on this request?
	140	+ *
	141	+ * The deferred translated write runs as a PHP shutdown function, which
	142	+ * fires after a `wp_die()` or a bare `exit()` exactly as it does after a
	143	+ * clean render. Only finalize_buffer() sets this, and only at the point
	144	+ * where it has the full buffer in hand — so an aborted render leaves it
	145	+ * false and the writer declines rather than caching a truncated page
	146	+ * under the real key.
	147	+ *
	148	+ * @var bool
	149	+ */
	150	+ private static $render_completed = false;
	151	+
	152	+ /**
	153	+ * Minifier::purge_stamp() when this request's cache buffer opened.
	154	+ *
	155	+ * A render names its minified and combined files while it runs and is
	156	+ * stored when it ends. A purge that deletes those files in between would
	157	+ * otherwise leave a stored page linking files that are gone, for the
	158	+ * whole TTL. The stamp changes whenever such a purge deletes anything, so
	159	+ * a different value at store time means "do not store this one".
	160	+ *
	161	+ * Null when maybe_start_cache() opened no buffer. A direct call (tests,
	162	+ * add-ons) has nothing to compare against and stores as before.
	163	+ *
	164	+ * @var string|null
	165	+ */
	166	+ private static $asset_stamp_at_open = null;
	167	+
	168	+ /**
	169	+ * The snapshot above, carried to the deferred (translated) writer.
	170	+ *
	171	+ * @var string|null
	172	+ */
	173	+ private static $deferred_asset_stamp = null;
	174	+
	175	+ /**
	176	+ * Hooks that get an argument-aware handler instead of a blanket purge.
	177	+ *
	178	+ * Each fires on an ordinary visitor action — an order, a review, a
	179	+ * registration — where purge_all() cannot see WHAT changed and so wiped
	180	+ * the whole cache on every one. They are re-bound further down to
	181	+ * handlers that inspect the payload first.
	182	+ *
	183	+ * Listed here so the generic invalidation loop skips them. It binds a
	184	+ * closure (to name the cause), and a closure cannot be unbound by the
	185	+ * remove_action() pairs below — binding one would leave the coarse purge
	186	+ * running alongside its replacement and silently undo #243.
	187	+ */
	188	+ private const TARGETED_INVALIDATION_HOOKS = array(
	189	+ 'save_post',
	190	+ 'before_delete_post',
	191	+ 'trashed_post',
	192	+ 'comment_post',
	193	+ 'wp_set_comment_status',
	194	+ 'user_register',
	195	+ 'profile_update',
	196	+ );
	197	+
23	198	public function __construct() {
24		- add_action( 'template_redirect', array( $this, 'maybe_start_cache' ), 0 );
	199	+ /**
	200	+ * When the page-cache output buffer opens.
	201	+ *
	202	+ * Filterable because buffer ORDER decides what gets cached. PHP's
	203	+ * output buffers are LIFO: the last one opened is innermost, and its
	204	+ * callback runs first. A render-time translation plugin that opens
	205	+ * an outer buffer therefore translates AFTER we have already captured
	206	+ * and cached the raw HTML — see translation_buffer_compat().
	207	+ *
	208	+ * @param string $hook Hook to open the buffer on.
	209	+ * @param int $priority Priority for that hook.
	210	+ */
	211	+ $hook = (string) apply_filters( 'xspeed_cache_buffer_hook', 'template_redirect' );
	212	+ $priority = (int) apply_filters( 'xspeed_cache_buffer_priority', 0 );
	213	+ add_action( $hook, array( $this, 'maybe_start_cache' ), $priority );
25	214
	215	+ // When a render-time translation plugin is present, open one extra
	216	+ // buffer OUTSIDE its own so we can capture post-translation HTML.
	217	+ // TranslatePress opens on `init` priority 0, so we take a negative
	218	+ // priority to land outside it. This buffer only collects bytes for
	219	+ // the deferred cache write — it never modifies the response.
	220	+ add_action(
	221	+ 'init',
	222	+ static function () {
	223	+ if ( ! self::translation_plugin_active() ) {
	224	+ return;
	225	+ }
	226	+ // `init` fires on EVERY request type, and
	227	+ // translation_plugin_active() is a class_exists() check that
	228	+ // is true site-wide — so without this guard the buffer opened
	229	+ // on REST, admin-ajax, cron and WP-CLI too. None of those
	230	+ // reach template_redirect, so $deferred_key stays null and
	231	+ // the collected bytes are never released: a long-running
	232	+ // WP-CLI command copied every byte of its output into a
	233	+ // string that grew for the life of the process.
	234	+ if ( is_admin()
	235	+ || wp_doing_ajax()
	236	+ || wp_doing_cron()
	237	+ || ( defined( 'REST_REQUEST' ) && REST_REQUEST )
	238	+ || ( defined( 'WP_CLI' ) && WP_CLI )
	239	+ || ( defined( 'XMLRPC_REQUEST' ) && XMLRPC_REQUEST ) ) {
	240	+ return;
	241	+ }
	242	+ ob_start(
	243	+ static function ( $chunk ) {
	244	+ self::$translated_output .= $chunk;
	245	+ return $chunk;
	246	+ }
	247	+ );
	248	+ },
	249	+ (int) apply_filters( 'xspeed_translation_outer_buffer_priority', -100 )
	250	+ );
	251	+
26	252	// Events that should invalidate cached output. Beyond posts/comments,
27	253	// this covers user and term changes — the REST cache can serve
28	254	// /wp/v2/users, /wp/v2/categories, /wp/v2/tags, and these also affect
29	255	// rendered author bylines / term-archive pages. Without them, an edit
		@@ -29,9 +255,9 @@
29	255	// rendered author bylines / term-archive pages. Without them, an edit
30	256	// left the matching endpoint (and archives) stale for the full TTL.
31	257	// (FBS-82408)
32	258	$invalidate_hooks = array(
33		- 'save_post', 'deleted_post', 'trashed_post',
	259	+ 'save_post', 'before_delete_post', 'trashed_post',
34	260	'comment_post', 'wp_set_comment_status',
35	261	'switch_theme', 'activated_plugin', 'deactivated_plugin',
36	262	// Users → /wp/v2/users + author archives.
37	263	'profile_update', 'user_register', 'deleted_user',
		@@ -36,16 +262,222 @@
36	262	// Users → /wp/v2/users + author archives.
37	263	'profile_update', 'user_register', 'deleted_user',
38	264	// Terms → /wp/v2/{taxonomy} + term archives.
39	265	'created_term', 'edited_term', 'delete_term',
	266	+ // Menu structure changes (reorder, rename, assign to a location)
	267	+ // fire only here — the per-item `nav_menu_item` save_post does
	268	+ // not cover them. (#270 regression)
	269	+ 'wp_update_nav_menu',
40	270	);
41	271	foreach ( $invalidate_hooks as $hook ) {
42		- add_action( $hook, array( __CLASS__, 'purge_all' ) );
43		- add_action( $hook, array( 'XSpeed\\Minifier', 'purge_minified' ) );
	272	+ // Name the hook in the cause rather than binding purge_all bare.
	273	+ // Bound bare, WordPress passes the action's own first argument
	274	+ // into $cause — a term id, a user id, a menu id — so the activity
	275	+ // feed read "Cache purged (12)" and told the user nothing about
	276	+ // what happened. (#270 QA round 2)
	277	+ //
	278	+ // The four hooks that get an argument-aware handler below
	279	+ // (save_post, comment_post, user_register, profile_update) are
	280	+ // deliberately NOT wired here: a closure cannot be unbound by
	281	+ // remove_action(), so binding one would leave the coarse purge in
	282	+ // place alongside its replacement and silently undo #243. Skipping
	283	+ // them is equivalent — each is re-added with its own handler, and
	284	+ // each of those names its own cause.
	285	+ if ( in_array( $hook, self::TARGETED_INVALIDATION_HOOKS, true ) ) {
	286	+ continue;
	287	+ }
	288	+ add_action(
	289	+ $hook,
	290	+ static function () use ( $hook ): void {
	291	+ self::purge_all(
	292	+ 'hook:' . $hook,
	293	+ null,
	294	+ self::invalidation_for_hook( $hook )
	295	+ );
	296	+ }
	297	+ );
	298	+ // No purge_minified() here. Minified and combined files are named
	299	+ // by content, so a render after this purge links the same names
	300	+ // when nothing changed and new names when something did. Deleting
	301	+ // them only opened a window where cached and in-flight pages link
	302	+ // files that are gone, and on a network it took every subsite's
	303	+ // files with it.
44	304	}
45	305
	306	+ // Updating a plugin, theme or core changes the markup and the assets
	307	+ // a page is built from, but fires NONE of the hooks above: WordPress
	308	+ // does not deactivate and reactivate a plugin to update it, so
	309	+ // `activated_plugin` never runs and the cached HTML survives the
	310	+ // update untouched for the whole TTL — up to 7 days on the Aggressive
	311	+ // preset, 30 at the maximum.
	312	+ //
	313	+ // The stale copy is not merely old, it is wrong in a way the user
	314	+ // cannot see the cause of: they update a plugin to get a fix, the
	315	+ // cache keeps serving the pre-fix HTML, and the update looks like it
	316	+ // did nothing. Minified assets do regenerate on their own (they are
	317	+ // named by content), which makes it worse rather than better — the
	318	+ // cached pages still link the PREVIOUS names.
	319	+ //
	320	+ // Purge unconditionally on any completed update. Scoping it to
	321	+ // "plugins that enqueue front-end assets" is not knowable here, and a
	322	+ // cold cache after an update is the cheaper mistake. (#269)
	323	+ add_action( 'upgrader_process_complete', array( __CLASS__, 'purge_after_upgrade' ), 10, 2 );
	324	+ // The replacement signal has to outlive OUR listener: add-ons read it
	325	+ // through upgrade_replaced_code() from their own priority-10 callbacks,
	326	+ // and consuming it inside purge_after_upgrade() meant whoever
	327	+ // registered second saw false. Cleared at the END of the dispatch
	328	+ // instead, once every listener has had its turn.
	329	+ //
	330	+ // Depth-counted, because this action NESTS. Core hangs
	331	+ // Language_Pack_Upgrader::async_upgrade() on it at priority 20
	332	+ // (wp-admin/includes/admin-filters.php), and that runs a whole
	333	+ // upgrader of its own, which fires this same action again. A flat
	334	+ // reset therefore fired while the OUTER dispatch was still running —
	335	+ // on any site with pending translations — and every listener after
	336	+ // priority 20 read the cleared signal as false. Which is the bug this
	337	+ // pair exists to fix, back again and harder to see. (#303)
	338	+ add_action( 'upgrader_process_complete', array( __CLASS__, 'note_upgrade_dispatch' ), PHP_INT_MIN );
	339	+ add_action( 'upgrader_process_complete', array( __CLASS__, 'forget_cleared_destination' ), PHP_INT_MAX );
	340	+ // WordPress labels an upload-and-replace as an INSTALL, so the action
	341	+ // alone cannot tell "added beside nothing" from "replaced live code".
	342	+ // This filter fires only when the upgrader removed an existing copy,
	343	+ // which is exactly the difference. Registered as a filter listener
	344	+ // that returns its input untouched. (#303)
	345	+ add_filter( 'upgrader_clear_destination', array( __CLASS__, 'note_cleared_destination' ), 10, 4 );
	346	+ // …but `upgrader_clear_destination` fires whenever the upgrader was
	347	+ // ASKED to clear, not only when it removed something:
	348	+ // WP_Upgrader::clear_destination() returns true early when the
	349	+ // destination does not exist. Looked at before the delete, while the
	350	+ // old copy is still on disk. (#303)
	351	+ //
	352	+ // PHP_INT_MAX, because the folder name is only final once every other
	353	+ // listener has had its turn. Update libraries that normalise
	354	+ // `plugin-1.2.3/` to `plugin/` (Plugin Update Checker, EDD Software
	355	+ // Licensing, GitHub-sourced zips) rename the extracted directory on
	356	+ // this same filter at priority 10 or later, and core derives the real
	357	+ // destination from the FILTERED source. Measured at 10, a genuine
	358	+ // replacement read as "nothing was there" and the stale cache stayed.
	359	+ // note_cleared_destination() cross-checks the folder core actually
	360	+ // cleared against the one measured here, for a renamer that runs
	361	+ // later still. (#407 QA)
	362	+ add_filter( 'upgrader_source_selection', array( __CLASS__, 'note_destination_state' ), PHP_INT_MAX, 4 );
	363	+ // Unattended auto-updates are the case that matters most here: they
	364	+ // land overnight with nobody around to purge by hand, which is the
	365	+ // exact scenario the stale cache goes undiagnosed in. WordPress fires
	366	+ // this INSTEAD of a per-item upgrader_process_complete for some
	367	+ // background runs. Its payload is a results array keyed by type
	368	+ // rather than a hook_extra, so it needs its own handler — passing it
	369	+ // to purge_after_upgrade() landed it in the unused $upgrader slot and
	370	+ // left $type empty, which read as "invalidating" and purged the whole
	371	+ // cache for a language-pack-only run. Matches what LiteSpeed binds.
	372	+ // (#298)
	373	+ add_action( 'automatic_updates_complete', array( __CLASS__, 'purge_after_auto_updates' ), 10, 1 );
	374	+ // A Customizer publish changes theme mods, Additional CSS, the site
	375	+ // identity and widget areas, so markup and inline CSS change on every
	376	+ // page. It fires none of the hooks above. theme_mods_* is an ordinary
	377	+ // option, and Additional CSS is a non-viewable `custom_css` post that
	378	+ // the save_post gate rightly ignores. Without this, cached pages kept
	379	+ // the old header, colours and custom CSS for the whole TTL.
	380	+ add_action( 'customize_save_after', array( __CLASS__, 'on_customize_save' ), 10, 0 );
	381	+ // …except the four hooks above that fire on ordinary visitor actions.
	382	+ // Attached bare, purge_all() can't see WHAT changed, so on a store
	383	+ // every order, every product review and every checkout
	384	+ // account-creation wiped 100% of the cache — all anonymous happy-path
	385	+ // actions, so the cache never reached steady state (#243). Measured:
	386	+ // 3 orders across 36 pageviews took the hit rate from 83% to 50% and
	387	+ // the average response from 23ms to 57ms.
	388	+ //
	389	+ // HPOS does NOT help: WooCommerce still writes a
	390	+ // `shop_order_placehold` row into wp_posts to reserve the order ID,
	391	+ // so save_post fires either way. The gate therefore keys on POST-TYPE
	392	+ // VIEWABILITY, not on storage mode — which fixes both modes at once,
	393	+ // and generalises to Flamingo (#229) and Tutor LMS (#231) too.
	394	+ remove_action( 'save_post', array( __CLASS__, 'purge_all' ) );
	395	+ add_action( 'save_post', array( __CLASS__, 'on_save_post' ), 10, 2 );
	396	+ // Bracket every post save, so a WooCommerce product save that runs
	397	+ // inside one (wp-admin's Update) can tell on_save_post() is about to
	398	+ // clear the whole site for the same product. See purge_product().
	399	+ add_action( 'save_post', array( __CLASS__, 'on_post_save_start' ), 0, 2 );
	400	+ add_action( 'save_post', array( __CLASS__, 'on_post_save_end' ), PHP_INT_MAX, 1 );
	401	+ // The narrow purge runs here, after the REST API has set the terms
	402	+ // (it sets them after `save_post`), with the post as it was before.
	403	+ add_action( 'wp_after_insert_post', array( __CLASS__, 'on_after_insert_post' ), 10, 4 );
	404	+ add_action( 'shutdown', array( __CLASS__, 'flush_pending_saves' ), 1, 0 );
	405	+ add_action( 'update_option_sticky_posts', array( __CLASS__, 'on_sticky_posts_change' ), 10, 2 );
	406	+ // The first sticky post on a site creates the option instead.
	407	+ add_action( 'add_option_sticky_posts', array( __CLASS__, 'on_sticky_posts_added' ), 10, 2 );
	408	+ add_action( 'pre_post_update', array( __CLASS__, 'on_pre_post_update' ), 10, 2 );
	409	+ add_action( 'before_delete_post', array( __CLASS__, 'on_post_removed' ), 10, 2 );
	410	+ add_action( 'trashed_post', array( __CLASS__, 'on_post_removed' ), 10, 2 );
	411	+ // wp_delete_post() hands an attachment to wp_delete_attachment() and
	412	+ // returns BEFORE before_delete_post fires, so deleting media reached
	413	+ // neither hook above. Attachment pages are public and media appears in
	414	+ // galleries, so that left cached pages showing a file that is gone.
	415	+ // (dev caught this via `deleted_post`, which this branch replaced.)
	416	+ add_action( 'delete_attachment', array( __CLASS__, 'on_post_removed' ), 10, 2 );
	417	+
	418	+ remove_action( 'comment_post', array( __CLASS__, 'purge_all' ) );
	419	+ add_action( 'comment_post', array( __CLASS__, 'on_comment_post' ), 10, 3 );
	420	+ add_action( 'wp_set_comment_status', array( __CLASS__, 'on_comment_status' ), 10, 2 );
	421	+
	422	+ remove_action( 'user_register', array( __CLASS__, 'purge_all' ) );
	423	+ add_action( 'user_register', array( __CLASS__, 'on_user_change' ) );
	424	+
	425	+ remove_action( 'profile_update', array( __CLASS__, 'purge_all' ) );
	426	+ add_action( 'profile_update', array( __CLASS__, 'on_user_change' ) );
	427	+
	428	+ // Product data lives in post meta and lookup tables, NOT in wp_posts,
	429	+ // so WC_Product_Data_Store_CPT::update() takes a direct $wpdb->update()
	430	+ // branch and save_post never fires. Anchoring invalidation on
	431	+ // save_post therefore missed 100% of commerce-relevant mutations: a
	432	+ // REST price change, wc_update_product_stock(), a CLI ->save(), and
	433	+ // every scheduled sale start/end left the product page, the shop and
	434	+ // the category archives serving the old price and stock for the full
	435	+ // lifetime — the store quoting one price and charging another (#242).
	436	+ //
	437	+ // This MUST ship with the gate above: once orders stop purging
	438	+ // everything, the accidental invalidation that was masking this
	439	+ // disappears, and an order that reduces stock would leave the product
	440	+ // page stale.
	441	+ if ( class_exists( 'WooCommerce' ) ) {
	442	+ foreach ( array( 'woocommerce_update_product', 'woocommerce_new_product' ) as $wc_hook ) {
	443	+ add_action( $wc_hook, array( __CLASS__, 'on_product_saved' ) );
	444	+ }
	445	+ // wc_update_product_stock() writes the stock with SQL, saves the
	446	+ // product (which fires woocommerce_update_product above), then
	447	+ // fires *_set_stock. The *_before_set_stock actions open that
	448	+ // write, so the *_set_stock that closes it can tell the save
	449	+ // inside it already purged. With `$updating` set it skips the
	450	+ // save, and *_set_stock is then the only purge.
	451	+ add_action( 'woocommerce_product_before_set_stock', array( __CLASS__, 'on_product_stock_write' ) );
	452	+ add_action( 'woocommerce_variation_before_set_stock', array( __CLASS__, 'on_product_stock_write' ) );
	453	+ add_action( 'woocommerce_product_set_stock', array( __CLASS__, 'on_product_stock_set' ) );
	454	+ add_action( 'woocommerce_variation_set_stock', array( __CLASS__, 'on_product_stock_set' ) );
	455	+ add_action( 'woocommerce_product_set_stock_status', array( __CLASS__, 'purge_product' ) );
	456	+ add_action( 'woocommerce_variation_set_stock_status', array( __CLASS__, 'purge_product' ) );
	457	+ }
	458	+
46	459	add_action( 'update_option_xspeed_options', array( __CLASS__, 'on_settings_change' ), 10, 2 );
47	460
	461	+ // …and the same for every PER-MODULE option. The handler above only
	462	+ // ever watched the legacy `xspeed_options` blob, but every module has
	463	+ // since migrated to its own `xspeed_module_<slug>` option and no hook
	464	+ // followed — so changing Minify HTML, Lazy Load, Remove Query Strings
	465	+ // etc. left the cached HTML untouched until the TTL expired (24h by
	466	+ // default) and the feature read as broken. (#205)
	467	+ //
	468	+ // One central listener rather than a hook per module: it covers Pro
	469	+ // modules with no cross-repo change, and a new module can't forget to
	470	+ // wire it up.
	471	+ add_action( 'updated_option', array( __CLASS__, 'on_module_settings_change' ), 10, 1 );
	472	+ // `added_option` matters as much as `updated_option`: on a fresh install
	473	+ // a module's option doesn't exist yet, so the FIRST save of every panel
	474	+ // goes through add_option() and would otherwise skip the purge — the
	475	+ // original bug surviving one save per module. `deleted_option` covers a
	476	+ // reset-to-defaults, which changes rendered HTML just as much. (#205)
	477	+ add_action( 'added_option', array( __CLASS__, 'on_module_settings_change' ), 10, 1 );
	478	+ add_action( 'deleted_option', array( __CLASS__, 'on_module_settings_change' ), 10, 1 );
	479	+
48	480	add_action( 'admin_bar_menu', array( $this, 'admin_bar_purge' ), 100 );
49	481	add_action( 'admin_post_xspeed_purge', array( $this, 'handle_admin_bar_purge' ) );
50	482	}
51	483
		@@ -56,23 +488,1503 @@
56	488	// (Cache module). Keep this handler around for whatever still
57	489	// lives in the legacy blob (cache_enabled is special and goes
58	490	// through Cache::toggle anyway).
59	491
60		- // Any settings change — purge caches so changes take effect.
	492	+ // Any settings change — purge caches so changes take effect. Minified
	493	+ // files are named by content, so there is nothing to delete for them.
61	494	self::purge_all( 'settings change' );
62		- Minifier::purge_minified();
63	495	}
64	496
	497	+ /**
	498	+ * Modules whose settings cannot change rendered HTML, so a write to them
	499	+ * doesn't warrant throwing away the page cache.
	500	+ *
	501	+ * The safe default is to purge: a module is listed here only when it is
	502	+ * clearly incapable of altering front-end output (diagnostics, the MCP
	503	+ * server, licensing/telemetry surfaces). When in doubt, leave it off the
	504	+ * list — a needless purge costs a re-render, a missed one makes the
	505	+ * feature look broken. (#205)
	506	+ *
	507	+ * @return string[] Module slugs.
	508	+ */
	509	+ public static function non_rendering_modules(): array {
	510	+ return (array) apply_filters(
	511	+ 'xspeed_non_rendering_modules',
	512	+ array(
	513	+ 'mcp', // AI endpoint — no front-end output.
	514	+ 'health', // diagnostics only.
	515	+ 'support', // support snapshot.
	516	+ 'score', // PageSpeed/GTmetrix runner.
	517	+ 'migration', // one-shot importer.
	518	+ 'settings', // import/export surface.
	519	+ 'cache-coverage', // read-only reporting.
	520	+ 'ai-privacy', // consent flags for AI surfaces.
	521	+ 'database', // DB cleanup schedule — no HTML impact.
	522	+ // Pro slugs — listed by name rather than by asking Pro, so
	523	+ // Free stays unaware of it. A Pro module absent here simply
	524	+ // purges, which is the safe default.
	525	+ 'license',
	526	+ 'pro_status',
	527	+ 'analytics',
	528	+ 'performance-health',
	529	+ 'recommendations',
	530	+ 'ai-provider',
	531	+ 'migration-pro',
	532	+ )
	533	+ );
	534	+ }
	535	+
	536	+ /**
	537	+ * Purge when ANY module's settings option is written. (#205)
	538	+ *
	539	+ * Bound to `updated_option`, `added_option` and `deleted_option` — all three
	540	+ * fire for every option on the site, so the prefix test comes first and is
	541	+ * the cheap path for the ~99% of writes that aren't ours. All three pass the
	542	+ * option name first, which is why this can't hook purge_all() directly:
	543	+ * that takes $cause first, so every purge would be filed under a cause
	544	+ * literally named "xspeed_module_minify".
	545	+ *
	546	+ * @param string $option Option name that was just written or removed.
	547	+ */
	548	+ public static function on_module_settings_change( $option ): void {
	549	+ $option = (string) $option;
	550	+ $prefix = Settings_Manager::OPTION_PREFIX;
	551	+ if ( 0 !== strpos( $option, $prefix ) ) {
	552	+ return;
	553	+ }
	554	+
	555	+ $slug = substr( $option, strlen( $prefix ) );
	556	+ if ( '' === $slug || in_array( $slug, self::non_rendering_modules(), true ) ) {
	557	+ return;
	558	+ }
	559	+
	560	+ // Guard against re-entry: purge_all() can write options of its own (stats, timestamps), and a nested purge would
	561	+ // both waste work and risk recursing through this same hook.
	562	+ static $purging = false;
	563	+ if ( $purging ) {
	564	+ return;
	565	+ }
	566	+ $purging = true;
	567	+
	568	+ self::purge_all( 'settings change' );
	569	+
	570	+ $purging = false;
	571	+ }
	572	+
	573	+ /**
	574	+ * Stamp the request's cache decision on the response.
	575	+ *
	576	+ * `X-XSpeed-Cache` was only ever written on the serve-from-cache paths,
	577	+ * so a miss and a deliberate bypass both came back with no header at all
	578	+ * — indistinguishable from a `curl -I`, the first thing anyone reaches
	579	+ * for when a site "isn't caching" (issue #10). The reason slug rides
	580	+ * along on `X-XSpeed-Reason`, but only under WP_DEBUG so production
	581	+ * responses stay clean. Slugs are fixed per gate — never the matched
	582	+ * pattern, cookie or user-agent, which would echo request input back.
	583	+ *
	584	+ * @param string $value HIT (php) | MISS | BYPASS.
	585	+ * @param string $reason Fixed slug naming the gate, for BYPASS only.
	586	+ * @param int|null $lifetime_left On a HIT, the seconds the served entry has
	587	+ * left when it has a lifetime of its own;
	588	+ * null when it follows the site's. See
	589	+ * entry_lifetime_left().
	590	+ */
	591	+ private static function mark( string $value, string $reason = '', ?int $lifetime_left = null ): void {
	592	+ self::$status_header = $value;
	593	+ self::$bypass_reason = $reason;
	594	+ self::$edge_headers = array();
	595	+
	596	+ // A served-from-cache response may carry edge/CDN headers an add-on
	597	+ // contributes — `CDN-Cache-Control`, `Cache-Tag` and friends. Only a
	598	+ // HIT resolves them here. A BYPASS never does: the response was
	599	+ // deliberately excluded from our cache, so telling a CDN to hold it
	600	+ // for a month would cache at the edge exactly what we refused to
	601	+ // cache here. A MISS never does either, stored or not: it is the
	602	+ // first render, and the one most likely to be replaced once critical
	603	+ // CSS and unused CSS have been generated. Pinning it at the edge pins
	604	+ // the version xSpeed is about to improve on. The edge caches from the
	605	+ // first HIT instead — one render later, and the right one.
	606	+ //
	607	+ // Resolved before the headers_sent() guard so the decision is
	608	+ // recorded (and observable in tests) even on a request that can no
	609	+ // longer send headers; only the emission below is conditional.
	610	+ if ( 'HIT' === self::edge_status( $value ) ) {
	611	+ self::$edge_headers = self::edge_headers_for( 'HIT' );
	612	+ }
	613	+
	614	+ // Every status, not just a HIT. A page we declined to cache is the
	615	+ // one an edge most needs telling about: it goes out naked today, and
	616	+ // a CDN that stores HTML by default keeps somebody's cart.
	617	+ //
	618	+ // Resolved before the headers_sent() guard so the decision is
	619	+ // recorded (and observable in tests) even on a request that can no
	620	+ // longer send headers; only the emission below is conditional.
	621	+ self::$edge_headers = self::edge_headers_for( self::edge_status( $value ), 'request', $reason );
	622	+
	623	+ // The same countdown the drop-in applies to this entry, so the two
	624	+ // PHP serve paths tell the edge the same thing about one page.
	625	+ if ( null !== $lifetime_left && 'HIT' === self::edge_status( $value ) ) {
	626	+ self::$edge_headers = self::cap_edge_lifetime( self::$edge_headers, $lifetime_left );
	627	+ }
	628	+
	629	+ if ( headers_sent() ) {
	630	+ return;
	631	+ }
	632	+ header( 'X-XSpeed-Cache: ' . $value );
	633	+ if ( '' !== $reason && defined( 'WP_DEBUG' ) && WP_DEBUG ) {
	634	+ header( 'X-XSpeed-Reason: ' . $reason );
	635	+ }
	636	+ foreach ( self::$edge_headers as $name => $val ) {
	637	+ header( $name . ': ' . $val );
	638	+ }
	639	+ }
	640	+
	641	+ /**
	642	+ * Normalize an `X-XSpeed-Cache` value to the vocabulary the edge seam
	643	+ * speaks.
	644	+ *
	645	+ * The header value carries which layer served the page (`HIT (php)`,
	646	+ * `HIT (nginx)`, `HIT (static)`); nothing deciding what to tell a CDN
	647	+ * cares, and making a caller match on three spellings of one outcome is
	648	+ * how a rule ends up applied on two paths out of three.
	649	+ */
	650	+ private static function edge_status( string $value ): string {
	651	+ return 0 === strpos( $value, 'HIT' ) ? 'HIT' : $value;
	652	+ }
	653	+
	654	+ /**
	655	+ * Hash a generated rule set so the rules can identify themselves.
	656	+ *
	657	+ * @param string[] $lines Every line of the rule set EXCEPT the marker.
	658	+ */
	659	+ private static function rules_hash( array $lines ): string {
	660	+ return substr( sha1( implode( "\n", $lines ) ), 0, 8 );
	661	+ }
	662	+
	663	+ /**
	664	+ * Insert the self-describing marker directive into a generated rule set.
	665	+ *
	666	+ * The hash is taken over the rule set WITHOUT this line, and that is the
	667	+ * whole trick: hashing the finished text instead would mean the act of
	668	+ * adding the marker changed the value the marker advertises, the probe
	669	+ * would never see a match, and every correctly installed block would
	670	+ * report itself out of date forever. The one property worth a test of its
	671	+ * own — RewriteProbeRulesStateTest covers it.
	672	+ *
	673	+ * More than one template is allowed because Apache needs the same marker
	674	+ * twice, under two environment-variable names (see rewrite_block_lines).
	675	+ * All of them carry the SAME hash, taken over the marker-less rule set, so
	676	+ * adding the second directive cannot change the value either advertises.
	677	+ *
	678	+ * @param string[] $lines The rule set, with no marker line in it.
	679	+ * @param string[] $templates sprintf templates for the directives; `%s` is the hash.
	680	+ * @param int $at Index to insert the marker at.
	681	+ * @return string[]
	682	+ */
	683	+ private static function with_rules_marker( array $lines, array $templates, int $at ): array {
	684	+ $hash = self::rules_hash( $lines );
	685	+ $directives = array();
	686	+ foreach ( $templates as $template ) {
	687	+ $directives[] = sprintf( $template, $hash );
	688	+ }
	689	+ array_splice( $lines, $at, 0, $directives );
	690	+ return $lines;
	691	+ }
	692	+
	693	+ /**
	694	+ * The rules hash the CURRENT settings generate, i.e. what a correctly
	695	+ * installed rule set would be sending back.
	696	+ *
	697	+ * Read out of the generated artifact rather than recomputed, so there is
	698	+ * exactly one definition of the hash and no way for the generator and the
	699	+ * expectation to drift apart. Empty on a server whose fast path we do not
	700	+ * generate rules for.
	701	+ */
	702	+ public static function rules_marker_expected(): string {
	703	+ $type = Server::type();
	704	+ if ( Server::NGINX === $type ) {
	705	+ return self::extract_rules_marker( (string) self::nginx_snippet() );
	706	+ }
	707	+ if ( Server::APACHE === $type ) {
	708	+ return self::extract_rules_marker( implode( "\n", self::rewrite_block_lines() ) );
	709	+ }
	710	+ return '';
	711	+ }
	712	+
	713	+ /** Pull the marker value out of a generated rule set ('' when absent). */
	714	+ public static function extract_rules_marker( string $source ): string {
	715	+ if ( preg_match( '/' . preg_quote( self::RULES_HEADER, '/' ) . ' "([0-9a-f]{8})"/', $source, $m ) ) {
	716	+ return $m[1];
	717	+ }
	718	+ return '';
	719	+ }
	720	+
	721	+ /**
	722	+ * Fingerprint of every setting that feeds the generated server rules.
	723	+ *
	724	+ * Values are hashed rather than stored: this map is written from a read
	725	+ * path and has no business becoming a second copy of the user's exclusion
	726	+ * lists. A per-key hash is enough — the point is to name WHICH setting
	727	+ * moved between two rule versions, not to reconstruct the old value.
	728	+ *
	729	+ * @return array<string,string>
	730	+ */
	731	+ public static function rules_inputs(): array {
	732	+ $cache_opts = Settings_Manager::get( 'cache' );
	733	+ $fingerprint = static function ( $value ): string {
	734	+ $flat = array();
	735	+ foreach ( (array) $value as $key => $item ) {
	736	+ $flat[] = $key . '=' . ( is_scalar( $item ) ? (string) $item : '' );
	737	+ }
	738	+ return substr( sha1( implode( "\x1f", $flat ) ), 0, 8 );
	739	+ };
	740	+
	741	+ return array(
	742	+ 'excluded_cookies' => $fingerprint( $cache_opts['excluded_cookies'] ?? array() ),
	743	+ 'bypass_user_agents' => $fingerprint( $cache_opts['bypass_user_agents'] ?? array() ),
	744	+ 'excluded_urls' => $fingerprint( $cache_opts['excluded_urls'] ?? array() ),
	745	+ 'edge_headers' => $fingerprint( self::edge_headers_for( 'HIT', 'rules' ) ),
	746	+ 'static_dir' => $fingerprint( array( XSPEED_CACHE_STATIC_DIR ) ),
	747	+ );
	748	+ }
	749	+
	750	+ /**
	751	+ * Remember which settings produced a rules version.
	752	+ *
	753	+ * Without this a stale verdict can only say "stale". With it, the hash the
	754	+ * server sent back is a key into what the site's settings looked like when
	755	+ * those rules were generated, so the dashboard can name what changed since
	756	+ * the user last pasted. Bounded to the last few versions — the map exists
	757	+ * to explain a recent drift, not to keep a history.
	758	+ *
	759	+ * @param array<string,string> $inputs Fingerprint from rules_inputs().
	760	+ */
	761	+ private static function remember_rules_inputs( string $hash, array $inputs ): void {
	762	+ if ( '' === $hash ) {
	763	+ return;
	764	+ }
	765	+ $map = get_option( self::RULES_INPUTS_OPTION, array() );
	766	+ if ( ! is_array( $map ) ) {
	767	+ $map = array();
	768	+ }
	769	+ if ( isset( $map[ $hash ] ) && $map[ $hash ] === $inputs ) {
	770	+ return;
	771	+ }
	772	+ $map[ $hash ] = $inputs;
	773	+ if ( count( $map ) > self::RULES_INPUTS_KEPT ) {
	774	+ $map = array_slice( $map, -self::RULES_INPUTS_KEPT, null, true );
	775	+ }
	776	+ update_option( self::RULES_INPUTS_OPTION, $map, false );
	777	+ }
	778	+
	779	+ /**
	780	+ * Which settings changed between the installed rules and the current ones.
	781	+ *
	782	+ * Empty when the installed version predates the map (nothing to compare
	783	+ * against) — the caller then says "out of date" without naming a cause,
	784	+ * which is honest.
	785	+ *
	786	+ * @param array<string,string> $current Fingerprint from rules_inputs().
	787	+ * @return string[] Setting keys.
	788	+ */
	789	+ private static function changed_rules_inputs( string $observed, array $current ): array {
	790	+ $map = get_option( self::RULES_INPUTS_OPTION, array() );
	791	+ if ( ! is_array( $map ) || ! isset( $map[ $observed ] ) || ! is_array( $map[ $observed ] ) ) {
	792	+ return array();
	793	+ }
	794	+
	795	+ $was = $map[ $observed ];
	796	+ $changed = array();
	797	+ foreach ( $current as $key => $value ) {
	798	+ if ( ! array_key_exists( $key, $was ) || $was[ $key ] !== $value ) {
	799	+ $changed[] = $key;
	800	+ }
	801	+ }
	802	+ return $changed;
	803	+ }
	804	+
	805	+ /**
	806	+ * Whether the rules the server is running are the rules these settings
	807	+ * generate.
	808	+ *
	809	+ * Nothing in WordPress can read a hand-pasted nginx server block, so
	810	+ * before this the dashboard could only guess — and guessed by telling
	811	+ * everyone to re-paste after every settings change. The generated rules
	812	+ * now carry their own hash and the probe reads it back:
	813	+ *
	814	+ * current — the marker matches what these settings generate.
	815	+ * stale — a marker came back, from a different version of the rules.
	816	+ * absent — the probe reached a verdict and saw no marker: either no
	817	+ * rules are installed (the request fell through to PHP) or
	818	+ * they predate the marker. Either way the fix is the same.
	819	+ * unknown — the probe could not tell, or this server has no rule set we
	820	+ * generate.
	821	+ *
	822	+ * A marker outranks the probe's own `active` verdict: the marker is direct
	823	+ * evidence of which rules answered, while `active` is inferred from
	824	+ * response shape.
	825	+ *
	826	+ * Scope: the static-cache rules only — nginx_snippet() on nginx, the
	827	+ * .htaccess block on Apache. full_nginx_server_block() pastes those
	828	+ * alongside other modules' directives, and a change to one of those does
	829	+ * NOT move this hash. Hashing the aggregate would mean the marker inside
	830	+ * the location block had to know the text it is embedded in, and the
	831	+ * snippet would hash differently depending on which caller asked for it.
	832	+ * Callers wording this for a human should say "cache rules", not "your
	833	+ * nginx config".
	834	+ *
	835	+ * `copied` is the mirror of what this admin last pasted — see
	836	+ * rules_copied(). It is always present, null included, because a client
	837	+ * keys on the key existing to decide whether the server remembers at all.
	838	+ *
	839	+ * @param array $probe Raw result from probe_static_rewrite().
	840	+ * @return array{expected:string,observed:string,state:string,changed:string[],copied:array{hash:string,at:int}|null}
	841	+ */
	842	+ public static function rules_state( array $probe ): array {
	843	+ $expected = self::rules_marker_expected();
	844	+ $observed = (string) ( $probe['rules'] ?? '' );
	845	+ $copied = self::rules_copied();
	846	+
	847	+ if ( '' === $expected ) {
	848	+ return array(
	849	+ 'expected' => '',
	850	+ 'observed' => $observed,
	851	+ 'state' => 'unknown',
	852	+ 'changed' => array(),
	853	+ 'copied' => $copied,
	854	+ );
	855	+ }
	856	+
	857	+ $inputs = self::rules_inputs();
	858	+ self::remember_rules_inputs( $expected, $inputs );
	859	+
	860	+ if ( '' !== $observed ) {
	861	+ return array(
	862	+ 'expected' => $expected,
	863	+ 'observed' => $observed,
	864	+ 'state' => $observed === $expected ? 'current' : 'stale',
	865	+ 'changed' => $observed === $expected ? array() : self::changed_rules_inputs( $observed, $inputs ),
	866	+ 'copied' => $copied,
	867	+ );
	868	+ }
	869	+
	870	+ // `absent` is a claim about what is installed, so it takes a probe that
	871	+ // completed a round trip and read the response headers. A result that
	872	+ // is still pending, one whose loopback failed, one a CDN answered, and
	873	+ // one that never got off the ground (no host in home_url, no writable
	874	+ // probe dir — neither of which sets `inconclusive`, and both of which
	875	+ // arrive here with no status code) all leave us knowing nothing.
	876	+ if ( empty( $probe['code'] ) || ! empty( $probe['pending'] ) || ! empty( $probe['inconclusive'] ) ) {
	877	+ return array(
	878	+ 'expected' => $expected,
	879	+ 'observed' => '',
	880	+ 'state' => 'unknown',
	881	+ 'changed' => array(),
	882	+ 'copied' => $copied,
	883	+ );
	884	+ }
	885	+
	886	+ return array(
	887	+ 'expected' => $expected,
	888	+ 'observed' => '',
	889	+ 'state' => 'absent',
	890	+ 'changed' => array(),
	891	+ 'copied' => $copied,
	892	+ );
	893	+ }
	894	+
	895	+ /**
	896	+ * Which version of the rules this admin says they pasted into the server.
	897	+ *
	898	+ * Their claim, not evidence — the probe is the evidence, and where the
	899	+ * probe can answer this is ignored. It exists for the `unknown` state: a
	900	+ * host whose loopback is blocked, or one behind a CDN that answers the
	901	+ * probe itself, where nothing can read back what is installed. There the
	902	+ * only thing left to go on is that someone said they had done it, and
	903	+ * without a record of that the panel asks every admin to paste the block
	904	+ * again forever.
	905	+ *
	906	+ * Per user rather than per site, because it is a claim a person made. A
	907	+ * second admin on the same site has not pasted anything and should not be
	908	+ * told the work is done. Null when nobody has claimed this version, when
	909	+ * the stored value is not a shape we wrote, or when there is no current
	910	+ * user at all (WP-CLI, cron).
	911	+ *
	912	+ * @return array{hash:string,at:int}|null
	913	+ */
	914	+ public static function rules_copied(): ?array {
	915	+ if ( ! function_exists( 'get_current_user_id' ) || ! function_exists( 'get_user_meta' ) ) {
	916	+ return null;
	917	+ }
	918	+ $user_id = (int) get_current_user_id();
	919	+ if ( $user_id <= 0 ) {
	920	+ return null;
	921	+ }
	922	+
	923	+ $stored = get_user_meta( $user_id, self::RULES_COPIED_META, true );
	924	+ if ( ! is_array( $stored ) ) {
	925	+ return null;
	926	+ }
	927	+
	928	+ $hash = (string) ( $stored['hash'] ?? '' );
	929	+ $at = (int) ( $stored['at'] ?? 0 );
	930	+ if ( ! self::is_rules_hash( $hash ) || $at <= 0 ) {
	931	+ return null;
	932	+ }
	933	+
	934	+ return array(
	935	+ 'hash' => $hash,
	936	+ 'at' => $at,
	937	+ );
	938	+ }
	939	+
	940	+ /**
	941	+ * Record that this admin pasted the rules whose marker is $hash.
	942	+ *
	943	+ * Rejects anything that is not one of our markers rather than storing it,
	944	+ * so the mirror can only ever hold a value rules_marker_expected() could
	945	+ * also produce — a stored string that matches nothing would read as "a
	946	+ * different version is installed" forever.
	947	+ *
	948	+ * @param string $hash The 8-hex rules marker the admin copied.
	949	+ * @return array{hash:string,at:int}|null The stored record, or null if refused.
	950	+ */
	951	+ public static function remember_rules_copied( string $hash ): ?array {
	952	+ // Trimmed but not case-folded: extract_rules_marker() reads a marker
	953	+ // back in lower case only, so an upper-case claim would never match
	954	+ // anything the probe could observe. Refuse it rather than store a
	955	+ // value that can only ever read as a different version.
	956	+ $hash = trim( $hash );
	957	+ if ( ! self::is_rules_hash( $hash ) ) {
	958	+ return null;
	959	+ }
	960	+ if ( ! function_exists( 'get_current_user_id' ) || ! function_exists( 'update_user_meta' ) ) {
	961	+ return null;
	962	+ }
	963	+ $user_id = (int) get_current_user_id();
	964	+ if ( $user_id <= 0 ) {
	965	+ return null;
	966	+ }
	967	+
	968	+ $record = array(
	969	+ 'hash' => $hash,
	970	+ 'at' => time(),
	971	+ );
	972	+ update_user_meta( $user_id, self::RULES_COPIED_META, $record );
	973	+
	974	+ return $record;
	975	+ }
	976	+
	977	+ /** Whether a string is shaped like one of our rules markers. */
	978	+ public static function is_rules_hash( string $hash ): bool {
	979	+ return 1 === preg_match( '/^[0-9a-f]{8}$/', $hash );
	980	+ }
	981	+
	982	+ /** Record a bypass gate and answer "don't cache" in one statement. */
	983	+ private static function bypass( string $reason ): bool {
	984	+ self::mark( 'BYPASS', $reason );
	985	+ return false;
	986	+ }
	987	+
	988	+ /** The X-XSpeed-Cache value decided for this request ('' if none yet). */
	989	+ public static function status_header(): string {
	990	+ return self::$status_header;
	991	+ }
	992	+
	993	+ /** The bypass gate slug for this request ('' unless BYPASS). */
	994	+ public static function bypass_reason(): string {
	995	+ return self::$bypass_reason;
	996	+ }
	997	+
	998	+ /**
	999	+ * The edge/CDN pairs sent on this request ('' if none were).
	1000	+ *
	1001	+ * @return array<string,string>
	1002	+ */
	1003	+ public static function edge_headers(): array {
	1004	+ return self::$edge_headers;
	1005	+ }
	1006	+
	1007	+ /**
	1008	+ * Bypass gates that do NOT ask a cache in front of us to stand down.
	1009	+ *
	1010	+ * Every other slug does. The split is the reason this reads the gate
	1011	+ * rather than the status: a bypass usually means "this response is
	1012	+ * personal, or someone decided this page is never stored", and an edge
	1013	+ * holding one of those does precisely what we refused to do. These two
	1014	+ * mean something else.
	1015	+ *
	1016	+ * `cache-disabled` is the user switching OUR page cache off. Nothing
	1017	+ * about the page became personal. Sending `no-store` on every page of a
	1018	+ * site whose owner chose a different cache would make a local toggle a
	1019	+ * site-wide side effect on infrastructure we do not own.
	1020	+ *
	1021	+ * `non-frontend` is admin, REST, cron and AJAX. Not ours to describe:
	1022	+ * WordPress already nocaches admin, and a REST caller sets its own
	1023	+ * policy.
	1024	+ */
	1025	+ private const HOLD_EXEMPT_BYPASS = array( 'cache-disabled', 'non-frontend' );
	1026	+
	1027	+ /**
	1028	+ * Bypass gates that describe the SHAPE of the request rather than the
	1029	+ * visitor or the page.
	1030	+ *
	1031	+ * These still hold, but only once we have evidence of an edge — the same
	1032	+ * bar a MISS has to clear. The difference matters because the default
	1033	+ * excluded-URL list contains `/feed/`, the sitemap and `/wp-json/`, and
	1034	+ * `query-param` catches `?lang=fr`, `?paged=2`, and every page of a
	1035	+ * plain-permalink site.
	1036	+ *
	1037	+ * xSpeed refuses those because IT cannot key on a query string, not
	1038	+ * because the response is private. A CDN keys on the full URL and caches
	1039	+ * them correctly. Holding them unconditionally would have meant every
	1040	+ * default install stopped its feed and sitemap being edge-cached — a
	1041	+ * performance regression shipped to sites that never had a CDN in the
	1042	+ * first place, in the name of protecting them from one.
	1043	+ *
	1044	+ * The gates left out of this list are about the visitor (`logged-in`,
	1045	+ * `excluded-cookie`) or are somebody stating outright that this page is
	1046	+ * never to be stored (`donotcachepage`, `post-excluded`, `filtered`).
	1047	+ * Those hold whether or not we can see an edge.
	1048	+ */
	1049	+ private const REQUEST_SHAPE_BYPASS = array( 'query-param', 'non-get', 'user-agent' );
	1050	+
	1051	+ /**
	1052	+ * Default exclusions that are about the site's plumbing, not its content.
	1053	+ *
	1054	+ * `excluded-url` covers two unlike things. The default list carries
	1055	+ * `/cart`, `/checkout`, `/my-account` and `/wp-login` — personal pages,
	1056	+ * and the reason this feature exists. It also carries the entries below:
	1057	+ * feeds, sitemaps, the REST root, the front controller. Those are public,
	1058	+ * cacheable, and hammered by pollers; a CDN keys on the full URL and
	1059	+ * serves them correctly, so telling it to stop is a cost with no benefit.
	1060	+ *
	1061	+ * Matched as exact strings against the stored list, never as patterns
	1062	+ * against the path. Three bugs came out of doing it the other way round:
	1063	+ * `strpos( $uri, '/feed' )` matched `/my-account/feedback/`, reading the
	1064	+ * whole URI let `/cart/?utm_source=/feed/` disguise a cart as a feed, and
	1065	+ * a bare `index.php` — which is in this list, and which every URL contains
	1066	+ * on an "almost pretty" permalink site — made every page on such a site
	1067	+ * look personal. Comparing the LIST ENTRY rather than the path cannot make
	1068	+ * any of those mistakes, and it keeps a pattern the site owner added
	1069	+ * themselves on the personal side where it belongs.
	1070	+ */
	1071	+ private const STRUCTURAL_EXCLUSIONS = array(
	1072	+ '/wp-json/',
	1073	+ '/xmlrpc.php',
	1074	+ '~wp-.*\.php',
	1075	+ '/feed/',
	1076	+ 'index.php',
	1077	+ '/robots.txt',
	1078	+ // Both spellings, and no entry here is ever retired. This is a
	1079	+ // RECOGNITION list, not a source of truth: it is matched against
	1080	+ // whatever the site has STORED, and a site that saved its settings
	1081	+ // before `~sitemap(_index)?\.xml` was widened to `sitemaps?` (for
	1082	+ // SEOPress, which ships sitemaps.xml) still has the old string in
	1083	+ // its option row. Dropping the old spelling when the default moved
	1084	+ // would read every upgraded site's sitemap exclusion as somebody's
	1085	+ // personal data and hold sitemaps off the CDN — the bug this whole
	1086	+ // predicate exists to prevent, reintroduced by a rename.
	1087	+ '~sitemaps?(_index)?\.xml',
	1088	+ '~sitemap(_index)?\.xml',
	1089	+ );
	1090	+ /**
	1091	+ * Header names no edge instruction may ever carry.
	1092	+ *
	1093	+ * These describe the transfer, not the caching policy, and one wrong
	1094	+ * value from a settings field is a white screen rather than a missing
	1095	+ * optimization.
	1096	+ */
	1097	+ private const NEVER_AN_EDGE_HEADER = array(
	1098	+ 'content-length',
	1099	+ 'content-encoding',
	1100	+ 'content-type',
	1101	+ 'transfer-encoding',
	1102	+ 'set-cookie',
	1103	+ 'location',
	1104	+ 'x-xspeed-cache',
	1105	+ 'x-xspeed-edge-hold',
	1106	+ // `X-XSpeed-Built` says when THIS PAGE's HTML was generated, which is
	1107	+ // what a downstream verifier compares against the moment it asked for
	1108	+ // a purge. Free owns it and never takes it from a filter, in any
	1109	+ // context — see the BUILT_HEADER docblock.
	1110	+ //
	1111	+ // Under `bake` a supplied value would be frozen into an artifact and
	1112	+ // report when the artifact was written: identical on every page and
	1113	+ // never moving. Under `request` it is no better, because the filter
	1114	+ // runs from mark() with no file and no mtime in reach, so the only
	1115	+ // value anything can produce there is time() — the moment of the
	1116	+ // SERVE, not of the build. Both make every purge check pass.
	1117	+ //
	1118	+ // Free stamps the real value where it has the file: the drop-in and
	1119	+ // serve_not_modified(), both from filemtime(). The static serve paths
	1120	+ // run no PHP and carry no stamp at all; their `Last-Modified` is read
	1121	+ // instead.
	1122	+ 'x-xspeed-built',
	1123	+ );
	1124	+
	1125	+ /**
	1126	+ * Reasons that hold the edge off even when we detected nothing in front.
	1127	+ *
	1128	+ * `none` confidence means no evidence of a proxy, which is not proof
	1129	+ * there is none — a transparent proxy and a host page cache both leave
	1130	+ * the request untouched. So the question is what a wasted header costs
	1131	+ * against what a missed one does, and the answer differs by reason.
	1132	+ *
	1133	+ * These two are correctness failures. A cart page stored by something we
	1134	+ * could not see is the defect this exists to fix, and a mobile-split page
	1135	+ * served to the wrong device is a wrong page rather than a slow one.
	1136	+ * Ninety bytes on a response that was never cacheable is a cheap premium.
	1137	+ *
	1138	+ * `miss` and `pending` are performance hedges, and a hedge against a
	1139	+ * cache that does not exist is noise on every first render. Skipping them
	1140	+ * has a second benefit: because per_entry_edge_headers() compares `store`
	1141	+ * against `bake`, a `pending` hold that never fires leaves the two
	1142	+ * agreeing, which keeps the page on the static tree.
	1143	+ *
	1144	+ * `query-variant` waits for evidence as well. It is about purges. An edge
	1145	+ * keeps a separate copy for every query string, and a purge of the plain
	1146	+ * URL never reaches them. With no edge in front there are no copies.
	1147	+ */
	1148	+ private const HOLD_WITHOUT_EVIDENCE = array( 'bypass', 'mobile-split' );
	1149	+
	1150	+ /**
	1151	+ * True only while query_variant_edge_headers() bakes the drop-in's
	1152	+ * answer for a URL no purge names.
	1153	+ *
	1154	+ * A bake has no request to read, so this is how it asks "what if this
	1155	+ * HIT carried a param no purge names?". The drop-in answers that for
	1156	+ * itself, per request. Never true outside that one call.
	1157	+ *
	1158	+ * @var bool
	1159	+ */
	1160	+ private static $baking_query_variant = false;
	1161	+
	1162	+ /**
	1163	+ * Is a module still going to change this page after this response?
	1164	+ *
	1165	+ * Free itself never says yes — nothing in Free defers work past the
	1166	+ * request. Minification and combining write their file and return its URL
	1167	+ * inside the same render; the LCP preload is chosen by parsing the HTML
	1168	+ * being sent. It is the question that matters to anything caching in
	1169	+ * front of us, so Free asks it on their behalf and lets whoever owns the
	1170	+ * deferred work answer.
	1171	+ *
	1172	+ * Answer TRUE while the work is outstanding for the page being served.
	1173	+ * The cost of a false yes is one extra origin hit; the cost of a false no
	1174	+ * is an un-optimized page pinned at the edge for the full lifetime, which
	1175	+ * is the failure this exists to prevent — so when in doubt, say yes.
	1176	+ *
	1177	+ * Asked on a `request` only, and that boundary is the whole safety of it.
	1178	+ *
	1179	+ * A `bake` is generated once, in an admin or CLI request, and serves every
	1180	+ * static HIT on the site; a per-page answer frozen into it would be wrong
	1181	+ * for every other page.
	1182	+ *
	1183	+ * A `store` is worse, and cost a live site an afternoon. The pairs written
	1184	+ * at store time go into the `.meta` sidecar, which the drop-in replays on
	1185	+ * every later HIT — before plugins load, so nothing can re-ask this
	1186	+ * question. A hold written there therefore outlives the state that caused
	1187	+ * it, and the only thing that clears it is the page being stored again. On
	1188	+ * a site where the deferred work never completes, every re-store re-pins
	1189	+ * it, and the page is never edge-cacheable again. The symptom is a cache
	1190	+ * HIT carrying `no-store` and `X-XSpeed-Edge-Hold: pending` on a page
	1191	+ * whose deferred work finished long ago — the sidecar answering with
	1192	+ * state nothing can re-ask.
	1193	+ *
	1194	+ * Holding the MISS is what this is for, and it is enough: that response is
	1195	+ * the un-optimized one. The copy we then store is what an edge should
	1196	+ * mirror, and when the work does land the module purges the page, which
	1197	+ * reaches the edge. The purge is the correctness mechanism; this is only
	1198	+ * meant to cover the single render before it.
	1199	+ *
	1200	+ * @param string $context `request`, `store` or `bake`.
	1201	+ */
	1202	+ public static function edge_optimization_pending( string $context = 'request' ): bool {
	1203	+ if ( 'request' !== $context ) {
	1204	+ return false;
	1205	+ }
	1206	+
	1207	+ /**
	1208	+ * Filter: xspeed_edge_optimization_pending
	1209	+ *
	1210	+ * @param bool $pending Whether deferred work will still change this page.
	1211	+ */
	1212	+ return (bool) apply_filters( 'xspeed_edge_optimization_pending', false );
	1213	+ }
	1214	+
	1215	+ /**
	1216	+ * Does mobile cache split this URL into two renders?
	1217	+ *
	1218	+ * With `mobile_separate` on, Free keys its cache on device and serves a
	1219	+ * different page to a phone than to a desktop at the SAME url. No CDN
	1220	+ * varies on User-Agent, so an edge holding one of those renders serves it
	1221	+ * to everyone: whichever device asked first decides what the other sees,
	1222	+ * for the whole lifetime. A wrong page, not a slow one.
	1223	+ *
	1224	+ * Read from the stored option rather than through Settings_Manager: this
	1225	+ * is consulted from the serve path, where the module registry may not
	1226	+ * have run.
	1227	+ */
	1228	+ private static function mobile_cache_splits_html(): bool {
	1229	+ $stored = self::stored_cache_opts();
	1230	+ return ! empty( $stored['mobile_separate'] );
	1231	+ }
	1232	+
	1233	+ /**
	1234	+ * Is this cached page being served for a URL that no purge names?
	1235	+ *
	1236	+ * Free serves `/post?utm_source=x` from the entry stored for `/post`,
	1237	+ * which is what the ignored-params list is for. An edge does not. It
	1238	+ * keys on the full URL, so every query string becomes its own copy. A
	1239	+ * purge that names `/post` clears one copy and leaves the others for the
	1240	+ * whole edge lifetime. A newsletter link can then serve last month's
	1241	+ * page. So such a HIT is held, and the edge keeps only URLs a purge can
	1242	+ * name. See query_carries_unpurged_param() for which query strings count.
	1243	+ *
	1244	+ * A HIT only. A MISS is already held as `miss`, and a BYPASS never
	1245	+ * reached the cache. And `request` only, because the query string belongs
	1246	+ * to the request, not to the entry. One stored file answers `/post` and
	1247	+ * every variant of it, so a hold written into its sidecar under `store`
	1248	+ * would be replayed by the drop-in for the plain URL as well. A `bake`
	1249	+ * says no unless query_variant_edge_headers() is asking for the drop-in.
	1250	+ *
	1251	+ * @param string $status `HIT`, `MISS` or `BYPASS`.
	1252	+ * @param string $context `request`, `store` or `bake`.
	1253	+ */
	1254	+ private static function serves_query_variant( string $status, string $context ): bool {
	1255	+ if ( 'HIT' !== $status ) {
	1256	+ return false;
	1257	+ }
	1258	+ if ( 'bake' === $context ) {
	1259	+ return self::$baking_query_variant;
	1260	+ }
	1261	+
	1262	+ return 'request' === $context && self::query_carries_unpurged_param();
	1263	+ }
	1264	+
	1265	+ /**
	1266	+ * Does this request's query string carry a param that keeps its URL out
	1267	+ * of every purge?
	1268	+ *
	1269	+ * Two kinds do. A param the cache key leaves out, which is anything on
	1270	+ * the ignored-params list, judged by query_key_is_ignored() against the
	1271	+ * same setting should_cache() reads. And the search and query-form feed
	1272	+ * params (`s`, FEED_QUERY_PARAMS). Those have entries keyed their own
	1273	+ * way, but they belong to opt-in caches whose URLs no purge names either.
	1274	+ *
	1275	+ * Any other param that reaches a HIT is part of the page's own address,
	1276	+ * which a purge names, so it is not held. A plain-permalink route such
	1277	+ * as `/?page_id=2` is the case this leaves alone.
	1278	+ */
	1279	+ private static function query_carries_unpurged_param(): bool {
	1280	+ $query_raw = isset( $_SERVER['QUERY_STRING'] ) ? (string) wp_unslash( $_SERVER['QUERY_STRING'] ) : ''; // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- parsed for its keys only, as should_cache() does; never echoed or stored.
	1281	+ if ( '' === trim( $query_raw ) ) {
	1282	+ return false;
	1283	+ }
	1284	+
	1285	+ parse_str( $query_raw, $params );
	1286	+ $cache_opts = Settings_Manager::get( 'cache' );
	1287	+ $ignored = is_array( $cache_opts['ignored_query_params'] ?? null ) ? $cache_opts['ignored_query_params'] : array();
	1288	+ foreach ( array_keys( $params ) as $key ) {
	1289	+ $key = (string) $key;
	1290	+ if ( 's' === $key || in_array( $key, self::FEED_QUERY_PARAMS, true ) ) {
	1291	+ return true;
	1292	+ }
	1293	+ if ( self::query_key_is_ignored( $key, $ignored ) ) {
	1294	+ return true;
	1295	+ }
	1296	+ }
	1297	+
	1298	+ return false;
	1299	+ }
	1300	+
	1301	+ /**
	1302	+ * The edge answer the drop-in sends for a cached page served for a URL
	1303	+ * no purge names, or an empty array when that answer is the same as the
	1304	+ * plain URL's.
	1305	+ *
	1306	+ * The drop-in runs before plugins load and cannot ask edge_headers_for(),
	1307	+ * so this is baked in next to the plain answer. The drop-in applies it
	1308	+ * when a param in the query string matches the ignored-params list it
	1309	+ * already reads (`.ignored-query-params`, written from the same setting
	1310	+ * by sync_query_allowlist()). Search and feed params never reach it,
	1311	+ * because it hands those requests to PHP. The nginx and Apache
	1312	+ * rules need no copy. Both refuse any request with a query string
	1313	+ * (`if ($args)`, `RewriteCond %{QUERY_STRING} ^$`), so a variant always
	1314	+ * reaches PHP.
	1315	+ *
	1316	+ * Empty when the two answers agree. That covers no edge being known,
	1317	+ * a filter vetoing the hold, and a site where every page is held
	1318	+ * already (mobile-split). The drop-in then sends what it sends for the
	1319	+ * plain URL, including any sidecar the page has.
	1320	+ *
	1321	+ * @return array<string,string>
	1322	+ */
	1323	+ public static function query_variant_edge_headers(): array {
	1324	+ $plain = self::edge_headers_for( 'HIT', 'bake' );
	1325	+
	1326	+ self::$baking_query_variant = true;
	1327	+ try {
	1328	+ $variant = self::edge_headers_for( 'HIT', 'bake' );
	1329	+ } finally {
	1330	+ self::$baking_query_variant = false;
	1331	+ }
	1332	+
	1333	+ return $variant === $plain ? array() : $variant;
	1334	+ }
	1335	+
	1336	+ /**
	1337	+ * Why, if at all, a cache in front of us should refuse to store this.
	1338	+ *
	1339	+ * @param string $status `HIT`, `MISS` or `BYPASS`.
	1340	+ * @param string $context `request`, `store` or `bake`.
	1341	+ * @param string $bypass_reason The gate slug, for BYPASS only.
	1342	+ * @return string '' or one of bypass|bypass-shape|miss|mobile-split|pending|query-variant.
	1343	+ */
	1344	+ private static function edge_hold_reason( string $status, string $context, string $bypass_reason ): string {
	1345	+ $reason = '';
	1346	+
	1347	+ // The two exempt gates are answered before anything else, or a site
	1348	+ // with Separate Mobile Cache on would keep holding after the page
	1349	+ // cache was switched off — which is exactly the "a local toggle must
	1350	+ // not become a site-wide side effect on infrastructure we do not own"
	1351	+ // rule below, defeated by the ordering rather than by the logic.
	1352	+ if ( 'BYPASS' === $status && in_array( $bypass_reason, self::HOLD_EXEMPT_BYPASS, true ) ) {
	1353	+ /** This filter is documented below. */
	1354	+ return (string) apply_filters( 'xspeed_edge_hold_reason', '', $status, $context, $bypass_reason );
	1355	+ }
	1356	+
	1357	+ // First, because it is the only reason true in every context: the
	1358	+ // setting is a property of the site, not of one request, so it is the
	1359	+ // one thing a baked artifact can honestly assert.
	1360	+ //
	1361	+ // It is also the only reason that holds a HIT — a response we DID
	1362	+ // cache — and that is deliberate rather than an artefact of the
	1363	+ // ordering. With mobile_separate on we key the cache by device and
	1364	+ // serve different HTML to a phone than to a desktop at the same URL.
	1365	+ // No CDN varies on User-Agent, so an edge holding one of those
	1366	+ // renders serves it to everyone and whichever device asked first
	1367	+ // decides what the other sees. Our copy is fine; theirs would be a
	1368	+ // wrong page. The static path is switched off in this mode anyway
	1369	+ // (static_rewrite_allowed()), so these hits come from the drop-in,
	1370	+ // which carries the same baked answer.
	1371	+ if ( self::mobile_cache_splits_html() ) {
	1372	+ $reason = 'mobile-split';
	1373	+ } elseif ( 'BYPASS' === $status ) {
	1374	+ $shaped = in_array( $bypass_reason, array( 'excluded-url', 'query-param' ), true )
	1375	+ ? ! self::path_is_a_personal_exclusion( $bypass_reason )
	1376	+ : in_array( $bypass_reason, self::REQUEST_SHAPE_BYPASS, true );
	1377	+ $reason = $shaped ? 'bypass-shape' : 'bypass';
	1378	+ } elseif ( self::edge_optimization_pending( $context ) ) {
	1379	+ $reason = 'pending';
	1380	+ } elseif ( 'MISS' === $status ) {
	1381	+ $reason = 'miss';
	1382	+ } elseif ( self::serves_query_variant( $status, $context ) ) {
	1383	+ // Last, so it only adds a hold where there was none. A variant
	1384	+ // still waiting for its CSS says `pending`, which is also true,
	1385	+ // and the CSS modules are still asked on every HIT as before.
	1386	+ $reason = 'query-variant';
	1387	+ }
	1388	+
	1389	+ /**
	1390	+ * Filter: xspeed_edge_hold_reason
	1391	+ *
	1392	+ * Return '' to veto a hold, or a reason string to force one.
	1393	+ *
	1394	+ * @param string $reason '' or bypass|bypass-shape|miss|mobile-split|pending|query-variant.
	1395	+ * @param string $status `HIT`, `MISS` or `BYPASS`.
	1396	+ * @param string $context `request`, `store` or `bake`.
	1397	+ * @param string $bypass_reason The gate slug, for BYPASS only.
	1398	+ */
	1399	+ return (string) apply_filters( 'xspeed_edge_hold_reason', $reason, $status, $context, $bypass_reason );
	1400	+ }
	1401	+
	1402	+ /**
	1403	+ * Was this page excluded because it is personal, or because it is
	1404	+ * plumbing we cannot key a cache entry on?
	1405	+ *
	1406	+ * Answers by removing the structural defaults from the site's own
	1407	+ * exclusion list and asking whether anything is left that matches. So a
	1408	+ * feed matches only `/feed/` and comes back false; `/my-account/feedback/`
	1409	+ * matches `/my-account` and comes back true; and on an "almost pretty"
	1410	+ * permalink site, where every path contains `index.php`, an ordinary page
	1411	+ * matches nothing else and is correctly treated as public.
	1412	+ *
	1413	+ * The path only, never the query string — a visitor writes that, and
	1414	+ * `/cart/?utm_source=/feed/` must not be able to talk a cart out of its
	1415	+ * hold. It is also what `should_cache()` matches the list against.
	1416	+ *
	1417	+ * Asked for a `query-param` bypass too, because the query gate runs
	1418	+ * BEFORE the URL gate, so `/cart/?add-to-cart=12` reports `query-param`
	1419	+ * and never reaches `excluded-url` at all. Which gate fired first says
	1420	+ * nothing about whose data is on the page.
	1421	+ */
	1422	+ private static function path_is_a_personal_exclusion( string $bypass_reason ): bool {
	1423	+ $path = self::request_path();
	1424	+ if ( '' === $path ) {
	1425	+ return false;
	1426	+ }
	1427	+
	1428	+ // Through Settings_Manager, not the raw option, because the schema's
	1429	+ // default IS the structural list and a fresh install has never
	1430	+ // written the option. Read raw, every site that has not visited the
	1431	+ // settings screen looks like a site with no exclusions at all, takes
	1432	+ // the contradiction branch below, and reports its feeds as personal.
	1433	+ //
	1434	+ // Safe here where `mobile_cache_splits_html()` is not: we are only
	1435	+ // ever called with a bypass reason, and those come from
	1436	+ // `should_cache()`, which resolved the same settings through
	1437	+ // `Settings_Manager::get()` to produce them.
	1438	+ $opts = Settings_Manager::get( 'cache' );
	1439	+ $excluded = is_array( $opts['excluded_urls'] ?? null ) ? $opts['excluded_urls'] : array();
	1440	+ if ( array() === $excluded ) {
	1441	+ // An `excluded-url` bypass with no exclusion list is a
	1442	+ // contradiction — something excluded the request and the list
	1443	+ // cannot say what — so assume personal, because a wasted header
	1444	+ // costs a little origin traffic while a missing one serves
	1445	+ // somebody's basket to a stranger. A `query-param` bypass with an
	1446	+ // empty list is just an ordinary page carrying a parameter, and
	1447	+ // says nothing about the path at all.
	1448	+ return 'excluded-url' === $bypass_reason;
	1449	+ }
	1450	+
	1451	+ $personal = array_values(
	1452	+ array_filter(
	1453	+ $excluded,
	1454	+ static fn ( $pattern ) => ! in_array( (string) $pattern, self::STRUCTURAL_EXCLUSIONS, true )
	1455	+ )
	1456	+ );
	1457	+
	1458	+ return array() !== $personal && self::path_matches_exclusions( $personal, $path );
	1459	+ }
	1460	+
	1461	+ /**
	1462	+ * The edge/CDN headers to send on a response with this cache status.
	1463	+ *
	1464	+ * @param string $status `HIT`, `MISS` or `BYPASS`.
	1465	+ * @param string $context `request` when resolved per request on the
	1466	+ * PHP serve path, `store` when resolved for
	1467	+ * one entry's sidecar, `bake` when resolved
	1468	+ * once and frozen into the drop-in, `rules`
	1469	+ * when resolved once for the nginx or Apache
	1470	+ * static block.
	1471	+ * @param string $bypass_reason The gate slug, for BYPASS only.
	1472	+ * @return array<string,string>
	1473	+ */
	1474	+ public static function edge_headers_for( string $status, string $context = 'request', string $bypass_reason = '' ): array {
	1475	+ // `rules` is a bake in every respect but one: the cache-headers
	1476	+ // filter is told it is answering for a pasted server rule. Such a
	1477	+ // rule serves every static HIT for as long as it stays pasted, and
	1478	+ // nothing regenerates it when the site's expiry or a page's own
	1479	+ // lifetime (a nonce cap) changes, so a lifetime given there cannot
	1480	+ // follow the page. The drop-in is rewritten by auto_heal(); a paste
	1481	+ // is not.
	1482	+ $filter_context = $context;
	1483	+ if ( 'rules' === $context ) {
	1484	+ $context = 'bake';
	1485	+ }
	1486	+
	1487	+ $base = array();
	1488	+ if ( 'HIT' === $status ) {
	1489	+ /**
	1490	+ * Filter: xspeed_edge_cache_headers
	1491	+ *
	1492	+ * Response headers to add to a cached HTML response. The lifetime
	1493	+ * is HIT-only: it is a promise that this copy is worth keeping,
	1494	+ * and neither a first render nor a page we refused to cache is
	1495	+ * one. The filter is also asked with `MISS` when a first render
	1496	+ * is held, and only the `Cache-Tag` from that answer is sent, so
	1497	+ * a purge can name a copy an edge stored despite the hold.
	1498	+ *
	1499	+ * The same filter feeds four regimes and `$context` says which.
	1500	+ * On the PHP serve path it runs per request (`request`); at store
	1501	+ * time it runs for one entry (`store`); when the drop-in is
	1502	+ * generated it runs once (`bake`) and the result answers for
	1503	+ * every drop-in HIT on the site; when the nginx or Apache static
	1504	+ * block is generated it runs once (`rules`). Anything per-page — a
	1505	+ * post id in a cache tag, say — must be skipped under `bake` and
	1506	+ * `rules`. A server rule serves every static HIT for as long as it
	1507	+ * stays pasted, so a lifetime here can't follow the page: send
	1508	+ * none under `rules`.
	1509	+ *
	1510	+ * @param array<string,string> $headers Header name => value.
	1511	+ * @param string $status `HIT`, or `MISS` when only the tag of a held first render is wanted.
	1512	+ * @param string $context `request`, `store`, `bake` or `rules`.
	1513	+ */
	1514	+ $base = self::sanitize_edge_headers( (array) apply_filters( 'xspeed_edge_cache_headers', array(), 'HIT', $filter_context ) );
	1515	+ }
	1516	+
	1517	+ $reason = self::edge_hold_reason( $status, $context, $bypass_reason );
	1518	+ if ( '' === $reason ) {
	1519	+ return $base;
	1520	+ }
	1521	+ $detected = Edge_Provider::detect( $context );
	1522	+ if ( Edge_Provider::is_off( $detected ) ) {
	1523	+ return $base;
	1524	+ }
	1525	+ if ( Edge_Provider::NONE === $detected['confidence']
	1526	+ && ! in_array( $reason, self::HOLD_WITHOUT_EVIDENCE, true ) ) {
	1527	+ return $base;
	1528	+ }
	1529	+
	1530	+ $hold = Edge_Provider::hold_headers( $detected['provider'] );
	1531	+
	1532	+ /**
	1533	+ * Filter: xspeed_edge_hold_headers
	1534	+ *
	1535	+ * The last word on what a hold INSTRUCTS. Runs before sanitising, so
	1536	+ * a value that cannot be sent as a header is still dropped, and
	1537	+ * before `X-XSpeed-Edge-Hold` is added, so it cannot rewrite the
	1538	+ * reason xSpeed held the page for — that is a diagnosis, not an
	1539	+ * instruction, and a forged one sends a reader after the wrong
	1540	+ * module.
	1541	+ *
	1542	+ * @param array<string,string> $hold Header name => value.
	1543	+ * @param array<string,string> $detected Provider, confidence, source.
	1544	+ * @param string $reason Why the hold fired.
	1545	+ * @param string $context `request`, `store` or `bake`.
	1546	+ */
	1547	+ $hold = (array) apply_filters( 'xspeed_edge_hold_headers', $hold, $detected, $reason, $context );
	1548	+
	1549	+ // A hold replaces the lifetime rather than sitting beside it: the two
	1550	+ // describe the same response and would contradict each other. The
	1551	+ // cache tag survives, because a later purge still has to be able to
	1552	+ // name whatever the edge picked up on its own terms.
	1553	+ //
	1554	+ // On a HIT the tag came with `$base`. A MISS has no `$base`, and that
	1555	+ // is the case that mattered most: the first render after any purge.
	1556	+ // An edge whose rule overrides the origin's lifetime stores it
	1557	+ // despite the hold, and with no tag on it the next tag purge cannot
	1558	+ // reach it, so an edit stayed stale for the edge's whole lifetime
	1559	+ // (QA, 2026-09-23). So a held MISS asks the same filter for its tag
	1560	+ // and keeps the tag alone; the lifetime in the answer is dropped,
	1561	+ // because the hold is the instruction for this response.
	1562	+ $tag = $base['Cache-Tag'] ?? '';
	1563	+ if ( '' === $tag && 'MISS' === $status ) {
	1564	+ $tagged = self::sanitize_edge_headers( (array) apply_filters( 'xspeed_edge_cache_headers', array(), 'MISS', $filter_context ) );
	1565	+ $tag = $tagged['Cache-Tag'] ?? '';
	1566	+ }
	1567	+ if ( '' !== $tag ) {
	1568	+ $hold['Cache-Tag'] = $tag;
	1569	+ }
	1570	+
	1571	+ // Never argue with a stronger answer WordPress already gave. It sends
	1572	+ // `no-store, private` of its own accord on a logged-in, 404 or
	1573	+ // password-protected response, from WP::send_headers() — which runs
	1574	+ // before template_redirect, so it is already on the wire by the time
	1575	+ // we get here. Ours is the weaker statement of the two; replacing it
	1576	+ // would be a downgrade dressed as a fix. Only meaningful per request:
	1577	+ // a bake has no response to inspect.
	1578	+ if ( 'request' === $context && isset( $hold['Cache-Control'] ) && self::cache_control_already_stronger() ) {
	1579	+ unset( $hold['Cache-Control'] );
	1580	+ }
	1581	+
	1582	+ // A page we refused to cache must not carry a validator either. A
	1583	+ // `Last-Modified` left on it invites a conditional request, and a
	1584	+ // shared cache that gets a 304 back serves the copy it should not
	1585	+ // have stored. Only on a bypass, and only per request: a MISS is
	1586	+ // about to be stored by us, so its validator is ours to keep.
	1587	+ if ( 'request' === $context && 'bypass' === $reason && ! headers_sent() ) {
	1588	+ header_remove( 'Last-Modified' );
	1589	+ }
	1590	+
	1591	+ $hold = self::sanitize_edge_headers( $hold );
	1592	+
	1593	+ // Name the reason in the hold set itself, rather than sending it
	1594	+ // separately from mark().
	1595	+ //
	1596	+ // "Why is my page not being cached at the edge?" is the question this
	1597	+ // answers, and mark() could only answer it on the PHP serve path. The
	1598	+ // other emitters send whatever this function returns and never ran
	1599	+ // mark() at all — so the responses hardest to explain went out
	1600	+ // carrying `no-store` with nothing beside it to say why. Chiefly the
	1601	+ // drop-in, which serves from the `.meta` sidecar written under
	1602	+ // `store` and from the literal baked under `bake`, before plugins
	1603	+ // load and with no way to re-ask (the symptom
	1604	+ // edge_optimization_pending() describes above).
	1605	+ //
	1606	+ // The nginx and Apache blocks are a third path in principle and
	1607	+ // almost never in practice: they are only installed when
	1608	+ // static_rewrite_allowed() is true, and the one reason a stock site
	1609	+ // can hold in their bake is `mobile-split`, which is exactly what
	1610	+ // makes that false. `query-variant` is baked for the drop-in alone,
	1611	+ // since both blocks refuse a query string. They will carry a hold
	1612	+ // where a site forces one through `xspeed_edge_hold_reason`, and
	1613	+ // otherwise have none to carry.
	1614	+ //
	1615	+ // Added AFTER sanitising and banned in NEVER_AN_EDGE_HEADER, so
	1616	+ // neither of the two filters above can forge a reason or suppress the
	1617	+ // real one.
	1618	+ //
	1619	+ // Reduced to the slug CHARACTER CLASS, not checked against the six
	1620	+ // slugs: `xspeed_edge_hold_reason` is documented as able to force a
	1621	+ // reason, and a site that forces its own deserves to see it. What is
	1622	+ // not negotiable is the shape, because this value reaches an
	1623	+ // .htaccess and an nginx conf as well as a response header — so no
	1624	+ // CR/LF, no `$`, no `%`, no `\`, and a length a config file can hold.
	1625	+ $slug = preg_replace( '/[^a-z0-9-]/', '', strtolower( $reason ) );
	1626	+ if ( is_string( $slug ) && '' !== $slug ) {
	1627	+ $hold['X-XSpeed-Edge-Hold'] = substr( $slug, 0, 32 );
	1628	+ }
	1629	+
	1630	+ return $hold;
	1631	+ }
	1632	+
	1633	+ /** Has something already sent a Cache-Control at least as strict as ours? */
	1634	+ private static function cache_control_already_stronger(): bool {
	1635	+ foreach ( headers_list() as $line ) {
	1636	+ if ( 0 !== stripos( $line, 'cache-control:' ) ) {
	1637	+ continue;
	1638	+ }
	1639	+ if ( preg_match( '/\b(?:no-store|private)\b/i', $line ) ) {
	1640	+ return true;
	1641	+ }
	1642	+ }
	1643	+
	1644	+ return false;
	1645	+ }
	1646	+
	1647	+ /**
	1648	+ * Edge headers that belong to THIS page rather than to every page.
	1649	+ *
	1650	+ * `edge_headers_for('HIT','bake')` is the answer frozen into the drop-in
	1651	+ * and the server rules: one set, serving the whole site. But the answer
	1652	+ * for one URL can legitimately differ — a page whose deferred work is
	1653	+ * still outstanding, say — and that answer has nowhere to live, because
	1654	+ * the baked set is all the fast paths know about.
	1655	+ *
	1656	+ * So ask again in a `store` context, with the request still in scope, and
	1657	+ * return the pairs only when they differ from the baked ones. Identical is
	1658	+ * the overwhelmingly common case and writes nothing: pages do not pay a
	1659	+ * sidecar for an answer the drop-in already has.
	1660	+ *
	1661	+ * Memoised because two callers ask within one store — the sidecar writer
	1662	+ * and the static-tree guard — and the filters behind it are not required
	1663	+ * to be cheap.
	1664	+ *
	1665	+ * A page with a lifetime of its own also gets its own pairs, whenever
	1666	+ * they grant an edge any lifetime at all. The lifetime is cut to the
	1667	+ * page's (see cap_edge_lifetime()), and the pairs are returned even when
	1668	+ * the cut leaves them equal to the baked ones. Returning them keeps the
	1669	+ * page off the static tree, and it has to: only the two PHP paths can
	1670	+ * count a lifetime down as the copy ages. The web server sends the baked
	1671	+ * value from whatever age the file has reached, so a page capped to its
	1672	+ * nonce would reach the edge with hours of dead nonce still to serve.
	1673	+ *
	1674	+ * write_meta() resolves that lifetime and passes it on the first call.
	1675	+ * The static-tree guards ask afterwards and read the memo. Both store
	1676	+ * paths call write_meta() before their guard.
	1677	+ *
	1678	+ * @param int|null $own_ttl The entry's own lifetime in seconds, when it
	1679	+ * differs from the site's (the sidecar `ttl`).
	1680	+ * @return array<string,string> Empty when this page needs no override.
	1681	+ */
	1682	+ private static function per_entry_edge_headers( ?int $own_ttl = null ): array {
	1683	+ if ( is_array( self::$per_entry_edge ) ) {
	1684	+ return self::$per_entry_edge;
	1685	+ }
	1686	+ $baked = self::edge_headers_for( 'HIT', 'bake' );
	1687	+ $request = self::edge_headers_for( 'HIT', 'store' );
	1688	+ if ( null !== $own_ttl && self::grants_edge_lifetime( $request ) ) {
	1689	+ self::$per_entry_edge = self::cap_edge_lifetime( $request, $own_ttl );
	1690	+ return self::$per_entry_edge;
	1691	+ }
	1692	+ self::$per_entry_edge = ( $request === $baked ) ? array() : $request;
	1693	+
	1694	+ return self::$per_entry_edge;
	1695	+ }
	1696	+
	1697	+ /**
	1698	+ * Cut every lifetime an edge header grants down to `$seconds`.
	1699	+ *
	1700	+ * The lifetime in a HIT's pairs comes from `xspeed_edge_cache_headers`
	1701	+ * and describes the site, so it says nothing of a page whose own lifetime
	1702	+ * is shorter: one carrying a nonce (#236), one with a per-post expiry,
	1703	+ * one a `xspeed_cache_max_age` filter shortened. xSpeed rebuilds that page
	1704	+ * on time, and an edge holding it for the site's lifetime goes on serving
	1705	+ * the old copy anyway. Nothing tells the edge when our copy expires,
	1706	+ * because an expiry is not a purge. For a nonce page that is a broken
	1707	+ * form for every visitor until the next purge.
	1708	+ *
	1709	+ * Only shortens. A `max-age` or `s-maxage` already under `$seconds` is
	1710	+ * kept, so a hold's `s-maxage=0` stays 0. Only headers named `*-Control`
	1711	+ * are touched; a `Cache-Tag` that happens to contain the text is not a
	1712	+ * directive.
	1713	+ *
	1714	+ * @param array<string,string> $headers Header name => value.
	1715	+ * @param int $seconds The most any of them may grant.
	1716	+ * @return array<string,string>
	1717	+ */
	1718	+ public static function cap_edge_lifetime( array $headers, int $seconds ): array {
	1719	+ $seconds = max( 0, $seconds );
	1720	+ foreach ( $headers as $name => $value ) {
	1721	+ if ( ! preg_match( self::EDGE_LIFETIME_HEADER, (string) $name ) ) {
	1722	+ continue;
	1723	+ }
	1724	+ $capped = preg_replace_callback(
	1725	+ self::EDGE_LIFETIME_DIRECTIVE,
	1726	+ static function ( array $m ) use ( $seconds ): string {
	1727	+ return $m[1] . '=' . min( (int) $m[2], $seconds );
	1728	+ },
	1729	+ (string) $value
	1730	+ );
	1731	+ if ( is_string( $capped ) ) {
	1732	+ $headers[ $name ] = $capped;
	1733	+ }
	1734	+ }
	1735	+
	1736	+ return $headers;
	1737	+ }
	1738	+
	1739	+ /**
	1740	+ * Does any `*-Control` header in the set let an edge keep the response?
	1741	+ *
	1742	+ * @param array<string,string> $headers Header name => value.
	1743	+ */
	1744	+ private static function grants_edge_lifetime( array $headers ): bool {
	1745	+ foreach ( $headers as $name => $value ) {
	1746	+ if ( ! preg_match( self::EDGE_LIFETIME_HEADER, (string) $name ) ) {
	1747	+ continue;
	1748	+ }
	1749	+ if ( preg_match_all( self::EDGE_LIFETIME_DIRECTIVE, (string) $value, $m ) ) {
	1750	+ foreach ( $m[2] as $seconds ) {
	1751	+ if ( (int) $seconds > 0 ) {
	1752	+ return true;
	1753	+ }
	1754	+ }
	1755	+ }
	1756	+ }
	1757	+
	1758	+ return false;
	1759	+ }
	1760	+
	1761	+ /**
	1762	+ * Seconds a cached entry has left, when it has a lifetime of its own.
	1763	+ *
	1764	+ * Read from the sidecar `ttl`, which write_meta() records only when the
	1765	+ * entry's lifetime differs from the site's. That is the drop-in's rule
	1766	+ * too, so both PHP serve paths count down the same entries. Null for an
	1767	+ * entry that follows the site's lifetime: what the edge is told about
	1768	+ * those is the site's lifetime, unchanged.
	1769	+ *
	1770	+ * @param array<string,mixed> $meta The entry's sidecar, from read_meta().
	1771	+ * @param string $file The cached file being served.
	1772	+ */
	1773	+ private static function entry_lifetime_left( array $meta, string $file ): ?int {
	1774	+ $ttl = isset( $meta['ttl'] ) ? (int) $meta['ttl'] : 0;
	1775	+ if ( $ttl < 1 ) {
	1776	+ return null;
	1777	+ }
	1778	+ $mtime = file_exists( $file ) ? filemtime( $file ) : false;
	1779	+ if ( false === $mtime ) {
	1780	+ return null;
	1781	+ }
	1782	+
	1783	+ return max( 0, $ttl - ( time() - (int) $mtime ) );
	1784	+ }
	1785	+
	1786	+ /**
	1787	+ * Render baked pairs as a PHP array literal for the drop-in.
	1788	+ *
	1789	+ * Single-quoted literals with quotes escaped, because the result is
	1790	+ * written into a PHP file that must still parse. Values reaching here
	1791	+ * have already been through sanitize_edge_headers(), so neither name nor
	1792	+ * value can carry a newline.
	1793	+ *
	1794	+ * @param array<string,string> $headers Name => value.
	1795	+ */
	1796	+ private static function edge_headers_literal( array $headers ): string {
	1797	+ if ( array() === $headers ) {
	1798	+ return 'array()';
	1799	+ }
	1800	+ // var_export(), not hand-rolled quoting. A single-quoted PHP string
	1801	+ // escapes BOTH `'` and `\\`, and escaping only the first is how a
	1802	+ // value ending in a backslash — `X-Foo: C:\path\` from the custom
	1803	+ // headers box — leaves the literal unterminated. That file is
	1804	+ // included on every request once WP_CACHE is on, so the result is a
	1805	+ // parse error on the front end AND in wp-admin, with no way back
	1806	+ // except deleting the file over SSH.
	1807	+ $parts = array();
	1808	+ foreach ( $headers as $name => $value ) {
	1809	+ $parts[] = var_export( (string) $name, true ) . ' => ' . var_export( (string) $value, true );
	1810	+ }
	1811	+
	1812	+ return 'array( ' . implode( ', ', $parts ) . ' )';
	1813	+ }
	1814	+
	1815	+ /**
	1816	+ * Quote a header value for an nginx / Apache directive.
	1817	+ *
	1818	+ * Both accept a double-quoted string with backslash escapes, and both
	1819	+ * refuse to load a config where the quoting is wrong — a mis-escaped
	1820	+ * value takes the whole vhost down, not just this header.
	1821	+ */
	1822	+ private static function quote_directive_value( string $value ): string {
	1823	+ return str_replace( array( '\\', '"' ), array( '\\\\', '\\"' ), $value );
	1824	+ }
	1825	+
	1826	+ /**
	1827	+ * The same directive twice — once per name Apache can expose the
	1828	+ * rewrite's environment variable under.
	1829	+ *
	1830	+ * `RewriteRule ... [E=XSPEED_STATIC_HIT:1]` in a per-directory context is
	1831	+ * an INTERNAL REDIRECT: Apache re-enters the request with the substituted
	1832	+ * path, and every variable set on the first pass is renamed with a
	1833	+ * `REDIRECT_` prefix for the second. `env=XSPEED_STATIC_HIT` is evaluated
	1834	+ * on that second pass, where nothing answers to that name any more, so
	1835	+ * the directive never fires — dropping the headers from precisely the
	1836	+ * responses they exist for. The rules marker rides on the same gate, so
	1837	+ * the probe also read its own marker as missing and called correctly
	1838	+ * installed rules stale.
	1839	+ *
	1840	+ * It cannot be written once: `env=` takes a single name with no
	1841	+ * alternation, and `expr=` — which could express both — is not dependable
	1842	+ * on LiteSpeed, which reads this same block. So both are emitted; the one
	1843	+ * whose variable is unset on a given pass does nothing.
	1844	+ *
	1845	+ * @param string $directive The directive, without its `env=` clause.
	1846	+ * @return string[]
	1847	+ */
	1848	+ private static function static_hit_directives( string $directive ): array {
	1849	+ return array(
	1850	+ $directive . ' env=XSPEED_STATIC_HIT',
	1851	+ $directive . ' env=REDIRECT_XSPEED_STATIC_HIT',
	1852	+ );
	1853	+ }
	1854	+
	1855	+ /**
	1856	+ * Keep only pairs that can be sent as a header verbatim.
	1857	+ *
	1858	+ * These values reach three different emitters — PHP's header(), an nginx
	1859	+ * `add_header` and an Apache `Header always set` — so a name with a space
	1860	+ * or a value carrying CR/LF is not merely malformed, it is a
	1861	+ * response-splitting vector in the first and a broken server config in
	1862	+ * the other two. Names must be token-shaped; values lose CR/LF and are
	1863	+ * dropped if nothing survives.
	1864	+ *
	1865	+ * @param array<mixed,mixed> $headers Raw pairs.
	1866	+ * @return array<string,string>
	1867	+ */
	1868	+ public static function sanitize_edge_headers( array $headers ): array {
	1869	+ $clean = array();
	1870	+ foreach ( $headers as $name => $value ) {
	1871	+ // Never let one of these through, whoever asked. They describe the
	1872	+ // transfer rather than the caching policy, and getting one wrong
	1873	+ // from a settings field is a white screen: `Content-Encoding: gzip`
	1874	+ // on an uncompressed body, a `Content-Length` that disagrees with
	1875	+ // the bytes. `X-XSpeed-Cache` is ours and a second copy would lie
	1876	+ // to whoever reads it.
	1877	+ if ( is_string( $name ) && in_array( strtolower( $name ), self::NEVER_AN_EDGE_HEADER, true ) ) {
	1878	+ continue;
	1879	+ }
	1880	+ // `\z`, not `$`: PCRE's `$` also matches immediately BEFORE a
	1881	+ // trailing newline, so "Cache-Tag\n" passes a `$` check and gets
	1882	+ // concatenated raw into the generated .htaccess — splitting one
	1883	+ // Header directive across two lines, which is a syntax error
	1884	+ // Apache reports as a 500 on every request while `httpd -t` stays
	1885	+ // green (.htaccess is parsed per request, not at load).
	1886	+ if ( ! is_string( $name ) || ! preg_match( '/^[A-Za-z0-9-]+\z/', $name ) ) {
	1887	+ continue;
	1888	+ }
	1889	+ if ( ! is_string( $value ) && ! is_numeric( $value ) ) {
	1890	+ continue;
	1891	+ }
	1892	+ $value = trim( str_replace( array( "\r", "\n" ), '', (string) $value ) );
	1893	+ if ( '' === $value ) {
	1894	+ continue;
	1895	+ }
	1896	+ // `$` is a variable reference in an nginx string and `%` is a
	1897	+ // format tag to Apache's mod_headers, which rejects an
	1898	+ // unrecognised one — in .htaccess that is a 500 on every request
	1899	+ // while `httpd -t` still reports OK, because .htaccess is parsed
	1900	+ // per request. `\` escapes the quote in the PHP literal baked into
	1901	+ // the drop-in. None of them can be escaped reliably in all three
	1902	+ // places at once, and nothing a cache reads needs any of them, so
	1903	+ // the value is dropped rather than mangled.
	1904	+ if ( preg_match( '/[$%\\\\]/', $value ) ) {
	1905	+ continue;
	1906	+ }
	1907	+ $clean[ $name ] = $value;
	1908	+ }
	1909	+
	1910	+ return $clean;
	1911	+ }
	1912	+
	1913	+ /**
	1914	+ * Bypass gates that describe THE VISITOR rather than THIS REQUEST.
	1915	+ *
	1916	+ * Only these may be recorded in the bypass cookie. A visitor-scoped
	1917	+ * verdict stays true for the visitor's next request — they are still
	1918	+ * logged in, still hold a cart cookie — so the web server can act on
	1919	+ * it without booting PHP.
	1920	+ *
	1921	+ * Every other gate describes the request in front of us: its method,
	1922	+ * its URL, its query string, the client's user agent. Persisting one
	1923	+ * of those pins a visitor to the uncached path over a property that
	1924	+ * was never theirs to begin with. (#218)
	1925	+ */
	1926	+ private const VISITOR_SCOPED_BYPASS = array( 'logged-in', 'excluded-cookie' );
	1927	+
	1928	+ /**
	1929	+ * Whether $reason describes the visitor (persist it) or merely this
	1930	+ * request (don't).
	1931	+ *
	1932	+ * Split out as a pure function because it is the whole decision behind
	1933	+ * the bypass cookie, and the cookie write itself (setcookie()) can't be
	1934	+ * asserted in a unit test.
	1935	+ */
	1936	+ public static function bypass_is_visitor_scoped( string $reason ): bool {
	1937	+ return in_array( $reason, self::VISITOR_SCOPED_BYPASS, true );
	1938	+ }
	1939	+
65	1940	public function maybe_start_cache() {
66	1941	if ( ! self::should_cache() ) {
	1942	+ // PHP has just evaluated the FULL exclusion rule list — including
	1943	+ // the `~regex` patterns the server config can't express — and
	1944	+ // decided this response must not be served from cache. Record that
	1945	+ // verdict in the conventional bypass cookie so the web server can
	1946	+ // enforce it on subsequent requests without starting PHP.
	1947	+ //
	1948	+ // This is what stops most settings changes from needing an nginx
	1949	+ // reload: the config tests one fixed cookie name forever, and the
	1950	+ // rule list behind it can change freely.
	1951	+ //
	1952	+ // But ONLY when the verdict is about the visitor. A request-shape
	1953	+ // gate — `non-get` above all — says nothing about who is asking,
	1954	+ // and persisting it pinned that visitor to the uncached path for
	1955	+ // the rest of their session: one search-form POST, one comment,
	1956	+ // one `curl -I` from an uptime monitor, and every later GET
	1957	+ // bypassed. It could not self-heal either, because the bypass
	1958	+ // cookie is itself in excluded_cookies, so the next GET bypassed
	1959	+ // with `excluded-cookie` and landed right back here, where
	1960	+ // sync_bypass_cookie()'s no-change short-circuit left the cookie
	1961	+ // exactly where it was. (#218)
	1962	+ if ( self::bypass_is_visitor_scoped( self::bypass_reason() ) ) {
	1963	+ self::sync_bypass_cookie( true );
	1964	+ }
67	1965	return;
68	1966	}
69	1967
	1968	+ // Cacheable: clear any stale bypass cookie, or a visitor who once
	1969	+ // had a cart would keep skipping the fast path long after checkout.
	1970	+ self::sync_bypass_cookie( false );
	1971	+
70	1972	$key = self::cache_key();
71	1973	$file = self::cache_file_for( $key );
72	1974
73	1975	if ( file_exists( $file ) && ! self::is_expired( $file ) ) {
74		- Hit_Counter::record_hit();
	1976	+ // Symmetric with the miss branch below: a bot, scanner or one of
	1977	+ // xSpeed's own warm/benchmark requests that lands a HIT must not
	1978	+ // inflate the ratio either — excluding only their misses would
	1979	+ // shrink the denominator while their hits kept feeding the
	1980	+ // numerator, making the displayed ratio MORE optimistic than
	1981	+ // before the exclusion existed.
	1982	+ if ( self::miss_is_excluded() ) {
	1983	+ Hit_Counter::record_excluded();
	1984	+ } else {
	1985	+ Hit_Counter::record_hit();
	1986	+ }
75	1987	// Emit the HIT marker on THIS path too. The drop-in
76	1988	// (advanced-cache.php) sends "HIT (php)" and the nginx static
77	1989	// rewrite sends "HIT (nginx)", but this template_redirect
78	1990	// serve path — the one that runs when the drop-in isn't loaded
		@@ -78,16 +1990,18 @@
78	1990	// serve path — the one that runs when the drop-in isn't loaded
79	1991	// (e.g. WP_CACHE not true) — previously streamed the cached
80	1992	// file with NO marker, so a genuine HIT looked like a MISS in
81	1993	// the response headers. Same header + value as the drop-in.
82		- if ( ! headers_sent() ) {
83		- header( 'X-XSpeed-Cache: HIT (php)' );
84		- }
	1994	+ //
	1995	+ // The sidecar is read first because the HIT's edge lifetime
	1996	+ // depends on it: an entry with a lifetime of its own may not be
	1997	+ // kept at the edge past it. See entry_lifetime_left().
	1998	+ $meta = self::read_meta( $key );
	1999	+ self::mark( 'HIT (php)', '', self::entry_lifetime_left( $meta, $file ) );
85	2000	// Replay stored response bits so the HIT matches the original:
86	2001	// a non-HTML Content-Type (cached feeds, sitemaps) and a non-200
87	2002	// status (a cached 404 must serve 404, not 200). No-op for
88	2003	// ordinary pages, which write no .meta.
89		- $meta = self::read_meta( $key );
90	2004	if ( ! headers_sent() ) {
91	2005	if ( ! empty( $meta['status'] ) && function_exists( 'http_response_code' ) ) {
92	2006	http_response_code( (int) $meta['status'] );
93	2007	}
		@@ -126,16 +2040,33 @@
126	2040	// Apache. See maybe_emit_lscache_headers() for the full rationale.
127	2041	self::maybe_emit_lscache_headers();
128	2042
129	2043	// We're about to render fresh + cache → miss for this request.
130		- Hit_Counter::record_miss();
	2044	+ // …UNLESS this request is a 404 or a known bot/scanner. Those reach the
	2045	+ // render path too, but counting them as cache misses makes the ratio
	2046	+ // meaningless — a wave of `/wp-x7.php` scanner 404s reads as a collapsing
	2047	+ // cache when nothing is wrong. Runs at template_redirect (priority 0), so
	2048	+ // is_404() is already resolved. Excluded requests are tallied separately
	2049	+ // for the "you absorbed N scanner hits" line, not dropped. (#118)
	2050	+ if ( self::miss_is_excluded() ) {
	2051	+ Hit_Counter::record_excluded();
	2052	+ } else {
	2053	+ Hit_Counter::record_miss();
	2054	+ }
131	2055
	2056	+ // Stamp it, so "eligible but not cached yet" is visibly different
	2057	+ // from "deliberately bypassed" (issue #10). Headers can't be sent
	2058	+ // after the body starts, so this has to happen here, not in
	2059	+ // finalize_buffer() — nothing has been output at template_redirect.
	2060	+ self::mark( 'MISS' );
132	2061
	2062	+
133	2063	// WP < 6.9 fallback: ob_start() with a callback, paired with an
134	2064	// explicit shutdown close so the buffer lifecycle is visible to
135	2065	// reviewers and Plugin Check, instead of relying on PHP's implicit
136	2066	// request-end flush. We record our nesting level so close_buffer()
137	2067	// flushes ONLY the buffer we opened.
	2068	+ self::$asset_stamp_at_open = class_exists( '\\XSpeed\\Minifier' ) ? Minifier::purge_stamp() : null;
138	2069	ob_start( array( __CLASS__, 'finalize_buffer' ) );
139	2070	self::$buffer_level = ob_get_level();
140	2071
141	2072	add_action( 'shutdown', array( __CLASS__, 'close_buffer' ), 0 );
		@@ -159,20 +2090,214 @@
159	2090	}
160	2091	self::$buffer_level = null;
161	2092	}
162	2093
	2094	+ /**
	2095	+ * Are we buffering this request?
	2096	+ *
	2097	+ * Asked by Css_Combine_Buffer, which needs the finished HTML but must not
	2098	+ * open a second buffer when this one is already going to hand it the page
	2099	+ * through `xspeed_cache_final_html`. False here means the request is not
	2100	+ * cacheable — cache off, excluded URL, logged in — and the combiner has to
	2101	+ * provide its own buffer or it silently stops working. (#195)
	2102	+ */
	2103	+ public static function is_buffering(): bool {
	2104	+ return null !== self::$buffer_level;
	2105	+ }
	2106	+
	2107	+ /**
	2108	+ * Is a render-time translation plugin going to wrap our output buffer?
	2109	+ *
	2110	+ * TranslatePress opens its translation buffer on `init` priority 0. We
	2111	+ * open ours on `template_redirect`, which runs much later, so ours nests
	2112	+ * INSIDE theirs. PHP unwinds output buffers LIFO — innermost callback
	2113	+ * first — so `finalize_buffer()` saw the raw, pre-translation HTML and
	2114	+ * cached that, while the live visitor still got the translated bytes from
	2115	+ * TRP's outer buffer.
	2116	+ *
	2117	+ * Result: the first (MISS) visitor to /fr/some-page/ got correct French;
	2118	+ * every visitor after got English body text under a `lang="fr-FR"`
	2119	+ * document, plus TRP's internal `#TRPLINKPROCESSED` link markers, which
	2120	+ * TRP strips at the very end of its own buffer and which therefore leak
	2121	+ * into anything captured from inside it.
	2122	+ *
	2123	+ * Note the ordering cannot be fixed from TRP's side: its
	2124	+ * `trp_start_output_buffer_priority` filter only moves the PRIORITY on
	2125	+ * `init`, and `init` always fires before `template_redirect` whatever the
	2126	+ * priority. The buffer that has to move is ours.
	2127	+ *
	2128	+ * Detected by main class rather than plugin path, so a renamed directory
	2129	+ * or a bundled copy still matches.
	2130	+ */
	2131	+ public static function translation_plugin_active(): bool {
	2132	+ $active = class_exists( 'TRP_Translate_Press' );
	2133	+
	2134	+ /**
	2135	+ * Whether to treat this request as wrapped by a translation buffer.
	2136	+ *
	2137	+ * Lets a site add another render-time translation plugin (or opt out)
	2138	+ * without patching the engine.
	2139	+ *
	2140	+ * @param bool $active
	2141	+ */
	2142	+ return (bool) apply_filters( 'xspeed_translation_plugin_active', $active );
	2143	+ }
	2144	+
	2145	+ /**
	2146	+ * Write the cache file for a request whose output was wrapped by a
	2147	+ * render-time translation plugin.
	2148	+ *
	2149	+ * Registered as a PHP shutdown function (not a WP `shutdown` action) so
	2150	+ * it runs after PHP has unwound the output-buffer stack — by which point
	2151	+ * the translation plugin's callback has transformed the bytes and its
	2152	+ * internal markers are gone.
	2153	+ *
	2154	+ * finalize_buffer() has already applied the status gate, the
	2155	+ * xspeed_cache_final_html filter and HTML minification to the
	2156	+ * untranslated copy and then declined to write it. Here we re-run only
	2157	+ * what's needed on the translated bytes: minify, write, and fire the
	2158	+ * same downstream hooks so Brotli / static-tree listeners behave
	2159	+ * identically to the ordinary path.
	2160	+ */
	2161	+ public static function write_deferred_translated_cache(): void {
	2162	+ $key = self::$deferred_key;
	2163	+ self::$deferred_key = null;
	2164	+
	2165	+ // Release the collected bytes BEFORE the early return, so the static
	2166	+ // is cleared on every path rather than only when a key survived.
	2167	+ $full = self::$translated_output;
	2168	+ self::$translated_output = '';
	2169	+
	2170	+ $completed = self::$render_completed;
	2171	+ self::$render_completed = false;
	2172	+
	2173	+ $asset_stamp = self::$deferred_asset_stamp;
	2174	+ self::$deferred_asset_stamp = null;
	2175	+
	2176	+ if ( null === $key ) {
	2177	+ return;
	2178	+ }
	2179	+
	2180	+ // Did the render actually finish?
	2181	+ //
	2182	+ // This runs as a PHP shutdown function, which fires after a wp_die()
	2183	+ // or a bare exit() just as readily as after a clean render — but in
	2184	+ // those cases finalize_buffer() never returned, so the bytes we hold
	2185	+ // are a page that was cut off partway through. The length and
	2186	+ // TRPLINKPROCESSED checks below don't catch that: a fatal after the
	2187	+ // footer's translated markup is both over 255 bytes and free of TRP
	2188	+ // markers, i.e. truncated but entirely plausible. Caching it would
	2189	+ // freeze a half-rendered page under the real key for the full TTL.
	2190	+ //
	2191	+ // Serving this one URL uncached is the cheap failure; the corrupt
	2192	+ // cache entry is the expensive one.
	2193	+ if ( ! $completed ) {
	2194	+ return;
	2195	+ }
	2196	+
	2197	+ if ( strlen( $full ) < 255 ) {
	2198	+ return;
	2199	+ }
	2200	+
	2201	+ // Refuse to cache a copy still carrying the translation plugin's
	2202	+ // internal link markers. TRP strips these at the very end of its own
	2203	+ // buffer, so their presence means we captured too early — and a
	2204	+ // cached page containing them is SEO-visible damage. Better to serve
	2205	+ // this URL uncached than to freeze broken markup for the full TTL.
	2206	+ if ( false !== strpos( $full, 'TRPLINKPROCESSED' ) ) {
	2207	+ return;
	2208	+ }
	2209	+
	2210	+ $minify_opts = Settings_Manager::get( 'minify' );
	2211	+ if ( ! empty( $minify_opts['minify_html'] ) ) {
	2212	+ $full = Minifier::minify_html( $full );
	2213	+ }
	2214	+ $full = self::signed( $full );
	2215	+
	2216	+ // Per-site directory: on multisite every blog shares this tree, so
	2217	+ // entries are bucketed by host to keep one site's purge from
	2218	+ // sweeping the whole network. (#6)
	2219	+ self::ensure_host_dir();
	2220	+
	2221	+ // Never author a cache entry from a request that carried a query
	2222	+ // string: cache_key() files it under the BARE url, so the params'
	2223	+ // render would be served to every clean-URL visitor (#241).
	2224	+ if ( self::query_string_blocks_write() ) {
	2225	+ return;
	2226	+ }
	2227	+
	2228	+ // Same guard as finalize_buffer(): the translation plugin's buffer
	2229	+ // adds time between render and store, not less.
	2230	+ if ( self::assets_purged_since( $asset_stamp ) ) {
	2231	+ return;
	2232	+ }
	2233	+
	2234	+ $file = self::cache_file_for( $key );
	2235	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- WP_Filesystem requires admin context for credentials; this runs on a frontend shutdown where it's unavailable.
	2236	+ file_put_contents( $file, $full, LOCK_EX );
	2237	+
	2238	+ /** This action is documented in includes/class-cache.php */
	2239	+ do_action( 'xspeed_flat_file_written', $file, $full );
	2240	+
	2241	+ self::write_meta( $key, $full );
	2242	+
	2243	+ // Static tree too, under the same gates finalize_buffer() applies —
	2244	+ // otherwise deferring the write would silently cost translated pages
	2245	+ // the web-server fast path and leave them on the slower drop-in.
	2246	+ // The static tree cannot replay a sidecar. A file served straight by
	2247	+ // the web server carries the headers baked into the rule that serves
	2248	+ // the whole site — the very answer this entry exists because it
	2249	+ // disagreed with. Same reasoning as the status and content-type
	2250	+ // cases: what the fast path cannot replay belongs on the drop-in path.
	2251	+ if ( self::static_rewrite_allowed()
	2252	+ && self::response_is_plain_html()
	2253	+ && array() === self::per_entry_edge_headers() ) {
	2254	+ self::store_static( $full );
	2255	+ }
	2256	+ }
	2257	+
	2258	+ /**
	2259	+ * Did a purge delete minified or combined files after $stamp was taken?
	2260	+ *
	2261	+ * @param string|null $stamp Minifier::purge_stamp() when the render began,
	2262	+ * or null when no snapshot was taken.
	2263	+ */
	2264	+ private static function assets_purged_since( ?string $stamp ): bool {
	2265	+ if ( null === $stamp || ! class_exists( '\\XSpeed\\Minifier' ) ) {
	2266	+ return false;
	2267	+ }
	2268	+ return Minifier::purge_stamp() !== $stamp;
	2269	+ }
	2270	+
163	2271	public static function should_cache() {
	2272	+ // Reset first: a single request only reaches this once (the sole
	2273	+ // caller is maybe_start_cache()), but tests and any future caller
	2274	+ // must never inherit the previous request's verdict.
	2275	+ self::$status_header = '';
	2276	+ self::$bypass_reason = '';
	2277	+ self::$edge_headers = array();
	2278	+ self::$per_entry_edge = null;
	2279	+ // Under PHP-FPM a process serves one request and this is moot. Under
	2280	+ // a persistent worker runtime it is not: without it, an answer
	2281	+ // resolved from one visitor's forgeable headers would be reused for
	2282	+ // every later request the worker handles.
	2283	+ Edge_Provider::forget();
	2284	+
164	2285	$opts = Settings::get();
165	2286	if ( empty( $opts['cache_enabled'] ) ) {
166		- return false;
	2287	+ return self::bypass( 'cache-disabled' );
167	2288	}
168	2289
169		- if ( is_user_logged_in() || is_admin() || ( defined( 'DOING_AJAX' ) && DOING_AJAX ) || ( defined( 'DOING_CRON' ) && DOING_CRON ) || ( defined( 'REST_REQUEST' ) && REST_REQUEST ) ) {
170		- return false;
	2290	+ if ( is_user_logged_in() ) {
	2291	+ return self::bypass( 'logged-in' );
171	2292	}
172	2293
	2294	+ if ( is_admin() || ( defined( 'DOING_AJAX' ) && DOING_AJAX ) || ( defined( 'DOING_CRON' ) && DOING_CRON ) || ( defined( 'REST_REQUEST' ) && REST_REQUEST ) ) {
	2295	+ return self::bypass( 'non-frontend' );
	2296	+ }
	2297	+
173	2298	if ( defined( 'DONOTCACHEPAGE' ) && DONOTCACHEPAGE ) {
174		- return false;
	2299	+ return self::bypass( 'donotcachepage' );
175	2300	}
176	2301
177	2302	// All exclusion knobs now owned by CacheModule.
178	2303	$cache_opts = Settings_Manager::get( 'cache' );
		@@ -178,9 +2303,9 @@
178	2303	$cache_opts = Settings_Manager::get( 'cache' );
179	2304
180	2305	$method = isset( $_SERVER['REQUEST_METHOD'] ) ? strtoupper( sanitize_text_field( wp_unslash( $_SERVER['REQUEST_METHOD'] ) ) ) : '';
181	2306	if ( 'GET' !== $method ) {
182		- return false;
	2307	+ return self::bypass( 'non-get' );
183	2308	}
184	2309
185	2310	// Search-results requests carry a `s` query param, which the
186	2311	// query-string gate below would normally reject as "dynamic". An
		@@ -207,13 +2332,35 @@
207	2332	* @param bool $cache_feed Whether to cache this feed request.
208	2333	*/
209	2334	$cache_feed = $is_feed_request && (bool) apply_filters( 'xspeed_should_cache_feed', false );
210	2335
	2336	+ // WordPress's virtual robots.txt (and virtual favicon) are not HTML:
	2337	+ // caching one runs it through the whole HTML pipeline, which stamped
	2338	+ // the footer comment onto text/plain and let HTML minification
	2339	+ // collapse robots.txt to a single line — a line-based format, so
	2340	+ // every directive after the first was lost and crawlers read an
	2341	+ // invalid file. No opt-in filter here: there is no correct way to
	2342	+ // treat these as pages. (Reported live on a customer site.)
	2343	+ if ( ( function_exists( 'is_robots' ) && is_robots() )
	2344	+ || ( function_exists( 'is_favicon' ) && is_favicon() ) ) {
	2345	+ return self::bypass( 'non-html' );
	2346	+ }
	2347	+
211	2348	// Query string handling: anything OUTSIDE the ignored-params
212	2349	// allow-list (utm_*, fbclid, gclid by default) means a unique
213	2350	// request that we don't want to share with the canonical cache
214	2351	// entry. Skip cache rather than poison the key.
215		- $query_raw = isset( $_SERVER['QUERY_STRING'] ) ? sanitize_text_field( wp_unslash( $_SERVER['QUERY_STRING'] ) ) : '';
	2352	+ //
	2353	+ // Parse the RAW query string, NOT a sanitize_text_field() copy:
	2354	+ // that filter strips percent-encoded octets (%XX), so `?%73=…`
	2355	+ // would lose its `s` key here while WordPress still decodes it to
	2356	+ // a search request — the gate would wave the request through and
	2357	+ // cache_key() would file the search page under the bare URL,
	2358	+ // letting an attacker poison the homepage cache with `/?%73=<spam>`.
	2359	+ // parse_str() does its own urldecoding, matching WP's own parse, and
	2360	+ // only the KEYS are used below (fed to Glob_Matcher → preg_match,
	2361	+ // never echoed or executed), so no sanitization is needed here.
	2362	+ $query_raw = isset( $_SERVER['QUERY_STRING'] ) ? wp_unslash( $_SERVER['QUERY_STRING'] ) : ''; // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- see note above: parse_str() urldecodes to match WP; only keys are consumed, via preg_match, never output.
216	2363	if ( '' !== $query_raw ) {
217	2364	$ignored = is_array( $cache_opts['ignored_query_params'] ?? null ) ? $cache_opts['ignored_query_params'] : array();
218	2365	parse_str( $query_raw, $params );
219	2366	foreach ( $params as $key => $_ ) {
		@@ -222,23 +2369,24 @@
222	2369	continue;
223	2370	}
224	2371	// Allow query-form feed params through when feed caching opted
225	2372	// this request in (?feed=rss2 / &withcomments=1 on feeds).
226		- if ( $cache_feed && in_array( $key, array( 'feed', 'withcomments', 'withoutcomments' ), true ) ) {
	2373	+ if ( $cache_feed && in_array( $key, self::FEED_QUERY_PARAMS, true ) ) {
227	2374	continue;
228	2375	}
229	2376	if ( ! self::query_key_is_ignored( (string) $key, $ignored ) ) {
230		- return false;
	2377	+ // Slug only — never the param name, which is attacker-
	2378	+ // controlled and would be reflected into a header.
	2379	+ return self::bypass( 'query-param' );
231	2380	}
232	2381	}
233	2382	}
234	2383
235		- $request_uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
236		- $path = (string) strtok( $request_uri, '?' );
	2384	+ $path = self::request_path();
237	2385
238	2386	$excluded_urls = is_array( $cache_opts['excluded_urls'] ?? null ) ? $cache_opts['excluded_urls'] : array();
239		- if ( ! $cache_feed && Glob_Matcher::any_match( $excluded_urls, $path ) ) {
240		- return false;
	2387	+ if ( ! $cache_feed && self::path_matches_exclusions( $excluded_urls, $path ) ) {
	2388	+ return self::bypass( 'excluded-url' );
241	2389	}
242	2390
243	2391	// Cookie-based exclusion. We only check cookie NAMES (matching
244	2392	// values would leak content-sensitive logic into the cache key
		@@ -245,10 +2393,21 @@
245	2393	// rules); presence of any matching cookie name skips cache.
246	2394	$excluded_cookies = is_array( $cache_opts['excluded_cookies'] ?? null ) ? $cache_opts['excluded_cookies'] : array();
247	2395	if ( ! empty( $excluded_cookies ) && ! empty( $_COOKIE ) ) {
248	2396	foreach ( array_keys( $_COOKIE ) as $cookie_name ) {
	2397	+ // Our own bypass cookie is a RECORD of a previous verdict, not
	2398	+ // evidence about this visitor, so it never gets a vote here.
	2399	+ // Letting it match made the verdict self-confirming: once set,
	2400	+ // it produced `excluded-cookie` forever, which re-set it, and
	2401	+ // no later request could ever re-evaluate the visitor on the
	2402	+ // rules that actually describe them. The web server still acts
	2403	+ // on the cookie without booting PHP; when PHP does boot it is
	2404	+ // authoritative and re-decides from scratch. (#218)
	2405	+ if ( Server_Rules::BYPASS_COOKIE === $cookie_name ) {
	2406	+ continue;
	2407	+ }
249	2408	if ( Glob_Matcher::any_match( $excluded_cookies, (string) $cookie_name ) ) {
250		- return false;
	2409	+ return self::bypass( 'excluded-cookie' );
251	2410	}
252	2411	}
253	2412	}
254	2413
		@@ -259,9 +2418,9 @@
259	2418	if ( ! empty( $bypass_uas ) ) {
260	2419	$ua = isset( $_SERVER['HTTP_USER_AGENT'] ) ? sanitize_text_field( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ) ) : '';
261	2420	foreach ( $bypass_uas as $needle ) {
262	2421	if ( '' !== $needle && false !== stripos( $ua, (string) $needle ) ) {
263		- return false;
	2422	+ return self::bypass( 'user-agent' );
264	2423	}
265	2424	}
266	2425	}
267	2426
		@@ -268,9 +2427,9 @@
268	2427	// Per-post override (Phase 3.4). Honored only on singular
269	2428	// post-context requests — archives / 404s / taxonomies use the
270	2429	// global policy above.
271	2430	if ( Cache_Rules::should_skip_for_post( Cache_Rules::current_post_id() ) ) {
272		- return false;
	2431	+ return self::bypass( 'post-excluded' );
273	2432	}
274	2433
275	2434	/**
276	2435	* Final say on whether the current request is cacheable.
		@@ -290,9 +2449,16 @@
290	2449	* advanced-cache.php.
291	2450	*
292	2451	* @param bool $should_cache Whether to cache the current request.
293	2452	*/
294		- return (bool) apply_filters( 'xspeed_should_cache', true );
	2453	+ if ( ! apply_filters( 'xspeed_should_cache', true ) ) {
	2454	+ // One slug for every listener — a third-party callback name is
	2455	+ // not ours to put in a response header. Which listener vetoed is
	2456	+ // a WP_DEBUG-level question the filter itself can answer.
	2457	+ return self::bypass( 'filtered' );
	2458	+ }
	2459	+
	2460	+ return true;
295	2461	}
296	2462
297	2463	/**
298	2464	* Whether the current request is a 404 we may cache.
		@@ -336,8 +2502,99 @@
336	2502	* search_term() / cache_key()) so different searches stay distinct.
337	2503	* The xspeed-pro search cache flips the filter; Free never caches
338	2504	* search results on its own.
339	2505	*/
	2506	+ /**
	2507	+ * Whether this response was rendered for a query string and therefore
	2508	+ * must not be STORED under the bare-URL key.
	2509	+ *
	2510	+ * should_cache() lets a request through when every key is on the
	2511	+ * `ignored_query_params` allow-list, and cache_key() then drops the
	2512	+ * query string so `/post` and `/post?utm_source=x` share one entry.
	2513	+ * Sharing on READ is the point of the allow-list and stays. Sharing on
	2514	+ * WRITE is a cache-poisoning vector: the response was rendered *with*
	2515	+ * those params, and WordPress reflects REQUEST_URI into form actions,
	2516	+ * share links, canonical helpers and plugin smart tags. One anonymous
	2517	+ * GET to a cold URL therefore freezes an attacker-chosen variant under
	2518	+ * the clean URL's key, served for the whole TTL by the drop-in and by
	2519	+ * the web server — neither of which runs these checks (issue #241).
	2520	+ *
	2521	+ * The allow-list keeps its benefit: a visitor arriving on
	2522	+ * `?utm_source=…` is still SERVED the canonical cached entry. Only the
	2523	+ * write is skipped, so the entry is authored by a clean request.
	2524	+ *
	2525	+ * This is the same reasoning as the `should_cache_search()` guard in
	2526	+ * store_static() (#191), generalised to the allow-listed params.
	2527	+ */
	2528	+ public static function request_has_query_string(): bool {
	2529	+ $query = isset( $_SERVER['QUERY_STRING'] )
	2530	+ ? (string) wp_unslash( $_SERVER['QUERY_STRING'] ) // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- only tested for emptiness; never echoed, stored or used as a path.
	2531	+ : '';
	2532	+
	2533	+ return '' !== trim( $query );
	2534	+ }
	2535	+
	2536	+ /**
	2537	+ * Whether this request's query string is empty or holds only params the
	2538	+ * cache ignores (`ignored_query_params`, utm_* and the like), so the
	2539	+ * page is the one the bare URL serves.
	2540	+ *
	2541	+ * The same test should_cache() applies, without its search and feed
	2542	+ * exceptions: those are keyed apart from the bare URL.
	2543	+ */
	2544	+ public static function query_has_only_ignored_params(): bool {
	2545	+ $query_raw = isset( $_SERVER['QUERY_STRING'] ) ? wp_unslash( $_SERVER['QUERY_STRING'] ) : ''; // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- as in should_cache(): only keys are read, via preg_match.
	2546	+ if ( '' === trim( (string) $query_raw ) ) {
	2547	+ return true;
	2548	+ }
	2549	+ $cache_opts = Settings_Manager::get( 'cache' );
	2550	+ $ignored = is_array( $cache_opts['ignored_query_params'] ?? null ) ? $cache_opts['ignored_query_params'] : array();
	2551	+ parse_str( (string) $query_raw, $params );
	2552	+ foreach ( $params as $key => $_ ) {
	2553	+ if ( ! self::query_key_is_ignored( (string) $key, $ignored ) ) {
	2554	+ return false;
	2555	+ }
	2556	+ }
	2557	+ return true;
	2558	+ }
	2559	+
	2560	+ /**
	2561	+ * Would authoring a cache entry from THIS request file a query-string
	2562	+ * render under the bare URL?
	2563	+ *
	2564	+ * The one predicate both write sites ask, so they cannot drift.
	2565	+ *
	2566	+ * Two shapes are exempt because cache_key() does NOT drop their query —
	2567	+ * it folds the distinguishing part into the key, so each variant gets
	2568	+ * its own entry and none is filed under the bare URL:
	2569	+ *
	2570	+ * - searches, keyed by `|s=<term>` (#191)
	2571	+ * - feeds, keyed by `|feed=<type>` — `/?feed=rss2` is the ONLY feed URL
	2572	+ * core generates on plain permalinks, so treating it as poisonable
	2573	+ * made feed caching a no-op on exactly the sites that need it
	2574	+ *
	2575	+ * @return bool True when the write must be skipped.
	2576	+ */
	2577	+ public static function query_string_blocks_write(): bool {
	2578	+ if ( ! self::request_has_query_string() ) {
	2579	+ return false;
	2580	+ }
	2581	+
	2582	+ if ( self::should_cache_search() ) {
	2583	+ return false;
	2584	+ }
	2585	+
	2586	+ // Feed caching is opt-in, via the same filter should_cache() reads
	2587	+ // to admit the feed params in the first place.
	2588	+ if ( function_exists( 'is_feed' ) && is_feed()
	2589	+ && (bool) apply_filters( 'xspeed_should_cache_feed', false )
	2590	+ ) {
	2591	+ return false;
	2592	+ }
	2593	+
	2594	+ return true;
	2595	+ }
	2596	+
340	2597	public static function should_cache_search(): bool {
341	2598	if ( ! function_exists( 'is_search' ) || ! is_search() ) {
342	2599	return false;
343	2600	}
		@@ -377,15 +2634,240 @@
377	2634	}
378	2635
379	2636	/**
380	2637	* Is this query-string key on the ignored-params allow-list? Supports
381		- * trailing-star globs (`utm_*` matches `utm_source`, `utm_medium`,
382		- * etc.) so users don't have to enumerate every UTM variant.
	2638	+ * globs (`utm_*` matches `utm_source`, `utm_medium`, etc.) so users
	2639	+ * don't have to enumerate every UTM variant, and `~regex`.
	2640	+ *
	2641	+ * Matching is whole-name, not "contains" — a param name is an
	2642	+ * identifier, not a path. Under the old contains match the shipped
	2643	+ * default `ref` also swallowed `preference`, `product_ref` and
	2644	+ * `referrer`: those params were dropped from the cache key, so
	2645	+ * `/shop?preference=1` was served — and, on a cold entry, WRITTEN as —
	2646	+ * `/shop`. Same for `_ga` vs `_gallery`, and for the unanchored
	2647	+ * `~utm_…` default vs `my_utm_source`. A param name that is genuinely
	2648	+ * unknown now bypasses the cache, which is the safe direction.
383	2649	*/
384	2650	private static function query_key_is_ignored( string $key, array $ignored ): bool {
385		- return Glob_Matcher::any_match( $ignored, $key );
	2651	+ if ( in_array( $key, self::NEVER_IGNORED_QUERY_PARAMS, true ) ) {
	2652	+ return false;
	2653	+ }
	2654	+ return Glob_Matcher::any_match_name( $ignored, $key );
386	2655	}
387	2656
	2657	+ /**
	2658	+ * Query params no ignored-params entry can match, glob or regex.
	2659	+ *
	2660	+ * A measuring request asks for the page as it is before optimisation
	2661	+ * (`xspeed_css=off`), with a one-time value (`xspeed_nc`) so no cache
	2662	+ * has a copy of it. The answer must be rendered for that request. A
	2663	+ * list entry such as `xspeed_*` or `*` would make both params
	2664	+ * decoration: the drop-in would serve the canonical, already-optimised
	2665	+ * entry before any plugin loads, and the measurement would describe
	2666	+ * the optimised page instead of the source.
	2667	+ */
	2668	+ public const NEVER_IGNORED_QUERY_PARAMS = array( 'xspeed_css', 'xspeed_nc' );
	2669	+
	2670	+ /**
	2671	+ * The params a query-form feed may carry (`/?feed=rss2`) once feed
	2672	+ * caching has opted the request in. should_cache() lets them through,
	2673	+ * and serves_query_variant() holds a HIT that carries one.
	2674	+ */
	2675	+ private const FEED_QUERY_PARAMS = array( 'feed', 'withcomments', 'withoutcomments' );
	2676	+
	2677	+ /**
	2678	+ * The one spelling of a URL path that every cache key is built from.
	2679	+ *
	2680	+ * WordPress stores a non-ASCII slug percent-encoded, so a page called
	2681	+ * `關於我們` is requested as `/%e9%97%9c%e6%96%bc%e6%88%91%e5%80%91/`. The
	2682	+ * same page also arrives as `/%E9%97%9C…/` (what a browser sends for an
	2683	+ * address typed or pasted into it) and as raw UTF-8 bytes. WordPress
	2684	+ * renders the same page for all three, so they get one key: escapes are
	2685	+ * lowercased (WordPress's own spelling, so a permalink comes back
	2686	+ * unchanged) and any byte outside printable ASCII is escaped the same way.
	2687	+ * Null bytes are dropped, as the drop-in does.
	2688	+ *
	2689	+ * Nothing is decoded. `/ab%6Fut/` stays a separate entry from `/about/`.
	2690	+ * Only spellings of the same bytes are merged, because merging spellings
	2691	+ * WordPress may route differently would let one page be served for
	2692	+ * another. A printable-ASCII path with no escapes comes back unchanged,
	2693	+ * so ordinary pages keep the keys they had.
	2694	+ *
	2695	+ * The path used to go through sanitize_text_field(), which deletes every
	2696	+ * `%XX` octet: `/第九屆-當代藝術-tagboat-award-特展/` was keyed as
	2697	+ * `/--tagboat-award-/`, every page whose slug differed only in non-ASCII
	2698	+ * characters shared one entry, and an all-non-ASCII slug became `//`,
	2699	+ * which store_static() wrote over the home page's static file.
	2700	+ *
	2701	+ * The drop-in carries a copy of this transform, because it runs before
	2702	+ * WordPress and this class load. Change both together.
	2703	+ *
	2704	+ * @param string $path A URL path, without the query string.
	2705	+ */
	2706	+ public static function normalize_path( string $path ): string {
	2707	+ return self::path_with_escape_case( $path, false );
	2708	+ }
	2709	+
	2710	+ /**
	2711	+ * The spellings of one path that a cache in front of the site may hold.
	2712	+ *
	2713	+ * xSpeed keys every escape spelling of a path as one entry
	2714	+ * (normalize_path()). A CDN does not: Cloudflare keeps `/%E9%97%9C…/`,
	2715	+ * the spelling a browser sends, apart from `/%e9%97%9c…/`, the spelling
	2716	+ * of WordPress's own links. A purge that named one left the other
	2717	+ * serving the old page until its edge lifetime ran out.
	2718	+ *
	2719	+ * Returns the path as given, then normalize_path()'s spelling (lower-case
	2720	+ * escapes), then the same with upper-case escapes. Both are built from
	2721	+ * the path the local sweep cleared, so a cache in front is never asked
	2722	+ * about a page xSpeed did not purge. Duplicates drop out, so a path with
	2723	+ * no escapes has one spelling. Trailing-slash forms are the caller's job.
	2724	+ *
	2725	+ * @param string $path A URL path, without the query string.
	2726	+ * @return string[]
	2727	+ */
	2728	+ public static function escape_spellings( string $path ): array {
	2729	+ return array_values(
	2730	+ array_unique(
	2731	+ array( $path, self::path_with_escape_case( $path, false ), self::path_with_escape_case( $path, true ) )
	2732	+ )
	2733	+ );
	2734	+ }
	2735	+
	2736	+ /**
	2737	+ * normalize_path() with the escapes in the case asked for.
	2738	+ *
	2739	+ * @param string $path A URL path, without the query string.
	2740	+ * @param bool $upper Upper-case escapes, or lower (the key's spelling).
	2741	+ */
	2742	+ private static function path_with_escape_case( string $path, bool $upper ): string {
	2743	+ return (string) preg_replace_callback(
	2744	+ '/%[0-9a-fA-F]{2}|[^\x21-\x7E]/',
	2745	+ static function ( array $m ) use ( $upper ): string {
	2746	+ $escape = '%' === $m[0][0] ? $m[0] : sprintf( '%%%02x', ord( $m[0] ) );
	2747	+ return $upper ? strtoupper( $escape ) : strtolower( $escape );
	2748	+ },
	2749	+ str_replace( "\0", '', $path )
	2750	+ );
	2751	+ }
	2752	+
	2753	+ /**
	2754	+ * Percent-encode every byte 0x80 and up, lowercase hex.
	2755	+ *
	2756	+ * @param string $value A path or a whole URL.
	2757	+ */
	2758	+ private static function encode_non_ascii( string $value ): string {
	2759	+ return (string) preg_replace_callback(
	2760	+ '/[\x80-\xff]/',
	2761	+ static function ( array $m ): string {
	2762	+ return '%' . bin2hex( $m[0] );
	2763	+ },
	2764	+ $value
	2765	+ );
	2766	+ }
	2767	+
	2768	+ /**
	2769	+ * Where a URL path lives in the static tree, relative to the host
	2770	+ * directory, with a leading slash and no trailing one ('' for the home
	2771	+ * page). Null when the path must not be written there.
	2772	+ *
	2773	+ * Decoded, because that is what the web server looks up: nginx builds the
	2774	+ * file name from `$uri` and Apache from `%{REQUEST_URI}`, and both hold
	2775	+ * the decoded path. A file stored under the encoded name is never found.
	2776	+ *
	2777	+ * Decoding is only safe for the escapes WordPress itself writes, which
	2778	+ * encode the bytes of non-ASCII letters (0x80 and up). An escaped ASCII
	2779	+ * byte is refused, because the server decodes it before the lookup:
	2780	+ * `%2F` would become a directory, `%2E%2E` a parent, and `%6F` would
	2781	+ * make `/ab%6Fut/` and `/about/` share one file although they are
	2782	+ * separate cache entries. The decoded path must also be valid UTF-8, with
	2783	+ * no control byte, backslash or `%`, no `..` anywhere and no `.`
	2784	+ * segment. A refused page is still cached by the drop-in; it only loses
	2785	+ * the no-PHP path.
	2786	+ *
	2787	+ * @param string $path A URL path, without the query string.
	2788	+ */
	2789	+ public static function static_path( string $path ): ?string {
	2790	+ if ( '' === $path || false !== strpos( $path, "\0" ) ) {
	2791	+ return null;
	2792	+ }
	2793	+ if ( preg_match_all( '/%([0-9a-fA-F]{2})/', $path, $escapes ) ) {
	2794	+ foreach ( $escapes[1] as $hex ) {
	2795	+ if ( hexdec( $hex ) < 0x80 ) {
	2796	+ return null;
	2797	+ }
	2798	+ }
	2799	+ }
	2800	+ $decoded = rawurldecode( $path );
	2801	+ if ( 1 !== preg_match( '//u', $decoded ) || preg_match( '/[\x00-\x1f\x7f\\\\%]/', $decoded ) ) {
	2802	+ return null;
	2803	+ }
	2804	+ $decoded = (string) preg_replace( '#/+#', '/', $decoded );
	2805	+ if ( false !== strpos( $decoded, '..' ) || preg_match( '#(^|/)\.(/|$)#', $decoded ) ) {
	2806	+ return null;
	2807	+ }
	2808	+ return rtrim( $decoded, '/' );
	2809	+ }
	2810	+
	2811	+ /**
	2812	+ * The current request's path, normalized, without the query string.
	2813	+ *
	2814	+ * @param string $fallback Returned when the server sent no REQUEST_URI.
	2815	+ */
	2816	+ private static function request_path( string $fallback = '' ): string {
	2817	+ if ( ! isset( $_SERVER['REQUEST_URI'] ) ) {
	2818	+ return $fallback;
	2819	+ }
	2820	+ // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- normalize_path() is the sanitizer. sanitize_text_field() deletes percent-encoded octets and broke every non-ASCII slug (see normalize_path()). The value is hashed, matched, or checked by static_path() before it touches the disk.
	2821	+ $uri = (string) wp_unslash( $_SERVER['REQUEST_URI'] );
	2822	+ return self::normalize_path( (string) strtok( $uri, '?' ) );
	2823	+ }
	2824	+
	2825	+ /**
	2826	+ * An Excluded URLs entry with its escapes in lower case.
	2827	+ *
	2828	+ * The request path is matched in normalize_path()'s spelling, so an entry
	2829	+ * copied from Chrome's address bar (`/%E8%81%AF…/`) never matched it.
	2830	+ * Only `%XX` sequences change; the rest of the entry, including a `~`
	2831	+ * regex, is left as typed.
	2832	+ *
	2833	+ * @param string $pattern One Excluded URLs entry.
	2834	+ */
	2835	+ public static function normalize_exclusion( string $pattern ): string {
	2836	+ return (string) preg_replace_callback(
	2837	+ '/%[0-9a-fA-F]{2}/',
	2838	+ static function ( array $m ): string {
	2839	+ return strtolower( $m[0] );
	2840	+ },
	2841	+ $pattern
	2842	+ );
	2843	+ }
	2844	+
	2845	+ /**
	2846	+ * Does an exclusion list match this path, in either spelling?
	2847	+ *
	2848	+ * An admin may paste an exclusion as `/購物車`, as WordPress spells it, or
	2849	+ * as Chrome shows it in upper case. The entry's escapes are lowercased to
	2850	+ * match the path, and the decoded path is tried too, which is also what
	2851	+ * the nginx rule matches (`$uri` is decoded).
	2852	+ *
	2853	+ * @param string[] $patterns Exclusion entries.
	2854	+ * @param string $path Output of normalize_path().
	2855	+ */
	2856	+ private static function path_matches_exclusions( array $patterns, string $path ): bool {
	2857	+ $patterns = array_map(
	2858	+ static function ( $pattern ): string {
	2859	+ return self::normalize_exclusion( (string) $pattern );
	2860	+ },
	2861	+ $patterns
	2862	+ );
	2863	+ if ( Glob_Matcher::any_match( $patterns, $path ) ) {
	2864	+ return true;
	2865	+ }
	2866	+ $decoded = rawurldecode( $path );
	2867	+ return $decoded !== $path && Glob_Matcher::any_match( $patterns, $decoded );
	2868	+ }
	2869	+
388	2870	public static function cache_key() {
389	2871	$host = isset( $_SERVER['HTTP_HOST'] ) ? sanitize_text_field( wp_unslash( $_SERVER['HTTP_HOST'] ) ) : 'default';
390	2872
391	2873	// Cacheable 404s share ONE generic per-host entry — keying them by
		@@ -395,14 +2877,13 @@
395	2877	if ( self::should_cache_404() ) {
396	2878	return md5( $host . '|404' );
397	2879	}
398	2880
399		- $uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '/';
400	2881	// Strip the query string from the key so /post and /post?utm_*=…
401	2882	// share the same cache entry. should_cache() above already
402	2883	// rejected requests with non-ignored params, so by the time we
403	2884	// build the key the only params left are safe to drop.
404		- $uri = (string) strtok( $uri, '?' );
	2885	+ $uri = self::request_path( '/' );
405	2886
406	2887	// Optional device bucket: when mobile_separate is on, mobile and
407	2888	// desktop responses live in different cache files so themes that
408	2889	// serve different HTML by device (AMP, WPtouch, Jetpack mobile)
		@@ -459,10 +2940,300 @@
459	2940	}
460	2941	return (bool) preg_match( '/(Mobile|Android|Silk\/|Kindle|BlackBerry|Opera Mini|Opera Mobi)/i', $ua );
461	2942	}
462	2943
	2944	+ /**
	2945	+ * Filesystem-safe directory name for a host, or '' when unusable.
	2946	+ *
	2947	+ * The charset MUST match the static tree (store_static()) and the
	2948	+ * drop-in's own copy, or the paths disagree about where an entry lives.
	2949	+ * The colon of `host:port` is stripped: it is legal in a Host header but
	2950	+ * not portable in a path.
	2951	+ *
	2952	+ * @param string $host Raw host, e.g. from HTTP_HOST.
	2953	+ * @return string Safe directory segment, or '' if nothing usable remains.
	2954	+ */
	2955	+ /**
	2956	+ * The host segment of the STATIC tree — `xspeed-static/<host>/…`, which
	2957	+ * the web server resolves without PHP.
	2958	+ *
	2959	+ * Different from host_dir(): here the port is folded INTO the segment
	2960	+ * (`localhost:8080` → `localhost8080`) rather than dropped, because the
	2961	+ * generated server rules have to reproduce this from their own variables
	2962	+ * and nginx's `$host` has no port to drop — see the `$xspeed_host`
	2963	+ * derivation in nginx_snippet(). Shared by the write and the purge so the
	2964	+ * two can't drift; when they did, purging a page on a ported host deleted
	2965	+ * nothing and the stale copy kept being served by the rewrite.
	2966	+ */
	2967	+ public static function static_host_dir( string $host ): string {
	2968	+ return (string) preg_replace( '/[^a-zA-Z0-9.\-]/', '', $host );
	2969	+ }
	2970	+
	2971	+ public static function host_dir( string $host ): string {
	2972	+ $host = str_replace( "\0", '', $host );
	2973	+ // Drop the port BEFORE filtering, or `example.com:8080` collapses to
	2974	+ // `example.com8080` — which both loses the boundary and could collide
	2975	+ // with a real host of that name.
	2976	+ $colon = strpos( $host, ':' );
	2977	+ if ( false !== $colon ) {
	2978	+ $host = substr( $host, 0, $colon );
	2979	+ }
	2980	+ $host = preg_replace( '/[^a-zA-Z0-9.\-]/', '', $host );
	2981	+ // Collapse any run of dots so no traversal sequence can survive the
	2982	+ // charset filter (`a/../b` would otherwise reduce to `a..b`).
	2983	+ $host = preg_replace( '/\.{2,}/', '.', (string) $host );
	2984	+ $host = trim( (string) $host, '.-' );
	2985	+ return '' === $host ? '' : $host;
	2986	+ }
	2987	+
	2988	+ /**
	2989	+ * The per-site bucket a cache entry belongs to: `<host>` on a single
	2990	+ * site, `<host>/<path-prefix>` for a subdirectory multisite blog.
	2991	+ *
	2992	+ * On multisite every blog shares one cache directory, and a flat md5
	2993	+ * filename carries no clue which site wrote it — so purging one subsite
	2994	+ * swept the whole network cold. (#6)
	2995	+ *
	2996	+ * Host alone is NOT enough: a subdirectory network (the common layout)
	2997	+ * puts every blog on the same host, so `example.com/` and
	2998	+ * `example.com/siteb/` would share a bucket and keep purging each other.
	2999	+ * The path prefix is what separates them, and it is derivable from the
	3000	+ * REQUEST_URI alone — which matters because the drop-in must compute
	3001	+ * this identical value before WordPress (and get_blog_details()) exist.
	3002	+ *
	3003	+ * Subdomain and domain-mapped networks differ by host already, so they
	3004	+ * get a bare host bucket and are unaffected.
	3005	+ *
	3006	+ * @param string $host Raw host.
	3007	+ * @param string $uri Raw REQUEST_URI (query string is ignored).
	3008	+ * @return string Bucket path, always non-empty.
	3009	+ */
	3010	+ public static function site_bucket( string $host, string $uri ): string {
	3011	+ $dir = self::host_dir( $host );
	3012	+ if ( '' === $dir ) {
	3013	+ $dir = 'default';
	3014	+ }
	3015	+
	3016	+ $prefix = self::site_path_prefix();
	3017	+ return '' === $prefix ? $dir : $dir . '/' . $prefix;
	3018	+ }
	3019	+
	3020	+ /**
	3021	+ * The current blog's path prefix as a single safe segment ('' for the
	3022	+ * root blog or a non-multisite install). `/siteb/` becomes `siteb`;
	3023	+ * a nested `/a/b/` becomes `a-b` so the bucket stays one level deep.
	3024	+ *
	3025	+ * Written to a sidecar for the drop-in by sync_site_paths().
	3026	+ */
	3027	+ public static function site_path_prefix(): string {
	3028	+ if ( ! function_exists( 'is_multisite' ) || ! is_multisite() ) {
	3029	+ return '';
	3030	+ }
	3031	+ if ( function_exists( 'is_subdomain_install' ) && is_subdomain_install() ) {
	3032	+ return ''; // Hosts already differ; no prefix needed.
	3033	+ }
	3034	+ $path = function_exists( 'get_blog_details' ) ? (string) get_blog_details()->path : '/';
	3035	+ return self::path_prefix_segment( $path );
	3036	+ }
	3037	+
	3038	+ /**
	3039	+ * The bucket an arbitrary URL's cache entry lives in.
	3040	+ *
	3041	+ * `site_bucket()` answers for the CURRENT request; this answers for a URL
	3042	+ * that may belong to another blog entirely — which is what a per-URL purge
	3043	+ * is usually doing (WP-CLI, cron, the MCP tool, a network-admin action).
	3044	+ *
	3045	+ * The blog is resolved from the URL itself: on a subdirectory network
	3046	+ * `get_blog_details()` is asked which blog owns `<host><path>`, and its
	3047	+ * registered path becomes the prefix. Deriving the prefix from the URL's
	3048	+ * first path segment directly would be wrong — `/shop/` on the main blog
	3049	+ * is a page, not a subsite, and would send the purge into a bucket that
	3050	+ * does not exist. (QA B2 on #166)
	3051	+ *
	3052	+ * @param string $host Host of the URL being purged.
	3053	+ * @param string $path Path of the URL being purged.
	3054	+ * @return string Bucket path, always non-empty.
	3055	+ */
	3056	+ public static function bucket_for_url( string $host, string $path ): string {
	3057	+ $dir = self::host_dir( $host );
	3058	+ if ( '' === $dir ) {
	3059	+ $dir = 'default';
	3060	+ }
	3061	+
	3062	+ if ( ! function_exists( 'is_multisite' ) || ! is_multisite() ) {
	3063	+ return $dir;
	3064	+ }
	3065	+ if ( function_exists( 'is_subdomain_install' ) && is_subdomain_install() ) {
	3066	+ return $dir; // Hosts already differ; no prefix.
	3067	+ }
	3068	+ if ( ! function_exists( 'get_blog_details' ) ) {
	3069	+ return $dir;
	3070	+ }
	3071	+
	3072	+ // Longest registered blog path that prefixes this URL wins, so
	3073	+ // `/one/2026/post/` resolves to blog `/one/` and not to the root blog.
	3074	+ $blog = self::blog_for_path( $host, $path );
	3075	+ if ( null === $blog ) {
	3076	+ return $dir;
	3077	+ }
	3078	+ $prefix = self::path_prefix_segment( (string) $blog );
	3079	+ return '' === $prefix ? $dir : $dir . '/' . $prefix;
	3080	+ }
	3081	+
	3082	+ /**
	3083	+ * The registered path of the blog that owns `<host><path>`, or null.
	3084	+ *
	3085	+ * Uses get_blog_details() with a domain/path pair rather than scanning
	3086	+ * every blog, so a large network costs one lookup per candidate segment
	3087	+ * instead of a full table read.
	3088	+ */
	3089	+ private static function blog_for_path( string $host, string $path ): ?string {
	3090	+ $segments = array_values( array_filter( explode( '/', trim( $path, '/' ) ) ) );
	3091	+
	3092	+ // Try the longest candidate first: /a/b/ before /a/ before /.
	3093	+ for ( $take = min( count( $segments ), 2 ); $take >= 1; $take-- ) {
	3094	+ $candidate = '/' . implode( '/', array_slice( $segments, 0, $take ) ) . '/';
	3095	+ $details = get_blog_details(
	3096	+ array(
	3097	+ 'domain' => $host,
	3098	+ 'path' => $candidate,
	3099	+ ),
	3100	+ false
	3101	+ );
	3102	+ if ( $details && ! empty( $details->path ) ) {
	3103	+ return (string) $details->path;
	3104	+ }
	3105	+ }
	3106	+ return null;
	3107	+ }
	3108	+
	3109	+ /**
	3110	+ * Normalise a blog path ('/', '/siteb/', '/a/b/') into a single
	3111	+ * filesystem-safe segment. Shared with the drop-in's copy.
	3112	+ */
	3113	+ public static function path_prefix_segment( string $path ): string {
	3114	+ $path = trim( str_replace( "\0", '', $path ), '/' );
	3115	+ if ( '' === $path ) {
	3116	+ return '';
	3117	+ }
	3118	+ $path = preg_replace( '/[^a-zA-Z0-9._\-\/]/', '', $path );
	3119	+ $path = str_replace( '/', '-', (string) $path );
	3120	+ return trim( (string) $path, '.-' );
	3121	+ }
	3122	+
	3123	+ /**
	3124	+ * The current blog's path as the static tree stores it — real slashes
	3125	+ * preserved, because that tree mirrors the URL
	3126	+ * (`xspeed-static/{host}{request_uri}/index.html`) rather than using a
	3127	+ * single flattened segment. '' for a root blog / single site.
	3128	+ */
	3129	+ public static function site_path_raw(): string {
	3130	+ if ( ! function_exists( 'is_multisite' ) || ! is_multisite() ) {
	3131	+ return '';
	3132	+ }
	3133	+ if ( function_exists( 'is_subdomain_install' ) && is_subdomain_install() ) {
	3134	+ return '';
	3135	+ }
	3136	+ $path = function_exists( 'get_blog_details' ) ? (string) get_blog_details()->path : '/';
	3137	+ $path = trim( str_replace( "\0", '', $path ), '/' );
	3138	+ if ( '' === $path ) {
	3139	+ return '';
	3140	+ }
	3141	+ $path = preg_replace( '#[^a-zA-Z0-9._\-/]#', '', $path );
	3142	+ return trim( (string) $path, '/' );
	3143	+ }
	3144	+
	3145	+ /**
	3146	+ * Static-tree root for the current site: `<host>` plus the blog's real
	3147	+ * path. Mirrors store_static()'s layout so a scoped purge deletes
	3148	+ * exactly this blog's pages.
	3149	+ */
	3150	+ public static function current_static_scope(): string {
	3151	+ // Same switch_to_blog() caveat as current_host_dir() — see current_host().
	3152	+ // Keep the port folded into the segment exactly as store_static() does.
	3153	+ $dir = self::static_host_dir( self::current_host() );
	3154	+ if ( '' === $dir ) {
	3155	+ $dir = 'default';
	3156	+ }
	3157	+ $path = self::site_path_raw();
	3158	+ return '' === $path ? $dir : $dir . '/' . $path;
	3159	+ }
	3160	+
	3161	+ /**
	3162	+ * The bucket for the CURRENT request. Never empty, so an entry is never
	3163	+ * written to the tree root (which is what the unscoped sweeps used to
	3164	+ * delete indiscriminately).
	3165	+ */
	3166	+ public static function current_host_dir(): string {
	3167	+ $host = self::current_host();
	3168	+ return self::site_bucket( $host, self::request_path( '/' ) );
	3169	+ }
	3170	+
	3171	+ /**
	3172	+ * The host the CURRENT blog is served from.
	3173	+ *
	3174	+ * Deliberately NOT just $_SERVER['HTTP_HOST']: inside a
	3175	+ * switch_to_blog() the request header still names whichever site is
	3176	+ * serving the admin screen, while the cache entries we want belong to
	3177	+ * the switched-to blog. On a subdomain network the host IS the bucket,
	3178	+ * so reading the header there would make Pro's per-site "purge this
	3179	+ * site" button clear the network admin's own cache instead — the very
	3180	+ * bug this scoping exists to fix, surviving in one topology.
	3181	+ *
	3182	+ * get_blog_details() follows the switch, so prefer it whenever we are
	3183	+ * on multisite, and fall back to the request header otherwise.
	3184	+ */
	3185	+ public static function current_host(): string {
	3186	+ if ( function_exists( 'is_multisite' ) && is_multisite() && function_exists( 'get_blog_details' ) ) {
	3187	+ $details = get_blog_details();
	3188	+ if ( $details && ! empty( $details->domain ) ) {
	3189	+ return (string) $details->domain;
	3190	+ }
	3191	+ }
	3192	+
	3193	+ if ( isset( $_SERVER['HTTP_HOST'] ) ) {
	3194	+ return sanitize_text_field( wp_unslash( $_SERVER['HTTP_HOST'] ) );
	3195	+ }
	3196	+
	3197	+ /*
	3198	+ * No request header — WP-CLI, or WP-Cron driven by system cron.
	3199	+ *
	3200	+ * Returning '' here made the bucket resolve to the literal `default`
	3201	+ * while HTTP requests were writing to `<host>/`, so a scheduled purge
	3202	+ * swept an empty directory and reported success, and get_stats()
	3203	+ * reported 0 cached pages on a site with a full cache. That is the
	3204	+ * normal setup on any host running DISABLE_WP_CRON, which is most of
	3205	+ * them. Fall back to the site's own registered host. (QA D4 on #166)
	3206	+ */
	3207	+ if ( function_exists( 'home_url' ) ) {
	3208	+ $parts = function_exists( 'wp_parse_url' ) ? wp_parse_url( home_url( '/' ) ) : parse_url( home_url( '/' ) ); // phpcs:ignore WordPress.WP.AlternativeFunctions.parse_url_parse_url -- early-boot fallback only.
	3209	+ if ( is_array( $parts ) && ! empty( $parts['host'] ) ) {
	3210	+ return (string) $parts['host'];
	3211	+ }
	3212	+ }
	3213	+
	3214	+ return '';
	3215	+ }
	3216	+
	3217	+ /**
	3218	+ * Ensure the current site's cache directory exists, with the silence
	3219	+ * index in both it and the shared root. Returns the directory.
	3220	+ */
	3221	+ public static function ensure_host_dir(): string {
	3222	+ $dir = XSPEED_CACHE_DIR . '/' . self::current_host_dir();
	3223	+ if ( ! file_exists( XSPEED_CACHE_DIR ) ) {
	3224	+ wp_mkdir_p( XSPEED_CACHE_DIR );
	3225	+ self::write_silence( XSPEED_CACHE_DIR );
	3226	+ }
	3227	+ if ( ! file_exists( $dir ) ) {
	3228	+ wp_mkdir_p( $dir );
	3229	+ self::write_silence( $dir );
	3230	+ }
	3231	+ return $dir;
	3232	+ }
	3233	+
463	3234	public static function cache_file_for( $key ) {
464		- return XSPEED_CACHE_DIR . '/' . $key . '.html';
	3235	+ return XSPEED_CACHE_DIR . '/' . self::current_host_dir() . '/' . $key . '.html';
465	3236	}
466	3237
467	3238	/**
468	3239	* If a precompressed Brotli sibling (`<file>.br`) exists and the client
		@@ -493,8 +3264,11 @@
493	3264	$br = $file . '.br';
494	3265	if ( ! is_string( $br ) || ! file_exists( $br ) || ! is_readable( $br ) ) {
495	3266	return null;
496	3267	}
	3268	+ if ( ! self::brotli_sibling_is_usable( $file, $br ) ) {
	3269	+ return null; // fall through to the plain .html
	3270	+ }
497	3271	header( 'Content-Encoding: br' );
498	3272	header( 'Vary: Accept-Encoding', false );
499	3273	// The byte length changes for the compressed body — drop any
500	3274	// Content-Length the caller may have set so the stream isn't
		@@ -503,8 +3277,217 @@
503	3277	return $br;
504	3278	}
505	3279
506	3280	/**
	3281	+ * Is a precompressed `.br` sibling safe to serve?
	3282	+ *
	3283	+ * Existence is not enough. The sibling is written with a plain
	3284	+ * file_put_contents() — no atomic rename — so a crash, a full disk, or a
	3285	+ * read that races the write leaves a TRUNCATED file behind. Serving that
	3286	+ * with `Content-Encoding: br` hands the browser a stream it cannot
	3287	+ * inflate: it renders nothing at all (document.body is null) and the
	3288	+ * navigation can hang. A 16-byte .br for a 172KB page reproduces it
	3289	+ * exactly. (#286)
	3290	+ *
	3291	+ * Brotli has no magic number, and no byte-level marker distinguishes a
	3292	+ * truncated stream from a short valid one (the ISLAST bit is bit-packed,
	3293	+ * not byte-aligned). So this checks only what CAN be known by stat:
	3294	+ *
	3295	+ * - Not empty. A zero-byte sibling is unambiguously broken.
	3296	+ * - Not older than the HTML. A stale sibling would serve the PREVIOUS
	3297	+ * revision of the page under the current entry's ETag.
	3298	+ *
	3299	+ * A size-RATIO floor was tried here and removed. Brotli's ratio is
	3300	+ * unbounded on repetitive input: a ~1 MB page of table rows or a product
	3301	+ * grid — the ordinary shape of a big generated page — compresses to
	3302	+ * about 0.04%, so a 2% floor rejected a perfectly good sibling and sent
	3303	+ * visitors the uncompressed page instead, silently. Measured: 963 KB of
	3304	+ * repeated markup → 89 bytes at q5 (0.009%). No floor can separate
	3305	+ * "impossibly small" from "extremely compressible" for arbitrary HTML.
	3306	+ *
	3307	+ * Truncation is prevented at the WRITE side instead — see
	3308	+ * write_atomic(), which the Brotli writer uses so a partial file is
	3309	+ * never visible under the final name. Detection at read time cannot be
	3310	+ * made correct; not creating the bad file can.
	3311	+ *
	3312	+ * Anything suspicious returns false and the caller streams the plain
	3313	+ * .html — slower, always correct. Serving an uninflatable body is worse
	3314	+ * than serving no compression at all.
	3315	+ *
	3316	+ * @param string $file Absolute path to the .html cache file.
	3317	+ * @param string $br Absolute path to its .br sibling.
	3318	+ * @return bool True when the sibling may be served.
	3319	+ */
	3320	+ /**
	3321	+ * Write a cache sidecar so a partial file is never visible.
	3322	+ *
	3323	+ * `file_put_contents()` truncates the target and then fills it, so any
	3324	+ * reader arriving mid-write — or any crash, full disk, or killed worker
	3325	+ * — leaves a SHORT file under the real name. For HTML that degrades to a
	3326	+ * clipped page; for a `.br` sibling it is worse, because a truncated
	3327	+ * brotli stream is not a short page but an UNINFLATABLE one: the browser
	3328	+ * renders nothing at all and the navigation can hang.
	3329	+ *
	3330	+ * Writing to a unique temp file in the same directory and renaming is
	3331	+ * atomic on POSIX, so readers see either the previous complete file or
	3332	+ * the new complete file, never a partial one. This is the half of #286
	3333	+ * that is actually fixable — a read-time heuristic cannot tell a
	3334	+ * truncated brotli stream from a very small valid one, but a truncated
	3335	+ * file that never becomes visible needs no detection.
	3336	+ *
	3337	+ * @param string $path Absolute destination path.
	3338	+ * @param string $contents Bytes to write.
	3339	+ * @return bool True when the destination now holds exactly $contents.
	3340	+ */
	3341	+ public static function write_atomic( string $path, string $contents ): bool {
	3342	+ $dir = dirname( $path );
	3343	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_is_writable -- WP_Filesystem needs admin creds unavailable on a frontend cache write; this is our own cache dir.
	3344	+ if ( ! is_dir( $dir ) || ! is_writable( $dir ) ) {
	3345	+ return false;
	3346	+ }
	3347	+
	3348	+ // Same directory, so the rename stays on one filesystem — a rename
	3349	+ // across devices is a copy and loses atomicity.
	3350	+ $tmp = @tempnam( $dir, '.xspeed-tmp-' ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- a failure returns false and the caller skips the write.
	3351	+ if ( ! is_string( $tmp ) || '' === $tmp ) {
	3352	+ return false;
	3353	+ }
	3354	+
	3355	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- WP_Filesystem needs admin creds unavailable on a frontend cache write; target is our own cache dir.
	3356	+ $written = @file_put_contents( $tmp, $contents ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- handled by the length check below.
	3357	+
	3358	+ // A short write is exactly the failure this function exists to
	3359	+ // prevent, so verify the byte count before publishing the file.
	3360	+ if ( false === $written || $written !== strlen( $contents ) ) {
	3361	+ @unlink( $tmp ); // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort cleanup of our own temp file; non-fatal.
	3362	+ return false;
	3363	+ }
	3364	+
	3365	+ // tempnam() creates the file 0600; cache files must stay readable by
	3366	+ // the web server, which may run as a different user.
	3367	+ @chmod( $tmp, defined( 'FS_CHMOD_FILE' ) ? FS_CHMOD_FILE : 0644 ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_chmod, WordPress.PHP.NoSilencedErrors.Discouraged -- the web server may run as another uid and must be able to read the published file; a chmod failure is not fatal.
	3368	+
	3369	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.rename_rename, WordPress.PHP.NoSilencedErrors.Discouraged -- the atomic publish this function exists for; WP_Filesystem offers no atomic rename and needs admin creds.
	3370	+ if ( ! @rename( $tmp, $path ) ) {
	3371	+ @unlink( $tmp ); // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort cleanup; non-fatal.
	3372	+ return false;
	3373	+ }
	3374	+
	3375	+ return true;
	3376	+ }
	3377	+
	3378	+ public static function brotli_sibling_is_usable( string $file, string $br ): bool {
	3379	+ $br_size = (int) @filesize( $br ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- a stat failure means "don't serve it", handled by the <= 0 check.
	3380	+ if ( $br_size <= 0 ) {
	3381	+ return false;
	3382	+ }
	3383	+
	3384	+ $html_size = (int) @filesize( $file ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- as above.
	3385	+ if ( $html_size <= 0 ) {
	3386	+ return false;
	3387	+ }
	3388	+
	3389	+ // A sibling older than the page it compresses is stale.
	3390	+ $br_mtime = (int) @filemtime( $br ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- as above.
	3391	+ $html_mtime = (int) @filemtime( $file ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- as above.
	3392	+ if ( $br_mtime > 0 && $html_mtime > 0 && $br_mtime < $html_mtime ) {
	3393	+ return false;
	3394	+ }
	3395	+
	3396	+ // The writer recorded how many bytes it produced. Where that record
	3397	+ // exists, truncation is a certainty rather than an inference: a
	3398	+ // stream shorter than its own declared length cannot inflate, and
	3399	+ // one that matches was published whole. This is what a size ratio
	3400	+ // could never be — brotli's ratio is unbounded on repetitive input,
	3401	+ // so a 0.01% sibling of a generated page is genuinely valid.
	3402	+ //
	3403	+ // Absent for a sibling written before this version, or by an add-on
	3404	+ // that writes the file directly. That case keeps the checks above
	3405	+ // and no more, which is where a pre-existing truncated file on a
	3406	+ // live site still slips through — write_atomic() stops NEW ones,
	3407	+ // but it cannot retroactively vouch for what is already on disk.
	3408	+ $expected = self::brotli_expected_size( $br );
	3409	+ if ( $expected > 0 && $br_size !== $expected ) {
	3410	+ return false;
	3411	+ }
	3412	+
	3413	+ return true;
	3414	+ }
	3415	+
	3416	+ /**
	3417	+ * Path of the sidecar recording a `.br` sibling's complete byte count.
	3418	+ *
	3419	+ * Kept beside the sibling as `<file>.html.br.size` rather than folded
	3420	+ * into the entry's `.meta`: the static tree the web server serves has no
	3421	+ * `.meta` at all, and the two trees must answer this question the same
	3422	+ * way. Every path that deletes a `.br` deletes this with it.
	3423	+ *
	3424	+ * @param string $br Absolute path to the `.br` sibling.
	3425	+ * @return string Absolute path to its size sidecar.
	3426	+ */
	3427	+ public static function brotli_size_sidecar( string $br ): string {
	3428	+ return $br . '.size';
	3429	+ }
	3430	+
	3431	+ /**
	3432	+ * The byte count the writer recorded for a `.br` sibling, or 0 when no
	3433	+ * record exists (a sibling predating this version, or written by an
	3434	+ * add-on that bypassed write_brotli_sibling()).
	3435	+ *
	3436	+ * @param string $br Absolute path to the `.br` sibling.
	3437	+ * @return int Expected size in bytes, or 0 when unknown.
	3438	+ */
	3439	+ public static function brotli_expected_size( string $br ): int {
	3440	+ $sidecar = self::brotli_size_sidecar( $br );
	3441	+ if ( ! is_file( $sidecar ) ) {
	3442	+ return 0;
	3443	+ }
	3444	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- our own cache dir; WP_Filesystem needs admin creds unavailable on a frontend HIT.
	3445	+ $raw = @file_get_contents( $sidecar ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- an unreadable sidecar means "unknown", handled by the cast below.
	3446	+ return max( 0, (int) trim( (string) $raw ) );
	3447	+ }
	3448	+
	3449	+ /**
	3450	+ * Publish a `.br` sibling together with the record of its own length.
	3451	+ *
	3452	+ * The single writer every producer of a `.br` should route through — the
	3453	+ * Pro Brotli module included. Publishing the body atomically stops a
	3454	+ * truncated file from ever becoming visible; recording the byte count
	3455	+ * lets the serve path prove wholeness for the files that already exist
	3456	+ * on disk when this ships.
	3457	+ *
	3458	+ * Order matters: the size sidecar is removed first and written last, so
	3459	+ * a reader arriving mid-update sees "no record" (checks above still
	3460	+ * apply) rather than the previous body's length against the new body.
	3461	+ *
	3462	+ * @param string $br Absolute path to the `.br` sibling to write.
	3463	+ * @param string $contents Compressed bytes.
	3464	+ * @return bool True when both the sibling and its size record are in place.
	3465	+ */
	3466	+ public static function write_brotli_sibling( string $br, string $contents ): bool {
	3467	+ $sidecar = self::brotli_size_sidecar( $br );
	3468	+ if ( is_file( $sidecar ) ) {
	3469	+ wp_delete_file( $sidecar );
	3470	+ }
	3471	+
	3472	+ if ( ! self::write_atomic( $br, $contents ) ) {
	3473	+ return false;
	3474	+ }
	3475	+
	3476	+ if ( self::write_atomic( $sidecar, (string) strlen( $contents ) ) ) {
	3477	+ return true;
	3478	+ }
	3479	+
	3480	+ // The body landed but its length did not. That sibling is servable
	3481	+ // and unguarded — exactly the file this function exists to prevent —
	3482	+ // and the caller has no way to know. Withdraw it: a MISS costs one
	3483	+ // uncompressed response, where an unguarded sibling can cost a blank
	3484	+ // page for as long as the entry lives.
	3485	+ wp_delete_file( $br );
	3486	+ return false;
	3487	+ }
	3488	+
	3489	+ /**
507	3490	* Sidecar metadata file for a cache entry. Holds response bits the HIT
508	3491	* path must replay — Content-Type (cached feeds → application/rss+xml,
509	3492	* sitemaps → text/xml) and status (a cached 404 must serve 404, not
510	3493	* 200). JSON, one tiny file per entry, written only when there's
		@@ -510,17 +3493,19 @@
510	3493	* 200). JSON, one tiny file per entry, written only when there's
511	3494	* something non-default to replay.
512	3495	*/
513	3496	public static function cache_meta_for( $key ) {
514		- return XSPEED_CACHE_DIR . '/' . $key . '.meta';
	3497	+ return XSPEED_CACHE_DIR . '/' . self::current_host_dir() . '/' . $key . '.meta';
515	3498	}
516	3499
517	3500	/**
518	3501	* Read the .meta sidecar for a cache entry as an array, or [] if none.
519		- * Keys: 'content_type' (string), 'status' (int). Used on the HIT path
520		- * to replay them before streaming the file.
	3502	+ * Keys: 'content_type' (string), 'status' (int), 'ttl' (int seconds).
	3503	+ * Used on the HIT path to replay content-type/status before streaming
	3504	+ * the file, and by Cache_GC to age an entry by its own TTL rather than
	3505	+ * the global one — hence public.
521	3506	*/
522		- private static function read_meta( $key ): array {
	3507	+ public static function read_meta( $key ): array {
523	3508	$meta_file = self::cache_meta_for( $key );
524	3509	if ( ! file_exists( $meta_file ) ) {
525	3510	return array();
526	3511	}
		@@ -537,8 +3522,19 @@
537	3522	* and returns true (caller should exit without a body). Returns false to
538	3523	* proceed with a normal 200 body. Lets aggregators/browsers skip
539	3524	* re-downloading an unchanged cached response. (FBS-82407 #5)
540	3525	*
	3526	+ * Also stamps `X-XSpeed-Built` from the same mtime. This is the PHP serve
	3527	+ * path's build time, and the only place on it that holds the file: mark()
	3528	+ * has already run by the time we get here and resolved the edge-header
	3529	+ * filter without one. Both are emitted, and a purge verifier prefers the
	3530	+ * stamp: `Last-Modified` carries the same integer, but it is a generic
	3531	+ * header that the origin-side cache layer such a verifier exists to
	3532	+ * detect — or any proxy in between — may rewrite to its own store time,
	3533	+ * which would turn a stale origin into a pass. Nothing but xSpeed's own
	3534	+ * serve code writes `X-XSpeed-Built`, so a value older than the purge is
	3535	+ * proof the origin answered with old HTML.
	3536	+ *
541	3537	* @param string $file Absolute path to the cache .html file.
542	3538	* @return bool True when a 304 was sent.
543	3539	*/
544	3540	public static function serve_not_modified( string $file ): bool {
		@@ -549,8 +3545,12 @@
549	3545	$last_modified = gmdate( 'D, d M Y H:i:s', $mtime ) . ' GMT';
550	3546	$etag = '"' . md5( $file . '|' . $mtime ) . '"';
551	3547	header( 'Last-Modified: ' . $last_modified );
552	3548	header( 'ETag: ' . $etag );
	3549	+ // Before the 304 branch below, so a conditional request that gets a
	3550	+ // bodyless 304 still carries the stamp. A verifier's fetch may well
	3551	+ // be conditional, and a 304 with no build time reads as unverifiable.
	3552	+ header( self::BUILT_HEADER . ': ' . $mtime );
553	3553
554	3554	$ims = isset( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ? trim( sanitize_text_field( wp_unslash( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) ) : '';
555	3555	$inm = isset( $_SERVER['HTTP_IF_NONE_MATCH'] ) ? trim( sanitize_text_field( wp_unslash( $_SERVER['HTTP_IF_NONE_MATCH'] ) ) ) : '';
556	3556
		@@ -586,9 +3586,45 @@
586	3586	* @param int $max_age Computed max-age in seconds.
587	3587	*/
588	3588	$max_age = (int) apply_filters( 'xspeed_cache_max_age', $max_age );
589	3589
590		- return ( time() - filemtime( $file ) ) > $max_age;
	3590	+ // Honour the per-entry TTL the .meta sidecar carries, when it is
	3591	+ // SHORTER than what we just resolved. The sidecar records the TTL
	3592	+ // this specific entry was written under — a nonce cap (#236), a Pro
	3593	+ // feed/404 expiry — and the drop-in already reads it. is_expired()
	3594	+ // did not, so on the engine path a capped entry was still served for
	3595	+ // the full configured lifetime: exactly the stale nonce the cap
	3596	+ // exists to prevent. Only ever shortens, so an entry can never be
	3597	+ // kept alive past the configured maximum by a stale sidecar.
	3598	+ // Derive the sidecar from the FILE we were handed rather than
	3599	+ // recomputing cache_key(): callers legitimately ask about an entry
	3600	+ // that isn't the current request's (Cache_GC sweeps, Pro's warmer),
	3601	+ // and cache_key() would answer for the wrong one — besides needing a
	3602	+ // request context this function has no business requiring.
	3603	+ $meta_file = preg_replace( '/\.html$/', '.meta', (string) $file );
	3604	+ if ( is_string( $meta_file ) && $meta_file !== $file && is_readable( $meta_file ) ) {
	3605	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- our own cache dir; WP_Filesystem needs admin creds unavailable on a frontend read.
	3606	+ $raw = file_get_contents( $meta_file );
	3607	+ $decoded = is_string( $raw ) ? json_decode( $raw, true ) : null;
	3608	+ if ( is_array( $decoded ) && isset( $decoded['ttl'] ) ) {
	3609	+ $entry_ttl = (int) $decoded['ttl'];
	3610	+ if ( $entry_ttl > 0 && ( $max_age < 1 || $entry_ttl < $max_age ) ) {
	3611	+ $max_age = $entry_ttl;
	3612	+ }
	3613	+ }
	3614	+ }
	3615	+
	3616	+ // A missing file is "expired" — the caller should re-render. Guard
	3617	+ // filemtime() rather than letting it warn: callers legitimately ask
	3618	+ // about a file that isn't there (Pro's predictive warmer probes for
	3619	+ // freshness, and Cache_GC can collect an entry between the check and
	3620	+ // the read), and on a site with WP_DEBUG the warning is noise.
	3621	+ $mtime = file_exists( $file ) ? filemtime( $file ) : false;
	3622	+ if ( false === $mtime ) {
	3623	+ return true;
	3624	+ }
	3625	+
	3626	+ return ( time() - (int) $mtime ) > $max_age;
591	3627	}
592	3628
593	3629	/**
594	3630	* Accumulator for the full response body across all output-handler phases.
		@@ -619,8 +3655,13 @@
619	3655
620	3656	$full = self::$accumulated;
621	3657	self::$accumulated = '';
622	3658
	3659	+ // Consumed here, on every final path, so a later call can never
	3660	+ // compare against this request's snapshot.
	3661	+ $asset_stamp = self::$asset_stamp_at_open;
	3662	+ self::$asset_stamp_at_open = null;
	3663	+
623	3664	if ( strlen( $full ) < 255 ) {
624	3665	return $buffer;
625	3666	}
626	3667
		@@ -642,8 +3683,28 @@
642	3683	// the first visitor sees unminified HTML, every cache hit after that
643	3684	// is minified.
644	3685	$single_chunk = ( $buffer === $full );
645	3686
	3687	+ /**
	3688	+ * Filter: xspeed_cache_final_html
	3689	+ *
	3690	+ * Last chance to transform the fully-rendered page HTML before it is
	3691	+ * minified and written to the cache file. Runs on cache MISS only, so
	3692	+ * whatever a listener injects here is baked into the cached HTML and
	3693	+ * replayed on every subsequent HIT (the drop-in short-circuits before
	3694	+ * PHP on a HIT — a wp_head hook would never fire there).
	3695	+ *
	3696	+ * The Preload module uses this to inject the LCP-image <link rel=preload>
	3697	+ * + preconnect hints and add fetchpriority="high" to the hero <img>.
	3698	+ * Keep listeners fast and idempotent; this is the on-wire body.
	3699	+ *
	3700	+ * @param string $full Complete page HTML.
	3701	+ */
	3702	+ $full = (string) apply_filters( 'xspeed_cache_final_html', $full );
	3703	+ if ( $single_chunk ) {
	3704	+ $buffer = $full;
	3705	+ }
	3706	+
646	3707	// minify_html now owned by the Minify module; read through the
647	3708	// module's storage so this stays consistent with the engine that
648	3709	// applies CSS/JS minification.
649	3710	$minify_opts = Settings_Manager::get( 'minify' );
		@@ -653,27 +3714,129 @@
653	3714	$buffer = $full;
654	3715	}
655	3716	}
656	3717
657		- if ( ! file_exists( XSPEED_CACHE_DIR ) ) {
658		- wp_mkdir_p( XSPEED_CACHE_DIR );
659		- self::write_silence( XSPEED_CACHE_DIR );
	3718	+ // AFTER minification on purpose — the HTML minifier strips comments,
	3719	+ // so signing earlier would erase the signature from every minified
	3720	+ // page. Baked into the cached bytes so all three serve paths (nginx
	3721	+ // static rewrite, .htaccess, the PHP drop-in) carry it identically.
	3722	+ $full = self::signed( $full );
	3723	+ if ( $single_chunk ) {
	3724	+ $buffer = $full;
660	3725	}
661	3726
662		- // Path safety: cache_file_for() builds `XSPEED_CACHE_DIR . '/' . $key . '.html'`
663		- // where $key comes from md5() — guaranteed to be exactly 32 lowercase
664		- // hex chars, so no traversal sequence ('..', '/', null byte, etc.)
665		- // can appear. The write is therefore always inside XSPEED_CACHE_DIR.
666		- $key = self::cache_key();
	3727	+ // Per-site directory — see ensure_host_dir(). (#6)
	3728	+ self::ensure_host_dir();
	3729	+
	3730	+ // Path safety: cache_file_for() builds
	3731	+ // `XSPEED_CACHE_DIR . '/' . <host> . '/' . $key . '.html'` where $key
	3732	+ // comes from md5() — guaranteed to be exactly 32 lowercase hex chars —
	3733	+ // and <host> is filtered by host_dir() to [A-Za-z0-9.-] with leading
	3734	+ // dots trimmed, so no traversal sequence ('..', '/', null byte, etc.)
	3735	+ // can appear in either segment. The write is therefore always inside
	3736	+ // XSPEED_CACHE_DIR.
	3737	+ $key = self::cache_key();
	3738	+
	3739	+ // Query-string gate. should_cache() waved this request through
	3740	+ // because every param is on the ignored_query_params allow-list, and
	3741	+ // cache_key() drops the query so reads share the canonical entry.
	3742	+ // That sharing is safe on READ but not on WRITE: this response was
	3743	+ // rendered WITH the params, and WordPress reflects REQUEST_URI into
	3744	+ // form actions, share links and plugin smart tags — so storing it
	3745	+ // would serve an attacker-chosen variant under the clean URL for the
	3746	+ // whole TTL (#241).
	3747	+ //
	3748	+ // This sits BELOW the transforms deliberately. Returning above them
	3749	+ // also skipped xspeed_cache_final_html, and every listener disables
	3750	+ // its own fallback ob_start() when the page cache is on precisely
	3751	+ // because that filter is the shared transport — so a visitor
	3752	+ // arriving on ?utm_source=… was served HTML with no LCP preload, no
	3753	+ // preconnect, no CDN rewrite, no CSS combine and no HTML minify.
	3754	+ // That is the ad-click and newsletter cohort getting the least
	3755	+ // optimised page on the site. Only the WRITE is skipped, which is
	3756	+ // what this fix was always meant to do — and it is where the
	3757	+ // deferred writer has always placed its own copy of the guard.
	3758	+ if ( self::query_string_blocks_write() ) {
	3759	+ return $buffer;
	3760	+ }
	3761	+
	3762	+ // A purge deleted minified or combined files while this page was
	3763	+ // rendering, so it may link names that are gone. Serve it, but do
	3764	+ // not store it; the next request renders against the files as they
	3765	+ // are now.
	3766	+ if ( self::assets_purged_since( $asset_stamp ) ) {
	3767	+ return $buffer;
	3768	+ }
667	3769	$file = self::cache_file_for( $key );
	3770	+
	3771	+ // A render-time translation plugin (TranslatePress) wraps our buffer,
	3772	+ // so the bytes we hold here are still UNTRANSLATED — its callback has
	3773	+ // not run yet, and writing now would cache English under a French URL
	3774	+ // and bake in its internal #TRPLINKPROCESSED markers. Hand off to
	3775	+ // shutdown, where the outer buffer has already translated, and let
	3776	+ // the pass-through below deliver this request untouched.
	3777	+ if ( self::translation_plugin_active() ) {
	3778	+ self::$deferred_key = $key;
	3779	+ self::$deferred_asset_stamp = $asset_stamp;
	3780	+ // Reaching here means finalize_buffer() ran to completion: the
	3781	+ // status gate passed, should_cache() said yes, and PHP handed us
	3782	+ // the whole buffer. A wp_die() or exit() mid-render unwinds the
	3783	+ // buffer stack WITHOUT calling this callback, so the flag stays
	3784	+ // false and the shutdown writer declines — see the guard there.
	3785	+ self::$render_completed = true;
	3786	+ // A PHP shutdown function, not a WP `shutdown` action: this must
	3787	+ // run after the output-buffer stack has unwound, and WP's
	3788	+ // shutdown action fires while our outer buffer is still open.
	3789	+ register_shutdown_function( array( __CLASS__, 'write_deferred_translated_cache' ) );
	3790	+ return $buffer;
	3791	+ }
	3792	+
668	3793	// phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- WP_Filesystem requires admin context for credentials; cache writes happen on frontend requests where it's unavailable.
669		- file_put_contents( $file, $full, LOCK_EX );
	3794	+ $stored = file_put_contents( $file, $full, LOCK_EX );
670	3795
	3796	+ /*
	3797	+ * No edge headers on a MISS. Not even a stored one.
	3798	+ *
	3799	+ * A MISS is the FIRST render, and it is the render most likely to be
	3800	+ * replaced: critical CSS and unused CSS are generated after the fact
	3801	+ * and applied to later requests, so the copy written here is the
	3802	+ * pre-optimization one. Telling a CDN to hold it pins exactly the
	3803	+ * version xSpeed is about to improve on — reported from a live site,
	3804	+ * where Cloudflare had cached an unoptimized first render.
	3805	+ *
	3806	+ * `CDN-Cache-Control` is why it reaches the edge at all: Cloudflare
	3807	+ * honours it as the CDN-targeted directive whatever its own cache
	3808	+ * rules say, so an origin header is enough to pin HTML for the whole
	3809	+ * TTL even where edge page caching is switched off.
	3810	+ *
	3811	+ * A HIT is the safe moment and the honest one: it means xSpeed is
	3812	+ * serving its stored copy, that copy is what the edge would mirror,
	3813	+ * and a later regeneration purges it — which reaches the edge through
	3814	+ * the purge actions. So the edge caches from the second visitor on,
	3815	+ * one render later than before and the right one.
	3816	+ */
	3817	+
	3818	+ /**
	3819	+ * Fires after the flat hash cache file ({md5}.html) is written.
	3820	+ *
	3821	+ * Mirror of `xspeed_static_file_written` for the flat cache. The PHP
	3822	+ * serve path (Cache::maybe_serve_brotli / the drop-in) serves THIS
	3823	+ * file and looks for a `{md5}.html.br` sibling — which only the Pro
	3824	+ * Brotli listener on this hook writes. Without it the .br sibling was
	3825	+ * never created and the PHP path could never serve Brotli (FBS-83039,
	3826	+ * Blocker 2): the static-tree .br (written on xspeed_static_file_written)
	3827	+ * lives in a different cache layout the PHP path never reads.
	3828	+ *
	3829	+ * @param string $file Absolute path to the flat cache file just written.
	3830	+ * @param string $full The HTML written to it.
	3831	+ */
	3832	+ do_action( 'xspeed_flat_file_written', $file, $full );
	3833	+
671	3834	// Persist a non-default Content-Type so the HIT path can replay it
672	3835	// (cached feeds must serve application/rss+xml, not text/html).
673	3836	// Only written when the response set a content-type other than
674	3837	// the HTML default — pages don't pay for an extra file.
675		- self::write_meta( $key );
	3838	+ self::write_meta( $key, $full );
676	3839
677	3840	// Static-cache tree (xspeed-static/{host}{path}/index.html). The
678	3841	// .htaccess rewrite block serves this file directly via the web
679	3842	// server, bypassing PHP for ~3-5× lower TTFB vs the drop-in path.
		@@ -688,9 +3851,16 @@
688	3851	// 200, FBS-82406) or a non-HTML content-type (a cached feed would go
689	3852	// out as text/html, FBS-82407). The web server serves these .html files
690	3853	// directly with no PHP, so there's no .meta replay — keep them on the
691	3854	// drop-in / PHP path instead, which DOES replay status + content-type.
692		- if ( self::static_rewrite_allowed() && self::response_is_plain_html() ) {
	3855	+ // The static tree cannot replay a sidecar. A file served straight by
	3856	+ // the web server carries the headers baked into the rule that serves
	3857	+ // the whole site — the very answer this entry exists because it
	3858	+ // disagreed with. Same reasoning as the status and content-type
	3859	+ // cases: what the fast path cannot replay belongs on the drop-in path.
	3860	+ if ( self::static_rewrite_allowed()
	3861	+ && self::response_is_plain_html()
	3862	+ && array() === self::per_entry_edge_headers() ) {
693	3863	self::store_static( $full );
694	3864	}
695	3865
696	3866	return $buffer;
		@@ -702,30 +3872,163 @@
702	3872	* rewrite block points at this path so cache hits skip PHP
703	3873	* entirely. Caller already minified/finalized $html.
704	3874	*
705	3875	* Path safety: $host is restricted to a `[a-zA-Z0-9.\-]` allowlist;
706		- * $uri has its query string stripped, null bytes removed, '..'
707		- * sequences collapsed, and after concatenation we verify the
708		- * resolved real path stays inside XSPEED_CACHE_STATIC_DIR before
709		- * any write. Anything off the happy path returns silently.
	3876	+ * the path goes through static_path(), which decodes it the way the
	3877	+ * web server will and refuses anything that could leave the host
	3878	+ * directory or share a file with another page. After the directory is
	3879	+ * created we verify its real path is inside XSPEED_CACHE_STATIC_DIR
	3880	+ * before any write. Anything off the happy path returns silently.
	3881	+ *
	3882	+ * INVARIANT — the static tree is keyed by `{host}{path}` and NOTHING
	3883	+ * else, and both generated rewrites refuse any request that carries a
	3884	+ * query string at all (`RewriteCond %{QUERY_STRING} ^$` on Apache,
	3885	+ * `if ($args)` in nginx_snippet()). So a response may only be stored
	3886	+ * here when cache_key() adds no discriminator beyond `{host}{path}`:
	3887	+ * a query-keyed entry can never be *served* from here, only mis-served
	3888	+ * as the bare path. Any future opt-in that folds a query param into the
	3889	+ * key needs a guard below, exactly like the search one.
710	3890	*/
	3891	+ /**
	3892	+ * Transient holding the most recent static-tree refusal.
	3893	+ *
	3894	+ * Short-lived on purpose: it describes what the last cacheable render
	3895	+ * actually did, so a stale entry would keep warning about a page whose
	3896	+ * nonces have since been removed. A site that still refuses simply
	3897	+ * rewrites it on the next render. (#372)
	3898	+ */
	3899	+ private const STATIC_SKIP_TRANSIENT = 'xspeed_static_skip';
	3900	+
	3901	+ /**
	3902	+ * Remember why a page was kept out of the static tree, for Health.
	3903	+ *
	3904	+ * Records the URL, the reason, and — for the nonce case — the distinct
	3905	+ * nonce KEYS found, which is what makes the finding actionable: the names
	3906	+ * (`eael_login_nonce`, `post_grid_pagination_nonce`, …) trace straight back
	3907	+ * to the plugin emitting them, and it is usually a widget the site does not
	3908	+ * use on that page. Only key names are kept, never the nonce values.
	3909	+ *
	3910	+ * @param string $reason Machine-readable refusal reason.
	3911	+ * @param string $html The response, for extracting the nonce keys.
	3912	+ */
	3913	+ private static function note_static_skip( string $reason, string $html = '' ): void {
	3914	+ if ( ! function_exists( 'set_transient' ) ) {
	3915	+ return;
	3916	+ }
	3917	+
	3918	+ $keys = array();
	3919	+ if ( 'nonce' === $reason && '' !== $html ) {
	3920	+ // Must recognise the SAME shapes response_has_nonce() refuses on,
	3921	+ // or a page is skipped and reported with no keys at all — which is
	3922	+ // most of them, since the plain `name="_wpnonce"` form field is the
	3923	+ // commonest shape by far and only the JSON one was handled here.
	3924	+ // The keys are the actionable half of the message, so a mismatch
	3925	+ // leaves the admin with bad news and nothing to act on.
	3926	+ //
	3927	+ // Both alternations capture the KEY only: each value pattern sits
	3928	+ // outside the capture group, so a nonce secret can never be stored.
	3929	+ $found = array();
	3930	+ if ( preg_match_all( '/name=["\']([a-z0-9_\-\[\]]*nonce[a-z0-9_\-\[\]]*)["\']/i', $html, $m ) ) {
	3931	+ $found = array_merge( $found, $m[1] );
	3932	+ }
	3933	+ if ( preg_match_all( '/["\']([a-z0-9_\-]*nonce[a-z0-9_\-]*)["\']\s*:\s*["\'][a-f0-9]{8,}["\']/i', $html, $m ) ) {
	3934	+ $found = array_merge( $found, $m[1] );
	3935	+ }
	3936	+ // The query-arg shape (`?_wpnonce=…`) has no key name to report
	3937	+ // beyond the literal, so name it explicitly rather than reporting
	3938	+ // nothing for a page that was genuinely refused.
	3939	+ if ( preg_match( '/[?&]_wpnonce=/i', $html ) ) {
	3940	+ $found[] = '_wpnonce';
	3941	+ }
	3942	+ $keys = array_slice( array_values( array_unique( $found ) ), 0, 10 );
	3943	+ }
	3944	+
	3945	+ set_transient(
	3946	+ self::STATIC_SKIP_TRANSIENT,
	3947	+ array(
	3948	+ 'reason' => $reason,
	3949	+ 'url' => esc_url_raw( self::request_path() ),
	3950	+ 'keys' => $keys,
	3951	+ 'at' => time(),
	3952	+ ),
	3953	+ HOUR_IN_SECONDS
	3954	+ );
	3955	+ }
	3956	+
	3957	+ /**
	3958	+ * The most recent static-tree refusal, or an empty array when there is none.
	3959	+ *
	3960	+ * @return array{reason:string,url:string,keys:string[],at:int}|array{}
	3961	+ */
	3962	+ public static function last_static_skip(): array {
	3963	+ $stored = function_exists( 'get_transient' ) ? get_transient( self::STATIC_SKIP_TRANSIENT ) : false;
	3964	+ return is_array( $stored ) && ! empty( $stored['reason'] ) ? $stored : array();
	3965	+ }
	3966	+
711	3967	private static function store_static( string $html ): void {
	3968	+ // Search results are keyed by term in cache_key() (`|s=<term>`) but
	3969	+ // carry the *path* of whatever URL was searched from — for the usual
	3970	+ // `/?s=<term>` that path is `/`. Writing them here would file the
	3971	+ // results page as `{host}/index.html` and the web server would serve
	3972	+ // it to every visitor as the homepage: an unauthenticated visitor
	3973	+ // poisons the front page with one request. Searches stay on the
	3974	+ // drop-in, which replays the term-keyed entry correctly. (#191)
	3975	+ //
	3976	+ // This is a superset of the query-string check the exclusion gate
	3977	+ // does: it also covers `/?%73=<term>`, which decodes to the same
	3978	+ // search (the shape #109 fixed on the gate side).
	3979	+ if ( self::should_cache_search() ) {
	3980	+ return;
	3981	+ }
	3982	+
	3983	+ // Same hazard for the allow-listed query params: store_static()
	3984	+ // strips the query and files the response under the bare path, which
	3985	+ // the web server then serves to every visitor of the clean URL with
	3986	+ // no PHP involved at all — so none of the engine's checks can catch
	3987	+ // it later (#241). The callers already gate on this, but the guard
	3988	+ // is repeated here because this tree is the most dangerous of the
	3989	+ // three write sites and must not depend on its callers.
	3990	+ if ( self::request_has_query_string() ) {
	3991	+ return;
	3992	+ }
	3993	+
	3994	+ // A nonce-bearing page is served here with NO PHP: no TTL check and
	3995	+ // no .meta replay, so the per-entry cap that keeps the drop-in honest
	3996	+ // (#236) cannot reach a file once it is written. Only Cache_GC removes
	3997	+ // it, and until it does the page hands every visitor the same nonce —
	3998	+ // which, once that nonce dies, breaks every anonymous form on it.
	3999	+ //
	4000	+ // Refusing outright was the safe answer, and it cost every
	4001	+ // nonce-bearing page the static tree entirely: a site whose homepage
	4002	+ // carries one unused login nonce ran PHP on every request forever.
	4003	+ // The nonce's own remaining life is the better gate — the page is
	4004	+ // written and its deadline recorded below for GC to enforce.
	4005	+ //
	4006	+ // A nonce we cannot put a clock on is still refused, and that refusal
	4007	+ // is still recorded: it stays completely silent otherwise, because the
	4008	+ // drop-in answers HIT while Health reports the fast path active from a
	4009	+ // probe that writes its OWN file and never proves real pages reach the
	4010	+ // tree. (#372)
	4011	+ $nonce_ttl = self::response_has_nonce( $html ) ? self::nonce_capped_ttl( $html, 0 ) : 0;
	4012	+ if ( self::response_has_nonce( $html ) && $nonce_ttl < 1 ) {
	4013	+ self::note_static_skip( 'nonce', $html );
	4014	+ return;
	4015	+ }
	4016	+
712	4017	$host = isset( $_SERVER['HTTP_HOST'] ) ? sanitize_text_field( wp_unslash( $_SERVER['HTTP_HOST'] ) ) : '';
713		- $uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
714		- $host = preg_replace( '/[^a-zA-Z0-9.\-]/', '', $host );
715		- $uri = str_replace( "\0", '', $uri );
716		- $uri = (string) strtok( $uri, '?' );
	4018	+ $host = self::static_host_dir( $host );
	4019	+ $uri = self::request_path();
717	4020	if ( '' === $host || '' === $uri ) {
718	4021	return;
719	4022	}
720		- // Collapse any traversal sequences before path resolution.
721		- $uri = preg_replace( '#/+#', '/', $uri );
722		- if ( false !== strpos( $uri, '..' ) ) {
	4023	+ // Decoded the way the web server will decode it, or refused.
	4024	+ $rel = self::static_path( $uri );
	4025	+ if ( null === $rel ) {
723	4026	return;
724	4027	}
725	4028
726	4029	$base = rtrim( XSPEED_CACHE_STATIC_DIR, '/' );
727		- $dir = $base . '/' . $host . rtrim( $uri, '/' );
	4030	+ $dir = $base . '/' . $host . $rel;
728	4031	$file = $dir . '/index.html';
729	4032
730	4033	// Resolve the parent against the cache root to be sure the
731	4034	// final path is inside our tree even if the OS does anything
		@@ -740,11 +4043,28 @@
740	4043	}
741	4044	if ( ! is_dir( $dir ) ) {
742	4045	return;
743	4046	}
	4047	+ // static_path() already refuses every traversal spelling. This
	4048	+ // catches a directory in the tree that resolves somewhere else.
	4049	+ $dir_real = realpath( $dir );
	4050	+ $static_real = realpath( $base );
	4051	+ if ( false === $dir_real || false === $static_real || 0 !== strpos( $dir_real . '/', $static_real . '/' ) ) {
	4052	+ return;
	4053	+ }
744	4054	// phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- Same rationale as the flat-hash cache write above: WP_Filesystem isn't available on frontend requests, and the cache write must happen during shutdown.
745	4055	$written = file_put_contents( $file, $html, LOCK_EX );
746	4056
	4057	+ // A nonce-bearing page expires on the nonce's schedule, not the site's.
	4058	+ // Nothing reads this file at serve time — the web server hands over
	4059	+ // index.html without PHP — so the deadline is recorded beside it for
	4060	+ // GC, which is the only thing that can enforce it. Written before the
	4061	+ // action below so a listener that shells out cannot race the sweep.
	4062	+ if ( false !== $written && $nonce_ttl > 0 ) {
	4063	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- same rationale as the write above.
	4064	+ file_put_contents( $dir . '/.xspeed-expires', (string) ( time() + $nonce_ttl ), LOCK_EX );
	4065	+ }
	4066	+
747	4067	if ( false !== $written ) {
748	4068	/**
749	4069	* Fires after a static cache file (index.html) is written.
750	4070	*
		@@ -796,9 +4116,236 @@
796	4116	}
797	4117	return true;
798	4118	}
799	4119
800		- private static function write_meta( string $key ): void {
	4120	+ /**
	4121	+ * Append the cache signature comment to a finished page.
	4122	+ *
	4123	+ * The plugin's one outward version signal: external scanners (the
	4124	+ * xspeedcache.com speed test among them) read it to detect xSpeed and
	4125	+ * its version on a cached page, the way other cache plugins sign their
	4126	+ * output. Callers apply it AFTER HTML minification — the minifier strips
	4127	+ * comments — and before every cache write, so all serve paths carry the
	4128	+ * same bytes.
	4129	+ *
	4130	+ * The generation time is baked in here, at write time, in UTC. It is the
	4131	+ * moment the cached bytes were produced — NOT the moment they were served
	4132	+ * — because all three serve paths replay the same stored file, and two of
	4133	+ * them (the nginx/`.htaccess` static rewrite) run no PHP at all and so
	4134	+ * could never stamp a serve-time value. Reading the age of a page is the
	4135	+ * point: `generated` plus the current clock tells you how stale it is.
	4136	+ * `gmdate()` (not `current_time()`) keeps the value comparable across
	4137	+ * sites regardless of the configured timezone.
	4138	+ *
	4139	+ * @param string $html Finished page HTML.
	4140	+ * @return string HTML with the signature appended (or unchanged when a
	4141	+ * filter removed it).
	4142	+ */
	4143	+ private static function signed( string $html ): string {
	4144	+ $version = defined( 'XSPEED_VERSION' ) ? XSPEED_VERSION : '';
	4145	+ $generated = gmdate( 'Y-m-d H:i:s' ) . ' UTC';
	4146	+ // The literal ' | xspeedcache.com' must survive intact, and what
	4147	+ // precedes it is where an edition suffix lands: Pro appends itself by
	4148	+ // str_replace()-ing on that exact token
	4149	+ // (Pro_Plugin::sign_cache_signature). So the stamp goes AFTER it —
	4150	+ // placed before, it sits between the version and the anchor and
	4151	+ // composes as "generated <date> + Pro v1.1.3".
	4152	+ $signature = sprintf(
	4153	+ '<!-- Page cached by xSpeed Cache v%s | xspeedcache.com | generated %s -->',
	4154	+ $version,
	4155	+ $generated
	4156	+ );
	4157	+
	4158	+ /**
	4159	+ * Filter: xspeed_cache_signature
	4160	+ *
	4161	+ * The HTML comment appended to every cached page. Add-ons append
	4162	+ * their own edition/version here; white-label setups return '' to
	4163	+ * remove the comment entirely. Must remain a valid HTML comment (or
	4164	+ * an empty string) — it ships inside the cached body.
	4165	+ *
	4166	+ * @param string $signature The signature comment.
	4167	+ * @param string $version The plugin version baked into it.
	4168	+ * @param string $generated The write-time timestamp baked into it,
	4169	+ * formatted `Y-m-d H:i:s UTC`.
	4170	+ */
	4171	+ $signature = (string) apply_filters( 'xspeed_cache_signature', $signature, $version, $generated );
	4172	+ if ( '' === trim( $signature ) ) {
	4173	+ return $html;
	4174	+ }
	4175	+ return $html . "\n" . $signature;
	4176	+ }
	4177	+
	4178	+ /**
	4179	+ * Does this response carry a WordPress nonce?
	4180	+ *
	4181	+ * Anonymous nonces depend only on the tick (user 0, empty session
	4182	+ * token), so they are identical for every visitor — which is exactly why
	4183	+ * they cache "successfully" and then fail silently once the tick moves.
	4184	+ *
	4185	+ * Matches any form field whose NAME contains "nonce" — `_wpnonce`,
	4186	+ * `_wpnonce_<action>`, Tutor's `_tutor_nonce`, CF7's `_wpcf7_nonce` and
	4187	+ * WooCommerce's `woocommerce-add-to-cart-nonce` (which does NOT start
	4188	+ * with an underscore, so a `_`-anchored pattern misses it) — plus the
	4189	+ * `_wpnonce=` form used in nonce-bearing URLs. Deliberately keyed on
	4190	+ * `name=` so prose, CSS classes and data attributes don't false-positive.
	4191	+ *
	4192	+ * @param string $html Rendered response body.
	4193	+ */
	4194	+ public static function response_has_nonce( string $html ): bool {
	4195	+ if ( '' === $html ) {
	4196	+ return false;
	4197	+ }
	4198	+
	4199	+ /*
	4200	+ * Three shapes, because a nonce reaches the page in three ways:
	4201	+ *
	4202	+ * 1. A form field name — `_wpnonce`, `woocommerce-login-nonce`, and
	4203	+ * the GROUPED names form builders emit (`data[_wpnonce]`,
	4204	+ * `frm[nonce]`). The character class deliberately allows `[` and
	4205	+ * `]` so grouping does not hide the field: form builders are
	4206	+ * exactly the kind of plugin #236 is about, and a missed page
	4207	+ * keeps the old broken behaviour silently.
	4208	+ * 2. A query argument (`?_wpnonce=`) on a link.
	4209	+ * 3. A nonce handed to the page's own scripts rather than placed in
	4210	+ * a visible form — `wp_localize_script()` output and inline JSON
	4211	+ * both land as a `"nonce":"…"`-shaped pair.
	4212	+ */
	4213	+ return 1 === preg_match(
	4214	+ '/(name=["\'][a-z0-9_\-\[\]]*nonce[a-z0-9_\-\[\]]*["\']'
	4215	+ . '|[?&]_wpnonce='
	4216	+ . '|["\'][a-z0-9_\-]*nonce[a-z0-9_\-]*["\']\s*:\s*["\'][a-f0-9]{8,}["\'])/i',
	4217	+ $html
	4218	+ );
	4219	+ }
	4220	+
	4221	+ /**
	4222	+ * The TTL (seconds) a response may be cached for, capped to the nonce
	4223	+ * lifetime when it carries one.
	4224	+ *
	4225	+ * WordPress nonces are valid for at most `nonce_life` — 24h by default —
	4226	+ * because wp_verify_nonce() accepts the current tick and the previous
	4227	+ * one. Our own lifetime maximum is 720h and the shipped Aggressive
	4228	+ * preset is 168h, so on any site configured above 24h every anonymous
	4229	+ * front-end form carried a DEAD nonce for the majority of the cache's
	4230	+ * life and every submission was rejected — with the other plugin's error
	4231	+ * string ("Nonce not matched"), so the report never reached us (#236).
	4232	+ *
	4233	+ * `nonce_life` is the MAXIMUM a nonce can live, not the minimum, so it
	4234	+ * is the wrong number to cap with. wp_nonce_tick() buckets time into
	4235	+ * `nonce_life / 2` slices; a nonce minted x seconds into its bucket is
	4236	+ * valid for `nonce_life - x`, where x can be as large as a full bucket.
	4237	+ * Capping the entry at `nonce_life` therefore still served a dead nonce
	4238	+ * for up to half of every entry's life — 0-12h of each 24h entry,
	4239	+ * averaging 6h, re-rolled by every purge so it reads as intermittent.
	4240	+ * Capping at the guaranteed-valid remainder closes the window at every
	4241	+ * tick phase, at the cost of caching nonce-bearing pages for 12h rather
	4242	+ * than 24h.
	4243	+ *
	4244	+ * Capping is per-entry, so only nonce-bearing pages pay for it; the rest
	4245	+ * of the site keeps the configured lifetime.
	4246	+ *
	4247	+ * @param string $html Rendered response body.
	4248	+ * @param int $ttl Otherwise-resolved TTL in seconds.
	4249	+ * @return int TTL to actually use.
	4250	+ */
	4251	+ /**
	4252	+ * The nonce lifetime to cap against, in seconds.
	4253	+ *
	4254	+ * `nonce_life` is a TWO-argument filter in core:
	4255	+ *
	4256	+ * $nonce_life = apply_filters( 'nonce_life', DAY_IN_SECONDS, $action );
	4257	+ *
	4258	+ * Applying it with one argument is not merely incomplete — a callback
	4259	+ * that declares both parameters as required (the documented shape, and
	4260	+ * what a site branching per action must write) raises ArgumentCountError
	4261	+ * the moment we call it. That fatal lands in the shutdown cache write,
	4262	+ * so the visitor still sees a perfectly normal page while the sidecar is
	4263	+ * never written: the entry then keeps the FULL configured lifetime
	4264	+ * carrying a dead nonce, which is precisely the bug #236 set out to fix.
	4265	+ * Worse, the entry stays that way until a purge, even after the site
	4266	+ * removes whatever customised the lifetime.
	4267	+ *
	4268	+ * We are inspecting rendered markup, so we cannot know which action
	4269	+ * minted the nonce we found. Two consequences:
	4270	+ *
	4271	+ * 1. We pass `''` as the action. A per-action callback therefore sees
	4272	+ * the same "unknown action" value core itself passes when a nonce is
	4273	+ * created with no action, and can branch on it deliberately.
	4274	+ * 2. A page may carry nonces from SEVERAL actions with different
	4275	+ * lifetimes. The entry can only have one TTL, so the safe choice is
	4276	+ * the SHORTEST lifetime any action on the site resolves to — capping
	4277	+ * to a longer one would serve a dead nonce for the shorter action.
	4278	+ * Sites can narrow this with `xspeed_cache_nonce_life_actions`.
	4279	+ *
	4280	+ * @param string $html Response body being cached.
	4281	+ * @return int Nonce lifetime in seconds (0 = do not cap).
	4282	+ */
	4283	+ private static function nonce_life_seconds( string $html ): int {
	4284	+ /**
	4285	+ * Filter the nonce actions whose lifetimes are consulted when
	4286	+ * capping a cache entry.
	4287	+ *
	4288	+ * The default `''` is the "action unknown" case — we are reading
	4289	+ * rendered HTML, not minting a nonce. A site whose `nonce_life`
	4290	+ * callback shortens specific actions can list them here so the cap
	4291	+ * accounts for the shortest one that could appear on the page.
	4292	+ *
	4293	+ * @since 1.1.8
	4294	+ * @param string[] $actions Nonce actions to resolve.
	4295	+ * @param string $html The response body being cached.
	4296	+ */
	4297	+ $actions = (array) apply_filters( 'xspeed_cache_nonce_life_actions', array( '' ), $html );
	4298	+ if ( empty( $actions ) ) {
	4299	+ $actions = array( '' );
	4300	+ }
	4301	+
	4302	+ $shortest = 0;
	4303	+ foreach ( $actions as $action ) {
	4304	+ // Both arguments, exactly as core passes them.
	4305	+ $life = (int) apply_filters( 'nonce_life', DAY_IN_SECONDS, (string) $action );
	4306	+ if ( $life < 1 ) {
	4307	+ continue;
	4308	+ }
	4309	+ if ( 0 === $shortest || $life < $shortest ) {
	4310	+ $shortest = $life;
	4311	+ }
	4312	+ }
	4313	+
	4314	+ return $shortest;
	4315	+ }
	4316	+
	4317	+ public static function nonce_capped_ttl( string $html, int $ttl ): int {
	4318	+ if ( ! self::response_has_nonce( $html ) ) {
	4319	+ return $ttl;
	4320	+ }
	4321	+
	4322	+ $nonce_life = self::nonce_life_seconds( $html );
	4323	+ if ( $nonce_life < 1 ) {
	4324	+ return $ttl;
	4325	+ }
	4326	+
	4327	+ // Half of nonce_life is the GUARANTEED-valid remainder — see above.
	4328	+ $guaranteed = max( 1, intdiv( $nonce_life, 2 ) );
	4329	+ $capped = ( $ttl > 0 ) ? min( $ttl, $guaranteed ) : $guaranteed;
	4330	+
	4331	+ /**
	4332	+ * Filter the nonce-capped TTL for a cache entry.
	4333	+ *
	4334	+ * Escape hatch for a site whose nonce-shaped markup is decorative —
	4335	+ * return the uncapped $ttl to keep the configured lifetime. Most
	4336	+ * sites should leave this alone: serving a dead nonce breaks every
	4337	+ * anonymous form on the page.
	4338	+ *
	4339	+ * @param int $capped TTL after the nonce cap (seconds).
	4340	+ * @param int $ttl TTL before the cap (seconds).
	4341	+ * @param int $nonce_life Current nonce lifetime (seconds).
	4342	+ * @param string $html The response body being cached.
	4343	+ */
	4344	+ return (int) apply_filters( 'xspeed_cache_nonce_ttl_cap', $capped, $ttl, $nonce_life, $html );
	4345	+ }
	4346	+
	4347	+ private static function write_meta( string $key, string $html = '' ): void {
801	4348	$content_type = '';
802	4349	foreach ( headers_list() as $header ) {
803	4350	if ( 0 === stripos( $header, 'content-type:' ) ) {
804	4351	$content_type = trim( substr( $header, strlen( 'content-type:' ) ) );
		@@ -819,15 +4366,52 @@
819	4366	// call is_expired() / the xspeed_cache_max_age filter (they run before
820	4367	// WP), so persist the resolved max-age here whenever it differs from
821	4368	// the plain page TTL — e.g. the Pro feed cache's 12h vs the 24h page
822	4369	// default. The fast paths read this to expire correctly. (FBS-82407)
823		- $opts = Settings_Manager::get( 'cache' );
824		- $default_ttl = (int) $opts['cache_expiry'] * HOUR_IN_SECONDS;
825		- $ttl = (int) apply_filters( 'xspeed_cache_max_age', $default_ttl );
	4370	+ // This MUST resolve the TTL the same way is_expired() does, including
	4371	+ // the per-post override — the sidecar is the only channel that can
	4372	+ // carry a per-entry TTL into the pre-boot fast paths. Omitting the
	4373	+ // override here left an editor's "expire this post after 1h" visible
	4374	+ // to the engine but invisible to the drop-in, which kept serving the
	4375	+ // entry until the global lifetime elapsed (#240 AC#3). Handing the
	4376	+ // filter the same base as is_expired() also keeps a filter that
	4377	+ // SCALES its input (e.g. $max_age * 2) consistent between the two.
	4378	+ $opts = Settings_Manager::get( 'cache' );
	4379	+ $default_ttl = (int) $opts['cache_expiry'] * HOUR_IN_SECONDS;
	4380	+ $max_age = $default_ttl;
	4381	+ $post_override = Cache_Rules::expiry_override_seconds_for_post( Cache_Rules::current_post_id() );
	4382	+ if ( null !== $post_override ) {
	4383	+ $max_age = $post_override;
	4384	+ }
	4385	+ /** This filter is documented in includes/class-cache.php */
	4386	+ $ttl = (int) apply_filters( 'xspeed_cache_max_age', $max_age );
	4387	+
	4388	+ // A response carrying a nonce may not outlive that nonce, however
	4389	+ // long the site's configured lifetime is (#236). This runs AFTER the
	4390	+ // max-age filter so it caps whatever the filter resolved rather than
	4391	+ // being overridden by it — a Pro module lengthening the TTL must not
	4392	+ // be able to reintroduce a dead nonce.
	4393	+ $ttl = self::nonce_capped_ttl( $html, $ttl );
	4394	+
826	4395	if ( $ttl > 0 && $ttl !== $default_ttl ) {
827	4396	$meta['ttl'] = $ttl;
828	4397	}
829	4398
	4399	+ // This entry's edge headers, when they differ from the site-wide set
	4400	+ // baked into the drop-in. The sidecar is the only channel that can
	4401	+ // carry a per-page answer into the pre-boot fast path, and the drop-in
	4402	+ // REPLACES the baked set with it rather than merging: the two describe
	4403	+ // the same response, so merging would leave the baked lifetime in
	4404	+ // place beside the hold meant to overrule it.
	4405	+ //
	4406	+ // The lifetime resolved above goes with it, under the same condition
	4407	+ // as the `ttl` key: a page that does not follow the site's lifetime
	4408	+ // may not be kept at the edge past its own either.
	4409	+ $edge = self::per_entry_edge_headers( isset( $meta['ttl'] ) ? $ttl : null );
	4410	+ if ( array() !== $edge ) {
	4411	+ $meta['edge_headers'] = $edge;
	4412	+ }
	4413	+
830	4414	// Nothing to replay → no sidecar.
831	4415	if ( empty( $meta ) ) {
832	4416	return;
833	4417	}
		@@ -845,49 +4429,2189 @@
845	4429	* Activity log to give users context (e.g.
846	4430	* 'post saved', 'settings change', 'manual',
847	4431	* 'theme switch').
848	4432	*/
849		- public static function purge_all( string $cause = 'manual' ) {
	4433	+ /**
	4434	+ * Purge the cache entries for ONE URL — every variant of it: the
	4435	+ * flat-hash entry (+ .meta / .html.br siblings), both device buckets
	4436	+ * (mobile_separate keys them separately), both trailing-slash forms,
	4437	+ * and the static-tree index.html (+ .br) the server rewrite serves.
	4438	+ * The rest of the cache is untouched — this is the surgical
	4439	+ * alternative to purge_all for "I just edited this one page".
	4440	+ *
	4441	+ * @param string $url Absolute URL, or site-relative path ("/about/").
	4442	+ * @param string $cause Who asked, for the purge log. See purge_all().
	4443	+ * @return int Number of cache files removed.
	4444	+ */
	4445	+ /**
	4446	+ * Post types that are not "viewable" but ARE the presentation layer.
	4447	+ *
	4448	+ * `is_post_type_viewable()` answers "does this type have a front end of
	4449	+ * its own?" — which is the right question for `shop_order`, but the
	4450	+ * wrong one for the types core uses to render every OTHER page. A
	4451	+ * template part, a global-styles record, a navigation or a synced
	4452	+ * pattern has no permalink, yet editing one changes how the whole site
	4453	+ * looks. Gating purges on viewability alone meant a Site Editor save
	4454	+ * invalidated nothing and visitors kept the old design for the full
	4455	+ * TTL — up to 30 days at the maximum lifetime. (#270 regression)
	4456	+ *
	4457	+ * @return string[]
	4458	+ */
	4459	+ /**
	4460	+ * Could this post change alter anything an anonymous visitor had cached?
	4461	+ *
	4462	+ * Deleting one post fired a full purge for the post AND for every stored
	4463	+ * revision, because wp_delete_post() removes each revision through
	4464	+ * wp_delete_post() again and every one of those fires before_delete_post
	4465	+ * with post_type 'revision'. A post with six revisions cost seven whole-
	4466	+ * site sweeps, each one also announcing to LiteSpeed, purging the object
	4467	+ * cache network-wide on Redis, rewriting the stats option and running
	4468	+ * every xspeed_after_purge_all listener -- including Pro's Cloudflare
	4469	+ * purge, so seven API calls. Trashing cost two, via save_post and then
	4470	+ * trashed_post. (QA #348)
	4471	+ *
	4472	+ * The check lives here, ahead of purge_all(), so one early return covers
	4473	+ * the local sweep, the server-cache announcement and both action hooks.
	4474	+ * It deliberately does NOT live inside purge_all(): a manual, CLI or
	4475	+ * explicit caller asked for a purge and must get one.
	4476	+ *
	4477	+ * @param int $post_id Post being saved or removed.
	4478	+ * @param mixed $post Post object when the hook passed one.
	4479	+ * @param string $event 'save' or 'remove'.
	4480	+ */
	4481	+ private static function post_change_is_cacheable_content( $post_id, $post, string $event ): bool {
	4482	+ $post_id = (int) $post_id;
	4483	+
	4484	+ // Only `save_post` and `before_delete_post` hand over a post object.
	4485	+ // `trashed_post` passes ( $post_id, $previous_status ) -- a STRING --
	4486	+ // so reaching for ->post_status on the second argument finds nothing
	4487	+ // and the status rule below would never fire. Read the row instead.
	4488	+ if ( ! is_object( $post ) && function_exists( 'get_post' ) ) {
	4489	+ $post = get_post( $post_id );
	4490	+ }
	4491	+
	4492	+ $type = is_object( $post ) && isset( $post->post_type )
	4493	+ ? (string) $post->post_type
	4494	+ : (string) ( function_exists( 'get_post_type' ) ? get_post_type( $post_id ) : '' );
	4495	+ if ( '' === $type ) {
	4496	+ return false;
	4497	+ }
	4498	+
	4499	+ // A revision is a copy of content nobody can browse to.
	4500	+ if ( 'revision' === $type ) {
	4501	+ return false;
	4502	+ }
	4503	+ if ( function_exists( 'wp_is_post_revision' ) && wp_is_post_revision( $post_id ) ) {
	4504	+ return false;
	4505	+ }
	4506	+ if ( function_exists( 'wp_is_post_autosave' ) && wp_is_post_autosave( $post_id ) ) {
	4507	+ return false;
	4508	+ }
	4509	+
	4510	+ $status = is_object( $post ) && isset( $post->post_status ) ? (string) $post->post_status : '';
	4511	+
	4512	+ // Clicking "Add New" inserts an auto-draft and fires save_post. There
	4513	+ // is nothing cached of a post that has never existed publicly.
	4514	+ if ( 'auto-draft' === $status ) {
	4515	+ return false;
	4516	+ }
	4517	+
	4518	+ // Unknown/!viewable → nothing anonymous can see changed, UNLESS the
	4519	+ // type is itself part of how pages render (#270 regression).
	4520	+ if ( function_exists( 'is_post_type_viewable' )
	4521	+ && ! is_post_type_viewable( $type )
	4522	+ && ! in_array( $type, self::presentation_post_types(), true )
	4523	+ ) {
	4524	+ return false;
	4525	+ }
	4526	+
	4527	+ // Deleting something that was already invisible changes no cached
	4528	+ // page: the transition that hid it purged at the time. This is what
	4529	+ // makes emptying a trash of a hundred posts cost nothing rather than
	4530	+ // a hundred full sweeps.
	4531	+ //
	4532	+ // It also collapses trashing to a single purge: wp_trash_post() fires
	4533	+ // save_post first, where the post is genuinely disappearing from
	4534	+ // listings and SHOULD purge, then trashed_post, by which point the
	4535	+ // row reads 'trash' and is skipped. A status we cannot read, on a row
	4536	+ // that still reports a type, means assume viewable -- erring toward
	4537	+ // an extra purge, never toward serving a stale page. A row that is
	4538	+ // gone entirely reports no type either and was refused above.
	4539	+ // 'inherit' is an INTERNAL status in core, so is_post_status_viewable()
	4540	+ // says no -- but an attachment carrying it is genuinely public. Judge
	4541	+ // those on the post type alone, which is already checked above.
	4542	+ if ( 'remove' === $event && '' !== $status && 'inherit' !== $status
	4543	+ && function_exists( 'is_post_status_viewable' )
	4544	+ && ! is_post_status_viewable( $status )
	4545	+ ) {
	4546	+ return false;
	4547	+ }
	4548	+
	4549	+ return true;
	4550	+ }
	4551	+
	4552	+ public static function presentation_post_types(): array {
	4553	+ $types = array(
	4554	+ 'wp_template', // Site Editor templates.
	4555	+ 'wp_template_part', // Header / footer / reusable parts.
	4556	+ 'wp_global_styles', // Colours, typography, spacing.
	4557	+ 'wp_navigation', // Navigation block menus.
	4558	+ 'nav_menu_item', // Classic menus.
	4559	+ 'wp_block', // Synced patterns / reusable blocks.
	4560	+ );
	4561	+
	4562	+ /**
	4563	+ * Filter the non-viewable post types that still invalidate the cache.
	4564	+ *
	4565	+ * Add a type here when it has no front end of its own but changes
	4566	+ * how other pages render (a theme's own layout CPT, for example).
	4567	+ *
	4568	+ * @param string[] $types Post type slugs.
	4569	+ */
	4570	+ return (array) apply_filters( 'xspeed_presentation_post_types', $types );
	4571	+ }
	4572	+
	4573	+ /**
	4574	+ * Describe a broad hook invalidation for response-cache adapters.
	4575	+ *
	4576	+ * Term, menu, theme and plugin changes can alter navigation, archives or
	4577	+ * markup across the site, so they require a site response-cache purge.
	4578	+ * Content saves also require this scope while their local operation is a
	4579	+ * complete bucket sweep.
	4580	+ *
	4581	+ * A new term is `content`, not `presentation`. It has no posts yet, so no
	4582	+ * page renders it until a post is saved with it, and that save is its own
	4583	+ * content purge. Classed as presentation, it cleared the host's whole
	4584	+ * nginx cache every time a post was published with a tag that did not
	4585	+ * exist yet, which is most publishing. Renaming or deleting a term stays
	4586	+ * presentation: the new name shows on every post in the term, and Nginx
	4587	+ * Helper purges only the homepage for either. (QA #448)
	4588	+ *
	4589	+ * @return array{scope:string,intent:string,urls:array<int,string>}
	4590	+ */
	4591	+ private static function invalidation_for_hook( string $hook ): array {
	4592	+ $presentation = array(
	4593	+ 'switch_theme',
	4594	+ 'activated_plugin',
	4595	+ 'deactivated_plugin',
	4596	+ 'edited_term',
	4597	+ 'delete_term',
	4598	+ 'wp_update_nav_menu',
	4599	+ );
	4600	+
	4601	+ return array(
	4602	+ 'scope' => 'site',
	4603	+ 'intent' => in_array( $hook, $presentation, true ) ? 'presentation' : 'content',
	4604	+ 'urls' => array(),
	4605	+ );
	4606	+ }
	4607	+
	4608	+
	4609	+ /**
	4610	+ * save_post → purge only when the saved thing can appear on a cached page.
	4611	+ *
	4612	+ * Revisions and autosaves are never rendered. Non-viewable post types —
	4613	+ * WooCommerce's `shop_order` / `shop_order_placehold` / `shop_order_refund`
	4614	+ * / `shop_coupon`, Flamingo's `flamingo_inbound` (#229), Tutor's
	4615	+ * `tutor_enrolled` (#231) — are invisible to anonymous visitors, so
	4616	+ * writing one changes nothing that is cached. (#243)
	4617	+ *
	4618	+ * The exception is the presentation types above, which are non-viewable
	4619	+ * yet render every page — they are allow-listed BEFORE the viewability
	4620	+ * test. (#270 regression)
	4621	+ *
	4622	+ * @param int $post_id Saved post ID.
	4623	+ * @param \WP_Post $post Saved post object.
	4624	+ */
	4625	+ public static function on_save_post( $post_id, $post = null ): void {
	4626	+ if ( ! self::post_change_is_cacheable_content( $post_id, $post, 'save' ) ) {
	4627	+ return;
	4628	+ }
	4629	+
	4630	+ $post_type = is_object( $post ) && isset( $post->post_type )
	4631	+ ? (string) $post->post_type
	4632	+ : (string) get_post_type( $post_id );
	4633	+
	4634	+ // Name the trigger rather than logging a bare numeric id — the old
	4635	+ // wiring passed the post ID into $cause, so the log read
	4636	+ // "Cache purged (46)" with no indication of what caused it. (#243)
	4637	+ $presentation = in_array( $post_type, self::presentation_post_types(), true );
	4638	+
	4639	+ // Clearing only the affected pages needs the post's terms, and the
	4640	+ // REST API sets those after `save_post`. Note the post and purge on
	4641	+ // `wp_after_insert_post`; flush_pending_saves() covers a save that
	4642	+ // never gets there.
	4643	+ if ( ! $presentation && self::narrow_purge_applies( $post_type ) ) {
	4644	+ self::$pending_saves[ (int) $post_id ] = true;
	4645	+ return;
	4646	+ }
	4647	+
	4648	+ self::purge_all(
	4649	+ 'post:' . $post_type,
	4650	+ null,
	4651	+ array(
	4652	+ // purge_all() sweeps every local response in this site's bucket.
	4653	+ // Without dependency tracking, the server cache must match that
	4654	+ // same boundary or unrelated pages can remain stale there.
	4655	+ 'scope' => 'site',
	4656	+ 'intent' => $presentation ? 'presentation' : 'content',
	4657	+ 'urls' => array(),
	4658	+ )
	4659	+ );
	4660	+ }
	4661	+
	4662	+ /**
	4663	+ * Reasons a change that would have cleared only its own pages cleared
	4664	+ * the whole site, published as `fallback` in the purge context.
	4665	+ *
	4666	+ * - THEME_LIST: the change alters a post or comment list the theme draws
	4667	+ * on pages the rules cannot name.
	4668	+ * - LIMIT: the affected pages are more than Affected_Pages::LIMIT.
	4669	+ * - PENDING: the save never reached `wp_after_insert_post`, so there was
	4670	+ * no before-copy to work the old address out from.
	4671	+ * - FILTER: `xspeed_purge_affected_pages` returned false.
	4672	+ * - LISTING: the record of pages that run a post list of their own
	4673	+ * (Listing_Pages) cannot answer: a page of the type went unrecorded at
	4674	+ * its cap, more than Affected_Pages::LIMIT pages of the type would
	4675	+ * have to be named, or the index does not read back. Or the pages it
	4676	+ * named took the list past Affected_Pages::LIMIT.
	4677	+ *
	4678	+ * Every other purge publishes ''. A post type that always purges the
	4679	+ * whole site (a WooCommerce product) is a choice, not a fallback, and
	4680	+ * publishes '' too.
	4681	+ */
	4682	+ public const FALLBACK_THEME_LIST = 'theme_list';
	4683	+ public const FALLBACK_LIMIT = 'limit';
	4684	+ public const FALLBACK_PENDING = 'pending';
	4685	+ public const FALLBACK_FILTER = 'filter';
	4686	+ public const FALLBACK_LISTING = 'listing';
	4687	+
	4688	+ /**
	4689	+ * Posts noted by on_save_post() for a narrow purge, keyed by ID.
	4690	+ *
	4691	+ * @var array<int,bool>
	4692	+ */
	4693	+ private static $pending_saves = array();
	4694	+
	4695	+ /**
	4696	+ * Posts whose save purged their pages in this request, keyed by ID. That
	4697	+ * purge named page 1 of the posts page, so a sticky change made after
	4698	+ * it (the classic editor and Quick Edit stick after saving) has nothing
	4699	+ * left to clear there.
	4700	+ *
	4701	+ * @var array<int,bool>
	4702	+ */
	4703	+ private static $saves_purged = array();
	4704	+
	4705	+ /**
	4706	+ * Purge the pages a save affected, once WordPress has finished saving.
	4707	+ *
	4708	+ * @param int $post_id Post ID.
	4709	+ * @param \WP_Post $post Post as saved.
	4710	+ * @param bool $update Whether an existing post was updated.
	4711	+ * @param \WP_Post|null $post_before Post before the save, null when new.
	4712	+ */
	4713	+ public static function on_after_insert_post( $post_id, $post = null, $update = false, $post_before = null ): void { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed -- hook signature.
	4714	+ $post_id = (int) $post_id;
	4715	+ if ( ! isset( self::$pending_saves[ $post_id ] ) ) {
	4716	+ return;
	4717	+ }
	4718	+ unset( self::$pending_saves[ $post_id ] );
	4719	+ if ( ! $post instanceof \WP_Post ) {
	4720	+ $post = get_post( $post_id );
	4721	+ }
	4722	+ if ( ! $post instanceof \WP_Post ) {
	4723	+ return;
	4724	+ }
	4725	+ $post_before = $post_before instanceof \WP_Post ? $post_before : null;
	4726	+ if ( self::repeats_block_editor_save( $post, $post_before ) ) {
	4727	+ Affected_Pages::forget( $post_id );
	4728	+ return;
	4729	+ }
	4730	+ self::$saves_purged[ $post_id ] = true;
	4731	+ self::purge_post_change( $post, $post_before, 'post:' . $post->post_type );
	4732	+ }
	4733	+
	4734	+ /** Meta WordPress rewrites on every save, which says nothing about the page. */
	4735	+ private const SAVE_NOISE_META = array( '_edit_lock', '_edit_last', '_encloseme', '_pingme' );
	4736	+
	4737	+ /**
	4738	+ * Whether this save repeats the block editor save that just purged.
	4739	+ *
	4740	+ * The block editor saves a post through REST, then, when the screen has
	4741	+ * meta boxes (xSpeed's own Cache Rules box is one), posts them to
	4742	+ * post.php?meta-box-loader=1, which saves the post a second time. Both
	4743	+ * requests purged, so every save sent the same pages to every cache in
	4744	+ * front twice. The REST save notes what it purged for; the meta box
	4745	+ * request skips its purge when nothing a visitor sees has changed since:
	4746	+ * the post's fields, its terms and its meta. A meta box that saved meta
	4747	+ * the page prints (an SEO title, a custom field) still purges.
	4748	+ *
	4749	+ * @param \WP_Post $post Post as saved.
	4750	+ * @param \WP_Post|null $before Post before the save.
	4751	+ */
	4752	+ private static function repeats_block_editor_save( \WP_Post $post, ?\WP_Post $before ): bool {
	4753	+ // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- only names the request; WordPress verified the save's own nonce.
	4754	+ $meta_boxes = isset( $_GET['meta-box-loader'] );
	4755	+ $rest = defined( 'REST_REQUEST' ) && REST_REQUEST;
	4756	+ if ( ! $meta_boxes && ! $rest ) {
	4757	+ return false;
	4758	+ }
	4759	+ if ( ! Affected_Pages::is_public( $post ) && ! ( $before instanceof \WP_Post && Affected_Pages::is_public( $before ) ) ) {
	4760	+ return false;
	4761	+ }
	4762	+ $key = 'xspeed_saved_' . (int) $post->ID;
	4763	+ $fingerprint = self::save_fingerprint( $post );
	4764	+ if ( $meta_boxes ) {
	4765	+ if ( get_transient( $key ) === $fingerprint ) {
	4766	+ delete_transient( $key );
	4767	+ return true;
	4768	+ }
	4769	+ return false;
	4770	+ }
	4771	+ set_transient( $key, $fingerprint, 2 * MINUTE_IN_SECONDS );
	4772	+ return false;
	4773	+ }
	4774	+
	4775	+ /**
	4776	+ * A hash of what a save can change that a visitor sees: the post's own
	4777	+ * fields, its terms and its meta.
	4778	+ *
	4779	+ * @param \WP_Post $post Post as saved.
	4780	+ */
	4781	+ private static function save_fingerprint( \WP_Post $post ): string {
	4782	+ $fields = array();
	4783	+ foreach ( array( 'post_type', 'post_status', 'post_date', 'post_title', 'post_name', 'post_content', 'post_excerpt', 'post_parent', 'menu_order', 'post_author', 'post_password', 'comment_status' ) as $field ) {
	4784	+ $fields[ $field ] = (string) ( $post->$field ?? '' );
	4785	+ }
	4786	+ $terms = array();
	4787	+ $taxonomies = get_object_taxonomies( (string) $post->post_type );
	4788	+ if ( is_array( $taxonomies ) && array() !== $taxonomies ) {
	4789	+ $ids = wp_get_object_terms( (int) $post->ID, $taxonomies, array( 'fields' => 'tt_ids' ) );
	4790	+ $terms = is_array( $ids ) ? array_map( 'intval', $ids ) : array();
	4791	+ sort( $terms );
	4792	+ }
	4793	+ $meta = get_post_meta( (int) $post->ID );
	4794	+ $meta = is_array( $meta ) ? array_diff_key( $meta, array_flip( self::SAVE_NOISE_META ) ) : array();
	4795	+ ksort( $meta );
	4796	+ return md5( (string) wp_json_encode( array( $fields, $terms, $meta ) ) );
	4797	+ }
	4798	+
	4799	+ /**
	4800	+ * A save that never reached `wp_after_insert_post` still purges.
	4801	+ *
	4802	+ * `wp_insert_post()` called with `$fire_after_hooks = false` leaves that
	4803	+ * hook to its caller, and a caller can fail to fire it. Without this, the
	4804	+ * save would purge nothing at all. Site-wide, because there is no
	4805	+ * before-copy to work out the old address from.
	4806	+ */
	4807	+ public static function flush_pending_saves(): void {
	4808	+ if ( array() === self::$pending_saves ) {
	4809	+ return;
	4810	+ }
	4811	+ $ids = array_keys( self::$pending_saves );
	4812	+ self::$pending_saves = array();
	4813	+ self::purge_all(
	4814	+ 'post:pending',
	4815	+ null,
	4816	+ array(
	4817	+ 'scope' => 'site',
	4818	+ 'intent' => 'content',
	4819	+ 'urls' => array(),
	4820	+ 'fallback' => self::FALLBACK_PENDING,
	4821	+ )
	4822	+ );
	4823	+ foreach ( $ids as $id ) {
	4824	+ Affected_Pages::forget( (int) $id );
	4825	+ }
	4826	+ }
	4827	+
	4828	+ /**
	4829	+ * Before an update is written: note the post's neighbours, which a new
	4830	+ * date or category takes it away from. Only for a post visitors can see
	4831	+ * now, and only when the save will purge narrowly; that costs four
	4832	+ * queries per update.
	4833	+ *
	4834	+ * @param int $post_id Post ID.
	4835	+ * @param array $data Unused: the new values.
	4836	+ */
	4837	+ public static function on_pre_post_update( $post_id, $data = array() ): void { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed -- hook signature.
	4838	+ $post = get_post( (int) $post_id );
	4839	+ if ( ! $post instanceof \WP_Post || ! Affected_Pages::is_public( $post ) ) {
	4840	+ return;
	4841	+ }
	4842	+ if ( in_array( (string) $post->post_type, self::presentation_post_types(), true ) || ! self::narrow_purge_applies( (string) $post->post_type ) ) {
	4843	+ return;
	4844	+ }
	4845	+ Affected_Pages::remember_old_neighbours( $post );
	4846	+ }
	4847	+
	4848	+ /**
	4849	+ * A post was stuck or unstuck.
	4850	+ *
	4851	+ * A theme list that puts sticky posts first (Twenty Twenty-Five's "More
	4852	+ * posts" under every post) changes on every page that draws it, so the
	4853	+ * whole site goes. The block editor changes stickiness inside the save,
	4854	+ * and the save's own purge sees it then. The classic editor and Quick
	4855	+ * Edit change it after the save has purged, which is why this hook
	4856	+ * purges the posts no save is waiting on.
	4857	+ *
	4858	+ * @param mixed $old_value Sticky post IDs before.
	4859	+ * @param mixed $value Sticky post IDs after.
	4860	+ */
	4861	+ public static function on_sticky_posts_change( $old_value, $value ): void {
	4862	+ $blog_page = false;
	4863	+ foreach ( Affected_Pages::remember_sticky_change( $old_value, $value ) as $post_id ) {
	4864	+ if ( isset( self::$pending_saves[ $post_id ] ) ) {
	4865	+ continue;
	4866	+ }
	4867	+ $post = get_post( $post_id );
	4868	+ if ( ! $post instanceof \WP_Post || ! Affected_Pages::is_public( $post ) || ! self::narrow_purge_applies( (string) $post->post_type ) ) {
	4869	+ continue;
	4870	+ }
	4871	+ if ( Affected_Pages::lists_show_sticky( (string) $post->post_type ) ) {
	4872	+ self::purge_all(
	4873	+ 'sticky:' . $post->post_type,
	4874	+ null,
	4875	+ array(
	4876	+ 'scope' => 'site',
	4877	+ 'intent' => 'content',
	4878	+ 'urls' => array(),
	4879	+ 'fallback' => self::FALLBACK_THEME_LIST,
	4880	+ )
	4881	+ );
	4882	+ return;
	4883	+ }
	4884	+ // WordPress's own blog list puts sticky posts first on its first
	4885	+ // page, whatever the theme draws, so a post stuck or unstuck by
	4886	+ // code, WP-CLI or a plugin moves on that page. A save in this
	4887	+ // request already cleared it.
	4888	+ if ( 'post' === $post->post_type && ! isset( self::$saves_purged[ $post_id ] ) ) {
	4889	+ $blog_page = true;
	4890	+ }
	4891	+ }
	4892	+ if ( $blog_page ) {
	4893	+ $url = Affected_Pages::posts_page_url();
	4894	+ if ( '' !== $url ) {
	4895	+ self::purge_urls( array( $url ), 'sticky:post' );
	4896	+ }
	4897	+ }
	4898	+ }
	4899	+
	4900	+ /**
	4901	+ * The first post stuck on a site: WordPress creates `sticky_posts`
	4902	+ * instead of updating it, so update_option_sticky_posts never fires.
	4903	+ *
	4904	+ * @param string $option Option name.
	4905	+ * @param mixed $value Sticky post IDs.
	4906	+ */
	4907	+ public static function on_sticky_posts_added( $option, $value ): void { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundBeforeLastUsed -- hook signature.
	4908	+ self::on_sticky_posts_change( array(), $value );
	4909	+ }
	4910	+
	4911	+ /**
	4912	+ * Whether a content change to this post type may clear only the pages
	4913	+ * it affects, before looking at the post itself.
	4914	+ *
	4915	+ * Off when the setting is off, during an import (one full purge runs at
	4916	+ * the end), and for post types whose lists the rules do not know:
	4917	+ * WooCommerce products, whose shop and category pages purge_product()
	4918	+ * already handles.
	4919	+ *
	4920	+ * @param string $post_type Post type.
	4921	+ */
	4922	+ private static function narrow_purge_applies( string $post_type ): bool {
	4923	+ if ( defined( 'WP_IMPORTING' ) && WP_IMPORTING ) {
	4924	+ return false;
	4925	+ }
	4926	+ $opts = Settings_Manager::get( 'cache' );
	4927	+ if ( empty( $opts['purge_affected_only'] ) ) {
	4928	+ return false;
	4929	+ }
	4930	+ /**
	4931	+ * Filter the post types whose saves always purge the whole site.
	4932	+ *
	4933	+ * @param string[] $types Post type slugs.
	4934	+ */
	4935	+ $site_wide = (array) apply_filters( 'xspeed_site_wide_purge_post_types', array( 'product', 'product_variation' ) );
	4936	+ return ! in_array( $post_type, $site_wide, true );
	4937	+ }
	4938	+
	4939	+ /**
	4940	+ * Purge what a change to one post affects, or the whole site when the
	4941	+ * affected pages cannot be listed safely.
	4942	+ *
	4943	+ * The pages are the ones the rules name (Affected_Pages::for_post())
	4944	+ * and the recorded pages whose own post lists the change may alter
	4945	+ * (Listing_Pages::pages_for()).
	4946	+ *
	4947	+ * Site-wide when this change alters a post list the theme draws on
	4948	+ * pages the rules cannot name (Affected_Pages::lists_changed_by()), when
	4949	+ * the record of listing pages cannot answer, when the list is
	4950	+ * longer than Affected_Pages::LIMIT, or when the filter says so. Nothing
	4951	+ * when the post was not public before or after: no page anyone can see
	4952	+ * changed.
	4953	+ *
	4954	+ * @param \WP_Post $post Post as it is now.
	4955	+ * @param \WP_Post|null $before Post before the change.
	4956	+ * @param string $cause Purge log cause.
	4957	+ */
	4958	+ private static function purge_post_change( \WP_Post $post, ?\WP_Post $before, string $cause ): void {
	4959	+ // Checked before any list is consulted. A draft save moves the
	4960	+ // draft's date and can match a list of any kind, which would send a
	4961	+ // change nobody can see to a site-wide purge.
	4962	+ if ( ! Affected_Pages::is_public( $post ) && ! ( $before instanceof \WP_Post && Affected_Pages::is_public( $before ) ) ) {
	4963	+ Affected_Pages::forget( (int) $post->ID );
	4964	+ return;
	4965	+ }
	4966	+ $fallback = '';
	4967	+ $urls = null;
	4968	+ if ( Affected_Pages::lists_changed_by( $post, $before ) ) {
	4969	+ $fallback = self::FALLBACK_THEME_LIST;
	4970	+ } else {
	4971	+ $urls = Affected_Pages::for_post( $post, $before );
	4972	+ // Read before forget(): a plain edit is judged on the terms the
	4973	+ // save replaced.
	4974	+ $listing = Listing_Pages::enabled() ? Listing_Pages::pages_for( $post, $before ) : array();
	4975	+ if ( null === $listing ) {
	4976	+ $fallback = self::FALLBACK_LISTING;
	4977	+ $urls = null;
	4978	+ } else {
	4979	+ // Pages the rules did not name. Nginx Helper's own purge does
	4980	+ // not reach them either, so a fallback they cause has to say so.
	4981	+ $extra = array_diff( $listing, $urls );
	4982	+ $urls = array_values( array_unique( array_merge( $urls, $listing ) ) );
	4983	+ if ( count( $urls ) > Affected_Pages::LIMIT ) {
	4984	+ $fallback = array() === $extra ? self::FALLBACK_LIMIT : self::FALLBACK_LISTING;
	4985	+ $urls = null;
	4986	+ }
	4987	+ }
	4988	+ }
	4989	+ Affected_Pages::forget( (int) $post->ID );
	4990	+
	4991	+ if ( is_array( $urls ) ) {
	4992	+ /**
	4993	+ * Filter the pages a post change clears.
	4994	+ *
	4995	+ * Return false to purge the whole site instead.
	4996	+ *
	4997	+ * @param string[]|false $urls Absolute URLs.
	4998	+ * @param \WP_Post $post The post that changed.
	4999	+ */
	5000	+ $urls = apply_filters( 'xspeed_purge_affected_pages', $urls, $post );
	5001	+ if ( ! is_array( $urls ) ) {
	5002	+ $fallback = self::FALLBACK_FILTER;
	5003	+ }
	5004	+ }
	5005	+
	5006	+ if ( ! is_array( $urls ) ) {
	5007	+ self::purge_all(
	5008	+ $cause,
	5009	+ null,
	5010	+ array(
	5011	+ 'scope' => 'site',
	5012	+ 'intent' => 'content',
	5013	+ 'urls' => array(),
	5014	+ 'fallback' => $fallback,
	5015	+ )
	5016	+ );
	5017	+ return;
	5018	+ }
	5019	+ if ( array() !== $urls ) {
	5020	+ self::purge_urls( $urls, $cause );
	5021	+ }
	5022	+ }
	5023	+
	5024	+ /**
	5025	+ * Delete/trash invalidation while the post type is still available.
	5026	+ * The local and server response-cache sweeps share the same site boundary.
	5027	+ *
	5028	+ * @param int $post_id Removed post ID.
	5029	+ * @param object|null $post Post object supplied by core when available.
	5030	+ */
	5031	+ public static function on_post_removed( $post_id, $post = null ): void {
	5032	+ if ( ! self::post_change_is_cacheable_content( $post_id, $post, 'remove' ) ) {
	5033	+ return;
	5034	+ }
	5035	+
	5036	+ $post_type = is_object( $post ) && isset( $post->post_type )
	5037	+ ? (string) $post->post_type
	5038	+ : (string) get_post_type( $post_id );
	5039	+
	5040	+ if ( ! in_array( $post_type, self::presentation_post_types(), true ) && self::narrow_purge_applies( $post_type ) ) {
	5041	+ $object = $post instanceof \WP_Post ? $post : get_post( (int) $post_id );
	5042	+ if ( $object instanceof \WP_Post ) {
	5043	+ if ( 'attachment' === $post_type ) {
	5044	+ // Its own page and the post it is attached to. Pages that
	5045	+ // show the file keep an <img> to a file that is gone either
	5046	+ // way: a fresh render prints the same tag.
	5047	+ $urls = array();
	5048	+ $link = get_permalink( $object );
	5049	+ if ( is_string( $link ) && '' !== $link ) {
	5050	+ $urls[] = $link;
	5051	+ }
	5052	+ $parent = $object->post_parent > 0 ? get_post( (int) $object->post_parent ) : null;
	5053	+ if ( $parent instanceof \WP_Post && 'publish' === $parent->post_status ) {
	5054	+ $parent_link = get_permalink( $parent );
	5055	+ if ( is_string( $parent_link ) && '' !== $parent_link ) {
	5056	+ $urls[] = $parent_link;
	5057	+ }
	5058	+ }
	5059	+ if ( array() !== $urls ) {
	5060	+ self::purge_urls( $urls, 'post-removed:attachment' );
	5061	+ }
	5062	+ return;
	5063	+ }
	5064	+ // Still published here: `before_delete_post` runs before the
	5065	+ // row goes. Trashing reaches the save path instead.
	5066	+ self::purge_post_change( $object, null, 'post-removed:' . $post_type );
	5067	+ return;
	5068	+ }
	5069	+ }
	5070	+
	5071	+ self::purge_all(
	5072	+ 'post-removed:' . $post_type,
	5073	+ null,
	5074	+ array(
	5075	+ 'scope' => 'site',
	5076	+ // Match on_save_post: a presentation type changes how pages
	5077	+ // render rather than what they say.
	5078	+ 'intent' => in_array( $post_type, self::presentation_post_types(), true )
	5079	+ ? 'presentation'
	5080	+ : 'content',
	5081	+ 'urls' => array(),
	5082	+ )
	5083	+ );
	5084	+ }
	5085	+
	5086	+ /** Purge site responses when moderation changes visible comments. */
	5087	+ public static function on_comment_status( $comment_id, $status = '' ): void {
	5088	+ $comment = function_exists( 'get_comment' ) ? get_comment( (int) $comment_id ) : null;
	5089	+ $post_id = is_object( $comment ) && isset( $comment->comment_post_ID ) ? (int) $comment->comment_post_ID : 0;
	5090	+ if ( $post_id < 1 || ! function_exists( 'get_permalink' ) ) {
	5091	+ return;
	5092	+ }
	5093	+ $url = get_permalink( $post_id );
	5094	+ if ( ! is_string( $url ) || '' === $url ) {
	5095	+ return;
	5096	+ }
	5097	+ $post = function_exists( 'get_post' ) ? get_post( $post_id ) : null;
	5098	+ $narrow = $post instanceof \WP_Post && self::narrow_purge_applies( (string) $post->post_type );
	5099	+ if ( $narrow && ! Affected_Pages::site_lists_comments() ) {
	5100	+ $urls = Affected_Pages::for_comment( $post );
	5101	+ if ( array() !== $urls ) {
	5102	+ self::purge_urls( $urls, 'comment-status:' . (string) $status );
	5103	+ }
	5104	+ return;
	5105	+ }
	5106	+ self::purge_all(
	5107	+ 'comment-status:' . (string) $status,
	5108	+ null,
	5109	+ array(
	5110	+ 'scope' => 'site',
	5111	+ 'intent' => 'content',
	5112	+ 'urls' => array(),
	5113	+ // Narrow purges apply to this post, so the site-wide purge is
	5114	+ // for a recent-comments list on pages the rules cannot name.
	5115	+ 'fallback' => $narrow ? self::FALLBACK_THEME_LIST : '',
	5116	+ )
	5117	+ );
	5118	+ }
	5119	+
	5120	+ /**
	5121	+ * comment_post → purge just the commented-on URL, and only once the
	5122	+ * comment is actually visible.
	5123	+ *
	5124	+ * A comment held for moderation changes nothing on the front end, and an
	5125	+ * approved one changes exactly one page — not the whole site. Product
	5126	+ * reviews are comments and guest reviews are on by default, so under the
	5127	+ * old wiring any visitor could flush a store's entire cache, repeatedly,
	5128	+ * with no account. (#243)
	5129	+ *
	5130	+ * @param int $comment_id New comment ID.
	5131	+ * @param int|string $approved 1 when approved, 0 when held, 'spam'.
	5132	+ * @param array $data Comment data.
	5133	+ */
	5134	+ public static function on_comment_post( $comment_id, $approved = 0, $data = array() ): void {
	5135	+ if ( 1 !== (int) $approved ) {
	5136	+ return;
	5137	+ }
	5138	+ $post_id = is_array( $data ) && isset( $data['comment_post_ID'] ) ? (int) $data['comment_post_ID'] : 0;
	5139	+ if ( $post_id < 1 ) {
	5140	+ return;
	5141	+ }
	5142	+ // With narrow purges on, the comment pages and comment feeds go too.
	5143	+ // No site-wide fallback here: a visitor's comment must never be able
	5144	+ // to clear the whole site (#243).
	5145	+ $post = function_exists( 'get_post' ) ? get_post( $post_id ) : null;
	5146	+ if ( $post instanceof \WP_Post && self::narrow_purge_applies( (string) $post->post_type ) ) {
	5147	+ $urls = Affected_Pages::for_comment( $post );
	5148	+ if ( array() !== $urls ) {
	5149	+ self::purge_urls( $urls, 'comment' );
	5150	+ }
	5151	+ return;
	5152	+ }
	5153	+ $url = get_permalink( $post_id );
	5154	+ if ( is_string( $url ) && '' !== $url ) {
	5155	+ self::purge_url( $url, 'comment' );
	5156	+ }
	5157	+ }
	5158	+
	5159	+ /**
	5160	+ * user_register / profile_update → purge only when the user can author
	5161	+ * content that appears on the front end.
	5162	+ *
	5163	+ * A customer registering at checkout changes no rendered page, and cannot
	5164	+ * change an enqueued asset — so it must not purge the cache, and must not
	5165	+ * rebuild the minified bundles. Checkout account-creation fired FOUR
	5166	+ * full-site purges plus four purge_minified() runs in a single request
	5167	+ * before this gate. (#243)
	5168	+ *
	5169	+ * @param int $user_id Affected user.
	5170	+ */
	5171	+ public static function on_user_change( $user_id ): void {
	5172	+ $user = function_exists( 'get_userdata' ) ? get_userdata( (int) $user_id ) : null;
	5173	+ if ( ! $user ) {
	5174	+ return;
	5175	+ }
	5176	+
	5177	+ // Only roles that can publish can change a rendered page. WooCommerce
	5178	+ // customers and WordPress subscribers cannot.
	5179	+ if ( ! user_can( $user, 'edit_posts' ) ) {
	5180	+ return;
	5181	+ }
	5182	+
	5183	+ $url = get_author_posts_url( (int) $user_id );
	5184	+ if ( is_string( $url ) && '' !== $url ) {
	5185	+ self::purge_url( $url, 'user' );
	5186	+ }
	5187	+ }
	5188	+
	5189	+ /**
	5190	+ * Purge everything a product's price / stock / sale state is rendered on.
	5191	+ *
	5192	+ * The product permalink is not enough: the shop archive and the product's
	5193	+ * category and tag archives render the same price and Sale! badge, and
	5194	+ * #242 reproduces all three going stale together.
	5195	+ *
	5196	+ * Accepts a product ID or a WC_Product. A variation resolves to its
	5197	+ * parent, which is the page that actually renders.
	5198	+ *
	5199	+ * @param int|object $product Product ID or WC_Product.
	5200	+ */
	5201	+ public static function purge_product( $product ): void {
	5202	+ $product_id = is_object( $product ) && method_exists( $product, 'get_id' )
	5203	+ ? (int) $product->get_id()
	5204	+ : (int) $product;
	5205	+ if ( $product_id < 1 ) {
	5206	+ return;
	5207	+ }
	5208	+
	5209	+ // Variations are never rendered on their own URL.
	5210	+ $parent = (int) wp_get_post_parent_id( $product_id );
	5211	+ if ( $parent > 0 ) {
	5212	+ $product_id = $parent;
	5213	+ }
	5214	+
	5215	+ // wp-admin's Update saves the product through WooCommerce inside the
	5216	+ // post's own save_post, and Cache::on_save_post() then clears the
	5217	+ // whole site for it, since products are in
	5218	+ // xspeed_site_wide_purge_post_types. Sending these pages first only
	5219	+ // purged them twice. A price or stock change made without a post
	5220	+ // save (an order, the REST API, `$product->save()`) still purges here.
	5221	+ if ( self::site_wide_save_under_way( $product_id ) ) {
	5222	+ return;
	5223	+ }
	5224	+
	5225	+ $urls = array();
	5226	+
	5227	+ $permalink = get_permalink( $product_id );
	5228	+ if ( is_string( $permalink ) && '' !== $permalink ) {
	5229	+ $urls[] = $permalink;
	5230	+ }
	5231	+
	5232	+ // The shop archive.
	5233	+ if ( function_exists( 'wc_get_page_id' ) ) {
	5234	+ $shop_id = (int) wc_get_page_id( 'shop' );
	5235	+ if ( $shop_id > 0 ) {
	5236	+ $shop_url = get_permalink( $shop_id );
	5237	+ if ( is_string( $shop_url ) && '' !== $shop_url ) {
	5238	+ $urls[] = $shop_url;
	5239	+ }
	5240	+ }
	5241	+ }
	5242	+
	5243	+ // Every category / tag archive this product appears on.
	5244	+ foreach ( array( 'product_cat', 'product_tag' ) as $taxonomy ) {
	5245	+ $terms = get_the_terms( $product_id, $taxonomy );
	5246	+ if ( ! is_array( $terms ) ) {
	5247	+ continue;
	5248	+ }
	5249	+ foreach ( $terms as $term ) {
	5250	+ $term_url = get_term_link( $term );
	5251	+ if ( is_string( $term_url ) && '' !== $term_url ) {
	5252	+ $urls[] = $term_url;
	5253	+ }
	5254	+ }
	5255	+ }
	5256	+
	5257	+ // The front page, when it is not the shop page but still lists
	5258	+ // products (a block/shortcode storefront).
	5259	+ $front_id = (int) get_option( 'page_on_front' );
	5260	+ if ( $front_id > 0 ) {
	5261	+ $front_url = get_permalink( $front_id );
	5262	+ if ( is_string( $front_url ) && '' !== $front_url ) {
	5263	+ $urls[] = $front_url;
	5264	+ }
	5265	+ }
	5266	+
	5267	+ /**
	5268	+ * Filter the URLs purged when a product changes.
	5269	+ *
	5270	+ * A storefront that renders products somewhere else — a landing page,
	5271	+ * a custom archive — can add its URLs here rather than falling back
	5272	+ * to purging the whole site.
	5273	+ *
	5274	+ * @param string[] $urls URLs about to be purged.
	5275	+ * @param int $product_id The product that changed.
	5276	+ */
	5277	+ $urls = (array) apply_filters( 'xspeed_purge_product_urls', $urls, $product_id );
	5278	+
	5279	+ $targets = array();
	5280	+ foreach ( $urls as $url ) {
	5281	+ if ( is_scalar( $url ) && '' !== (string) $url ) {
	5282	+ $targets[] = (string) $url;
	5283	+ }
	5284	+ }
	5285	+ if ( array() === $targets ) {
	5286	+ return;
	5287	+ }
	5288	+
	5289	+ // One batch, as a post save sends: one purge-log row and one event
	5290	+ // naming every page, each in the spelling WordPress links to. A
	5291	+ // purge_url() per page published every page in both spellings,
	5292	+ // which doubled the calls to Nginx Helper, and wrote no purge-log
	5293	+ // row when xSpeed's own page cache was off and no file went.
	5294	+ // purge_urls() leaves the object cache alone, which matters here:
	5295	+ // this runs on every stock change at checkout.
	5296	+ self::purge_urls( array_values( array_unique( $targets ) ), 'product', 'content' );
	5297	+ }
	5298	+
	5299	+ /**
	5300	+ * Posts whose save_post is running in this request, keyed by ID, with
	5301	+ * the post as saved. Set before any other save_post listener and cleared
	5302	+ * after the last one.
	5303	+ *
	5304	+ * @var array<int,\WP_Post|null>
	5305	+ */
	5306	+ private static $saves_under_way = array();
	5307	+
	5308	+ /**
	5309	+ * A post save has started.
	5310	+ *
	5311	+ * @param int $post_id Post ID.
	5312	+ * @param \WP_Post|null $post Post as saved.
	5313	+ */
	5314	+ public static function on_post_save_start( $post_id, $post = null ): void {
	5315	+ self::$saves_under_way[ (int) $post_id ] = is_object( $post ) ? $post : null;
	5316	+ }
	5317	+
	5318	+ /**
	5319	+ * A post save has finished.
	5320	+ *
	5321	+ * @param int $post_id Post ID.
	5322	+ */
	5323	+ public static function on_post_save_end( $post_id ): void {
	5324	+ unset( self::$saves_under_way[ (int) $post_id ] );
	5325	+ }
	5326	+
	5327	+ /**
	5328	+ * Whether a save_post for this post is running now and will end in
	5329	+ * on_save_post() clearing the whole site: the same checks it makes.
	5330	+ *
	5331	+ * @param int $post_id Post ID.
	5332	+ */
	5333	+ private static function site_wide_save_under_way( int $post_id ): bool {
	5334	+ if ( ! array_key_exists( $post_id, self::$saves_under_way ) ) {
	5335	+ return false;
	5336	+ }
	5337	+ $post = self::$saves_under_way[ $post_id ];
	5338	+ if ( ! self::post_change_is_cacheable_content( $post_id, $post, 'save' ) ) {
	5339	+ return false;
	5340	+ }
	5341	+ $post_type = is_object( $post ) && isset( $post->post_type )
	5342	+ ? (string) $post->post_type
	5343	+ : (string) get_post_type( $post_id );
	5344	+ if ( in_array( $post_type, self::presentation_post_types(), true ) ) {
	5345	+ return true;
	5346	+ }
	5347	+ return ! self::narrow_purge_applies( $post_type );
	5348	+ }
	5349	+
	5350	+ /** Test seam: forget the post saves in progress. */
	5351	+ public static function reset_saves_under_way(): void {
	5352	+ self::$saves_under_way = array();
	5353	+ }
	5354	+
	5355	+ /**
	5356	+ * Adapter for the WooCommerce stock actions that pass a product OBJECT
	5357	+ * where the status actions pass an ID.
	5358	+ *
	5359	+ * No longer wired to a hook (on_product_stock_set() is); kept because
	5360	+ * it is public.
	5361	+ *
	5362	+ * @param object $product WC_Product (or variation).
	5363	+ */
	5364	+ public static function purge_product_object( $product ): void {
	5365	+ self::purge_product( $product );
	5366	+ }
	5367	+
	5368	+ /**
	5369	+ * Stock writes wc_update_product_stock() has opened in this request,
	5370	+ * keyed by product ID: true once the save inside the write has purged.
	5371	+ *
	5372	+ * Entries are removed when the write's *_set_stock arrives, so this
	5373	+ * holds only writes still in progress.
	5374	+ *
	5375	+ * @var array<int,bool>
	5376	+ */
	5377	+ private static $stock_writes = array();
	5378	+
	5379	+ /**
	5380	+ * A CRUD save of a product: purge its pages.
	5381	+ *
	5382	+ * Inside a wc_update_product_stock() write, this is the save that write
	5383	+ * makes, so note that the write's pages are already purged.
	5384	+ *
	5385	+ * @param int|object $product Product ID (what WooCommerce passes) or WC_Product.
	5386	+ */
	5387	+ public static function on_product_saved( $product ): void {
	5388	+ $product_id = self::product_id_of( $product );
	5389	+ if ( isset( self::$stock_writes[ $product_id ] ) ) {
	5390	+ self::$stock_writes[ $product_id ] = true;
	5391	+ }
	5392	+ self::purge_product( $product );
	5393	+ }
	5394	+
	5395	+ /**
	5396	+ * wc_update_product_stock() is about to write a product's stock.
	5397	+ *
	5398	+ * @param object $product WC_Product (or variation) whose stock changes.
	5399	+ */
	5400	+ public static function on_product_stock_write( $product ): void {
	5401	+ $product_id = self::product_id_of( $product );
	5402	+ if ( $product_id > 0 ) {
	5403	+ self::$stock_writes[ $product_id ] = false;
	5404	+ }
	5405	+ }
	5406	+
	5407	+ /**
	5408	+ * A product's stock changed: purge its pages, unless the save inside
	5409	+ * the same wc_update_product_stock() call already did.
	5410	+ *
	5411	+ * That save fires woocommerce_update_product for the same product a
	5412	+ * moment earlier, with the stock already written, so purging again
	5413	+ * here cleared the same pages twice in one call. Only that pairing is
	5414	+ * skipped: the flag is set by the save inside this write and cleared
	5415	+ * here, so the next write, a status change or a later save in the same
	5416	+ * request purges as usual, and so does a write made with `$updating`
	5417	+ * set, which skips the save. A *_set_stock that arrives without
	5418	+ * *_before_set_stock (WooCommerce's data store fires one mid-save when
	5419	+ * a CRUD save changes the quantity) is not part of a write and purges.
	5420	+ *
	5421	+ * @param object $product WC_Product (or variation).
	5422	+ */
	5423	+ public static function on_product_stock_set( $product ): void {
	5424	+ $product_id = self::product_id_of( $product );
	5425	+ $purged = ! empty( self::$stock_writes[ $product_id ] );
	5426	+ unset( self::$stock_writes[ $product_id ] );
	5427	+ if ( $purged ) {
	5428	+ return;
	5429	+ }
	5430	+ self::purge_product( $product );
	5431	+ }
	5432	+
	5433	+ /** Test seam: forget the stock writes in progress. */
	5434	+ public static function reset_stock_writes(): void {
	5435	+ self::$stock_writes = array();
	5436	+ }
	5437	+
	5438	+ /**
	5439	+ * The ID of a product passed as an ID or as a WC_Product.
	5440	+ *
	5441	+ * @param int|object $product Product ID or WC_Product.
	5442	+ */
	5443	+ private static function product_id_of( $product ): int {
	5444	+ if ( is_object( $product ) ) {
	5445	+ return method_exists( $product, 'get_id' ) ? (int) $product->get_id() : 0;
	5446	+ }
	5447	+ return is_numeric( $product ) ? (int) $product : 0;
	5448	+ }
	5449	+
	5450	+ /**
	5451	+ * Re-entry guard for the purge-event contract.
	5452	+ *
	5453	+ * A listener on `xspeed_after_purge_url` legitimately purges its own
	5454	+ * layer, and a server-cache or CDN adapter that calls back into xSpeed
	5455	+ * while doing so re-enters this method — unbounded, because each pass
	5456	+ * looks like a fresh purge.
	5457	+ *
	5458	+ * A single global flag stops too much: a nested purge of a DIFFERENT URL is
	5459	+ * a real purge whose listeners must hear about it. But a per-request
	5460	+ * "already published" set stops too much in the other direction — a
	5461	+ * network purge loops every blog in one request, and on a subdirectory
	5462	+ * network they share a host, so blogs 2..N would be silently skipped. It
	5463	+ * also grows for the life of the process.
	5464	+ *
	5465	+ * So the guard tracks what is IN FLIGHT, not what has been published: a
	5466	+ * target is marked while its own dispatch is on the stack and unmarked
	5467	+ * when it returns. Re-entering the same target recurses, so it is refused;
	5468	+ * purging the same URL again later is a new event and publishes. The set
	5469	+ * is bounded by call depth rather than by how many URLs a request touches.
	5470	+ *
	5471	+ * @var array<string,bool>
	5472	+ */
	5473	+ private static $purge_events_in_flight = array();
	5474	+
	5475	+ /** Monotonic count used to detect whether a delegated purge published. */
	5476	+ private static $purge_event_sequence = 0;
	5477	+
	5478	+ /**
	5479	+ * Publish a purge event exactly once, with bounded arguments.
	5480	+ *
	5481	+ * Deliberately carries only what an integration needs to invalidate its
	5482	+ * own copy: the canonical URL (or null for a full purge), the site host,
	5483	+ * the cause label, and how many files went. No filesystem paths, no cache
	5484	+ * contents, no request headers, no user data. The URL query and caller-
	5485	+ * supplied cause may nevertheless contain sensitive text, so listeners
	5486	+ * must redact them in logs or unrelated destinations that do not need the
	5487	+ * exact cache key.
	5488	+ *
	5489	+ * A listener that throws must not take the purge down with it: the files
	5490	+ * are already gone by the time we get here, and an integration's bad day
	5491	+ * is not a reason to report a failed purge to the caller.
	5492	+ *
	5493	+ * @param string $hook Hook name to emit.
	5494	+ * @param array<string,mixed> $context Bounded context, see above.
	5495	+ */
	5496	+ private static function dispatch_purge_event( string $hook, array $context ): void {
	5497	+ if ( ! function_exists( 'do_action' ) ) {
	5498	+ return;
	5499	+ }
	5500	+ // Every event carries `fallback`, so one handler can read both the
	5501	+ // per-URL and the full-purge shape. '' unless a narrow purge fell
	5502	+ // back to the whole site.
	5503	+ $context['fallback'] = isset( $context['fallback'] ) && is_string( $context['fallback'] ) ? $context['fallback'] : '';
	5504	+ $target = $hook . '|' . ( isset( $context['url'] ) ? (string) $context['url'] : '' )
	5505	+ . '|' . ( isset( $context['host'] ) ? (string) $context['host'] : '' );
	5506	+ if ( isset( self::$purge_events_in_flight[ $target ] ) ) {
	5507	+ return;
	5508	+ }
	5509	+ self::$purge_events_in_flight[ $target ] = true;
	5510	+ ++self::$purge_event_sequence;
	5511	+
	5512	+ // Our own integrations get their own try. Sharing one with the public
	5513	+ // action below meant a listener on the extension seam could throw and
	5514	+ // take the contract event down with it — the mirror of the failure
	5515	+ // this separation exists to prevent.
	5516	+ try {
	5517	+ // Built-in server-cache integrations run FIRST, and by a direct
	5518	+ // call rather than as listeners on the action below.
	5519	+ //
	5520	+ // WordPress stops dispatching an action's remaining callbacks when
	5521	+ // one of them throws. As a listener, our LiteSpeed forwarding
	5522	+ // would then be skipped by any unrelated third-party callback that
	5523	+ // happened to be registered earlier and blew up — and the visible
	5524	+ // result is the worst kind: xSpeed reports a successful purge while
	5525	+ // the server keeps serving stale HTML. Shipped behaviour must not
	5526	+ // be hostage to a listener's bug.
	5527	+ self::forward_to_server_caches( $context );
	5528	+ } catch ( \Throwable $e ) {
	5529	+ self::log_purge_listener_error( $hook, $e );
	5530	+ }
	5531	+
	5532	+ // The edge xCloud provides, through its purge plugin. Direct for the
	5533	+ // same reason, and in its own try so a failure here cannot cost the
	5534	+ // host page caches above or the public action below.
	5535	+ try {
	5536	+ if ( class_exists( __NAMESPACE__ . '\\Managed_Edge_Purge' ) ) {
	5537	+ Managed_Edge_Purge::forward( $context );
	5538	+ }
	5539	+ } catch ( \Throwable $e ) {
	5540	+ self::log_purge_listener_error( $hook, $e );
	5541	+ }
	5542	+
	5543	+ try {
	5544	+ self::do_action_isolated( $hook, $context );
	5545	+ } catch ( \Throwable $e ) { // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedCatch
	5546	+ // Swallow: see docblock. The purge succeeded regardless.
	5547	+ self::log_purge_listener_error( $hook, $e );
	5548	+ } finally {
	5549	+ unset( self::$purge_events_in_flight[ $target ] );
	5550	+ }
	5551	+ }
	5552	+
	5553	+ /**
	5554	+ * Run every listener on a purge hook, isolating each from the others.
	5555	+ *
	5556	+ * `do_action()` dispatches callbacks in one loop, so the first one to
	5557	+ * throw takes every LATER listener down with it. On a purge that meant a
	5558	+ * failing CDN integration silently cancelled the ones queued behind it —
	5559	+ * and because the throw was swallowed to keep the purge itself succeeding,
	5560	+ * the user was told the clear worked while two edges were never touched.
	5561	+ * Invisible unless WP_DEBUG happened to be on. (QA #348)
	5562	+ *
	5563	+ * Each callback gets its own try/catch here, so one integration's bad day
	5564	+ * costs only that integration. Priority order is preserved. Falls back to
	5565	+ * a plain `do_action()` when the filter registry is not the shape we
	5566	+ * expect, so an unusual environment degrades to the old behaviour rather
	5567	+ * than skipping listeners entirely.
	5568	+ *
	5569	+ * @param string $hook Hook name to emit.
	5570	+ * @param mixed $arg Single argument passed to each listener.
	5571	+ */
	5572	+ public static function do_action_isolated( string $hook, $arg ): void {
	5573	+ global $wp_filter;
	5574	+
	5575	+ // Walking $wp_filter by hand and calling each callback directly was the
	5576	+ // obvious way to do this, and it was wrong: it bypasses WordPress, so
	5577	+ // `current_filter()` came back empty, `did_action()` stayed at 0, the
	5578	+ // `all` hook never fired, and Query Monitor and Debug Bar could not see
	5579	+ // the very contract this class publishes. A shared handler branching on
	5580	+ // current_filter() picked the wrong branch. (QA #348 round 2, issue 3)
	5581	+ //
	5582	+ // So let do_action() dispatch — WordPress keeps its bookkeeping — and
	5583	+ // isolate one level down instead: each registered callback is swapped
	5584	+ // for a wrapper that runs it inside a try/catch. One listener throwing
	5585	+ // then costs only that listener, which is the whole point, without
	5586	+ // costing the hook its identity.
	5587	+ if ( ! isset( $wp_filter[ $hook ] ) || ! ( $wp_filter[ $hook ] instanceof \WP_Hook ) ) {
	5588	+ do_action( $hook, $arg );
	5589	+ return;
	5590	+ }
	5591	+
	5592	+ $hook_object = $wp_filter[ $hook ];
	5593	+ $original = $hook_object->callbacks;
	5594	+ if ( ! is_array( $original ) || array() === $original ) {
	5595	+ do_action( $hook, $arg );
	5596	+ return;
	5597	+ }
	5598	+
	5599	+ $wrapped = array();
	5600	+ $restorations = array();
	5601	+ foreach ( $original as $priority => $group ) {
	5602	+ if ( ! is_array( $group ) ) {
	5603	+ $wrapped[ $priority ] = $group;
	5604	+ continue;
	5605	+ }
	5606	+ foreach ( $group as $id => $registered ) {
	5607	+ if ( ! isset( $registered['function'] ) || ! is_callable( $registered['function'] ) ) {
	5608	+ $wrapped[ $priority ][ $id ] = $registered;
	5609	+ continue;
	5610	+ }
	5611	+ $callback = $registered['function'];
	5612	+ $wrapper = static function ( ...$args ) use ( $callback, $hook ) {
	5613	+ try {
	5614	+ return $callback( ...$args );
	5615	+ } catch ( \Throwable $e ) {
	5616	+ self::log_purge_listener_error( $hook, $e );
	5617	+ return null;
	5618	+ }
	5619	+ };
	5620	+ $wrapped[ $priority ][ $id ] = array(
	5621	+ // Keep accepted_args: a listener registered for 0 or 1
	5622	+ // arguments must still be called the way it asked.
	5623	+ 'accepted_args' => $registered['accepted_args'] ?? 1,
	5624	+ 'function' => $wrapper,
	5625	+ );
	5626	+ $restorations[ $priority ][ $id ] = array(
	5627	+ 'original' => $registered,
	5628	+ 'wrapper' => $wrapper,
	5629	+ );
	5630	+ }
	5631	+ }
	5632	+
	5633	+ $hook_object->callbacks = $wrapped;
	5634	+ try {
	5635	+ do_action( $hook, $arg );
	5636	+ } finally {
	5637	+ // Restore only wrappers still present. Native add/remove operations
	5638	+ // performed by listeners must survive this temporary substitution.
	5639	+ foreach ( $restorations as $priority => $group ) {
	5640	+ foreach ( $group as $id => $restore ) {
	5641	+ $current = $hook_object->callbacks[ $priority ][ $id ]['function'] ?? null;
	5642	+ if ( $current === $restore['wrapper'] ) {
	5643	+ $hook_object->callbacks[ $priority ][ $id ] = $restore['original'];
	5644	+ }
	5645	+ }
	5646	+ }
	5647	+ }
	5648	+ }
	5649	+
	5650	+ /**
	5651	+ * Name a listener that threw, under WP_DEBUG only.
	5652	+ *
	5653	+ * Gated like the rest of Free's diagnostics: a third-party listener
	5654	+ * throwing on every purge must not fill a production log.
	5655	+ */
	5656	+ private static function log_purge_listener_error( string $hook, \Throwable $e ): void {
	5657	+ // An \Error — a TypeError from one of OUR listeners, say — is a bug
	5658	+ // rather than a runtime condition a third party imposed on us, and
	5659	+ // swallowing it silently in production turns it into a purge that
	5660	+ // quietly stops working. Those are logged whatever WP_DEBUG says;
	5661	+ // third-party \Exceptions stay gated so a noisy integration cannot
	5662	+ // fill a production log.
	5663	+ $always = $e instanceof \Error;
	5664	+ if ( ( $always || ( defined( 'WP_DEBUG' ) && WP_DEBUG ) ) && function_exists( 'error_log' ) ) {
	5665	+ // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log -- names a third-party listener that threw during a purge.
	5666	+ error_log( '[xspeed] a ' . $hook . ' listener threw: ' . $e->getMessage() );
	5667	+ }
	5668	+ }
	5669	+
	5670	+ /**
	5671	+ * Test seam: clear the in-flight set left behind by an aborted dispatch,
	5672	+ * and the record of which saves purged in this request.
	5673	+ */
	5674	+ public static function reset_purge_events(): void {
	5675	+ self::$purge_events_in_flight = array();
	5676	+ self::$purge_event_sequence = 0;
	5677	+ self::$saves_purged = array();
	5678	+ }
	5679	+
	5680	+ /**
	5681	+ * Hand the purge to the caches we ship integrations for.
	5682	+ *
	5683	+ * Isolated from the public action on purpose — see dispatch_purge_event().
	5684	+ * Guarded so a missing class (a partial upgrade, a stripped build) cannot
	5685	+ * turn a working purge into a fatal.
	5686	+ *
	5687	+ * @param array<string,mixed> $context Bounded purge context.
	5688	+ */
	5689	+ private static function forward_to_server_caches( array $context ): void {
	5690	+ if ( class_exists( __NAMESPACE__ . '\\Server_Caches' ) ) {
	5691	+ Server_Caches::forward( $context );
	5692	+ }
	5693	+ }
	5694	+
	5695	+ /**
	5696	+ * `host[:port]` for a cache key, from a parsed URL.
	5697	+ *
	5698	+ * The port is kept, because `cache_key()` hashes the raw `HTTP_HOST` and
	5699	+ * that carries `:8080` on any install not served from 80/443 — dropping it
	5700	+ * computed a different md5, found no file, and reported "already cold"
	5701	+ * while the page kept serving HIT.
	5702	+ *
	5703	+ * A port that is the DEFAULT for the scheme is dropped, though, because
	5704	+ * `HTTP_HOST` does not carry one: a browser sends `Host: site.com` for
	5705	+ * `https://site.com:443/`. Keeping it hashed `site.com:443` against a file
	5706	+ * stored under `site.com` — the same silent no-op in the other direction,
	5707	+ * and the one QA hit passing a canonical URL with the port spelled out.
	5708	+ * (QA #348)
	5709	+ *
	5710	+ * @param array<string,mixed> $parts Output of wp_parse_url().
	5711	+ */
	5712	+ private static function host_port_of( array $parts ): string {
	5713	+ if ( ! isset( $parts['host'] ) ) {
	5714	+ return '';
	5715	+ }
	5716	+ $host = strtolower( (string) $parts['host'] );
	5717	+ if ( '' === $host || ! isset( $parts['port'] ) ) {
	5718	+ return $host;
	5719	+ }
	5720	+ $port = (int) $parts['port'];
	5721	+ $scheme = isset( $parts['scheme'] ) ? strtolower( (string) $parts['scheme'] ) : '';
	5722	+ if ( ( 'https' === $scheme && 443 === $port ) || ( 'http' === $scheme && 80 === $port ) ) {
	5723	+ return $host;
	5724	+ }
	5725	+ return $host . ':' . $port;
	5726	+ }
	5727	+
	5728	+ public static function purge_url( string $url, string $cause = 'manual' ): int {
	5729	+ // A URL that names nothing is not a purge of everything. An empty or
	5730	+ // blank string used to fall through to the home_url() default below
	5731	+ // and clear the HOMEPAGE — so a third party calling
	5732	+ // `purge_url( get_permalink( $id ) )` on a post whose permalink came
	5733	+ // back empty silently purged the front page instead of nothing. The
	5734	+ // CLI and the MCP tool reject empties before reaching this, so only
	5735	+ // direct API callers were exposed, but they are exactly the audience
	5736	+ // this public contract is for. (QA #348)
	5737	+ if ( '' === trim( $url ) ) {
	5738	+ return 0;
	5739	+ }
	5740	+ // parse_url() can turn raw UTF-8 into underscores (it depends on the
	5741	+ // host's C library and locale), so a pasted `/關於我們/` is encoded
	5742	+ // first. normalize_path() below gives the same result either way.
	5743	+ $url = self::encode_non_ascii( $url );
	5744	+ $parts = function_exists( 'wp_parse_url' ) ? wp_parse_url( $url ) : parse_url( $url ); // phpcs:ignore WordPress.WP.AlternativeFunctions.parse_url_parse_url -- fallback for early-boot contexts only.
	5745	+ if ( ! is_array( $parts ) ) {
	5746	+ return 0;
	5747	+ }
	5748	+ // Absolute URLs are accepted only for HTTP response caches. Schemes such
	5749	+ // as ftp:, file: and javascript: can parse cleanly but do not name a page
	5750	+ // xSpeed or a server response cache can invalidate. A leading-slash path
	5751	+ // remains a supported site-relative target.
	5752	+ if ( isset( $parts['scheme'] ) && ! in_array( strtolower( (string) $parts['scheme'] ), array( 'http', 'https' ), true ) ) {
	5753	+ return 0;
	5754	+ }
	5755	+ if ( isset( $parts['scheme'] ) && empty( $parts['host'] ) ) {
	5756	+ return 0;
	5757	+ }
	5758	+ // Reject a string that parsed but is not a URL we can act on: no
	5759	+ // scheme AND no host AND no leading-slash path means something like
	5760	+ // `ht!tp://[[[` or a bare word, which parse_url() hands back as a
	5761	+ // relative "path". Forwarding that produced `purge_url(/ht!tp://[[[)`
	5762	+ // — a nonsense tag sent to LiteSpeed for every malformed call.
	5763	+ if ( ! isset( $parts['scheme'] ) && ! isset( $parts['host'] ) ) {
	5764	+ $raw = isset( $parts['path'] ) ? (string) $parts['path'] : '';
	5765	+ if ( '' === $raw || '/' !== $raw[0] ) {
	5766	+ return 0;
	5767	+ }
	5768	+ }
	5769	+ // Keep the port. `cache_key()` hashes the raw `HTTP_HOST`, which
	5770	+ // carries `:8080` on any install not served from 80/443 — while
	5771	+ // parse_url() splits the port into its own component, so a purge that
	5772	+ // used the bare host computed a different md5, found no file, and
	5773	+ // reported "already cold". A silent no-op: the page kept serving HIT
	5774	+ // until its TTL ran out. Intranet installs, panel hosts on :8443 and
	5775	+ // proxies that forward `Host: site.com:8080` all hit this.
	5776	+ // A scheme-less `site.test:443/page/` is a supported explicit-host
	5777	+ // target. Infer a scheme only when it names THIS site's hostname: then
	5778	+ // its explicit default port is the same origin and the same local cache
	5779	+ // key. Never apply this to another host or to a non-default port.
	5780	+ if ( ! isset( $parts['scheme'] ) && isset( $parts['host'], $parts['port'] ) && function_exists( 'home_url' ) ) {
	5781	+ $home = function_exists( 'wp_parse_url' ) ? wp_parse_url( home_url( '/' ) ) : parse_url( home_url( '/' ) ); // phpcs:ignore WordPress.WP.AlternativeFunctions.parse_url_parse_url -- see above.
	5782	+ if ( is_array( $home ) && ! empty( $home['host'] ) && ! empty( $home['scheme'] )
	5783	+ && strtolower( (string) $home['host'] ) === strtolower( (string) $parts['host'] )
	5784	+ ) {
	5785	+ $home_scheme = strtolower( (string) $home['scheme'] );
	5786	+ $port = (int) $parts['port'];
	5787	+ $home_port = isset( $home['port'] )
	5788	+ ? (int) $home['port']
	5789	+ : ( 'https' === $home_scheme ? 443 : ( 'http' === $home_scheme ? 80 : 0 ) );
	5790	+ if ( $home_port === $port
	5791	+ && ( ( 'https' === $home_scheme && 443 === $port ) || ( 'http' === $home_scheme && 80 === $port ) )
	5792	+ ) {
	5793	+ $parts['scheme'] = $home_scheme;
	5794	+ }
	5795	+ }
	5796	+ }
	5797	+ $host = self::host_port_of( $parts );
	5798	+ if ( '' === $host && function_exists( 'home_url' ) ) {
	5799	+ $home = function_exists( 'wp_parse_url' ) ? wp_parse_url( home_url( '/' ) ) : parse_url( home_url( '/' ) ); // phpcs:ignore WordPress.WP.AlternativeFunctions.parse_url_parse_url -- see above.
	5800	+ if ( is_array( $home ) ) {
	5801	+ $host = self::host_port_of( $home );
	5802	+ }
	5803	+ }
	5804	+ if ( '' === $host ) {
	5805	+ return 0;
	5806	+ }
	5807	+ $path = isset( $parts['path'] ) ? (string) $parts['path'] : '/';
	5808	+ $path = '/' . ltrim( $path, '/' );
	5809	+ if ( false !== strpos( $path, '..' ) ) {
	5810	+ return 0;
	5811	+ }
	5812	+ // Same spelling cache_key() hashes, so a permalink, the same URL with
	5813	+ // `%E7` capitals, and a pasted `/關於我們/` all find the entry. The
	5814	+ // purge event below keeps the caller's spelling and adds the others
	5815	+ // (see escape_spellings()).
	5816	+ $key_path = self::normalize_path( $path );
	5817	+
	5818	+ // The cache key preserves REQUEST_URI's trailing-slash form, so
	5819	+ // purge both. Root stays a single '/'.
	5820	+ $forms = array( $key_path );
	5821	+ if ( '/' !== $key_path ) {
	5822	+ $forms[] = rtrim( $key_path, '/' );
	5823	+ $forms[] = rtrim( $key_path, '/' ) . '/';
	5824	+ }
	5825	+ $forms = array_unique( $forms );
	5826	+
	5827	+ /*
	5828	+ * Entries live under the bucket they were written for, and this URL's
	5829	+ * site may not be the one serving THIS request (a cross-site purge on
	5830	+ * multisite, WP-CLI, or cron). Build the directory from the URL's own
	5831	+ * host AND path. (#6)
	5832	+ *
	5833	+ * Host alone is wrong on a subdirectory network: `store()` wrote to
	5834	+ * `<host>/<prefix>/`, so looking in `<host>/` found nothing and the
	5835	+ * call reported "already cold" while the page kept serving HIT — a
	5836	+ * false success, which is worse than an error. The prefix has to come
	5837	+ * from the URL being purged rather than from the current blog, because
	5838	+ * the caller is usually purging some OTHER site. (QA B2 on #166)
	5839	+ */
	5840	+ $base = XSPEED_CACHE_DIR . '/' . self::bucket_for_url( $host, $path );
	5841	+
850	5842	$count = 0;
851		- if ( is_dir( XSPEED_CACHE_DIR ) ) {
852		- $files = glob( XSPEED_CACHE_DIR . '/*.html' );
853		- if ( $files ) {
854		- $count = count( $files );
855		- foreach ( $files as $f ) {
856		- wp_delete_file( $f );
	5843	+ foreach ( $forms as $uri ) {
	5844	+ // '' = mobile_separate off; '|m' / '|d' = the device buckets.
	5845	+ foreach ( array( '', '|m', '|d' ) as $device ) {
	5846	+ $key = md5( $host . $uri . $device );
	5847	+ $file = $base . '/' . $key . '.html';
	5848	+ if ( is_file( $file ) ) {
	5849	+ wp_delete_file( $file );
	5850	+ ++$count;
857	5851	}
	5852	+ foreach ( array( $base . '/' . $key . '.meta', $file . '.br', self::brotli_size_sidecar( $file . '.br' ) ) as $sidecar ) {
	5853	+ if ( is_file( $sidecar ) ) {
	5854	+ wp_delete_file( $sidecar );
	5855	+ }
	5856	+ }
858	5857	}
859		- // Remove the .meta sidecars (content-type for feeds/sitemaps)
860		- // alongside their .html entries. Not counted — they're not
861		- // cache "pages", just per-entry metadata.
862		- $meta = glob( XSPEED_CACHE_DIR . '/*.meta' );
863		- if ( $meta ) {
864		- foreach ( $meta as $m ) {
865		- wp_delete_file( $m );
	5858	+ }
	5859	+
	5860	+ // Static tree (served directly by the nginx/.htaccess rewrite).
	5861	+ // The static tree stores decoded names (see static_path()). A path
	5862	+ // static_path() refuses was never written there.
	5863	+ $rel = self::static_path( $key_path );
	5864	+ if ( defined( 'XSPEED_CACHE_STATIC_DIR' ) && null !== $rel ) {
	5865	+ // Same transform the write used — `localhost:8080` files under
	5866	+ // `localhost8080`, so the bare host found nothing here either.
	5867	+ $dir = rtrim( XSPEED_CACHE_STATIC_DIR, '/' ) . '/' . self::static_host_dir( $host ) . $rel;
	5868	+ $file = $dir . '/index.html';
	5869	+ if ( is_file( $file ) ) {
	5870	+ wp_delete_file( $file );
	5871	+ ++$count;
	5872	+ }
	5873	+ foreach ( array( $file . '.br', self::brotli_size_sidecar( $file . '.br' ) ) as $sidecar ) {
	5874	+ if ( is_file( $sidecar ) ) {
	5875	+ wp_delete_file( $sidecar );
866	5876	}
867	5877	}
868		- // Remove precompressed siblings (e.g. <key>.html.br from the Pro
869		- // Brotli module). Not counted — same as .meta. Without this a
870		- // purge leaves stale .br bodies behind: disk bloat, and a
871		- // staleness window if precompression is later disabled.
872		- $br = glob( XSPEED_CACHE_DIR . '/*.br' );
873		- if ( $br ) {
874		- foreach ( $br as $b ) {
875		- wp_delete_file( $b );
	5878	+ }
	5879	+
	5880	+ /*
	5881	+ * The per-URL purge event is published by `dispatch_purge_event()`
	5882	+ * below, NOT here.
	5883	+ *
	5884	+ * This branch used to publish it itself, with a raw `do_action` and a
	5885	+ * `{scope,url,urls,cause,count}` payload. #348 then landed the purge
	5886	+ * contract on dev: a canonical URL, `removed` rather than `count`,
	5887	+ * `intent`, per-listener isolation, and an in-flight guard so a
	5888	+ * listener that purges its own layer cannot re-enter the event.
	5889	+ *
	5890	+ * Keeping both meant every per-URL purge fired TWICE, in two payload
	5891	+ * shapes, and the raw call bypassed the guard — so a listener that
	5892	+ * called back into `purge_url()` recursed until the process ran out
	5893	+ * of memory. `CachePurgeEventContractTest::
	5894	+ * test_a_listener_re_purging_the_same_url_does_not_recurse` is what
	5895	+ * caught it, and it arrived from dev with the contract it defends.
	5896	+ *
	5897	+ * The contract wins: it is a superset of what this published, and it
	5898	+ * is what the LiteSpeed and nginx adapters are written against.
	5899	+ */
	5900	+
	5901	+ // purge_url_reported() writes this row itself once the event has
	5902	+ // gone out, so it can name the caches the purge was sent to.
	5903	+ if ( $count > 0 && null === self::$url_batch && null === self::$reported_url_purge ) {
	5904	+ Cache_Inventory::invalidate();
	5905	+ Activity_Log::record(
	5906	+ 'cache_purge_url',
	5907	+ sprintf(
	5908	+ /* translators: 1: cause of the purge, 2: URL or path, 3: number of files removed. */
	5909	+ __( 'Purged one URL (%1$s) — %2$s, %3$d file(s) removed', 'xspeed' ),
	5910	+ $cause,
	5911	+ $host . $path,
	5912	+ $count
	5913	+ ),
	5914	+ Activity_Log::INFO
	5915	+ );
	5916	+ }
	5917	+
	5918	+ /**
	5919	+ * Fires after one URL's cached copy has been purged.
	5920	+ *
	5921	+ * The single-URL counterpart to `xspeed_after_purge_all`. Subscribe
	5922	+ * here to invalidate a cache xSpeed does not own — a server-level
	5923	+ * cache such as LiteSpeed's LSCache, a reverse proxy, or a CDN — for
	5924	+ * the same URL.
	5925	+ *
	5926	+ * Only fires when the purge actually ran. A malformed URL, a URL with
	5927	+ * no resolvable host, or a traversal attempt returns earlier and
	5928	+ * publishes nothing, so a listener can treat this as "xSpeed purged
	5929	+ * this URL" rather than "xSpeed was asked to". `removed` may legitimately
	5930	+ * be 0: the URL was not in xSpeed's cache, which says nothing about
	5931	+ * whether it is in yours.
	5932	+ *
	5933	+ * Fires at most once per purge. A listener that calls back into
	5934	+ * xSpeed's purge API will not re-enter this event.
	5935	+ *
	5936	+ * @since 1.2.3
	5937	+ *
	5938	+ * @param array $context {
	5939	+ * Bounded description of the purge. URL queries and caller-supplied
	5940	+ * causes can contain sensitive values and are not logging fields.
	5941	+ *
	5942	+ * @type string $url Canonical scheme://host/path[?query] of the purged URL.
	5943	+ * The query is preserved because caches in front
	5944	+ * commonly key on it; xSpeed's own sweep is
	5945	+ * path-based, so `removed` describes that.
	5946	+ * @type string $host Host (with port when non-standard).
	5947	+ * @type string $path Path component, leading slash.
	5948	+ * @type string $cause Short label for who asked. See purge_all().
	5949	+ * @type int $removed Number of cache files removed.
	5950	+ * @type string $scope Actionable adapter scope: `urls`.
	5951	+ * @type string $intent Why responses changed: `content`.
	5952	+ * @type string[] $urls Exact response URLs to invalidate: the
	5953	+ * canonical URL first, then the same URL
	5954	+ * with the other trailing-slash spelling
	5955	+ * (none for the root). A path with
	5956	+ * percent-escapes adds the same pair with
	5957	+ * the escapes in lower case and in upper
	5958	+ * case, where those differ from it.
	5959	+ * @type string $fallback Always '' on this event. Present so both
	5960	+ * purge events share one shape; see
	5961	+ * `xspeed_after_purge`.
	5962	+ * }
	5963	+ */
	5964	+ $query = isset( $parts['query'] ) ? (string) $parts['query'] : '';
	5965	+ $url_scheme = isset( $parts['scheme'] ) ? strtolower( (string) $parts['scheme'] ) : '';
	5966	+ $canonical_url = self::canonical_purge_url( $host, $path, $query, $url_scheme );
	5967	+ // Every spelling the local sweep above cleared, because a cache in
	5968	+ // front keys each one on its own. Visitors reach a page as `/about/`
	5969	+ // while a caller often passes `/about` (or the reverse), and a
	5970	+ // non-ASCII page as `/%E9%97%9C…/` while get_permalink() passes
	5971	+ // `/%e9%97%9c…/`. Publishing one spelling left the edge serving the
	5972	+ // other, usually the one visitors actually use.
	5973	+ $event_urls = array();
	5974	+ foreach ( self::escape_spellings( $path ) as $spelling ) {
	5975	+ $event_urls[] = self::canonical_purge_url( $host, $spelling, $query, $url_scheme );
	5976	+ if ( '/' === $spelling ) {
	5977	+ continue;
	5978	+ }
	5979	+ $other = '/' === substr( $spelling, -1 ) ? rtrim( $spelling, '/' ) : $spelling . '/';
	5980	+ if ( '' !== $other ) {
	5981	+ $event_urls[] = self::canonical_purge_url( $host, $other, $query, $url_scheme );
	5982	+ }
	5983	+ }
	5984	+ // Inside purge_urls(): the batch publishes one event for every URL,
	5985	+ // in the trailing-slash form it was given. The local sweep above still
	5986	+ // took both forms. Escape spellings are still added, because the other
	5987	+ // escape case does not redirect: a cache in front keeps the browser's
	5988	+ // `%E9…` copy apart from the permalink's `%e9…` one.
	5989	+ if ( null !== self::$url_batch ) {
	5990	+ if ( '' === self::$url_batch['url'] ) {
	5991	+ self::$url_batch['url'] = $canonical_url;
	5992	+ self::$url_batch['host'] = $host;
	5993	+ self::$url_batch['path'] = $path;
	5994	+ }
	5995	+ self::$url_batch['removed'] += $count;
	5996	+ foreach ( self::escape_spellings( $path ) as $spelling ) {
	5997	+ self::$url_batch['urls'][ self::canonical_purge_url( $host, $spelling, $query, $url_scheme ) ] = true;
	5998	+ }
	5999	+ return $count;
	6000	+ }
	6001	+
	6002	+ self::dispatch_purge_event(
	6003	+ 'xspeed_after_purge_url',
	6004	+ array(
	6005	+ 'url' => $canonical_url,
	6006	+ 'host' => $host,
	6007	+ 'path' => $path,
	6008	+ 'cause' => $cause,
	6009	+ 'removed' => $count,
	6010	+ 'scope' => 'urls',
	6011	+ 'intent' => 'content',
	6012	+ 'urls' => array_values( array_unique( $event_urls ) ),
	6013	+ 'fallback' => '',
	6014	+ )
	6015	+ );
	6016	+
	6017	+ return $count;
	6018	+ }
	6019	+
	6020	+ /**
	6021	+ * The batch purge_urls() is collecting, or null outside one.
	6022	+ *
	6023	+ * @var array{url:string,host:string,path:string,removed:int,urls:array<string,bool>}|null
	6024	+ */
	6025	+ private static $url_batch = null;
	6026	+
	6027	+ /**
	6028	+ * The caches in front of PHP that took a purge while a report is open,
	6029	+ * keyed by label, or null when no report is open.
	6030	+ *
	6031	+ * @var array<string,bool>|null
	6032	+ */
	6033	+ private static $forward_report = null;
	6034	+
	6035	+ /**
	6036	+ * Note that a purge was handed to a cache in front of PHP: a server
	6037	+ * cache, a host cache, a CDN or an edge.
	6038	+ *
	6039	+ * The built-in adapters call this when they accept a purge, whether
	6040	+ * they send it now or queue it for the end of the request. A third-party
	6041	+ * adapter listening on `xspeed_after_purge_url` may call it too, so an
	6042	+ * operator's purge names it. Does nothing unless a caller opened a
	6043	+ * report with purge_url_reported().
	6044	+ *
	6045	+ * @param string $layer Name to show, such as "Nginx Helper".
	6046	+ */
	6047	+ public static function note_purge_forwarded( string $layer ): void {
	6048	+ if ( null === self::$forward_report || '' === trim( $layer ) ) {
	6049	+ return;
	6050	+ }
	6051	+ self::$forward_report[ $layer ] = true;
	6052	+ }
	6053	+
	6054	+ /**
	6055	+ * Run a purge and collect the caches in front of PHP it was sent to.
	6056	+ *
	6057	+ * @param callable $purge The purge to run.
	6058	+ * @return array{result:mixed,forwarded:string[]}
	6059	+ */
	6060	+ public static function report_forwarding( callable $purge ): array {
	6061	+ $outer = self::$forward_report;
	6062	+ self::$forward_report = array();
	6063	+ try {
	6064	+ $result = $purge();
	6065	+ } finally {
	6066	+ $forwarded = array_keys( (array) self::$forward_report );
	6067	+ self::$forward_report = null === $outer ? null : $outer + (array) self::$forward_report;
	6068	+ }
	6069	+ return array(
	6070	+ 'result' => $result,
	6071	+ 'forwarded' => $forwarded,
	6072	+ );
	6073	+ }
	6074	+
	6075	+ /**
	6076	+ * Set while purge_url_reported() runs, so purge_url() leaves the
	6077	+ * purge-log row to it. Null otherwise.
	6078	+ *
	6079	+ * @var bool|null
	6080	+ */
	6081	+ private static $reported_url_purge = null;
	6082	+
	6083	+ /**
	6084	+ * Purge one URL for an operator, and say where the purge went.
	6085	+ *
	6086	+ * purge_url() writes a purge-log row only when it removed a local file,
	6087	+ * because Pro's beacons call it on visitor requests. On a site whose
	6088	+ * pages are held only by a server cache (xSpeed's page cache off, nginx
	6089	+ * in front) an operator's purge then removed nothing locally, was sent
	6090	+ * to the server cache, and left no row and an "already cold" answer.
	6091	+ * This adds the row in that case. The CLI, the MCP tool (which runs the
	6092	+ * CLI) and the admin "Purge this URL" link use it.
	6093	+ *
	6094	+ * @param string $url Absolute URL or site-relative path.
	6095	+ * @param string $cause Who asked, for the purge log.
	6096	+ * @return array{removed:int,forwarded:string[]} Files removed here, and
	6097	+ * the caches the purge was sent to.
	6098	+ */
	6099	+ public static function purge_url_reported( string $url, string $cause ): array {
	6100	+ $outer = self::$reported_url_purge;
	6101	+ self::$reported_url_purge = true;
	6102	+ try {
	6103	+ $run = self::report_forwarding(
	6104	+ static function () use ( $url, $cause ): int {
	6105	+ return self::purge_url( $url, $cause );
876	6106	}
	6107	+ );
	6108	+ } finally {
	6109	+ self::$reported_url_purge = $outer;
	6110	+ }
	6111	+ $removed = (int) $run['result'];
	6112	+ $forwarded = $run['forwarded'];
	6113	+
	6114	+ if ( $removed > 0 ) {
	6115	+ Cache_Inventory::invalidate();
	6116	+ $message = array() === $forwarded
	6117	+ ? sprintf(
	6118	+ /* translators: 1: cause of the purge, 2: URL or path, 3: number of files removed. */
	6119	+ __( 'Purged one URL (%1$s) — %2$s, %3$d file(s) removed', 'xspeed' ),
	6120	+ $cause,
	6121	+ $url,
	6122	+ $removed
	6123	+ )
	6124	+ : sprintf(
	6125	+ /* translators: 1: cause of the purge, 2: URL or path, 3: number of files removed, 4: caches the purge was sent to. */
	6126	+ __( 'Purged one URL (%1$s) — %2$s, %3$d file(s) removed, sent to %4$s', 'xspeed' ),
	6127	+ $cause,
	6128	+ $url,
	6129	+ $removed,
	6130	+ implode( ', ', $forwarded )
	6131	+ );
	6132	+ Activity_Log::record( 'cache_purge_url', $message, Activity_Log::INFO );
	6133	+ } elseif ( array() !== $forwarded ) {
	6134	+ Activity_Log::record(
	6135	+ 'cache_purge_url',
	6136	+ sprintf(
	6137	+ /* translators: 1: cause of the purge, 2: URL or path, 3: caches the purge was sent to. */
	6138	+ __( 'Purged one URL (%1$s): %2$s, 0 file(s) removed here, sent to %3$s', 'xspeed' ),
	6139	+ $cause,
	6140	+ $url,
	6141	+ implode( ', ', $forwarded )
	6142	+ ),
	6143	+ Activity_Log::INFO
	6144	+ );
	6145	+ }
	6146	+
	6147	+ return array(
	6148	+ 'removed' => $removed,
	6149	+ 'forwarded' => $forwarded,
	6150	+ );
	6151	+ }
	6152	+
	6153	+ /**
	6154	+ * Purge several URLs as one purge: each URL's local copy goes as in
	6155	+ * purge_url(), then ONE `xspeed_after_purge_url` event carries every URL.
	6156	+ *
	6157	+ * One event rather than one per URL, so the purge log gets one line, an
	6158	+ * edge gets one batch, and a listener that counts purges counts one. The
	6159	+ * event is the same contract purge_url() publishes: `scope` is `urls`,
	6160	+ * `url` is the first URL, `urls` is all of them.
	6161	+ *
	6162	+ * Unlike purge_url(), `urls` holds each URL in the spelling it was given
	6163	+ * and not the other trailing-slash spelling too. Callers pass WordPress's
	6164	+ * own links (get_permalink(), get_term_link() and the like), which are
	6165	+ * the spelling visitors reach; the other spelling redirects to it, so a
	6166	+ * cache in front holds nothing stale under it. Both spellings doubled the
	6167	+ * list: a typical save named 34 pages as 67 URLs, past xCloud's 50-URL
	6168	+ * batch and the Hub's 30 per call. xSpeed's own sweep still removes both
	6169	+ * spellings of each. The escape spellings (escape_spellings()) are still
	6170	+ * listed, because `%E9…` does not redirect to `%e9…`; they add URLs only
	6171	+ * for a path with percent-escapes.
	6172	+ *
	6173	+ * The object cache is left alone, as purge_url() leaves it. WordPress
	6174	+ * already drops a post's own entries when the post, its terms or its
	6175	+ * comments change (clean_post_cache() and the like), so a flush here
	6176	+ * cleared nothing stale. What it did do: an approved visitor comment
	6177	+ * emptied Redis or Memcached for the whole site, as often as a visitor
	6178	+ * cared to comment. With a persistent object cache, transients live
	6179	+ * there too, so a flush could also drop work a purge listener had just
	6180	+ * queued in one. purge_all() still flushes.
	6181	+ *
	6182	+ * @param string[] $urls Absolute URLs or site-relative paths.
	6183	+ * @param string $cause Who asked, for the purge log.
	6184	+ * @param string $intent Why responses changed: `content` by default.
	6185	+ * @return int Cache files removed.
	6186	+ */
	6187	+ public static function purge_urls( array $urls, string $cause = 'manual', string $intent = 'content' ): int {
	6188	+ $outer = self::$url_batch;
	6189	+ self::$url_batch = array(
	6190	+ 'url' => '',
	6191	+ 'host' => '',
	6192	+ 'path' => '',
	6193	+ 'removed' => 0,
	6194	+ 'urls' => array(),
	6195	+ );
	6196	+ try {
	6197	+ foreach ( array_unique( array_filter( $urls, 'is_string' ) ) as $url ) {
	6198	+ self::purge_url( $url, $cause );
877	6199	}
	6200	+ } finally {
	6201	+ $batch = self::$url_batch;
	6202	+ self::$url_batch = $outer;
878	6203	}
	6204	+ if ( '' === $batch['url'] ) {
	6205	+ return 0;
	6206	+ }
	6207	+
	6208	+ Cache_Inventory::invalidate();
	6209	+ self::update_stats( array( 'last_purge' => time() ) );
	6210	+ // Same type as one URL's purge, so the purge log and the dashboard's
	6211	+ // drill-down list it with the others.
	6212	+ Activity_Log::record(
	6213	+ 'cache_purge_url',
	6214	+ sprintf(
	6215	+ /* translators: 1: number of pages, 2: cause of the purge, 3: number of files removed. */
	6216	+ _n( 'Purged %1$d page (%2$s), %3$d file(s) removed', 'Purged %1$d pages (%2$s), %3$d file(s) removed', count( $urls ), 'xspeed' ),
	6217	+ count( $urls ),
	6218	+ $cause,
	6219	+ $batch['removed']
	6220	+ ),
	6221	+ Activity_Log::INFO
	6222	+ );
	6223	+
	6224	+ self::dispatch_purge_event(
	6225	+ 'xspeed_after_purge_url',
	6226	+ array(
	6227	+ 'url' => $batch['url'],
	6228	+ 'host' => $batch['host'],
	6229	+ 'path' => $batch['path'],
	6230	+ 'cause' => $cause,
	6231	+ 'removed' => $batch['removed'],
	6232	+ 'scope' => 'urls',
	6233	+ 'intent' => $intent,
	6234	+ 'urls' => array_keys( $batch['urls'] ),
	6235	+ 'fallback' => '',
	6236	+ )
	6237	+ );
	6238	+
	6239	+ return $batch['removed'];
	6240	+ }
	6241	+
	6242	+ /** Host this site's purge is scoped to, for the purge-event context. */
	6243	+ private static function current_purge_host(): string {
	6244	+ if ( ! function_exists( 'home_url' ) ) {
	6245	+ return '';
	6246	+ }
	6247	+ $home = function_exists( 'wp_parse_url' ) ? wp_parse_url( home_url( '/' ) ) : parse_url( home_url( '/' ) ); // phpcs:ignore WordPress.WP.AlternativeFunctions.parse_url_parse_url -- host only.
	6248	+ if ( ! is_array( $home ) || empty( $home['host'] ) ) {
	6249	+ return '';
	6250	+ }
	6251	+ // Same default-port normalisation as purge_url(): a site whose
	6252	+ // home_url() carries `:443` (normal behind a proxy) otherwise stamps
	6253	+ // every full-purge event with a host that matches none of its own
	6254	+ // URLs, so the LiteSpeed forward stood down site-wide. (QA #348)
	6255	+ return self::host_port_of( $home );
	6256	+ }
	6257	+
	6258	+ /**
	6259	+ * Rebuild the canonical URL a purge applied to.
	6260	+ *
	6261	+ * Built from the parts the purge itself used, so a listener is told the
	6262	+ * URL we acted on rather than the string the caller happened to pass —
	6263	+ * those differ whenever the caller supplied a site-relative path, a
	6264	+ * different scheme, or a query string the cache key ignores.
	6265	+ */
	6266	+ private static function canonical_purge_url( string $host, string $path, string $query = '', string $url_scheme = '' ): string {
	6267	+ // The purged URL's own scheme wins. purge_url() explicitly supports
	6268	+ // cross-site purges (multisite, WP-CLI, cron), where composing the
	6269	+ // current site's scheme onto another site's host builds a URL that was
	6270	+ // never served — and a CDN listener then purges the wrong key and
	6271	+ // reports success.
	6272	+ if ( '' !== $url_scheme ) {
	6273	+ return $url_scheme . '://' . $host . $path . ( '' !== $query ? '?' . $query : '' );
	6274	+ }
	6275	+ $scheme = function_exists( 'is_ssl' ) && is_ssl() ? 'https' : 'http';
	6276	+ if ( function_exists( 'home_url' ) ) {
	6277	+ $home = function_exists( 'wp_parse_url' ) ? wp_parse_url( home_url( '/' ) ) : parse_url( home_url( '/' ) ); // phpcs:ignore WordPress.WP.AlternativeFunctions.parse_url_parse_url -- scheme only.
	6278	+ if ( is_array( $home ) && ! empty( $home['scheme'] ) ) {
	6279	+ $scheme = (string) $home['scheme'];
	6280	+ }
	6281	+ }
	6282	+ // The query is carried even though OUR sweep above is path-based.
	6283	+ // Caches in front commonly key on the full request line — LiteSpeed
	6284	+ // tags `/shop/?page=2` separately from `/shop/` — so publishing the
	6285	+ // bare path would have a listener confidently purge the wrong entry
	6286	+ // and report success. Telling it exactly what was asked for lets it
	6287	+ // act correctly; `removed` still describes only what WE removed.
	6288	+ return $scheme . '://' . $host . $path . ( '' !== $query ? '?' . $query : '' );
	6289	+ }
	6290	+
	6291	+ /**
	6292	+ * Sweep this site's cache files.
	6293	+ *
	6294	+ * On multisite every blog shares one cache directory, so an unscoped
	6295	+ * sweep here took the whole network cold — one subsite's settings save
	6296	+ * or post publish rebuilt every other site from PHP. Entries are stored
	6297	+ * per host (see host_dir()), and the sweep is scoped to match, so a
	6298	+ * purge originating on site-a leaves site-b's cache warm. (#6)
	6299	+ *
	6300	+ * Clears the files only: the flat tree, the static tree, the REST
	6301	+ * responses and the minified assets. The object-cache flush, the stats
	6302	+ * update, `xspeed_after_purge_all`, the `xspeed_after_purge` contract
	6303	+ * event and the log entry live in purge_all(), which is still the entry
	6304	+ * point for every existing caller. Split out so `wp xspeed purge` can
	6305	+ * report the local sweep as one line item and the object cache as
	6306	+ * another, each with its own status — see Purge_Runner.
	6307	+ *
	6308	+ * @param string|null $host Host to purge. Defaults to the current site.
	6309	+ * Pass '*' to sweep the ENTIRE tree — network
	6310	+ * admin's "purge all sites", and the migration
	6311	+ * of pre-#6 entries that sit in the tree root.
	6312	+ * @return array{pages:int,rest:int,assets:int,bytes:int} Entries removed
	6313	+ * per store, and the bytes freed by the two file sweeps
	6314	+ * that measure themselves.
	6315	+ */
	6316	+ public static function purge_local( ?string $host = null ): array {
	6317	+ $network_wide = ( '*' === $host );
	6318	+ self::$sweep_bytes = 0;
	6319	+ // The flat tree buckets by a flattened segment (host/a-b) while the
	6320	+ // static tree mirrors the URL (host/a/b), so they need separate
	6321	+ // scopes — see current_host_dir() vs current_static_scope().
	6322	+ $static_scope = '';
	6323	+ if ( null === $host || $network_wide ) {
	6324	+ $scope = $network_wide ? '' : self::current_host_dir();
	6325	+ $static_scope = $network_wide ? '' : self::current_static_scope();
	6326	+ } else {
	6327	+ $dir = self::host_dir( $host );
	6328	+ $scope = '' === $dir ? 'default' : $dir;
	6329	+ $static_dir = self::static_host_dir( $host );
	6330	+ $static_scope = '' === $static_dir ? 'default' : $static_dir;
	6331	+ }
	6332	+
	6333	+ $count = 0;
	6334	+ if ( is_dir( XSPEED_CACHE_DIR ) ) {
	6335	+ // Scoped to one host directory, or the whole tree (including the
	6336	+ // legacy top-level entries written before #6) when network-wide.
	6337	+ /*
	6338	+ * Network-wide sweeps go TWO levels deep, not one. A subdirectory
	6339	+ * subsite's bucket is `<host>/<prefix>/`, so globbing only
	6340	+ * `<cache>/*` reached the main site and left every subsite's
	6341	+ * entries in place. (QA D5 on #166)
	6342	+ *
	6343	+ * A scoped purge also has to cover its own nested buckets: when
	6344	+ * the main blog of a subdirectory network purges, `<host>/` is its
	6345	+ * bucket and `<host>/one/` belongs to another blog — so the scoped
	6346	+ * branch deliberately does NOT descend, which is what keeps
	6347	+ * site-level purges isolated.
	6348	+ */
	6349	+ $roots = $network_wide
	6350	+ ? array_merge(
	6351	+ array( XSPEED_CACHE_DIR ),
	6352	+ array_filter( (array) glob( XSPEED_CACHE_DIR . '/*', GLOB_ONLYDIR ) ),
	6353	+ array_filter( (array) glob( XSPEED_CACHE_DIR . '/*/*', GLOB_ONLYDIR ) )
	6354	+ )
	6355	+ : array( XSPEED_CACHE_DIR . '/' . $scope );
	6356	+
	6357	+ foreach ( $roots as $root ) {
	6358	+ /*
	6359	+ * min/ and rest/ are swept by their own purgers below; never
	6360	+ * treat them as host buckets.
	6361	+ *
	6362	+ * Checked on every path SEGMENT, not just the basename: now
	6363	+ * that the network-wide glob descends two levels it can reach
	6364	+ * `min/combined`, whose basename is `combined` and would sail
	6365	+ * past a basename-only test — deleting the combined
	6366	+ * stylesheets out from under the pages that link them.
	6367	+ */
	6368	+ if ( ! $network_wide || XSPEED_CACHE_DIR !== $root ) {
	6369	+ $relative = trim( str_replace( XSPEED_CACHE_DIR, '', (string) $root ), '/' );
	6370	+ $segments = '' === $relative ? array() : explode( '/', $relative );
	6371	+ if ( array_intersect( $segments, array( 'min', 'rest' ) ) ) {
	6372	+ continue;
	6373	+ }
	6374	+ }
	6375	+ if ( ! is_dir( $root ) ) {
	6376	+ continue;
	6377	+ }
	6378	+ $files = glob( $root . '/*.html' );
	6379	+ if ( $files ) {
	6380	+ $count += count( $files );
	6381	+ foreach ( $files as $f ) {
	6382	+ self::sweep_delete( $f );
	6383	+ }
	6384	+ }
	6385	+ // Remove the .meta sidecars (content-type for feeds/sitemaps)
	6386	+ // alongside their .html entries. Not counted — they're not
	6387	+ // cache "pages", just per-entry metadata.
	6388	+ $meta = glob( $root . '/*.meta' );
	6389	+ if ( $meta ) {
	6390	+ foreach ( $meta as $m ) {
	6391	+ self::sweep_delete( $m );
	6392	+ }
	6393	+ }
	6394	+ // Remove precompressed siblings (e.g. <key>.html.br from the Pro
	6395	+ // Brotli module). Not counted — same as .meta. Without this a
	6396	+ // purge leaves stale .br bodies behind: disk bloat, and a
	6397	+ // staleness window if precompression is later disabled.
	6398	+ $br = glob( $root . '/*.br' );
	6399	+ if ( $br ) {
	6400	+ foreach ( $br as $b ) {
	6401	+ self::sweep_delete( $b );
	6402	+ }
	6403	+ }
	6404	+ // `*.br` does not match `*.br.size` — same reason as the flat-root
	6405	+ // sweep above: a size record outliving its body would later be
	6406	+ // read against a different sibling's bytes.
	6407	+ $br_size = glob( $root . '/*.br.size' );
	6408	+ if ( $br_size ) {
	6409	+ foreach ( $br_size as $b ) {
	6410	+ self::sweep_delete( $b );
	6411	+ }
	6412	+ }
	6413	+ }
	6414	+ }
879	6415	// Static-cache tree purge — recursive because the layout is
880	6416	// xspeed-static/{host}/{path}/index.html, so a flat glob can't
881		- // reach everything.
	6417	+ // reach everything. Already host-segmented, so scoping is just a
	6418	+ // matter of starting one level down.
882	6419	if ( is_dir( XSPEED_CACHE_STATIC_DIR ) ) {
883		- $count += self::rmtree_html( XSPEED_CACHE_STATIC_DIR );
	6420	+ $static_root = $network_wide
	6421	+ ? XSPEED_CACHE_STATIC_DIR
	6422	+ : XSPEED_CACHE_STATIC_DIR . '/' . $static_scope;
	6423	+ if ( is_dir( $static_root ) ) {
	6424	+ $count += self::rmtree_html( $static_root );
	6425	+ }
884	6426	}
885	6427	// REST response cache (cache/xspeed/rest/*.json) — same purge
886	6428	// triggers (publish, settings change) invalidate it too.
887		- $count += Rest_Cache::purge();
	6429	+ $rest = Rest_Cache::purge();
	6430	+ $count += $rest;
	6431	+
	6432	+ // Minified + combined CSS/JS (cache/xspeed/min/ and min/combined/)
	6433	+ // go only on a NETWORK-wide sweep.
	6434	+ //
	6435	+ // They are named by content, so a site purge gains nothing by deleting
	6436	+ // them: the next render links the same names for unchanged sources
	6437	+ // and new names for changed ones. Deleting them did cost something.
	6438	+ // A page rendered just before the purge and stored just after linked
	6439	+ // files that were gone (unstyled until the TTL), and min/ is shared
	6440	+ // by every blog, so one subsite's purge broke every other subsite's
	6441	+ // cached pages. Orphans are Cache_GC's job; a network purge, an
	6442	+ // update, the explicit assets purge and deactivation still clear the
	6443	+ // tree, and the purge stamp stops a render in flight from being
	6444	+ // stored against deleted files.
	6445	+ $assets = ( $network_wide && class_exists( '\\XSpeed\\Minifier' ) ) ? Minifier::purge_minified() : 0;
	6446	+
	6447	+ return array(
	6448	+ 'pages' => $count - $rest,
	6449	+ 'rest' => $rest,
	6450	+ 'assets' => $assets,
	6451	+ 'bytes' => self::$sweep_bytes,
	6452	+ );
	6453	+ }
	6454	+
	6455	+ /**
	6456	+ * Flush the persistent object cache (Redis / Memcached).
	6457	+ *
	6458	+ * Runs regardless of whether the Object Cache module is currently
	6459	+ * enabled — a drop-in installed earlier keeps serving until flushed.
	6460	+ *
	6461	+ * @param bool $network_wide Flush every blog's entries. wp_cache_flush()
	6462	+ * is NETWORK-global, so on multisite the
	6463	+ * default prefers the blog-scoped group flush
	6464	+ * (WP 6.1+) — otherwise one site's purge drops
	6465	+ * every other site's object cache, the same bug
	6466	+ * #6 fixed for the page cache.
	6467	+ * @return bool Whether a flush was actually performed.
	6468	+ */
	6469	+ public static function flush_object_cache( bool $network_wide = false ): bool {
	6470	+ if ( ! $network_wide && is_multisite() && function_exists( 'wp_cache_flush_group' ) && function_exists( 'wp_cache_supports' ) && wp_cache_supports( 'flush_group' ) ) {
	6471	+ // Blog-scoped groups only; a shared/global group (site options,
	6472	+ // user meta) is intentionally left alone.
	6473	+ foreach ( array( 'options', 'posts', 'terms', 'post_meta', 'comment' ) as $group ) {
	6474	+ wp_cache_flush_group( $group );
	6475	+ }
	6476	+ return true;
	6477	+ }
	6478	+ if ( function_exists( 'wp_cache_flush' ) ) {
	6479	+ return (bool) wp_cache_flush();
	6480	+ }
	6481	+ return false;
	6482	+ }
	6483	+
	6484	+ /**
	6485	+ * Purge this site's cache: the local sweep, then the object cache, then
	6486	+ * the bookkeeping every caller expects (stats, `xspeed_after_purge_all`,
	6487	+ * inventory invalidation, purge log).
	6488	+ *
	6489	+ * @param string $cause Who asked, for the purge log.
	6490	+ * @param string|null $host See purge_local().
	6491	+ * @param array<string,mixed> $invalidation Public adapter policy. `scope`
	6492	+ * is urls/site/network/none,
	6493	+ * `intent` explains why, and
	6494	+ * `urls` supplies exact targets.
	6495	+ * @return int Page + REST entries removed.
	6496	+ */
	6497	+ public static function purge_all( string $cause = 'manual', ?string $host = null, array $invalidation = array() ) {
	6498	+ $network_wide = ( '*' === $host );
	6499	+ $adapter_scope = isset( $invalidation['scope'] ) && is_string( $invalidation['scope'] )
	6500	+ ? $invalidation['scope']
	6501	+ : ( $network_wide ? 'network' : 'site' );
	6502	+ if ( ! in_array( $adapter_scope, array( 'urls', 'site', 'network', 'none' ), true ) ) {
	6503	+ $adapter_scope = $network_wide ? 'network' : 'site';
	6504	+ }
	6505	+ if ( $network_wide ) {
	6506	+ $adapter_scope = 'network';
	6507	+ }
	6508	+ $intent = isset( $invalidation['intent'] ) && is_string( $invalidation['intent'] ) && '' !== $invalidation['intent']
	6509	+ ? $invalidation['intent']
	6510	+ : 'complete';
	6511	+ $urls = isset( $invalidation['urls'] ) && is_array( $invalidation['urls'] )
	6512	+ ? array_values( array_unique( array_filter( $invalidation['urls'], 'is_string' ) ) )
	6513	+ : array();
	6514	+ // This method always sweeps a complete local bucket. A narrower adapter
	6515	+ // announcement would claim unrelated local pages stayed warm when they
	6516	+ // did not, leaving their server copies stale. Until purge_all() gains
	6517	+ // dependency-aware local deletion, its response scope cannot be `urls`.
	6518	+ if ( 'urls' === $adapter_scope ) {
	6519	+ $adapter_scope = $network_wide ? 'network' : 'site';
	6520	+ }
	6521	+ if ( 'site' === $adapter_scope || 'network' === $adapter_scope || 'none' === $adapter_scope ) {
	6522	+ $urls = array();
	6523	+ }
	6524	+
	6525	+ $fallback = isset( $invalidation['fallback'] ) && is_string( $invalidation['fallback'] ) ? $invalidation['fallback'] : '';
	6526	+
	6527	+ $removed = self::purge_local( $host );
	6528	+ $count = $removed['pages'] + $removed['rest'];
	6529	+
	6530	+ self::flush_object_cache( $network_wide );
	6531	+
888	6532	self::update_stats( array( 'last_purge' => time() ) );
889	6533
	6534	+ // Fire AFTER the local sweep so module listeners (Critical CSS,
	6535	+ // Unused CSS, Cloudflare edge purge) run — this action had three
	6536	+ // registered listeners but was never emitted. Treat it as additive
	6537	+ // (CDN / edge invalidation), not the mechanism for clearing local
	6538	+ // files. (FBS-83114)
	6539	+ // Wrapped: this action predates the purge-event contract and has its
	6540	+ // own third-party listeners. One of them throwing used to abort
	6541	+ // purge_all() here, which now also means the contract event below
	6542	+ // never fires and a server cache keeps serving stale HTML. The local
	6543	+ // sweep is already done by this point, so swallowing is strictly safer
	6544	+ // than letting a listener decide the rest of the method runs.
	6545	+ try {
	6546	+ // Isolated per listener: one throwing used to cancel every
	6547	+ // listener queued behind it — Critical CSS, Unused CSS and the
	6548	+ // Cloudflare edge purge all hang off this hook. (QA #348)
	6549	+ self::do_action_isolated( 'xspeed_after_purge_all', $cause );
	6550	+ } catch ( \Throwable $e ) {
	6551	+ self::log_purge_listener_error( 'xspeed_after_purge_all', $e );
	6552	+ }
	6553	+
	6554	+ /**
	6555	+ * Fires after a full purge, with the same bounded context shape as
	6556	+ * `xspeed_after_purge_url`.
	6557	+ *
	6558	+ * Distinct from `xspeed_after_purge_all` on purpose. That action is
	6559	+ * the long-standing internal signal — it passes a bare `$cause` string
	6560	+ * and Free's own modules use it for local bookkeeping. This one is the
	6561	+ * documented contract for OUTSIDE integrations: same argument shape as
	6562	+ * the per-URL event, so a server-cache or CDN adapter can subscribe to
	6563	+ * both with one handler and branch on a null `url`.
	6564	+ *
	6565	+ * Fires at most once per purge, and not at all when a listener's own
	6566	+ * purge re-enters xSpeed.
	6567	+ *
	6568	+ * @since 1.2.3
	6569	+ *
	6570	+ * @param array $context {
	6571	+ * @type null $url Always null — a full purge has no single URL.
	6572	+ * @type string $host Host swept, or '*' for the entire tree.
	6573	+ * @type null $path Always null.
	6574	+ * @type string $cause Short label for who asked.
	6575	+ * @type int $removed Number of cache files removed.
	6576	+ * @type string $scope Adapter action: urls/site/network/none.
	6577	+ * @type string $intent content/presentation/complete or a caller-defined intent.
	6578	+ * @type string[] $urls Exact targets when scope is urls.
	6579	+ * @type string $fallback Why a change that would have cleared
	6580	+ * only its own pages cleared the whole site
	6581	+ * instead: `theme_list`, `limit`, `pending`
	6582	+ * or `filter`. Empty for every other purge.
	6583	+ * See the purge-event contract in
	6584	+ * docs/guides/hooks-and-filters.md.
	6585	+ * }
	6586	+ */
	6587	+ self::dispatch_purge_event(
	6588	+ 'xspeed_after_purge',
	6589	+ array(
	6590	+ 'url' => null,
	6591	+ 'host' => null === $host ? self::current_purge_host() : (string) $host,
	6592	+ 'path' => null,
	6593	+ 'cause' => $cause,
	6594	+ 'removed' => $count,
	6595	+ 'scope' => $adapter_scope,
	6596	+ 'intent' => $intent,
	6597	+ 'urls' => $urls,
	6598	+ 'fallback' => $fallback,
	6599	+ )
	6600	+ );
	6601	+
	6602	+ /*
	6603	+ * The generic event is published by the `dispatch_purge_event()` call
	6604	+ * directly above, NOT here. Same supersession as in `purge_url()`:
	6605	+ * this branch's raw `do_action` with a `count` payload predates #348's
	6606	+ * contract, and keeping both made a full purge publish twice.
	6607	+ */
	6608	+
	6609	+ // The list behind the "Cached pages" card is memoized for a minute;
	6610	+ // a purge has to drop it or the drill-down shows pages that no
	6611	+ // longer exist.
	6612	+ Cache_Inventory::invalidate();
	6613	+
890	6614	// Trigger of WP_CLI / hook / admin-bar purges all hit the same
891	6615	// path. Record once with the supplied cause so the dashboard
892	6616	// activity feed reads naturally.
893	6617	Activity_Log::record(
		@@ -894,11 +6618,1053 @@
894	6618	'cache_purged',
895	6619	sprintf( 'Cache purged (%s) — %d file%s removed', $cause, $count, 1 === $count ? '' : 's' ),
896	6620	Activity_Log::INFO
897	6621	);
	6622	+
	6623	+ return $count;
898	6624	}
899	6625
900	6626	/**
	6627	+ * Purge everything after a plugin / theme / core update completes.
	6628	+ *
	6629	+ * Bound to `upgrader_process_complete`, which is the only hook an update
	6630	+ * fires — no activation hook runs, so without this the cached HTML (and
	6631	+ * the asset URLs baked into it) outlives the code that produced it.
	6632	+ *
	6633	+ * Runs for plugin, theme and core updates alike, including bulk runs and
	6634	+ * auto-updates, and purges the WHOLE network rather than the current
	6635	+ * site — see the call below. Translation updates are skipped: they
	6636	+ * change no markup a cached page depends on, and language packs update
	6637	+ * often enough that purging on them would keep a multilingual site
	6638	+ * permanently cold.
	6639	+ *
	6640	+ * Note this cannot be folded into the `$invalidate_hooks` loop above:
	6641	+ * that binds `purge_all` directly, and `purge_all( string $cause )` would
	6642	+ * then receive the WP_Upgrader instance as its cause.
	6643	+ *
	6644	+ * @param mixed $upgrader WP_Upgrader instance (unused).
	6645	+ * @param array $hook_extra Context for the completed operation.
	6646	+ * @return void
	6647	+ */
	6648	+ public static function purge_after_upgrade( $upgrader = null, $hook_extra = array() ) {
	6649	+ $cleared = self::$upgrade_cleared_destination;
	6650	+
	6651	+ if ( ! self::upgrade_produced_something( $upgrader ) ) {
	6652	+ return;
	6653	+ }
	6654	+
	6655	+ if ( ! self::upgrade_should_purge( is_array( $hook_extra ) ? $hook_extra : array(), $cleared ) ) {
	6656	+ return;
	6657	+ }
	6658	+
	6659	+ self::purge_for_upgrade();
	6660	+ }
	6661	+
	6662	+ /**
	6663	+ * Whether this request's upgrader removed an existing copy.
	6664	+ *
	6665	+ * @var bool
	6666	+ */
	6667	+ private static $upgrade_cleared_destination = false;
	6668	+
	6669	+ /**
	6670	+ * How many `upgrader_process_complete` dispatches are on the stack.
	6671	+ *
	6672	+ * @var int
	6673	+ */
	6674	+ private static $upgrade_dispatch_depth = 0;
	6675	+
	6676	+ /**
	6677	+ * Enter an `upgrader_process_complete` dispatch.
	6678	+ *
	6679	+ * Bound at PHP_INT_MIN, so it runs before any listener that might read
	6680	+ * the replacement signal. Public because it is a hook target.
	6681	+ *
	6682	+ * @return void
	6683	+ */
	6684	+ public static function note_upgrade_dispatch(): void {
	6685	+ ++self::$upgrade_dispatch_depth;
	6686	+ }
	6687	+
	6688	+ /**
	6689	+ * Drop the replacement signal once every listener has read it.
	6690	+ *
	6691	+ * Bound at PHP_INT_MAX so a second upgrade in the same request starts
	6692	+ * clean, without taking the answer away from the add-on callbacks that
	6693	+ * run at the same priority as ours.
	6694	+ *
	6695	+ * Only the OUTERMOST dispatch clears it. A nested run — core's language
	6696	+ * pack upgrader, or any add-on that installs something from this hook —
	6697	+ * fires the action again, and clearing there would answer for a run that
	6698	+ * has not finished. Called directly (no dispatch on the stack) it still
	6699	+ * clears, which is what a test wants.
	6700	+ *
	6701	+ * Known limit: a nested run INHERITS the outer run's signal, because the
	6702	+ * only evidence we get is a filter that fires before the nested dispatch
	6703	+ * begins and carries no upgrader identity. So a fresh install performed
	6704	+ * from inside a replacement run reads as a replacement and purges once
	6705	+ * more than it needs to. A cold cache is the cheap direction, and the
	6706	+ * alternative — scoping the signal per upgrader — is not knowable from
	6707	+ * `upgrader_clear_destination`.
	6708	+ *
	6709	+ * The observed-destination signal is dropped here too. The two are read
	6710	+ * together and have to expire together: leaving "the directory was not
	6711	+ * there" behind would let a first install answer for whatever ran next
	6712	+ * in the same request, and that one's mistake is a cache left stale.
	6713	+ *
	6714	+ * @return void
	6715	+ */
	6716	+ public static function forget_cleared_destination(): void {
	6717	+ if ( self::$upgrade_dispatch_depth > 0 ) {
	6718	+ --self::$upgrade_dispatch_depth;
	6719	+ }
	6720	+
	6721	+ if ( 0 === self::$upgrade_dispatch_depth ) {
	6722	+ self::$upgrade_cleared_destination = false;
	6723	+ self::$upgrade_destination_existed = null;
	6724	+ self::$upgrade_destination_folder = '';
	6725	+ }
	6726	+ }
	6727	+
	6728	+ /**
	6729	+ * Whether the destination this run installs into was already there.
	6730	+ *
	6731	+ * Null while unknown — an upgrader whose target we cannot work out keeps
	6732	+ * the old behaviour rather than being guessed at.
	6733	+ *
	6734	+ * @var bool|null
	6735	+ */
	6736	+ private static $upgrade_destination_existed = null;
	6737	+
	6738	+ /**
	6739	+ * The folder name that answer was measured against, so the destination
	6740	+ * WordPress reports on `upgrader_clear_destination` can be checked
	6741	+ * against it. Empty when nothing was measured.
	6742	+ *
	6743	+ * @var string
	6744	+ */
	6745	+ private static $upgrade_destination_folder = '';
	6746	+
	6747	+ /**
	6748	+ * Note whether the package's destination exists, before it is cleared.
	6749	+ *
	6750	+ * `upgrader_source_selection` is the last hook that fires while the old
	6751	+ * copy is still on disk, and the extracted source folder name is the
	6752	+ * directory the package will install into. A pass-through listener: the
	6753	+ * source is returned untouched.
	6754	+ *
	6755	+ * @param mixed $source Extracted package directory.
	6756	+ * @param mixed $remote_src Unused; the package's remote source.
	6757	+ * @param mixed $upgrader The upgrader instance, if one was supplied.
	6758	+ * @param mixed $hook_extra Context supplied by the upgrader.
	6759	+ * @return mixed The source, unchanged.
	6760	+ */
	6761	+ public static function note_destination_state( $source, $remote_src = '', $upgrader = null, $hook_extra = array() ) {
	6762	+ self::$upgrade_destination_existed = null;
	6763	+ self::$upgrade_destination_folder = '';
	6764	+
	6765	+ $root = self::upgrade_destination_root( $upgrader, is_array( $hook_extra ) ? $hook_extra : array() );
	6766	+ if ( null !== $root && is_string( $source ) && '' !== $source ) {
	6767	+ $folder = basename( rtrim( $source, '/\\' ) );
	6768	+ if ( '' !== $folder ) {
	6769	+ self::$upgrade_destination_existed = is_dir( rtrim( $root, '/\\' ) . '/' . $folder );
	6770	+ self::$upgrade_destination_folder = $folder;
	6771	+ }
	6772	+ }
	6773	+
	6774	+ return $source;
	6775	+ }
	6776	+
	6777	+ /**
	6778	+ * Where a package of this kind installs to, or null if we cannot tell.
	6779	+ *
	6780	+ * @param mixed $upgrader The upgrader instance, if one was supplied.
	6781	+ * @param array $hook_extra Context supplied by the upgrader.
	6782	+ * @return string|null
	6783	+ */
	6784	+ private static function upgrade_destination_root( $upgrader, array $hook_extra ): ?string {
	6785	+ $type = isset( $hook_extra['type'] ) ? (string) $hook_extra['type'] : '';
	6786	+
	6787	+ if ( 'plugin' === $type || $upgrader instanceof \Plugin_Upgrader ) {
	6788	+ return defined( 'WP_PLUGIN_DIR' ) ? WP_PLUGIN_DIR : null;
	6789	+ }
	6790	+
	6791	+ if ( 'theme' === $type || $upgrader instanceof \Theme_Upgrader ) {
	6792	+ return function_exists( 'get_theme_root' ) ? (string) get_theme_root() : null;
	6793	+ }
	6794	+
	6795	+ return null;
	6796	+ }
	6797	+
	6798	+ /**
	6799	+ * Record that the upgrader cleared an existing destination.
	6800	+ *
	6801	+ * A pass-through listener on `upgrader_clear_destination`: WordPress only
	6802	+ * fires it when `clear_destination` was set AND something was there to
	6803	+ * remove, which is the one signal that separates an upload-and-replace
	6804	+ * from a first-time install. The filtered value is returned untouched.
	6805	+ *
	6806	+ * @param true|\WP_Error $removed Whether the destination was cleared.
	6807	+ * @return true|\WP_Error
	6808	+ */
	6809	+ public static function note_cleared_destination( $removed, $local_destination = '', $remote_destination = '', $hook_extra = array() ) {
	6810	+ if ( ! is_wp_error( $removed ) ) {
	6811	+ self::$upgrade_cleared_destination = true;
	6812	+ }
	6813	+
	6814	+ // $remote_destination is the directory WordPress actually cleared,
	6815	+ // derived from the source AFTER every `upgrader_source_selection`
	6816	+ // listener ran. If its folder is not the one note_destination_state()
	6817	+ // measured, a listener that ran after ours renamed the package, and
	6818	+ // the "was it there?" answer is about a directory that was never going
	6819	+ // to be written. Unknown is the answer that purges, so that is what it
	6820	+ // becomes. Only the last segment is compared: over FTP the remote
	6821	+ // path sits under the server's own root, not WP_PLUGIN_DIR. (#407 QA)
	6822	+ if ( is_string( $remote_destination ) && '' !== $remote_destination ) {
	6823	+ $cleared_folder = basename( rtrim( $remote_destination, '/\\' ) );
	6824	+ if ( '' !== $cleared_folder && $cleared_folder !== self::$upgrade_destination_folder ) {
	6825	+ self::$upgrade_destination_existed = null;
	6826	+ }
	6827	+ }
	6828	+
	6829	+ return $removed;
	6830	+ }
	6831	+
	6832	+ /**
	6833	+ * Did the completed run actually replace anything?
	6834	+ *
	6835	+ * `upgrader_process_complete` fires whether the run succeeded or failed —
	6836	+ * the failure branch in WP_Upgrader::run() only feeds the skin before the
	6837	+ * action fires. A run that installed nothing changed no markup, so purging
	6838	+ * for it is a cold cache bought for nothing.
	6839	+ *
	6840	+ * Deliberately conservative: this returns false ONLY when every result we
	6841	+ * can see is an error. An upgrader we cannot read, a mixed bulk run, or a
	6842	+ * missing result all fall through to purging, which is the safe direction
	6843	+ * everywhere else in this handler.
	6844	+ *
	6845	+ * @param mixed $upgrader WP_Upgrader instance, or anything else.
	6846	+ * @return bool
	6847	+ */
	6848	+ public static function upgrade_produced_something( $upgrader ): bool {
	6849	+ if ( ! is_object( $upgrader ) ) {
	6850	+ return true;
	6851	+ }
	6852	+
	6853	+ // A bulk run collects one entry per item; `result` alone would only
	6854	+ // describe the last of them.
	6855	+ if ( isset( $upgrader->results ) && is_array( $upgrader->results ) && ! empty( $upgrader->results ) ) {
	6856	+ foreach ( $upgrader->results as $result ) {
	6857	+ if ( ! is_wp_error( $result ) && ! empty( $result ) ) {
	6858	+ return true;
	6859	+ }
	6860	+ }
	6861	+ return false;
	6862	+ }
	6863	+
	6864	+ if ( ! property_exists( $upgrader, 'result' ) ) {
	6865	+ return true;
	6866	+ }
	6867	+
	6868	+ return ! is_wp_error( $upgrader->result ) && ! empty( $upgrader->result );
	6869	+ }
	6870	+
	6871	+ /**
	6872	+ * Decide whether a completed operation invalidates the cache.
	6873	+ *
	6874	+ * Split out from the handler so the decision is testable on its own:
	6875	+ * purge_all() reaches straight for glob() and unlink(), which a unit test
	6876	+ * cannot observe honestly, while every rule that matters lives here.
	6877	+ *
	6878	+ * @param array $hook_extra Context for the completed operation.
	6879	+ * @return bool
	6880	+ */
	6881	+ public static function upgrade_should_purge( array $hook_extra, bool $destination_cleared = false ): bool {
	6882	+ if ( ! self::upgrade_replaced_code( $hook_extra, $destination_cleared ) ) {
	6883	+ return false;
	6884	+ }
	6885	+
	6886	+ // An update to xSpeed ITSELF always purges, whatever the setting says.
	6887	+ // This plugin's own code is what rendered every cached page — the
	6888	+ // minifier, lazy-loader, resource hints and CDN rewriter all changed
	6889	+ // underneath it — so serving that HTML after an update means serving
	6890	+ // output from a version that no longer exists. Minified assets make it
	6891	+ // concrete rather than theoretical: their filenames are keyed on the
	6892	+ // source filemtime, so they regenerate under NEW hashes while the
	6893	+ // cached pages still link the old ones, and the page requests files
	6894	+ // that are no longer on disk. Offering an opt-out for that would be
	6895	+ // offering a broken site.
	6896	+ return self::upgrade_touches_xspeed( $hook_extra ) || self::purge_on_upgrade_enabled();
	6897	+ }
	6898	+
	6899	+ /**
	6900	+ * Did this completed run replace code that renders pages?
	6901	+ *
	6902	+ * The half of the decision that has nothing to do with our settings: it
	6903	+ * asks only whether live code changed underneath the output we cached.
	6904	+ * Add-ons that keep their own derived artifacts — generated CSS, captured
	6905	+ * selectors, fingerprints — need the same answer and must not have to
	6906	+ * rebuild these rules, or they drift apart. Call it with the hook's own
	6907	+ * `$hook_extra`; the upload-and-replace signal is read from this request.
	6908	+ *
	6909	+ * Deliberately independent of the "Purge After Updates" setting. That
	6910	+ * setting governs the page cache, not whether an add-on's derived data is
	6911	+ * still valid.
	6912	+ *
	6913	+ * @param array $hook_extra Context for the completed operation.
	6914	+ * @param bool|null $destination_cleared Override the recorded signal; null reads this request's.
	6915	+ * @return bool
	6916	+ */
	6917	+ public static function upgrade_replaced_code( array $hook_extra, ?bool $destination_cleared = null ): bool {
	6918	+ $cleared = null === $destination_cleared ? self::$upgrade_cleared_destination : $destination_cleared;
	6919	+
	6920	+ $type = isset( $hook_extra['type'] ) ? (string) $hook_extra['type'] : '';
	6921	+ $action = isset( $hook_extra['action'] ) ? (string) $hook_extra['action'] : '';
	6922	+
	6923	+ // `upgrader_process_complete` fires for INSTALLS as well as updates.
	6924	+ // A freshly installed plugin is inactive and a freshly installed theme
	6925	+ // is not the active one, so neither can change a single rendered page
	6926	+ // — but the first cut of this handler purged the whole tree anyway, so
	6927	+ // evaluating three plugins in a row emptied the cache three times.
	6928	+ //
	6929	+ // 'install' alone is NOT enough to skip on, because WordPress reports
	6930	+ // an upload-and-replace as an install: `Plugin_Upgrader::install()`
	6931	+ // hardcodes `action => install` and `overwrite_package` does not change
	6932	+ // it, so "Replace current with uploaded" and `wp plugin install <zip>
	6933	+ // --force` both arrive here labelled install while genuinely replacing
	6934	+ // live code. That is how a plugin distributed as a zip is updated, and
	6935	+ // skipping it put back the stale markup this handler exists to clear.
	6936	+ //
	6937	+ // The distinguishing signal is whether the destination was cleared:
	6938	+ // WP_Upgrader only fires `upgrader_clear_destination` when it removed
	6939	+ // something that was already there. Installing beside nothing does not.
	6940	+ if ( 'install' === $action && ! $cleared ) {
	6941	+ return false;
	6942	+ }
	6943	+
	6944	+ // A cleared destination is only evidence of a replacement if there was
	6945	+ // something in it. Core returns success from clear_destination() for a
	6946	+ // destination that never existed, so a first-time install arrived here
	6947	+ // looking exactly like an upload-and-replace and bought a cold cache
	6948	+ // for a plugin that is not even active yet. Only acted on when we
	6949	+ // positively know the directory was absent.
	6950	+ if ( 'install' === $action && false === self::$upgrade_destination_existed ) {
	6951	+ return false;
	6952	+ }
	6953	+
	6954	+ // 'translation' is the one update type that cannot change rendered
	6955	+ // markup. Anything else — including an empty type from a custom
	6956	+ // updater — is treated as cache-invalidating, because guessing wrong
	6957	+ // in that direction only costs a cold cache.
	6958	+ if ( 'translation' === $type ) {
	6959	+ return false;
	6960	+ }
	6961	+
	6962	+ return true;
	6963	+ }
	6964	+
	6965	+ /**
	6966	+ * Purge everything an update can invalidate.
	6967	+ *
	6968	+ * Network-wide ('*'), not the calling site's bucket. A plugin, theme or
	6969	+ * core update replaces code shared by EVERY site on the network, so a
	6970	+ * scoped purge would clear the site that happened to run the updater and
	6971	+ * leave every other subsite serving pre-update HTML for the whole TTL —
	6972	+ * the very bug this handler exists to fix, one level down. On single-site
	6973	+ * this is identical to the scoped call, since there is only ever one
	6974	+ * bucket.
	6975	+ *
	6976	+ * @return void
	6977	+ */
	6978	+ private static function purge_for_upgrade(): void {
	6979	+ // Network-wide, so purge_local() also clears min/.
	6980	+ self::purge_all( 'upgrade', '*' );
	6981	+ }
	6982	+
	6983	+ /**
	6984	+ * Purge after an unattended background update run.
	6985	+ *
	6986	+ * `automatic_updates_complete` passes ONE argument, and it is not a
	6987	+ * hook_extra: it is WordPress's results array, keyed by what was updated
	6988	+ * ('core', 'plugin', 'theme', 'translation'). Handing it to
	6989	+ * purge_after_upgrade() put it in the unused $upgrader slot and left the
	6990	+ * type empty, so a night on which only a language pack updated purged
	6991	+ * every cached page — the exact case the translation exemption exists to
	6992	+ * prevent, and WordPress auto-updates language packs by default.
	6993	+ *
	6994	+ * @param array $results Update results, keyed by type.
	6995	+ * @return void
	6996	+ */
	6997	+ public static function purge_after_auto_updates( $results = array() ): void {
	6998	+ if ( ! self::auto_updates_should_purge( is_array( $results ) ? $results : array() ) ) {
	6999	+ return;
	7000	+ }
	7001	+
	7002	+ self::purge_for_upgrade();
	7003	+ }
	7004	+
	7005	+ /**
	7006	+ * Decide whether a background update run invalidates the cache.
	7007	+ *
	7008	+ * @param array $results Update results, keyed by type.
	7009	+ * @return bool
	7010	+ */
	7011	+ public static function auto_updates_should_purge( array $results ): bool {
	7012	+ // An unrecognisable payload is treated as invalidating, the same
	7013	+ // direction every other unknown takes here.
	7014	+ if ( empty( $results ) ) {
	7015	+ return true;
	7016	+ }
	7017	+
	7018	+ // Failed items are listed alongside successful ones — WP_Automatic_Updater
	7019	+ // appends an entry whatever the outcome — and a night on which every
	7020	+ // update failed replaced no code, so it invalidates nothing.
	7021	+ $updated = array();
	7022	+ foreach ( $results as $type => $items ) {
	7023	+ if ( ! is_array( $items ) ) {
	7024	+ continue;
	7025	+ }
	7026	+ foreach ( $items as $item ) {
	7027	+ $result = is_object( $item ) && isset( $item->result ) ? $item->result : true;
	7028	+ if ( ! is_wp_error( $result ) && ! empty( $result ) ) {
	7029	+ $updated[] = (string) $type;
	7030	+ break;
	7031	+ }
	7032	+ }
	7033	+ }
	7034	+
	7035	+ if ( empty( $updated ) ) {
	7036	+ return false;
	7037	+ }
	7038	+
	7039	+ // Nothing but language packs: a language pack changes no markup a
	7040	+ // cached page depends on, and purging on one would keep a multilingual
	7041	+ // site permanently cold.
	7042	+ if ( array( 'translation' ) === array_values( array_unique( $updated ) ) ) {
	7043	+ return false;
	7044	+ }
	7045	+
	7046	+ return self::auto_updates_touch_xspeed( $results ) || self::purge_on_upgrade_enabled();
	7047	+ }
	7048	+
	7049	+ /**
	7050	+ * Does a background run include one of our own plugins?
	7051	+ *
	7052	+ * Same rule as a foreground self-update, read out of the results array's
	7053	+ * shape instead of a hook_extra: each plugin entry carries the update
	7054	+ * object on `->item->plugin`.
	7055	+ *
	7056	+ * @param array $results Update results, keyed by type.
	7057	+ * @return bool
	7058	+ */
	7059	+ private static function auto_updates_touch_xspeed( array $results ): bool {
	7060	+ if ( empty( $results['plugin'] ) || ! is_array( $results['plugin'] ) ) {
	7061	+ return false;
	7062	+ }
	7063	+
	7064	+ $ours = self::self_update_plugins();
	7065	+ foreach ( $results['plugin'] as $entry ) {
	7066	+ $item = is_object( $entry ) && isset( $entry->item ) ? $entry->item : null;
	7067	+ $file = is_object( $item ) && isset( $item->plugin ) ? (string) $item->plugin : '';
	7068	+ if ( '' !== $file && in_array( $file, $ours, true ) ) {
	7069	+ return true;
	7070	+ }
	7071	+ }
	7072	+
	7073	+ return false;
	7074	+ }
	7075	+
	7076	+ /**
	7077	+ * Is the "Purge After Updates" setting on?
	7078	+ *
	7079	+ * Gates THIRD-PARTY updates only — an xSpeed self-update ignores it, see
	7080	+ * purge_after_upgrade(). Defaults to true when the option has never been
	7081	+ * written, matching the schema default in CacheModule: an unset value on
	7082	+ * an existing install must not read as "the user turned this off".
	7083	+ *
	7084	+ * Unlike LiteSpeed, which ships the equivalent toggle OFF, this defaults
	7085	+ * ON — a cold cache costs one slow request, whereas stale HTML is a wrong
	7086	+ * page for up to the full TTL and the site owner has no way to tell why.
	7087	+ *
	7088	+ * @return bool
	7089	+ */
	7090	+ private static function purge_on_upgrade_enabled(): bool {
	7091	+ $opts = Settings_Manager::get( 'cache' );
	7092	+ return ! array_key_exists( 'purge_on_upgrade', $opts ) || ! empty( $opts['purge_on_upgrade'] );
	7093	+ }
	7094	+
	7095	+ /**
	7096	+ * Does this completed update include xSpeed itself?
	7097	+ *
	7098	+ * Mirrors the payload shapes Plugin::maybe_restore_after_update() reads:
	7099	+ * a single update carries 'plugin', a bulk run carries 'plugins'.
	7100	+ *
	7101	+ * @param array $hook_extra Context for the completed operation.
	7102	+ * @return bool
	7103	+ */
	7104	+ private static function upgrade_touches_xspeed( array $hook_extra ): bool {
	7105	+ if ( ! isset( $hook_extra['type'] ) || 'plugin' !== $hook_extra['type'] ) {
	7106	+ return false;
	7107	+ }
	7108	+
	7109	+ $updated = array();
	7110	+ if ( isset( $hook_extra['plugins'] ) && is_array( $hook_extra['plugins'] ) ) {
	7111	+ // Strings only: array_intersect() stringifies what it is given, so
	7112	+ // an object without __toString in a custom updater's payload would
	7113	+ // be a fatal rather than a miss.
	7114	+ $updated = array_filter( $hook_extra['plugins'], 'is_string' );
	7115	+ } elseif ( isset( $hook_extra['plugin'] ) && is_string( $hook_extra['plugin'] ) ) {
	7116	+ $updated = array( $hook_extra['plugin'] );
	7117	+ }
	7118	+
	7119	+ return (bool) array_intersect( self::self_update_plugins(), $updated );
	7120	+ }
	7121	+
	7122	+ /**
	7123	+ * Plugin files whose update counts as an update to us.
	7124	+ *
	7125	+ * The self-update rule is "our own code rendered this cached HTML, so it
	7126	+ * must not survive the code being replaced". That is true of any add-on
	7127	+ * that writes into the same page: an add-on inlines critical CSS, rewrites
	7128	+ * stylesheet links and image URLs, and produces the compressed and static
	7129	+ * copies, so its update leaves exactly the stale markup this rule exists
	7130	+ * to clear. Free cannot name an add-on, so it asks instead.
	7131	+ *
	7132	+ * Filter: xspeed_self_update_plugins
	7133	+ *
	7134	+ * Add-ons add their own `plugin_basename( __FILE__ )`. Entries are matched
	7135	+ * against the plugin files WordPress reports for the completed update, so
	7136	+ * a value that is not a `dir/file.php` basename simply never matches.
	7137	+ *
	7138	+ * @param string[] $plugins Plugin basenames treated as our own.
	7139	+ * @return string[]
	7140	+ */
	7141	+ private static function self_update_plugins(): array {
	7142	+ $ours = array( plugin_basename( XSPEED_FILE ) );
	7143	+
	7144	+ /** This filter is documented above. */
	7145	+ $filtered = apply_filters( 'xspeed_self_update_plugins', $ours );
	7146	+
	7147	+ // Our own file is merged back afterwards rather than trusted to survive
	7148	+ // the round trip. A listener that returns null, a bare string, or a
	7149	+ // list it built from scratch would otherwise drop it, and the plugin
	7150	+ // would quietly stop exempting its OWN update from the setting — a
	7151	+ // failure no add-on author would think to test for.
	7152	+ $claimed = array_filter( is_array( $filtered ) ? $filtered : array(), 'is_string' );
	7153	+
	7154	+ return array_values( array_unique( array_merge( $ours, array_filter( $claimed ) ) ) );
	7155	+ }
	7156	+
	7157	+ /**
	7158	+ * Invalidate caches of RENDERED output owned by other plugins.
	7159	+ *
	7160	+ * purge_all() sweeps only what xSpeed wrote. A page builder that stores
	7161	+ * rendered HTML or generated CSS of its own — Elementor's element cache
	7162	+ * and `uploads/elementor/css/`, and the equivalents in Beaver / Divi /
	7163	+ * Bricks / Oxygen — keeps whatever asset URLs were current when it was
	7164	+ * written, and no xSpeed purge has ever reached it.
	7165	+ *
	7166	+ * That only matters for rewrites that happen DURING render rather than on
	7167	+ * the finished page. Minify, combine, lazy-load and resource hints all run
	7168	+ * on `xspeed_cache_final_html` or a `template_redirect` buffer — after the
	7169	+ * builder has already stored its copy — so nothing they emit can leak.
	7170	+ * The CDN module's `wp_get_attachment_url` filter is the one that can.
	7171	+ *
	7172	+ * Called ONLY from purges where asset URLs themselves can have changed
	7173	+ * (a CDN settings write, an explicit Purge All). NOT from purge_all(),
	7174	+ * which also runs on every post publish — regenerating every builder CSS
	7175	+ * file that often would cost more than it saves, and the builder already
	7176	+ * invalidates its own copy for the post being saved.
	7177	+ *
	7178	+ * @param string $cause Who asked. Threaded through to the listeners and
	7179	+ * the activity log.
	7180	+ * @return string[] Labels of the caches that were actually cleared.
	7181	+ */
	7182	+ public static function purge_render_caches( string $cause = 'manual' ): array {
	7183	+ /**
	7184	+ * Clear render caches belonging to other plugins.
	7185	+ *
	7186	+ * A listener does its own work and appends a human-readable label for
	7187	+ * what it cleared, so the activity log can name it. Returning
	7188	+ * `$cleared` unchanged means "nothing of mine is installed" and is the
	7189	+ * correct no-op — never a failure.
	7190	+ *
	7191	+ * Detect the owning plugin by class or constant, not by an
	7192	+ * `is_plugin_active()` path check: a renamed plugin folder must not
	7193	+ * silently disable the integration.
	7194	+ *
	7195	+ * @param string[] $cleared Labels of caches cleared so far.
	7196	+ * @param string $cause Why the purge is happening.
	7197	+ */
	7198	+ $cleared = (array) apply_filters( 'xspeed_purge_third_party_render_caches', array(), $cause );
	7199	+
	7200	+ // Labels are strings destined for the activity feed. Anything else a
	7201	+ // third-party listener returns is dropped rather than coerced — a
	7202	+ // stray `0` or `null` in the log reads as a cache we cleared.
	7203	+ $cleared = array_values(
	7204	+ array_filter(
	7205	+ $cleared,
	7206	+ static function ( $label ) {
	7207	+ return is_string( $label ) && '' !== trim( $label );
	7208	+ }
	7209	+ )
	7210	+ );
	7211	+
	7212	+ if ( ! $cleared ) {
	7213	+ return $cleared;
	7214	+ }
	7215	+
	7216	+ // Logged separately from the page-cache purge above it. "I turned the
	7217	+ // CDN off and the images are still wrong" is only diagnosable if the
	7218	+ // feed says which OTHER plugin's cache was regenerated and when.
	7219	+ Activity_Log::record(
	7220	+ 'cache_purged',
	7221	+ sprintf( 'Render caches cleared (%s) — %s', $cause, implode( ', ', $cleared ) ),
	7222	+ Activity_Log::INFO
	7223	+ );
	7224	+
	7225	+ return $cleared;
	7226	+ }
	7227	+
	7228	+ /**
	7229	+ * The per-type purge menu, LiteSpeed-style. Each entry is a cache type
	7230	+ * the user can purge individually from the admin-bar dropdown. `visible`
	7231	+ * controls whether the item shows (active + licensed module only) — it
	7232	+ * NEVER limits Purge All, which always sweeps everything on disk.
	7233	+ *
	7234	+ * Pro registers its own types (Critical CSS, Unused CSS, …) by filtering
	7235	+ * `xspeed_purge_types`, so Free degrades gracefully when Pro is absent.
	7236	+ *
	7237	+ * @return array<string,array{label:string,visible:bool}>
	7238	+ */
	7239	+ public static function purge_types(): array {
	7240	+ $minify_on = false;
	7241	+ if ( class_exists( '\\XSpeed\\Settings_Manager' ) ) {
	7242	+ $min = Settings_Manager::get( 'minify' );
	7243	+ $minify_on = ! empty( $min['minify_css'] ) || ! empty( $min['minify_js'] ) || ! empty( $min['combine_css'] ) || ! empty( $min['combine_js'] );
	7244	+ }
	7245	+ // Object cache is "active" when an external object-cache drop-in is in
	7246	+ // use — the canonical WP signal, independent of our settings option.
	7247	+ $oc_on = function_exists( 'wp_using_ext_object_cache' ) && wp_using_ext_object_cache();
	7248	+
	7249	+ $types = array(
	7250	+ 'all' => array(
	7251	+ 'label' => __( 'Purge All', 'xspeed' ),
	7252	+ 'visible' => true,
	7253	+ ),
	7254	+ 'page' => array(
	7255	+ 'label' => __( 'Purge Page / Static Cache', 'xspeed' ),
	7256	+ 'visible' => true,
	7257	+ ),
	7258	+ 'assets' => array(
	7259	+ 'label' => __( 'Purge CSS / JS Cache', 'xspeed' ),
	7260	+ 'visible' => $minify_on,
	7261	+ ),
	7262	+ 'object' => array(
	7263	+ 'label' => __( 'Purge Object Cache', 'xspeed' ),
	7264	+ 'visible' => $oc_on,
	7265	+ ),
	7266	+ 'rest' => array(
	7267	+ 'label' => __( 'Purge REST Cache', 'xspeed' ),
	7268	+ 'visible' => true,
	7269	+ ),
	7270	+ );
	7271	+
	7272	+ /**
	7273	+ * Filter the admin-bar purge-type menu. Pro modules add their own
	7274	+ * (Critical CSS, Unused CSS, CDN). Adding a type here only adds a
	7275	+ * MENU item — purge_type() must know how to handle the same slug.
	7276	+ *
	7277	+ * @param array $types Map of slug => [label, visible].
	7278	+ */
	7279	+ return (array) apply_filters( 'xspeed_purge_types', $types );
	7280	+ }
	7281	+
	7282	+ /**
	7283	+ * Purge a single cache type by slug. 'all' delegates to purge_all();
	7284	+ * every other slug clears just its own artifacts. Unknown slugs (e.g. a
	7285	+ * Pro type) fan out via the `xspeed_purge_type_{slug}` action so the
	7286	+ * owning module can handle it. Returns the number of items removed where
	7287	+ * countable.
	7288	+ *
	7289	+ * @param string $type Cache type slug.
	7290	+ * @param string $cause Who asked. Threaded through so the purge log can
	7291	+ * tell an AI assistant's purge apart from a click —
	7292	+ * "the cache cleared four times today" is only
	7293	+ * actionable once you know what kept clearing it.
	7294	+ */
	7295	+ public static function purge_type( string $type, string $cause = 'manual' ): int {
	7296	+ switch ( $type ) {
	7297	+ case 'all':
	7298	+ $count = self::purge_all( $cause );
	7299	+ // "Purge All" is the user saying they don't trust anything
	7300	+ // stored anywhere — the one purge that should also reach
	7301	+ // caches of rendered output we don't own. purge_all() itself
	7302	+ // deliberately does NOT, because it also runs on every post
	7303	+ // publish. (See Render_Caches.)
	7304	+ self::purge_render_caches( $cause );
	7305	+ return $count;
	7306	+
	7307	+ case 'page':
	7308	+ $count = self::purge_pages();
	7309	+ self::update_stats( array( 'last_purge' => time() ) );
	7310	+ Cache_Inventory::invalidate();
	7311	+ self::record_partial_purge( 'page', $cause, $count );
	7312	+ self::announce_purge( $cause, $count );
	7313	+ return $count;
	7314	+
	7315	+ case 'assets':
	7316	+ return self::purge_assets( $cause );
	7317	+
	7318	+ case 'object':
	7319	+ if ( function_exists( 'wp_cache_flush' ) ) {
	7320	+ wp_cache_flush();
	7321	+ }
	7322	+ self::record_partial_purge( 'object cache', $cause, null );
	7323	+ return 0;
	7324	+
	7325	+ case 'rest':
	7326	+ $count = Rest_Cache::purge();
	7327	+ self::record_partial_purge( 'REST responses', $cause, $count );
	7328	+ self::announce_purge( $cause, $count );
	7329	+ return $count;
	7330	+
	7331	+ default:
	7332	+ return self::purge_type_unhandled( $type, $cause );
	7333	+ }
	7334	+ }
	7335	+
	7336	+ /**
	7337	+ * Purge this site's pages after a Customizer publish.
	7338	+ *
	7339	+ * A presentation change: every page's markup or inline CSS may differ, so
	7340	+ * the whole site bucket goes, as for a template or global-styles edit.
	7341	+ * min/ stays, because its files are named by content; this blog's
	7342	+ * manifests are dropped so the next render re-reads every source rather
	7343	+ * than trusting a signature. Bound with no arguments, because the hook
	7344	+ * passes the WP_Customize_Manager, which purge_all() would take as its
	7345	+ * cause.
	7346	+ */
	7347	+ public static function on_customize_save(): void {
	7348	+ self::purge_all(
	7349	+ 'customizer',
	7350	+ null,
	7351	+ array(
	7352	+ 'scope' => 'site',
	7353	+ 'intent' => 'presentation',
	7354	+ 'urls' => array(),
	7355	+ )
	7356	+ );
	7357	+ if ( class_exists( '\\XSpeed\\Minifier' ) ) {
	7358	+ Minifier::purge_manifests( Asset_Manifest::blog_id() );
	7359	+ }
	7360	+ }
	7361	+
	7362	+ /**
	7363	+ * Purge minified and combined CSS/JS, and the pages that link them.
	7364	+ *
	7365	+ * Scope follows who shares what:
	7366	+ *
	7367	+ * - Single site: min/ is deleted outright.
	7368	+ * - One site of a network: min/ is shared by every blog, so only this
	7369	+ * blog's manifests go. Its next render re-reads each source and
	7370	+ * rebuilds only what changed; no other blog loses a file it links.
	7371	+ * Outputs nothing links any more are left to Cache_GC.
	7372	+ * - $network: min/ and every blog's pages, network-wide.
	7373	+ *
	7374	+ * Deleting min/ without clearing the pages that link it left every
	7375	+ * cached page pointing at files that no longer exist. WordPress answers
	7376	+ * the missing asset by 301-ing to its pretty-permalink form and serving
	7377	+ * the 404 TEMPLATE as `HTTP 200 text/html`, which the browser accepts as
	7378	+ * a stylesheet and parses to zero rules — no console error, no network
	7379	+ * failure, no 4xx anywhere in devtools. The pages stayed broken for the
	7380	+ * rest of the TTL, and the admin who clicked could not see it: they are
	7381	+ * logged in, so their own requests bypass the page cache. (#244) So the
	7382	+ * pages go too, and when files were actually deleted the edge is told
	7383	+ * through `xspeed_after_purge_all`, or it keeps serving HTML that links
	7384	+ * them.
	7385	+ *
	7386	+ * The public `xspeed_after_purge` event carries intent `assets`: rendered
	7387	+ * markup did not change, only asset files did. A listener that keeps
	7388	+ * measurements of rendered pages (selectors, layout) can keep them.
	7389	+ *
	7390	+ * @param string $cause Who asked.
	7391	+ * @param bool $network Purge every blog's pages and all of min/.
	7392	+ * @return int Page entries removed.
	7393	+ */
	7394	+ public static function purge_assets( string $cause, bool $network = false ): int {
	7395	+ $deleted = 0;
	7396	+ $rest = 0;
	7397	+ if ( $network ) {
	7398	+ // purge_local('*') clears min/ itself on a network-wide sweep.
	7399	+ $removed = self::purge_local( '*' );
	7400	+ $count = (int) $removed['pages'];
	7401	+ $rest = (int) $removed['rest'];
	7402	+ $deleted = (int) $removed['assets'];
	7403	+ } else {
	7404	+ if ( class_exists( '\\XSpeed\\Minifier' ) && is_multisite() ) {
	7405	+ Minifier::purge_manifests( Asset_Manifest::blog_id() );
	7406	+ } elseif ( class_exists( '\\XSpeed\\Minifier' ) ) {
	7407	+ $deleted = Minifier::purge_minified();
	7408	+ }
	7409	+ $count = self::purge_pages();
	7410	+ }
	7411	+
	7412	+ self::update_stats( array( 'last_purge' => time() ) );
	7413	+ Cache_Inventory::invalidate();
	7414	+ self::record_partial_purge( 'assets', $cause, $count + $rest );
	7415	+
	7416	+ if ( $deleted > 0 || $network ) {
	7417	+ try {
	7418	+ self::do_action_isolated( 'xspeed_after_purge_all', $cause );
	7419	+ } catch ( \Throwable $e ) {
	7420	+ self::log_purge_listener_error( 'xspeed_after_purge_all', $e );
	7421	+ }
	7422	+ }
	7423	+
	7424	+ if ( ! $network ) {
	7425	+ self::announce_purge( $cause, $count, 'site', 'assets' );
	7426	+ } elseif ( function_exists( 'do_action' ) ) {
	7427	+ try {
	7428	+ self::dispatch_purge_event(
	7429	+ 'xspeed_after_purge',
	7430	+ array(
	7431	+ 'url' => null,
	7432	+ 'host' => '*',
	7433	+ 'path' => null,
	7434	+ 'cause' => $cause,
	7435	+ 'removed' => $count + $rest,
	7436	+ 'scope' => 'network',
	7437	+ 'intent' => 'assets',
	7438	+ 'urls' => array(),
	7439	+ )
	7440	+ );
	7441	+ } catch ( \Throwable $e ) {
	7442	+ self::log_purge_listener_error( 'xspeed_after_purge', $e );
	7443	+ }
	7444	+ }
	7445	+
	7446	+ return $count + $rest;
	7447	+ }
	7448	+
	7449	+ /**
	7450	+ * Delete this site's cached pages from both the flat and static trees.
	7451	+ *
	7452	+ * Extracted so the `assets` purge can reuse it: minified assets are a
	7453	+ * dependency of the cached HTML, so clearing them must clear the pages
	7454	+ * too or the pages are left referencing deleted files (#244).
	7455	+ *
	7456	+ * @return int Number of page entries removed.
	7457	+ */
	7458	+ private static function purge_pages(): int {
	7459	+ $count = 0;
	7460	+ // Scoped to this site — see purge_all(). (#6)
	7461	+ $scope = self::current_host_dir();
	7462	+ $flat_root = XSPEED_CACHE_DIR . '/' . $scope;
	7463	+ if ( is_dir( $flat_root ) ) {
	7464	+ foreach ( (array) glob( $flat_root . '/*.html' ) as $f ) {
	7465	+ wp_delete_file( $f );
	7466	+ ++$count;
	7467	+ }
	7468	+ foreach ( (array) glob( $flat_root . '/*.meta' ) as $m ) {
	7469	+ wp_delete_file( $m );
	7470	+ }
	7471	+ foreach ( (array) glob( $flat_root . '/*.br' ) as $b ) {
	7472	+ wp_delete_file( $b );
	7473	+ }
	7474	+ // `*.br` does not match `*.br.size`; a size record outliving its
	7475	+ // body would later be read against a DIFFERENT sibling's bytes.
	7476	+ foreach ( (array) glob( $flat_root . '/*.br.size' ) as $b ) {
	7477	+ wp_delete_file( $b );
	7478	+ }
	7479	+ }
	7480	+ $static_root = XSPEED_CACHE_STATIC_DIR . '/' . self::current_static_scope();
	7481	+ if ( is_dir( $static_root ) ) {
	7482	+ $count += self::rmtree_html( $static_root );
	7483	+ }
	7484	+
	7485	+ return $count;
	7486	+ }
	7487	+
	7488	+ /**
	7489	+ * A purge type this class does not own — a Pro or third-party module
	7490	+ * registered it via the `xspeed_purge_types` filter, so hand it off.
	7491	+ *
	7492	+ * @param string $type Purge-type slug.
	7493	+ * @param string $cause Who asked.
	7494	+ */
	7495	+ private static function purge_type_unhandled( string $type, string $cause ): int {
	7496	+ $event_sequence = self::$purge_event_sequence;
	7497	+ $hook = 'xspeed_purge_type_' . $type;
	7498	+ $has_handler = false !== has_action( $hook );
	7499	+ do_action( $hook );
	7500	+ self::record_partial_purge( $type, $cause, null );
	7501	+
	7502	+ // Announce, same as the types this class owns. Pro's "Purge Critical
	7503	+ // CSS" and "Purge Unused CSS" arrive here, and they change what a
	7504	+ // cached page CONTAINS — critical CSS is inlined into the HTML, so a
	7505	+ // server cache goes on serving pages with the old styles baked in.
	7506	+ // Fixing the three Free buttons and leaving these two silent left the
	7507	+ // same hole for the tier most likely to be using both plugins.
	7508	+ // (QA #348 round 2, issue 2)
	7509	+ //
	7510	+ // Unknown slugs must not turn into a site-wide purge merely because no
	7511	+ // handler exists. These are the response-changing Pro types Free knows;
	7512	+ // third parties can declare another through the filter. A registered
	7513	+ // handler plus this explicit response scope is the handled signal.
	7514	+ $scope = in_array( $type, array( 'critical-css', 'unused-css' ), true ) ? 'site' : 'none';
	7515	+ /**
	7516	+ * Declare whether a handled custom purge type changes cached responses.
	7517	+ *
	7518	+ * @since 1.2.3
	7519	+ * @param string $scope site/network/none.
	7520	+ * @param string $type Purge-type slug.
	7521	+ */
	7522	+ $scope = (string) apply_filters( 'xspeed_purge_type_response_scope', $scope, $type );
	7523	+ if ( $has_handler
	7524	+ && $event_sequence === self::$purge_event_sequence
	7525	+ && in_array( $scope, array( 'site', 'network' ), true )
	7526	+ ) {
	7527	+ self::announce_purge( $cause, 0, $scope, 'presentation' );
	7528	+ }
	7529	+
	7530	+ return 0;
	7531	+ }
	7532	+
	7533	+ /**
	7534	+ * Tell the server cache that a PARTIAL purge cleared cached responses.
	7535	+ *
	7536	+ * "Purge Page / Static Cache", "Purge CSS / JS Cache" and "Purge REST
	7537	+ * Cache" each delete cached RESPONSES for the whole site, so a cache in
	7538	+ * front of PHP is now serving copies xSpeed has just thrown away. Only
	7539	+ * "Purge All" announced itself, which left three of the four toolbar
	7540	+ * buttons doing exactly what this contract exists to prevent: clearing
	7541	+ * our copy while the server kept serving the stale one. The `assets` case
	7542	+ * was the sharpest — it deletes the minified bundles too, so LiteSpeed
	7543	+ * went on serving pages whose CSS and JS no longer exist. (QA #348)
	7544	+ *
	7545	+ * Sent as the full-purge shape (`url` null) because that is what happened:
	7546	+ * every cached page for this site went, not one address. `object` is not
	7547	+ * announced — flushing the object cache changes no rendered response a
	7548	+ * server cache could be holding.
	7549	+ *
	7550	+ * Public because Purge_Runner sweeps the local files itself, through
	7551	+ * purge_local(), rather than through purge_all() — so it has to announce
	7552	+ * on its own behalf or `wp xspeed purge` and the dashboard button clear
	7553	+ * our copy while LiteSpeed keeps serving the stale one.
	7554	+ *
	7555	+ * @param string $cause Who asked.
	7556	+ * @param int $removed Entries removed locally.
	7557	+ * @param string $scope Actionable adapter scope.
	7558	+ * @param string $intent Reason rendered responses changed.
	7559	+ */
	7560	+ public static function announce_purge( string $cause, int $removed, string $scope = 'site', string $intent = 'complete' ): void {
	7561	+ // Announcing is additive: the local sweep has already happened and
	7562	+ // succeeded. Notification must never be able to turn a working purge
	7563	+ // into a fatal, so anything the URL helpers do in an unusual context
	7564	+ // (early boot, a drop-in, a bare test harness) is contained here
	7565	+ // rather than propagating to the caller.
	7566	+ if ( ! function_exists( 'home_url' ) || ! function_exists( 'do_action' ) ) {
	7567	+ return;
	7568	+ }
	7569	+ try {
	7570	+ self::dispatch_purge_event(
	7571	+ 'xspeed_after_purge',
	7572	+ array(
	7573	+ 'url' => null,
	7574	+ 'host' => self::current_purge_host(),
	7575	+ 'path' => null,
	7576	+ 'cause' => $cause,
	7577	+ 'removed' => $removed,
	7578	+ 'scope' => $scope,
	7579	+ 'intent' => $intent,
	7580	+ 'urls' => array(),
	7581	+ )
	7582	+ );
	7583	+ } catch ( \Throwable $e ) {
	7584	+ self::log_purge_listener_error( 'xspeed_after_purge', $e );
	7585	+ }
	7586	+ }
	7587	+
	7588	+ /**
	7589	+ * Log a partial purge so the drill-down behind "Last purge" shows every
	7590	+ * clear, not only the full ones. Without this a site whose object cache
	7591	+ * is flushed on a schedule looks, from the log, like nothing happens.
	7592	+ *
	7593	+ * @param string $what Human label for the slice purged.
	7594	+ * @param string $cause Who asked.
	7595	+ * @param int|null $count Items removed, when countable.
	7596	+ */
	7597	+ private static function record_partial_purge( string $what, string $cause, ?int $count ): void {
	7598	+ $message = null === $count
	7599	+ ? sprintf(
	7600	+ /* translators: 1: what was purged, 2: cause of the purge. */
	7601	+ __( 'Purged %1$s (%2$s)', 'xspeed' ),
	7602	+ $what,
	7603	+ $cause
	7604	+ )
	7605	+ : sprintf(
	7606	+ /* translators: 1: what was purged, 2: cause of the purge, 3: number of files removed. */
	7607	+ __( 'Purged %1$s (%2$s) — %3$d file(s) removed', 'xspeed' ),
	7608	+ $what,
	7609	+ $cause,
	7610	+ $count
	7611	+ );
	7612	+
	7613	+ Activity_Log::record( 'cache_purged', $message, Activity_Log::INFO );
	7614	+
	7615	+ /*
	7616	+ * A partial purge is still a purge, and an edge in front of this site
	7617	+ * has to hear about it.
	7618	+ *
	7619	+ * "Purge Page / Static Cache" is always visible in the admin bar and
	7620	+ * clears every cached page for this site — the flat tree AND the
	7621	+ * static tree the generated nginx/Apache rules serve directly. It
	7622	+ * announced none of that: not `xspeed_after_purge_all`, which only
	7623	+ * purge_all() fires, and not the scoped actions. A CDN told to hold
	7624	+ * those pages went on serving the ones xSpeed had just deleted, for
	7625	+ * whatever lifetime it was given.
	7626	+ *
	7627	+ * Scope is `site` only for the two types that clear rendered HTML.
	7628	+ * An object-cache flush or a REST purge removes nothing an edge is
	7629	+ * holding, and announcing those as a site purge would have a CDN
	7630	+ * drop its whole cache every time a scheduled flush ran — worse than
	7631	+ * the silence this replaces. A type registered by another plugin
	7632	+ * through `xspeed_purge_types` is unknown here, so it says nothing
	7633	+ * rather than guessing.
	7634	+ *
	7635	+ * Not gated on `$count`, for the reason spelled out in purge_url():
	7636	+ * an empty local tree is not evidence that the edge is empty, and
	7637	+ * "Purge Page / Static Cache" with nothing left locally is precisely
	7638	+ * what someone clicks when the page they are looking at is stale.
	7639	+ * Answering that with silence made the button appear broken.
	7640	+ *
	7641	+ * That announcement is now `announce_purge()`'s, called beside this
	7642	+ * by the same callers (`page`, `assets`, `REST responses`). This
	7643	+ * function went back to being what its name says: a log entry. It
	7644	+ * used to publish as well, which double-fired every partial purge and
	7645	+ * — worse — announced `scope: none` for types #348's contract
	7646	+ * requires to stay silent about.
	7647	+ */
	7648	+ }
	7649	+
	7650	+ /**
	7651	+ * Clear the static tree only, leaving the flat cache in place.
	7652	+ *
	7653	+ * A narrower purge_all() for the case where only the web-server tree can
	7654	+ * be wrong: its files are keyed by `{host}{path}` and nothing else, so a
	7655	+ * response filed under the wrong path poisons it while the flat cache —
	7656	+ * keyed by cache_key(), discriminators included — stays correct. Avoids
	7657	+ * throwing away Critical CSS, minified bundles and the object cache to
	7658	+ * fix a static-only problem.
	7659	+ *
	7660	+ * @return int Number of index.html files removed.
	7661	+ */
	7662	+ public static function purge_static_tree(): int {
	7663	+ return self::rmtree_html( XSPEED_CACHE_STATIC_DIR );
	7664	+ }
	7665	+
	7666	+ /**
901	7667	* Recursively delete every `index.html` (and its precompressed
902	7668	* `index.html.br` sibling, if the Pro Brotli module wrote one) plus
903	7669	* empty directories inside the static-cache tree. Used by purge_all().
904	7670	* Returns the number of .html files removed so purge stats stay accurate
		@@ -904,8 +7670,24 @@
904	7670	* Returns the number of .html files removed so purge stats stay accurate
905	7671	* across the flat + static caches — .br siblings are not counted
906	7672	* (they're encodings of a page, not pages).
907	7673	*/
	7674	+ /**
	7675	+ * Delete a cache file, adding its size to the current sweep's byte
	7676	+ * total. filesize() is silenced and re-checked because the file can
	7677	+ * vanish between the glob and the unlink — a concurrent purge, or the
	7678	+ * cache GC — and a warning there would be noise, not news.
	7679	+ *
	7680	+ * @param string $file Absolute path inside the cache tree.
	7681	+ */
	7682	+ private static function sweep_delete( string $file ): void {
	7683	+ $size = @filesize( $file ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- the file may be gone already; see docblock.
	7684	+ if ( is_int( $size ) ) {
	7685	+ self::$sweep_bytes += $size;
	7686	+ }
	7687	+ wp_delete_file( $file );
	7688	+ }
	7689	+
908	7690	private static function rmtree_html( string $dir ): int {
909	7691	if ( ! is_dir( $dir ) ) {
910	7692	return 0;
911	7693	}
		@@ -929,14 +7711,16 @@
929	7711	@rmdir( $path );
930	7712	continue;
931	7713	}
932	7714	if ( substr( $entry, -5 ) === '.html' ) {
933		- wp_delete_file( $path );
	7715	+ self::sweep_delete( $path );
934	7716	++$removed;
935		- } elseif ( substr( $entry, -3 ) === '.br' ) {
936		- // Precompressed sibling (index.html.br). Remove it too so a
937		- // purge doesn't orphan stale Brotli bodies. Not counted.
938		- wp_delete_file( $path );
	7717	+ } elseif ( substr( $entry, -3 ) === '.br' || substr( $entry, -8 ) === '.br.size' ) {
	7718	+ // Precompressed sibling (index.html.br) and the record of its
	7719	+ // length. Remove both so a purge doesn't orphan stale Brotli
	7720	+ // bodies, or a size record that would later be read against a
	7721	+ // different sibling's bytes. Not counted.
	7722	+ self::sweep_delete( $path );
939	7723	}
940	7724	}
941	7725	return $removed;
942	7726	}
		@@ -953,25 +7737,42 @@
953	7737	}
954	7738	}
955	7739
956	7740	/**
	7741	+ * The raw xspeed_stats option as an array. Keys currently in use:
	7742	+ * 'last_purge', 'last_gc', 'gc_removed', 'gc_removed_total'.
	7743	+ */
	7744	+ public static function get_stats_option(): array {
	7745	+ $stats = get_option( 'xspeed_stats', array() );
	7746	+ return is_array( $stats ) ? $stats : array();
	7747	+ }
	7748	+
	7749	+ /**
957	7750	* Persist stats with autoload disabled — stats are only read in admin
958	7751	* contexts, so there is no reason to inflate every frontend request's
959	7752	* `wp_load_alloptions()` payload.
	7753	+ *
	7754	+ * MERGES into whatever is already stored. It used to overwrite, which
	7755	+ * was harmless while `last_purge` was the only key — with the GC keys
	7756	+ * alongside it, a purge would have wiped the GC history and vice versa.
960	7757	*/
961		- private static function update_stats( array $stats ) {
962		- if ( false === get_option( 'xspeed_stats' ) ) {
	7758	+ public static function update_stats( array $stats ) {
	7759	+ if ( false === get_option( 'xspeed_stats', false ) ) {
963	7760	add_option( 'xspeed_stats', $stats, '', 'no' );
964	7761	return;
965	7762	}
966		- update_option( 'xspeed_stats', $stats );
	7763	+ update_option( 'xspeed_stats', array_merge( self::get_stats_option(), $stats ) );
967	7764	}
968	7765
969	7766	public static function get_stats() {
970	7767	$count = 0;
971	7768	$size = 0;
972		- if ( is_dir( XSPEED_CACHE_DIR ) ) {
973		- $files = glob( XSPEED_CACHE_DIR . '/*.html' );
	7769	+ // This site's entries only — on multisite the tree is shared, so an
	7770	+ // unscoped count reported the whole network's pages on every
	7771	+ // subsite's dashboard. (#6)
	7772	+ $flat_root = XSPEED_CACHE_DIR . '/' . self::current_host_dir();
	7773	+ if ( is_dir( $flat_root ) ) {
	7774	+ $files = glob( $flat_root . '/*.html' );
974	7775	if ( $files ) {
975	7776	$count = count( $files );
976	7777	foreach ( $files as $f ) {
977	7778	$size += filesize( $f );
		@@ -994,8 +7795,12 @@
994	7795	Hit_Counter::collect_server_log_hits();
995	7796
996	7797	$stats = get_option( 'xspeed_stats', array() );
997	7798	$totals = Hit_Counter::totals_24h();
	7799	+ // One read of the ground truth for both fields below: it costs a
	7800	+ // stat of advanced-cache.php and a tokenize of wp-config.php, and
	7801	+ // this runs on every dashboard poll.
	7802	+ $serving = self::page_cache_operational();
998	7803	return array(
999	7804	'cached_pages' => $count,
1000	7805	'cache_size' => $size,
1001	7806	'last_purge' => isset( $stats['last_purge'] ) ? (int) $stats['last_purge'] : 0,
		@@ -1004,21 +7809,146 @@
1004	7809	// CacheHero stat grid + the Health module's panel.
1005	7810	'hits_24h' => $totals['hits'],
1006	7811	'misses_24h' => $totals['misses'],
1007	7812	'hit_ratio' => $totals['ratio'],
	7813	+ // Requests kept OUT of the ratio (404s + bots) — surfaced as its own
	7814	+ // "absorbed N scanner/bot requests" line rather than distorting the
	7815	+ // cache-performance number. (#118)
	7816	+ 'excluded_24h' => $totals['excluded'],
	7817	+ // True when an edge cache (Cloudflare) fronts the origin, so hits are
	7818	+ // absorbed before reaching PHP. The dashboard labels the ratio
	7819	+ // "origin-layer only" instead of implying it's the full picture. (#118)
	7820	+ 'edge_cache' => self::edge_cache_detected(),
	7821	+ // LiteSpeed Static Fast Path (#509): the web server serves hits
	7822	+ // with no PHP, no way to tag them, and no way to count them. The
	7823	+ // dashboard labels the ratio as PHP-layer only so a low number
	7824	+ // reads as the trade the user chose, not a fault.
	7825	+ //
	7826	+ // rewrite_installed() is part of the condition (QA on #513): when
	7827	+ // the .htaccess write failed (read-only file), hits still take
	7828	+ // the drop-in path and ARE counted — the disclosure would be the
	7829	+ // opposite of the truth. Health carries the "block missing"
	7830	+ // warning for that state; this flag only speaks when static
	7831	+ // serving is genuinely in effect.
	7832	+ 'static_hits_uncounted' => (
	7833	+ Server::LITESPEED === Server::type()
	7834	+ && ! empty( Settings::get()['cache_enabled'] )
	7835	+ && self::static_rewrite_allowed()
	7836	+ && self::rewrite_installed()
	7837	+ ),
	7838	+ /*
	7839	+ * Whether the page cache is actually SERVING, as opposed to
	7840	+ * switched on in settings. The hero read the setting alone and
	7841	+ * announced "Active — serving cached HTML"; a site whose
	7842	+ * advanced-cache.php had been taken over by another cache plugin
	7843	+ * got that line while every response carried
	7844	+ * `X-XSpeed-Cache: BYPASS`. The setting is the user's intent;
	7845	+ * this is the outcome, and the dashboard needs both to explain
	7846	+ * the difference.
	7847	+ */
	7848	+ 'page_cache_serving' => $serving,
	7849	+ /*
	7850	+ * Why not, when intent and outcome disagree. Only computed in
	7851	+ * that state — the detector sweep behind it is far more work than
	7852	+ * a stats call should do on an ordinary healthy site.
	7853	+ */
	7854	+ 'page_cache_blocked_reason' => ( ! $serving && ! empty( Settings::get()['cache_enabled'] ) )
	7855	+ ? ( self::acquisition_blocker() ?? self::not_serving_reason() )
	7856	+ : null,
1008	7857	);
1009	7858	}
1010	7859
1011	7860	/**
1012		- * Apply the user's enable/disable choice. Called only from the REST
1013		- * toggle endpoint, which is gated by current_user_can( 'manage_options' )
1014		- * and a verified REST nonce. This is the only place the drop-in and
1015		- * the WP_CACHE constant are written — they MUST NOT happen on
1016		- * register_activation_hook (WordPress.org review requirement).
	7861	+ * Why the cache is not serving, when nothing REFUSES to enable it.
1017	7862	*
	7863	+ * acquisition_blocker() answers "may we take the field", and since a
	7864	+ * foreign drop-in became takeable it answers null on a site where another
	7865	+ * plugin is nonetheless holding that file. Intent and outcome still
	7866	+ * disagree there, and the dashboard was left reporting the symptom -- not
	7867	+ * serving -- with no reason under it, which is exactly the state a user
	7868	+ * cannot act on.
	7869	+ *
	7870	+ * So this names the holder and says what to do: enabling takes it over.
	7871	+ */
	7872	+ private static function not_serving_reason(): ?string {
	7873	+ $owner = self::dropin_owner();
	7874	+ if ( self::DROPIN_FOREIGN !== $owner && self::DROPIN_UNREADABLE !== $owner ) {
	7875	+ return null;
	7876	+ }
	7877	+
	7878	+ if ( self::DROPIN_UNREADABLE === $owner ) {
	7879	+ return __( 'advanced-cache.php cannot be read, so xSpeed cannot tell whose page cache is installed.', 'xspeed' );
	7880	+ }
	7881	+
	7882	+ $label = Page_Cache_Detector::dropin_owner_label();
	7883	+ return $label
	7884	+ ? sprintf(
	7885	+ /* translators: %s: the page-caching plugin that owns advanced-cache.php. */
	7886	+ __( '%s is serving the page cache. Turn the xSpeed cache off and on again to take it over.', 'xspeed' ),
	7887	+ $label
	7888	+ )
	7889	+ : __( 'Another plugin is serving the page cache. Turn the xSpeed cache off and on again to take it over.', 'xspeed' );
	7890	+ }
	7891	+
	7892	+ /**
	7893	+ * Whether the current request should be kept OUT of the cache hit/miss
	7894	+ * ratio: a genuine 404, or a known bot / scanner. Runs at template_redirect
	7895	+ * time, so is_404() is resolved. (#118)
	7896	+ */
	7897	+ private static function miss_is_excluded(): bool {
	7898	+ if ( function_exists( 'is_404' ) && is_404() ) {
	7899	+ return true;
	7900	+ }
	7901	+ // A marked request is ours whatever its UA says: a renamed warmer,
	7902	+ // or a probe that has to send a browser's UA.
	7903	+ if ( Self_Traffic::request_is_marked() ) {
	7904	+ return true;
	7905	+ }
	7906	+ $ua = isset( $_SERVER['HTTP_USER_AGENT'] )
	7907	+ ? sanitize_text_field( wp_unslash( (string) $_SERVER['HTTP_USER_AGENT'] ) )
	7908	+ : '';
	7909	+ return Hit_Counter::is_bot_ua( $ua );
	7910	+ }
	7911	+
	7912	+ /**
	7913	+ * Whether an edge cache fronts this origin, so an unknown share of hits
	7914	+ * is served there and never counted here — which makes the origin ratio a
	7915	+ * partial view the dashboard has to label as such. (#118)
	7916	+ *
	7917	+ * This used to mean "the Cloudflare module is switched on", which answered
	7918	+ * no for every site fronted by anything else, and no for a site on
	7919	+ * Cloudflare that had never opened our Cloudflare panel. Both of those
	7920	+ * sites had their ratio presented as the whole story. Edge_Provider knows
	7921	+ * better and knows it per request, so ask it.
	7922	+ */
	7923	+ private static function edge_cache_detected(): bool {
	7924	+ return Edge_Provider::NONE !== Edge_Provider::detect()['confidence'];
	7925	+ }
	7926	+
	7927	+ /**
	7928	+ * Apply the user's enable/disable choice. Called from the REST toggle
	7929	+ * endpoint, which is gated by current_user_can( 'manage_options' ) and
	7930	+ * a verified REST nonce.
	7931	+ *
	7932	+ * This is the only path that ENABLES caching — a drop-in is never
	7933	+ * created for a user who hasn't opted in, which is the guideline that
	7934	+ * matters (a plugin must not install drop-ins or edit wp-config.php
	7935	+ * on a fresh activation). RESTORING the drop-in for a site that
	7936	+ * already has cache_enabled = true is a different act and is handled
	7937	+ * by restore_dropin_if_enabled() on activation and auto_heal() at
	7938	+ * runtime; without it every plugin update silently un-caches the site.
	7939	+ *
	7940	+ * Enabling is gated on acquisition_blocker(): if another plugin owns the
	7941	+ * drop-in, or WP_CACHE is written in a form we must not rewrite, nothing
	7942	+ * is written and the returned state carries `blocked` + a reason the
	7943	+ * caller can show. Callers must persist `cache_enabled` from the returned
	7944	+ * `enabled`, never from what they asked for.
	7945	+ *
1018	7946	* @param bool $enable User's choice.
1019	7947	* @return array{
1020	7948	* enabled: bool,
	7949	+ * blocked: bool,
	7950	+ * blocked_reason: ?string,
1021	7951	* dropin_installed: bool,
1022	7952	* wp_cache_constant: bool,
1023	7953	* wp_config_writable: bool,
1024	7954	* manual_snippet: ?string
		@@ -1023,29 +7953,294 @@
1023	7953	* wp_config_writable: bool,
1024	7954	* manual_snippet: ?string
1025	7955	* }
1026	7956	*/
1027		- public static function toggle( $enable ) {
	7957	+ public static function toggle( $enable, bool $consented = true ) {
	7958	+ Page_Cache_Detector::invalidate();
	7959	+ $expected = Page_Cache_Detector::inspect()['revision'];
	7960	+ /** Diagnostic seam; changing the expected revision can only force a safe refusal. */
	7961	+ $expected = (string) apply_filters( 'xspeed_page_cache_expected_revision', $expected );
	7962	+ $lock = self::page_cache_lock();
	7963	+ if ( ! is_resource( $lock ) ) {
	7964	+ return self::blocked_toggle_state( __( 'Could not lock page-cache ownership. Try again.', 'xspeed' ) );
	7965	+ }
	7966	+ $changed = false;
	7967	+ try {
	7968	+ Page_Cache_Detector::invalidate();
	7969	+ $fresh = Page_Cache_Detector::inspect()['revision'];
	7970	+ if ( ! hash_equals( (string) $expected, (string) $fresh ) ) {
	7971	+ return self::blocked_toggle_state( __( 'Page-cache ownership changed while xSpeed was checking it. Nothing was changed; try again.', 'xspeed' ) );
	7972	+ }
	7973	+ $before = self::page_cache_fingerprint();
	7974	+ $state = self::toggle_unlocked( (bool) $enable, $consented );
	7975	+ $changed = empty( $state['blocked'] ) && self::page_cache_fingerprint() !== $before;
	7976	+ return $state;
	7977	+ } finally {
	7978	+ flock( $lock, LOCK_UN );
	7979	+ fclose( $lock );
	7980	+
	7981	+ /*
	7982	+ * Announce the change to anything caching in front of us.
	7983	+ *
	7984	+ * Turning the page cache on or off changes what every URL on this
	7985	+ * site returns, and a CDN holding renders made under the old state
	7986	+ * goes on serving them for their whole lifetime. Nothing told it.
	7987	+ * OFF is the less obvious half and matters as much: the edge
	7988	+ * otherwise keeps serving pages from a cache the site no longer
	7989	+ * has.
	7990	+ *
	7991	+ * Only when something actually changed. A refused toggle wrote
	7992	+ * nothing — that is the whole point of the refusal — and purging
	7993	+ * after it would announce a change that did not happen. Nor does a
	7994	+ * toggle that found the cache already in the state it asked for:
	7995	+ * auto_heal() re-enables on every admin_init, and gating on "not
	7996	+ * refused" alone made every wp-admin page load empty the page
	7997	+ * cache and purge the edge (QA, 2026-09-23). The fingerprint is
	7998	+ * compared instead, so restoring a stripped drop-in still counts.
	7999	+ *
	8000	+ * After the writes and OUTSIDE the lock. Before them, a purge
	8001	+ * would repopulate from the state we are in the middle of leaving,
	8002	+ * which is how a "purge didn't work" report is born; inside them,
	8003	+ * it would hold single-occupancy ownership for the length of a
	8004	+ * filesystem sweep.
	8005	+ */
	8006	+ if ( $changed ) {
	8007	+ /*
	8008	+ * On shutdown, not inline. `purge_all()` sweeps the cache
	8009	+ * directory and fires the purge actions, and a listener on
	8010	+ * those can make an HTTP call to an edge — so running it here
	8011	+ * would make the toggle as slow as the sweep and couple its
	8012	+ * response to a third party. The Cloudflare Enterprise purge
	8013	+ * queue already defers for the same reason.
	8014	+ *
	8015	+ * Still after the writes: shutdown runs at the end of THIS
	8016	+ * request, with the new state on disk.
	8017	+ */
	8018	+ add_action(
	8019	+ 'shutdown',
	8020	+ static function () {
	8021	+ self::purge_all( 'page cache toggled' );
	8022	+ },
	8023	+ 20
	8024	+ );
	8025	+ }
	8026	+ }
	8027	+ }
	8028	+
	8029	+ /** Run the page-cache mutation while toggle() owns the scoped lock. */
	8030	+ /**
	8031	+ * @param bool $consented The user asked for this in the dashboard, so a
	8032	+ * foreign drop-in may be taken over. False on the
	8033	+ * unattended paths, which stand down instead.
	8034	+ */
	8035	+ /**
	8036	+ * What the page cache looks like on disk and in wp-config, as one string.
	8037	+ *
	8038	+ * `toggle()` compares it before and after its writes to tell a real ON/OFF
	8039	+ * flip, or a repaired drop-in, from a call that found everything already
	8040	+ * as asked. Only the latter must not announce a purge.
	8041	+ */
	8042	+ private static function page_cache_fingerprint(): string {
	8043	+ $dropin = self::read_file( WP_CONTENT_DIR . '/advanced-cache.php' );
	8044	+ return md5(
	8045	+ ( null === $dropin ? "\0none" : md5( $dropin ) )
	8046	+ . '|' . self::wp_cache_define_state()
	8047	+ . '|' . ( self::rewrite_installed() ? '1' : '0' )
	8048	+ . '|' . ( self::page_cache_operational() ? '1' : '0' )
	8049	+ );
	8050	+ }
	8051	+
	8052	+ private static function toggle_unlocked( bool $enable, bool $consented = true ) {
1028	8053	$enable = (bool) $enable;
1029	8054
1030	8055	if ( $enable ) {
1031		- $dropin_ok = self::install_dropin();
1032		- $wp_config_ok = self::set_wp_cache_constant( true );
	8056	+ /*
	8057	+ * Preflight. The drop-in and the WP_CACHE define are shared,
	8058	+ * single-occupancy state; if we do not own them, no part of this
	8059	+ * runs — not the drop-in, not wp-config.php, not the rewrite
	8060	+ * block. Refusing whole is the point: a partial enable leaves the
	8061	+ * site claiming a cache it cannot serve.
	8062	+ *
	8063	+ * Every caller routes through here (REST, onboarding, MCP, CLI,
	8064	+ * the optimize runner, Pro's migration), so the gate lives here
	8065	+ * rather than being re-implemented at each entry point.
	8066	+ *
	8067	+ * Except when there is nothing to acquire. A site where we
	8068	+ * already own the drop-in and are already serving is being asked
	8069	+ * to stay as it is, and the gate answers a different question —
	8070	+ * "is the field free to take" — which a merely ACTIVE competitor
	8071	+ * makes false. So "make sure caching is on", from an AI agent,
	8072	+ * the optimize runner or Pro's migration, came back as a refusal
	8073	+ * telling the user to deactivate a plugin on a site that was
	8074	+ * caching perfectly. The dashboard never saw it, because nobody
	8075	+ * presses Enable on a cache that is already enabled.
	8076	+ *
	8077	+ * Only the GATE is skipped. The writes below still run, and every
	8078	+ * one of them is individually idempotent — which matters, because
	8079	+ * this is the path CacheModule re-bakes the drop-in through when
	8080	+ * an exclusion rule or the TTL changes (#240, #251), and the path
	8081	+ * auto_heal() restores a stripped WP_CACHE through. Returning
	8082	+ * early here left both of those doing nothing at all, silently,
	8083	+ * on exactly the healthy sites this branch is about.
	8084	+ */
	8085	+ $reasserting = self::page_cache_operational() && self::DROPIN_XSPEED === self::dropin_owner();
	8086	+ $blocker = $reasserting ? null : self::acquisition_blocker();
	8087	+
	8088	+ /*
	8089	+ * Taking over another plugin's drop-in needs the user to have
	8090	+ * asked for it. On the dashboard they did -- they clicked the
	8091	+ * switch, having been told whose file it is. The UNATTENDED
	8092	+ * callers have no such click: restore_dropin_if_enabled() runs
	8093	+ * after a plugin update and auto_heal() on an admin page load,
	8094	+ * both from nothing more than `cache_enabled` still being true.
	8095	+ *
	8096	+ * A competitor installed since that flag was set would have its
	8097	+ * page cache seized by a background repair, which is the silent
	8098	+ * acquisition this plugin refuses to perform. So those callers
	8099	+ * pass $consented = false and stand down instead.
	8100	+ */
	8101	+ if ( null === $blocker && ! $consented && self::DROPIN_FOREIGN === self::dropin_owner() ) {
	8102	+ // Name the owner. This string is rendered by host plugins
	8103	+ // through Host::enable_page_cache(), and an unnamed refusal
	8104	+ // is what made every host invent its own explanation.
	8105	+ $owner_label = Page_Cache_Detector::dropin_owner_label();
	8106	+ return self::blocked_toggle_state(
	8107	+ $owner_label
	8108	+ ? sprintf(
	8109	+ /* translators: %s: the page-caching plugin that owns advanced-cache.php. */
	8110	+ __( '%s owns advanced-cache.php, so xSpeed left it alone. Enable the cache from the xSpeed dashboard to take it over.', 'xspeed' ),
	8111	+ $owner_label
	8112	+ )
	8113	+ : __( 'Another plugin owns advanced-cache.php, so xSpeed left it alone. Enable the cache from the xSpeed dashboard to take it over.', 'xspeed' )
	8114	+ );
	8115	+ }
	8116	+ if ( null !== $blocker ) {
	8117	+ Activity_Log::record(
	8118	+ 'cache_enable_blocked',
	8119	+ 'Cache not enabled — ' . $blocker,
	8120	+ Activity_Log::WARN
	8121	+ );
	8122	+
	8123	+ return self::blocked_toggle_state( $blocker );
	8124	+ }
	8125	+
	8126	+ $dropin_path = WP_CONTENT_DIR . '/advanced-cache.php';
	8127	+ $config_path = self::wp_config_path();
	8128	+ $dropin_before = file_exists( $dropin_path ) ? self::read_file( $dropin_path ) : null;
	8129	+ $config_before = '' !== $config_path ? self::read_file( $config_path ) : null;
	8130	+ $dropin_ok = self::install_dropin();
	8131	+ if ( ! $dropin_ok ) {
	8132	+ $partial = self::read_file( $dropin_path );
	8133	+ if ( is_string( $partial ) && xspeed_has_canonical_dropin_signature( $partial ) ) {
	8134	+ self::rollback_page_cache_artifacts( $dropin_path, $dropin_before, $partial, $config_path, $config_before, null );
	8135	+ }
	8136	+ /*
	8137	+ * Preflight said the field was clear, so this is a filesystem
	8138	+ * failure (or a drop-in that appeared in between). Without the
	8139	+ * drop-in there is no cache to enable, and persisting
	8140	+ * cache_enabled anyway is what produced sites reporting a
	8141	+ * healthy cache while serving every request uncached.
	8142	+ */
	8143	+ $reason = __( 'Could not write wp-content/advanced-cache.php. Check filesystem permissions.', 'xspeed' );
	8144	+ Activity_Log::record(
	8145	+ 'cache_enable_blocked',
	8146	+ 'Cache not enabled — ' . $reason,
	8147	+ Activity_Log::WARN
	8148	+ );
	8149	+
	8150	+ return array(
	8151	+ 'enabled' => false,
	8152	+ 'blocked' => true,
	8153	+ 'blocked_reason' => $reason,
	8154	+ 'dropin_installed' => false,
	8155	+ 'wp_cache_constant' => false,
	8156	+ 'rewrite_installed' => false,
	8157	+ 'wp_config_writable' => self::wp_config_writable(),
	8158	+ 'manual_snippet' => null,
	8159	+ 'nginx_snippet' => self::nginx_snippet(),
	8160	+ 'nginx_server_block' => self::full_nginx_server_block(),
	8161	+ );
	8162	+ }
	8163	+
	8164	+ $dropin_written = self::read_file( $dropin_path );
	8165	+ self::set_wp_cache_constant( true );
	8166	+ $config_written = '' !== $config_path ? self::read_file( $config_path ) : null;
	8167	+ Page_Cache_Detector::invalidate();
	8168	+ $dropin_ours = self::DROPIN_XSPEED === self::dropin_owner();
	8169	+ $constant_state = self::wp_cache_define_state();
	8170	+ $constant_ok = 'true' === $constant_state;
	8171	+
	8172	+ /*
	8173	+ * A wp-config.php we cannot write at all is a supported state, not
	8174	+ * a failed transaction. Plenty of managed hosts ship the file
	8175	+ * read-only; there the drop-in is ours and installed, the cache
	8176	+ * works the moment WP_CACHE exists, and the one line to paste
	8177	+ * comes back as `manual_snippet`. Rolling back instead left those
	8178	+ * hosts unable to turn the page cache on by any route — including
	8179	+ * when the user had already pasted the define, since the write
	8180	+ * fails on an unwritable file whatever value is already there.
	8181	+ *
	8182	+ * `undefined` ONLY. `false` looks eligible — this method would
	8183	+ * have rewritten it — but the snippet we hand back cannot work
	8184	+ * there: the file already says `define( 'WP_CACHE', false )`, the
	8185	+ * first define() call wins, and a user who pastes our line via
	8186	+ * FTP ends up with a cache that never serves AND a `duplicate`
	8187	+ * wp-config that blocks every future toggle in both directions.
	8188	+ * They have to edit the existing line, which means refusing here
	8189	+ * and saying so. `duplicate` and `dynamic` are refused by
	8190	+ * acquisition_blocker() before we get here, and if one appears in
	8191	+ * the race window it must still fail closed.
	8192	+ */
	8193	+ $manual_mode = ! $constant_ok
	8194	+ && 'undefined' === $constant_state
	8195	+ && ! self::can_write_wp_config();
	8196	+
	8197	+ if ( ! $dropin_ours || ( ! $constant_ok && ! $manual_mode ) ) {
	8198	+ if ( ! self::can_write_wp_config() ) {
	8199	+ $reason = 'false' === $constant_state
	8200	+ ? __( "wp-config.php is not writable and already contains define( 'WP_CACHE', false ). Change that line to true — adding a second one would leave the cache off and block xSpeed from changing it again.", 'xspeed' )
	8201	+ : __( 'xSpeed could not verify the complete page-cache write, and wp-config.php is not writable. Its changes were rolled back.', 'xspeed' );
	8202	+ } else {
	8203	+ $reason = __( 'xSpeed could not verify the complete page-cache write. Its changes were rolled back.', 'xspeed' );
	8204	+ }
	8205	+ self::rollback_page_cache_artifacts( $dropin_path, $dropin_before, $dropin_written, $config_path, $config_before, $config_written );
	8206	+ return self::blocked_toggle_state( $reason );
	8207	+ }
	8208	+ $wp_config_ok = $constant_ok;
1033	8209	$rewrite_ok = self::install_rewrite();
1034	8210	self::ensure_hits_log_file();
1035	8211	self::sync_mobile_flag();
1036	8212	$snippet = $wp_config_ok ? null : "define( 'WP_CACHE', true );";
	8213	+ Settings::update( array( 'cache_enabled' => true ) );
	8214	+ if ( empty( Settings::get()['cache_enabled'] ) ) {
	8215	+ self::remove_rewrite();
	8216	+ self::rollback_page_cache_artifacts( $dropin_path, $dropin_before, $dropin_written, $config_path, $config_before, $config_written );
	8217	+ delete_option( 'xspeed_page_cache_ownership_receipt' );
	8218	+ return self::blocked_toggle_state( __( 'xSpeed could not save the page-cache setting. Its file changes were rolled back.', 'xspeed' ) );
	8219	+ }
1037	8220
1038		- Activity_Log::record(
1039		- 'cache_enabled_event',
1040		- $wp_config_ok
1041		- ? 'Cache enabled. Drop-in installed, WP_CACHE constant set.'
1042		- : 'Cache enabled. Drop-in installed; wp-config.php not writable — add the WP_CACHE snippet manually.',
1043		- $wp_config_ok ? Activity_Log::SUCCESS : Activity_Log::WARN
1044		- );
	8221	+ /*
	8222	+ * Only when this call actually changed something. auto_heal() runs
	8223	+ * the enable transaction on every admin_init, and an unconditional
	8224	+ * entry filled the 50-slot log with identical "Cache enabled" lines
	8225	+ * within 50 wp-admin page loads, evicting every real event — plus
	8226	+ * an option write per admin request. The sentence is also false
	8227	+ * when nothing was installed.
	8228	+ */
	8229	+ if ( $dropin_written !== $dropin_before || $config_written !== $config_before ) {
	8230	+ Activity_Log::record(
	8231	+ 'cache_enabled_event',
	8232	+ $wp_config_ok
	8233	+ ? 'Cache enabled. Drop-in installed, WP_CACHE constant set.'
	8234	+ : 'Cache enabled. Drop-in installed; wp-config.php not writable — add the WP_CACHE snippet manually.',
	8235	+ $wp_config_ok ? Activity_Log::SUCCESS : Activity_Log::WARN
	8236	+ );
	8237	+ }
1045	8238
1046	8239	return array(
1047	8240	'enabled' => true,
	8241	+ 'blocked' => false,
	8242	+ 'blocked_reason' => null,
1048	8243	'dropin_installed' => (bool) $dropin_ok,
1049	8244	'wp_cache_constant' => (bool) $wp_config_ok,
1050	8245	'rewrite_installed' => (bool) $rewrite_ok,
1051	8246	'wp_config_writable' => self::wp_config_writable(),
		@@ -1058,26 +8253,168 @@
1058	8253	'nginx_server_block' => self::full_nginx_server_block(),
1059	8254	);
1060	8255	}
1061	8256
	8257	+ /*
	8258	+ * Whose advanced-cache.php is on disk decides how much of the disable
	8259	+ * below may run. Read it once, before anything is touched.
	8260	+ */
	8261	+ $owner = self::dropin_owner();
	8262	+ $not_ours = self::DROPIN_FOREIGN === $owner || self::DROPIN_UNREADABLE === $owner;
	8263	+ if ( ! self::set_wp_cache_constant( false ) ) {
	8264	+ /*
	8265	+ * The mirror of the enable path. A wp-config.php nobody can write
	8266	+ * does not trap the user in a cache they turned off: WP_CACHE on
	8267	+ * its own does nothing once advanced-cache.php is gone, and core
	8268	+ * simply skips the missing drop-in. Refusing here left the
	8269	+ * read-only managed hosts able to enable the page cache and never
	8270	+ * able to disable it again.
	8271	+ *
	8272	+ * A drop-in that is not ours reaches the same conclusion by a
	8273	+ * different road. WP_CACHE is then the switch for THEIR cache, so
	8274	+ * set_wp_cache_constant() refuses it — correctly, and permanently,
	8275	+ * because nothing the user does to xSpeed will make that file ours
	8276	+ * again. Treating that refusal as a failed disable was a trap with
	8277	+ * no exit: install any competing cache plugin while xSpeed's cache
	8278	+ * was on, and xSpeed's toggle could never be turned off again,
	8279	+ * while the dashboard went on claiming a cache that was serving
	8280	+ * nothing. Turning xSpeed off is entirely within our own state —
	8281	+ * our setting, our rewrite block — so it proceeds, and their
	8282	+ * constant and their file are left exactly as they are.
	8283	+ */
	8284	+ /*
	8285	+ * Every reason set_wp_cache_constant() refuses is structural
	8286	+ * except one, and the exception is the only one worth blocking
	8287	+ * on. It will not touch a constant it cannot prove is ours; it
	8288	+ * will not rewrite a define it cannot read as a literal —
	8289	+ * duplicate, dynamic, or inside a conditional; and it cannot
	8290	+ * write a file the filesystem will not let it write. None of
	8291	+ * those improve on a retry, and all of them leave a WP_CACHE
	8292	+ * that does nothing once our drop-in is gone. What is left — our
	8293	+ * own constant, in a shape we can rewrite, in a file we can
	8294	+ * write, and the write still failed — is a real I/O failure, and
	8295	+ * that one still refuses so the user is not told a cache was
	8296	+ * turned off while it goes on serving.
	8297	+ *
	8298	+ * The proof, not the drop-in, is the test. A user who pasted our
	8299	+ * manual snippet on a locked-down host has a WP_CACHE line with
	8300	+ * no receipt on it; if their drop-in later goes missing, we can
	8301	+ * never prove that line is ours, so refusing left the toggle
	8302	+ * stuck on with no way out but enabling first and disabling
	8303	+ * again. Nothing loads a drop-in that is not there, so the line
	8304	+ * is inert either way and the disable proceeds without it.
	8305	+ */
	8306	+ $leave_it = ! self::wp_cache_define_is_ours_to_remove( $owner )
	8307	+ || ! in_array( self::wp_cache_define_state(), array( 'true', 'false', 'undefined' ), true )
	8308	+ || ! self::can_write_wp_config();
	8309	+ if ( ! $leave_it ) {
	8310	+ return self::blocked_toggle_state( __( 'xSpeed could not safely remove its WP_CACHE setting. The cache remains enabled.', 'xspeed' ) );
	8311	+ }
	8312	+ }
1062	8313	self::remove_dropin();
1063		- self::set_wp_cache_constant( false );
	8314	+ if ( self::DROPIN_XSPEED === self::dropin_owner() ) {
	8315	+ // Put WP_CACHE back, and say so if we could not. Reporting a
	8316	+ // hardcoded `enabled: true` here claimed a working cache on a
	8317	+ // site whose constant we had just failed to restore.
	8318	+ // Put WP_CACHE back, then read the outcome off disk rather than
	8319	+ // trusting the write's return value — a write can report failure
	8320	+ // for a value that was already correct, and the question the
	8321	+ // caller needs answered is whether the cache serves.
	8322	+ self::set_wp_cache_constant( true );
	8323	+ return self::blocked_toggle_state(
	8324	+ self::page_cache_operational()
	8325	+ ? __( 'xSpeed could not remove its page-cache drop-in. The cache remains enabled.', 'xspeed' )
	8326	+ : __( 'xSpeed could not remove its page-cache drop-in, and could not put WP_CACHE back. The cache is not serving; check wp-config.php before changing the page cache again.', 'xspeed' )
	8327	+ );
	8328	+ }
1064	8329	self::remove_rewrite();
	8330	+ /*
	8331	+ * The .htaccess block serves cached HTML straight off disk without
	8332	+ * ever reaching PHP, so a block we failed to remove keeps answering
	8333	+ * requests from a cache the user just turned off — and nothing else
	8334	+ * in this method can stop it. remove_rewrite() also returns false
	8335	+ * when there is no .htaccess to clean, which is the ordinary case,
	8336	+ * so ask the file rather than trust the return value.
	8337	+ */
	8338	+ if ( self::rewrite_installed() ) {
	8339	+ if ( $not_ours ) {
	8340	+ // Nothing to roll back — under a foreign drop-in this method
	8341	+ // removed no drop-in and wrote no constant, and it could not
	8342	+ // put either back if it wanted to. Say what is actually left.
	8343	+ return self::blocked_toggle_state( __( 'xSpeed could not remove its rewrite rules from .htaccess, which would keep serving cached pages. Remove the xSpeed block from .htaccess by hand before turning the page cache off.', 'xspeed' ) );
	8344	+ }
	8345	+ /*
	8346	+ * Roll the disable back. Both calls can fail — a filesystem that
	8347	+ * would not let us remove the block may not let us write the
	8348	+ * drop-in either — and discarding their results reported an
	8349	+ * enabled cache over a site left with no drop-in and no
	8350	+ * constant. Fall through to the default state so the artifact
	8351	+ * fields are read from disk rather than asserted.
	8352	+ */
	8353	+ self::install_dropin();
	8354	+ self::set_wp_cache_constant( true );
	8355	+ // Both of those can fail — a filesystem that would not let us
	8356	+ // remove the block may not let us write the drop-in either — so
	8357	+ // the message follows what is on disk afterwards, not what the
	8358	+ // calls returned.
	8359	+ return self::blocked_toggle_state(
	8360	+ self::page_cache_operational()
	8361	+ ? __( 'xSpeed could not remove its rewrite rules from .htaccess, which would keep serving cached pages. The cache remains enabled.', 'xspeed' )
	8362	+ : __( 'xSpeed could not remove its rewrite rules from .htaccess, and could not restore the drop-in it had just removed. The cache is not serving, and the site may still return stale cached pages until the xSpeed block is removed from .htaccess by hand.', 'xspeed' )
	8363	+ );
	8364	+ }
1065	8365	// Drop the device-bucket marker too — with the drop-in gone there's
1066	8366	// nothing left to read it, and leaving it behind would dirty a fresh
1067	8367	// re-enable (and leaks across test runs).
1068	8368	self::sync_mobile_flag( false );
	8369	+ Settings::update( array( 'cache_enabled' => false ) );
	8370	+ if ( ! empty( Settings::get()['cache_enabled'] ) ) {
	8371	+ if ( $not_ours ) {
	8372	+ // Same as above: there is nothing of ours on disk to restore.
	8373	+ return self::blocked_toggle_state( __( 'xSpeed could not save the disabled state.', 'xspeed' ) );
	8374	+ }
	8375	+ self::install_dropin();
	8376	+ self::set_wp_cache_constant( true );
	8377	+ return self::blocked_toggle_state( __( 'xSpeed could not save the disabled state. The page cache was restored.', 'xspeed' ) );
	8378	+ }
1069	8379
	8380	+ // A WP_CACHE we could not remove because wp-config.php is read-only
	8381	+ // is left behind deliberately (see above) — say so rather than
	8382	+ // reporting a constant that is still in the file as gone.
	8383	+ $constant_left = 'true' === self::wp_cache_define_state();
	8384	+ /*
	8385	+ * Say why the constant is still there, because there are now three
	8386	+ * different reasons and they call for different advice. Keyed off the
	8387	+ * same facts $leave_it was, so the log cannot drift from the decision
	8388	+ * it is describing — it did, briefly, and reported a wp-config.php as
	8389	+ * unwritable when the real reason was that we could not prove the
	8390	+ * line was ours.
	8391	+ */
	8392	+ if ( self::DROPIN_UNREADABLE === $owner ) {
	8393	+ $log_message = 'Cache disabled. advanced-cache.php could not be read, so it and the WP_CACHE setting were left untouched.';
	8394	+ } elseif ( $not_ours ) {
	8395	+ $log_message = 'Cache disabled. Another plugin owns advanced-cache.php, so its drop-in and its WP_CACHE setting were left untouched.';
	8396	+ } elseif ( ! $constant_left ) {
	8397	+ $log_message = 'Cache disabled. Drop-in removed.';
	8398	+ } elseif ( ! self::wp_cache_define_is_ours_to_remove( $owner ) ) {
	8399	+ $log_message = 'Cache disabled. WP_CACHE was left in place — it carries no proof xSpeed wrote it, and it does nothing without a drop-in.';
	8400	+ } elseif ( ! self::can_write_wp_config() ) {
	8401	+ $log_message = 'Cache disabled. Drop-in removed; wp-config.php not writable, so WP_CACHE was left in place (harmless without the drop-in).';
	8402	+ } else {
	8403	+ $log_message = 'Cache disabled. Drop-in removed; WP_CACHE was left in place (harmless without the drop-in).';
	8404	+ }
1070	8405	Activity_Log::record(
1071	8406	'cache_disabled_event',
1072		- 'Cache disabled. Drop-in removed.',
1073		- Activity_Log::INFO
	8407	+ $log_message,
	8408	+ $constant_left ? Activity_Log::WARN : Activity_Log::INFO
1074	8409	);
1075	8410
1076	8411	return array(
1077	8412	'enabled' => false,
	8413	+ 'blocked' => false,
	8414	+ 'blocked_reason' => null,
1078	8415	'dropin_installed' => false,
1079		- 'wp_cache_constant' => false,
	8416	+ 'wp_cache_constant' => $constant_left,
1080	8417	'rewrite_installed' => false,
1081	8418	'wp_config_writable' => self::wp_config_writable(),
1082	8419	'manual_snippet' => null,
1083	8420	'nginx_snippet' => self::nginx_snippet(),
		@@ -1084,9 +8421,134 @@
1084	8421	'nginx_server_block' => self::full_nginx_server_block(),
1085	8422	);
1086	8423	}
1087	8424
	8425	+ /** Acquire the local lock that serializes page-cache ownership changes. */
	8426	+ private static function page_cache_lock() {
	8427	+ $path = WP_CONTENT_DIR . '/.xspeed-page-cache.lock';
	8428	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fopen,WordPress.PHP.NoSilencedErrors.Discouraged -- flock requires a local handle; failure is a safe blocked result.
	8429	+ $lock = @fopen( $path, 'c+' );
	8430	+ if ( ! is_resource( $lock ) || ! flock( $lock, LOCK_EX ) ) {
	8431	+ return false;
	8432	+ }
	8433	+ return $lock;
	8434	+ }
	8435	+
1088	8436	/**
	8437	+ * Build the stable response shape for a refused transaction.
	8438	+ *
	8439	+ * The artifact fields report what is ON DISK, not zeros. A refusal means
	8440	+ * xSpeed changed nothing — on a site already running our cache that is
	8441	+ * exactly the state where the drop-in and WP_CACHE are both still in
	8442	+ * place and still serving hits. Hardcoding false told the dashboard the
	8443	+ * cache had been dismantled every time a refusal was returned.
	8444	+ */
	8445	+ private static function blocked_toggle_state( string $reason ): array {
	8446	+ /*
	8447	+ * `enabled` answers ONE question: is the page cache operational right
	8448	+ * now. Not what was asked for, and not what the option says.
	8449	+ *
	8450	+ * WordPress loads advanced-cache.php only when WP_CACHE is truthy, so
	8451	+ * those two files together are the whole answer, and reading them is
	8452	+ * the only source that cannot go stale. Both of the alternatives were
	8453	+ * tried here and both produced wrong answers on real paths: a
	8454	+ * hardcoded false told a caller the cache had gone away on a site
	8455	+ * still serving hits, and the persisted setting told a caller the
	8456	+ * cache was healthy after a rollback had just removed the artifacts
	8457	+ * — the option is not written until the end of the transaction, so
	8458	+ * mid-transaction it is stale by construction.
	8459	+ *
	8460	+ * Deliberately not a parameter. Every branch that got to choose its
	8461	+ * own answer eventually chose wrong.
	8462	+ */
	8463	+ return array(
	8464	+ 'enabled' => self::page_cache_operational(),
	8465	+ 'blocked' => true,
	8466	+ 'blocked_reason' => $reason,
	8467	+ 'dropin_installed' => self::DROPIN_XSPEED === self::dropin_owner(),
	8468	+ 'wp_cache_constant' => 'true' === self::wp_cache_define_state(),
	8469	+ 'rewrite_installed' => self::rewrite_installed(),
	8470	+ 'wp_config_writable' => self::wp_config_writable(),
	8471	+ 'manual_snippet' => null,
	8472	+ 'nginx_snippet' => self::nginx_snippet(),
	8473	+ 'nginx_server_block' => self::full_nginx_server_block(),
	8474	+ );
	8475	+ }
	8476	+
	8477	+ /**
	8478	+ * The wp-config.php line a user must paste, or null when none is needed.
	8479	+ *
	8480	+ * Non-null only where the drop-in is ours and WP_CACHE is not set to true
	8481	+ * in a file we can write — the read-only managed host. Everywhere else the
	8482	+ * constant is ours to manage and there is nothing to ask for.
	8483	+ */
	8484	+ public static function manual_wp_cache_snippet(): ?string {
	8485	+ if ( self::DROPIN_XSPEED !== self::dropin_owner() ) {
	8486	+ return null;
	8487	+ }
	8488	+ if ( 'true' === self::wp_cache_define_state() ) {
	8489	+ return null;
	8490	+ }
	8491	+ return self::wp_config_writable() ? null : "define( 'WP_CACHE', true );";
	8492	+ }
	8493	+
	8494	+ /**
	8495	+ * Is the page cache serving right now?
	8496	+ *
	8497	+ * Two things decide it, and `WP_CACHE` is not one of them.
	8498	+ *
	8499	+ * xSpeed serves a cached page from `template_redirect` whenever the
	8500	+ * setting is on — see the `HIT (php)` mark on that path, which exists
	8501	+ * precisely for "the drop-in isn't loaded". `advanced-cache.php` and the
	8502	+ * `WP_CACHE` constant that loads it are the FAST path: they answer before
	8503	+ * WordPress boots, which is worth a lot of milliseconds and nothing at
	8504	+ * all to the question of whether pages are being served from cache.
	8505	+ *
	8506	+ * Conflating the two reported a dead cache over a live one. On a managed
	8507	+ * host with an unwritable wp-config.php — the exact case the manual
	8508	+ * snippet exists for — one card said "Your cache works on every request",
	8509	+ * "On, but not serving", "nothing will be cached until you add this line"
	8510	+ * and "hit ratio 67%", all at once, and told the user to edit a file they
	8511	+ * have no permission to write. The released 1.2.1 reported that site as
	8512	+ * active, correctly.
	8513	+ *
	8514	+ * So: the setting, and whether anyone else holds the drop-in. A foreign
	8515	+ * drop-in answers before WordPress loads us, so ours never runs and we
	8516	+ * genuinely are not serving. An unreadable one we must assume the same of.
	8517	+ * Everything else — our drop-in, or none at all — serves.
	8518	+ *
	8519	+ * Public because it is part of the host-plugin contract — see Host. A
	8520	+ * plugin that installed xSpeed needs to be able to say whether the cache
	8521	+ * it asked for is actually serving, and no combination of settings reads
	8522	+ * answers that.
	8523	+ */
	8524	+ public static function page_cache_operational(): bool {
	8525	+ $settings = Settings::get();
	8526	+ if ( empty( $settings['cache_enabled'] ) ) {
	8527	+ return false;
	8528	+ }
	8529	+ $owner = self::dropin_owner();
	8530	+ return self::DROPIN_FOREIGN !== $owner && self::DROPIN_UNREADABLE !== $owner;
	8531	+ }
	8532	+
	8533	+ /** Restore exact snapshots only while disk still matches our own write. */
	8534	+ private static function rollback_page_cache_artifacts( string $dropin_path, ?string $dropin_before, ?string $dropin_written, string $config_path, ?string $config_before, ?string $config_written ): void {
	8535	+ // Roll back only files that still carry xSpeed's just-written state.
	8536	+ if ( null !== $dropin_written && hash_equals( $dropin_written, (string) self::read_file( $dropin_path ) ) ) {
	8537	+ if ( null === $dropin_before ) {
	8538	+ wp_delete_file( $dropin_path );
	8539	+ } else {
	8540	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- Exact compare-and-swap rollback under the scoped lock.
	8541	+ file_put_contents( $dropin_path, $dropin_before );
	8542	+ }
	8543	+ }
	8544	+ if ( '' !== $config_path && null !== $config_before && null !== $config_written && hash_equals( $config_written, (string) self::read_file( $config_path ) ) && self::wp_cache_receipt_matches_source( $config_written ) ) {
	8545	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- Exact compare-and-swap rollback under the scoped lock.
	8546	+ file_put_contents( $config_path, $config_before );
	8547	+ }
	8548	+ }
	8549	+
	8550	+ /**
1089	8551	* Check wp-config.php writability via WP_Filesystem. Plugin Check flags
1090	8552	* direct is_writable() under WordPress.WP.AlternativeFunctions.
1091	8553	*/
1092	8554	private static function wp_config_writable() {
		@@ -1123,10 +8585,11 @@
1123	8585	* they don't share a user at all. A default-umask 0644 file is then
1124	8586	* unwritable by nginx, the access_log write silently fails, and the
1125	8587	* dashboard shows a 0% hit ratio even though static HITs are serving.
1126	8588	* So we widen the dir to 0777 and the file to 0666 — group/other write —
1127		- * so whatever uid nginx runs as can append. (The file holds only HIT
1128		- * request lines, no secrets.)
	8589	+ * so whatever uid nginx runs as can append. The file holds HIT request
	8590	+ * lines and must be protected like an access log: paths and queries can
	8591	+ * contain sensitive values.
1129	8592	*/
1130	8593	/**
1131	8594	* Directory holding the nginx hit log. Lives under uploads/, NOT the
1132	8595	* cache dir — uninstall.php and a cache purge both delete the cache
		@@ -1140,11 +8603,22 @@
1140	8603	* Falls back to the cache dir only if uploads is somehow unavailable.
1141	8604	*/
1142	8605	public static function hits_log_dir(): string {
1143	8606	if ( function_exists( 'wp_upload_dir' ) ) {
	8607	+ // One drop-in serves the whole network, so its hit log has one
	8608	+ // home: the main site's uploads. Resolved per blog, the path
	8609	+ // baked into the drop-in changed with whichever blog's admin
	8610	+ // last ran auto_heal(), and each rewrite read as a page-cache
	8611	+ // change and purged the site and the edge (QA, 2026-09-23).
	8612	+ // A subsite's uploads are `<main uploads>/sites/<id>`, so the
	8613	+ // suffix comes off rather than switching blogs to ask.
1144	8614	$uploads = wp_upload_dir( null, false );
1145	8615	if ( is_array( $uploads ) && empty( $uploads['error'] ) && ! empty( $uploads['basedir'] ) ) {
1146		- return rtrim( (string) $uploads['basedir'], '/' ) . '/xspeed';
	8616	+ $base = rtrim( (string) $uploads['basedir'], '/' );
	8617	+ if ( function_exists( 'is_multisite' ) && is_multisite() ) {
	8618	+ $base = (string) preg_replace( '#/sites/\d+$#', '', $base );
	8619	+ }
	8620	+ return $base . '/xspeed';
1147	8621	}
1148	8622	}
1149	8623	return XSPEED_CACHE_DIR;
1150	8624	}
		@@ -1169,12 +8643,218 @@
1169	8643	* and the fast pre-WP path was silently dead.
1170	8644	*
1171	8645	* @param bool|null $enabled Force a state; null reads the current setting.
1172	8646	*/
	8647	+ /**
	8648	+ * Write the subdirectory-multisite path list the drop-in needs to work
	8649	+ * out which blog a request belongs to.
	8650	+ *
	8651	+ * The drop-in runs before WordPress, so it cannot call is_multisite()
	8652	+ * or get_blog_details(). It can only see REQUEST_URI — so we persist the
	8653	+ * network's blog paths (one per line, longest first) next to the cache
	8654	+ * files, exactly as sync_mobile_flag() persists the device flag. The
	8655	+ * drop-in prefix-matches the URI against that list to pick the same
	8656	+ * bucket Cache::current_host_dir() picks. (#6)
	8657	+ *
	8658	+ * No file is written for a single site or a subdomain network — there
	8659	+ * the host alone identifies the blog and the bucket carries no prefix.
	8660	+ */
	8661	+ public static function sync_site_paths(): void {
	8662	+ $file = XSPEED_CACHE_DIR . '/.site-paths';
	8663	+
	8664	+ $needed = function_exists( 'is_multisite' ) && is_multisite()
	8665	+ && ( ! function_exists( 'is_subdomain_install' ) || ! is_subdomain_install() );
	8666	+
	8667	+ if ( ! $needed ) {
	8668	+ if ( file_exists( $file ) ) {
	8669	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- plain marker removal; non-fatal.
	8670	+ @unlink( $file );
	8671	+ }
	8672	+ return;
	8673	+ }
	8674	+
	8675	+ if ( ! function_exists( 'get_sites' ) ) {
	8676	+ return;
	8677	+ }
	8678	+
	8679	+ $paths = array();
	8680	+ foreach ( get_sites( array( 'number' => 0 ) ) as $site ) {
	8681	+ $prefix = self::path_prefix_segment( (string) $site->path );
	8682	+ if ( '' !== $prefix ) {
	8683	+ // Store the raw path so the drop-in can prefix-match a URI,
	8684	+ // alongside the segment it maps to.
	8685	+ $paths[ trim( (string) $site->path, '/' ) ] = $prefix;
	8686	+ }
	8687	+ }
	8688	+
	8689	+ if ( empty( $paths ) ) {
	8690	+ if ( file_exists( $file ) ) {
	8691	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- see above.
	8692	+ @unlink( $file );
	8693	+ }
	8694	+ return;
	8695	+ }
	8696	+
	8697	+ // Longest path first so /a/b wins over /a.
	8698	+ uksort(
	8699	+ $paths,
	8700	+ static function ( $x, $y ) {
	8701	+ return strlen( (string) $y ) <=> strlen( (string) $x );
	8702	+ }
	8703	+ );
	8704	+
	8705	+ $lines = array();
	8706	+ foreach ( $paths as $raw => $segment ) {
	8707	+ $lines[] = $raw . '|' . $segment;
	8708	+ }
	8709	+
	8710	+ if ( ! is_dir( XSPEED_CACHE_DIR ) && ! wp_mkdir_p( XSPEED_CACHE_DIR ) ) {
	8711	+ return;
	8712	+ }
	8713	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- read by the pre-WP drop-in; WP_Filesystem needs admin credentials unavailable here.
	8714	+ file_put_contents( $file, implode( "\n", $lines ), LOCK_EX );
	8715	+ }
	8716	+
	8717	+ /**
	8718	+ * Compile `ignored_query_params` into a regex the DROP-IN can use.
	8719	+ *
	8720	+ * Tracking traffic was cached but never served fast. should_cache()
	8721	+ * learned to allow `?utm_source=…` through and cache_key() strips the
	8722	+ * query, so `/post` and `/post?utm_source=x` share one entry — but the
	8723	+ * drop-in still bailed on ANY query string, so every visitor from an
	8724	+ * email or ad campaign paid a full WordPress boot to be handed a file
	8725	+ * that was already on disk. On a marketing site that is most of the
	8726	+ * paid traffic taking the slowest path. (#13)
	8727	+ *
	8728	+ * The drop-in runs before WordPress, so it cannot read the option or
	8729	+ * call Glob_Matcher. It gets a precompiled alternation instead, written
	8730	+ * next to the cache files exactly as sync_mobile_flag() writes the
	8731	+ * device flag. Regenerated whenever cache settings are saved.
	8732	+ *
	8733	+ * Only the KEYS matter: a param whose name is on the list contributes
	8734	+ * nothing to the response, so the entry keyed without it is correct.
	8735	+ * Anything not on the list means the drop-in must stand down and let
	8736	+ * PHP decide — the file is deleted rather than left stale when the
	8737	+ * list is empty, so a missing sidecar always fails safe.
	8738	+ */
	8739	+ public static function sync_query_allowlist(): void {
	8740	+ $file = XSPEED_CACHE_DIR . '/.ignored-query-params';
	8741	+
	8742	+ /*
	8743	+ * Stored read, not Settings_Manager::get() — this runs from boot(),
	8744	+ * before translation is legal (see stored_cache_opts()).
	8745	+ *
	8746	+ * A raw read applies no schema defaults, and this field's default is a
	8747	+ * long tracking-parameter list, NOT empty. Falling back to array()
	8748	+ * would strip that whole allow-list from the drop-in on any install
	8749	+ * that has never saved the Cache panel. So fall back to the schema's
	8750	+ * own default, read from the module without building its labels.
	8751	+ */
	8752	+ $opts = self::stored_cache_opts();
	8753	+ $ignored = is_array( $opts['ignored_query_params'] ?? null )
	8754	+ ? $opts['ignored_query_params']
	8755	+ : \XSpeed\Modules\Cache\CacheModule::default_ignored_query_params();
	8756	+
	8757	+ $parts = array();
	8758	+ foreach ( $ignored as $pattern ) {
	8759	+ $pattern = trim( (string) $pattern );
	8760	+ if ( '' === $pattern ) {
	8761	+ continue;
	8762	+ }
	8763	+ if ( '~' === $pattern[0] ) {
	8764	+ // Raw regex, PHP-side dialect. Keep it — unlike a server
	8765	+ // config, the drop-in runs the same PCRE engine, so the
	8766	+ // pattern behaves identically. Anchored below with the rest.
	8767	+ $body = substr( $pattern, 1 );
	8768	+ if ( '' !== $body && false !== @preg_match( '#^(?:' . $body . ')$#', '' ) ) { // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- a malformed user pattern must be dropped, not fatal.
	8769	+ $parts[] = $body;
	8770	+ }
	8771	+ continue;
	8772	+ }
	8773	+ // Glob semantics, same as Glob_Matcher: * is any run, ? is one.
	8774	+ $esc = preg_quote( $pattern, '#' );
	8775	+ $esc = str_replace( array( '\*', '\?' ), array( '.*', '.' ), $esc );
	8776	+ $parts[] = $esc;
	8777	+ }
	8778	+
	8779	+ if ( empty( $parts ) ) {
	8780	+ if ( file_exists( $file ) ) {
	8781	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- plain marker removal; non-fatal.
	8782	+ @unlink( $file );
	8783	+ }
	8784	+ return;
	8785	+ }
	8786	+
	8787	+ if ( ! is_dir( XSPEED_CACHE_DIR ) && ! wp_mkdir_p( XSPEED_CACHE_DIR ) ) {
	8788	+ return;
	8789	+ }
	8790	+
	8791	+ // The drop-in anchors this as `^…$`, so the lookahead refuses the
	8792	+ // never-ignored names whole, whatever entry would have matched them.
	8793	+ $never = implode( '|', array_map( static fn ( $p ) => preg_quote( $p, '#' ), self::NEVER_IGNORED_QUERY_PARAMS ) );
	8794	+ $payload = '(?!(?:' . $never . ')$)(?:' . implode( '|', array_unique( $parts ) ) . ')';
	8795	+
	8796	+ // Only write when the value actually changed. This runs from
	8797	+ // reconcile_mobile_separate() on CacheModule::boot(), so an
	8798	+ // unconditional write cost a file write and an exclusive lock on every
	8799	+ // request that boots WordPress — every MISS, every BYPASS, every admin
	8800	+ // screen, every REST call. sync_mobile_flag() below is the model: it
	8801	+ // touches the marker only when the setting flips.
	8802	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents, WordPress.PHP.NoSilencedErrors.Discouraged -- our own sidecar; an unreadable file falls through to the write below.
	8803	+ if ( is_readable( $file ) && (string) @file_get_contents( $file ) === $payload ) {
	8804	+ return;
	8805	+ }
	8806	+
	8807	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- read by the pre-WP drop-in; WP_Filesystem needs admin credentials unavailable here.
	8808	+ file_put_contents( $file, $payload, LOCK_EX );
	8809	+ }
	8810	+
	8811	+ /**
	8812	+ * CacheModule's STORED settings, read straight from the option.
	8813	+ *
	8814	+ * `Settings_Manager::get( 'cache' )` builds CacheModule's settings schema,
	8815	+ * whose labels are declared through `__()`. The reconcile chain below runs
	8816	+ * from `CacheModule::boot()` on `plugins_loaded` — before
	8817	+ * `after_setup_theme`, the point WordPress 6.7+ treats as safe to
	8818	+ * translate — so going through the schema there fires
	8819	+ * `_load_textdomain_just_in_time` on every request AND resolves the labels
	8820	+ * against a domain that is not loaded yet.
	8821	+ *
	8822	+ * The callers here need stored values, not schema metadata, so a raw read
	8823	+ * is equivalent. It applies NO defaults or coercion: read each key with a
	8824	+ * fallback matching the schema's own default.
	8825	+ *
	8826	+ * @return array<string,mixed>
	8827	+ */
	8828	+ private static function stored_cache_opts(): array {
	8829	+ $stored = get_option( Settings_Manager::OPTION_PREFIX . 'cache', array() );
	8830	+ return is_array( $stored ) ? $stored : array();
	8831	+ }
	8832	+
	8833	+ /**
	8834	+ * Strict truthiness for the LiteSpeed Static Fast Path opt-in.
	8835	+ *
	8836	+ * On non-LiteSpeed servers the key is out of the schema and carried by
	8837	+ * preserved_keys(), so a REST/MCP write lands VERBATIM — QA on #513
	8838	+ * stored the string "false" on Apache and the fast path installed
	8839	+ * itself the moment the site moved to LiteSpeed, because
	8840	+ * empty("false") is false. Only an explicit, unambiguous "yes" may
	8841	+ * enable a path that trades away hit tagging; any other value —
	8842	+ * "false", "no", arbitrary junk — stays OFF, which is the default the
	8843	+ * user never left.
	8844	+ */
	8845	+ private static function litespeed_optin_enabled( $value ): bool {
	8846	+ if ( true === $value || 1 === $value ) {
	8847	+ return true;
	8848	+ }
	8849	+ return is_string( $value )
	8850	+ && in_array( strtolower( trim( $value ) ), array( '1', 'true', 'on', 'yes' ), true );
	8851	+ }
	8852	+
1173	8853	public static function sync_mobile_flag( $enabled = null ): void {
1174	8854	if ( null === $enabled ) {
1175		- $opts = Settings_Manager::get( 'cache' );
1176		- $enabled = ! empty( $opts['mobile_separate'] );
	8855	+ $stored = self::stored_cache_opts();
	8856	+ $enabled = ! empty( $stored['mobile_separate'] );
1177	8857	}
1178	8858	$dir = XSPEED_CACHE_DIR;
1179	8859	$flag = $dir . '/.mobile-separate';
1180	8860	if ( $enabled ) {
		@@ -1187,9 +8867,9 @@
1187	8867	}
1188	8868	return;
1189	8869	}
1190	8870	if ( file_exists( $flag ) ) {
1191		- // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- plain marker removal; non-fatal.
	8871	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- plain marker removal; non-fatal.
1192	8872	@unlink( $flag );
1193	8873	}
1194	8874	}
1195	8875
		@@ -1217,9 +8897,9 @@
1217	8897	}
1218	8898	return;
1219	8899	}
1220	8900	if ( file_exists( $flag ) ) {
1221		- // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- plain marker removal; non-fatal.
	8901	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- plain marker removal; non-fatal.
1222	8902	@unlink( $flag );
1223	8903	}
1224	8904	}
1225	8905
		@@ -1240,8 +8920,16 @@
1240	8920	* reconcile, and toggle() handles install/teardown itself.
1241	8921	*/
1242	8922	public static function reconcile_mobile_separate(): void {
1243	8923	self::sync_mobile_flag();
	8924	+ if ( defined( 'XSPEED_CACHE_DIR' ) ) {
	8925	+ // Keep the drop-in's view of the network's blog paths current — a
	8926	+ // site added or removed changes which bucket its URLs belong to. (#6)
	8927	+ self::sync_site_paths();
	8928	+ // Keep the drop-in's copy of the query allow-list current — a param
	8929	+ // added in settings must reach the fast path too. (#13)
	8930	+ self::sync_query_allowlist();
	8931	+ }
1244	8932
1245	8933	// The rewrite/static reconciliation below needs the plugin's path
1246	8934	// constants. They're absent in early-boot / unit-test contexts where
1247	8935	// only the drop-in flag matters — bail to the flag-only behavior then.
		@@ -1257,8 +8945,31 @@
1257	8945
1258	8946	$rewrite_present = self::rewrite_installed();
1259	8947	$rewrite_wanted = self::static_rewrite_allowed();
1260	8948
	8949	+ // Did the thing that actually invalidates cache KEYS change?
	8950	+ // mobile_separate buckets entries as |d / |m, so flipping it makes
	8951	+ // stored entries mis-bucketed and they must go. A rewrite-state
	8952	+ // mismatch from anything else (e.g. mod_headers detection, a hand-
	8953	+ // edited .htaccess) changes no key at all — the same files are still
	8954	+ // valid, they're just served by PHP instead of by the web server.
	8955	+ // Purging there is what let one WP-CLI call wipe the whole cache on
	8956	+ // every bootstrap. (#138)
	8957	+ //
	8958	+ // Read the setting from the SAME place static_rewrite_allowed() and
	8959	+ // sync_mobile_flag() do — the cache module's settings, not the
	8960	+ // top-level xspeed_options — or this marker would track a key that
	8961	+ // never changes and a real flip would go unnoticed.
	8962	+ // Stored read — this runs from boot(); see stored_cache_opts().
	8963	+ $cache_opts = self::stored_cache_opts();
	8964	+ $mobile_now = ! empty( $cache_opts['mobile_separate'] );
	8965	+ $mobile_last = get_option( 'xspeed_last_mobile_separate', null );
	8966	+ $mobile_flipped = ( null !== $mobile_last && (bool) (int) $mobile_last !== $mobile_now );
	8967	+
	8968	+ if ( (string) (int) $mobile_now !== (string) $mobile_last ) {
	8969	+ update_option( 'xspeed_last_mobile_separate', $mobile_now ? '1' : '0', false );
	8970	+ }
	8971	+
1261	8972	if ( $rewrite_present === $rewrite_wanted ) {
1262	8973	// Already consistent — nothing flipped, leave caches intact so a
1263	8974	// plain settings save (e.g. expiry change) doesn't blow the cache.
1264	8975	return;
		@@ -1263,17 +8974,19 @@
1263	8974	// plain settings save (e.g. expiry change) doesn't blow the cache.
1264	8975	return;
1265	8976	}
1266	8977
1267		- // The setting flipped. Bring the rewrite into line and purge the
1268		- // now-misbucketed cache so the next request re-primes under the new
1269		- // device scheme.
	8978	+ // Bring the rewrite into line with what this server actually supports.
1270	8979	if ( $rewrite_wanted ) {
1271	8980	self::install_rewrite();
1272	8981	} else {
1273	8982	self::remove_rewrite();
1274	8983	}
1275		- self::purge_all( 'mobile_separate changed' );
	8984	+
	8985	+ // Only discard cache contents when the device bucketing changed.
	8986	+ if ( $mobile_flipped ) {
	8987	+ self::purge_all( 'mobile_separate changed' );
	8988	+ }
1276	8989	}
1277	8990
1278	8991	/**
1279	8992	* Whether the server-level static-rewrite fast path may be used.
		@@ -1297,10 +9010,12 @@
1297	9010	* `.htaccess` equivalent of nginx's per-location `access_log` to record
1298	9011	* the hit. The result was a cache that worked but was invisible: no HIT
1299	9012	* header and a hit-ratio frozen near 0%. Every OTHER server gives the
1300	9013	* user a visible HIT header + a counted hit (nginx via add_header +
1301		- * access_log in its snippet; Apache via .htaccess mod_headers, which it
1302		- * honors). To keep LiteSpeed CONSISTENT with the rest, we route its hits
	9014	+ * access_log in its snippet; Apache via the `<IfModule mod_headers.c>`
	9015	+ * block in rewrite_block_lines(), WHEN that module is loaded — when it is
	9016	+ * not, Apache takes this same drop-in fallback). To keep LiteSpeed
	9017	+ * CONSISTENT with the rest, we route its hits
1303	9018	* through the PHP drop-in instead — the drop-in emits
1304	9019	* `X-XSpeed-Cache: HIT (php)` and calls Hit_Counter inline, exactly the
1305	9020	* observable behavior the other servers get. The cost is the drop-in's
1306	9021	* ~30ms TTFB vs the static path's ~10ms, paid only on LiteSpeed; in
		@@ -1308,34 +9023,501 @@
1308	9023	* the truth there. (Apache keeps the static fast path — it honors the
1309	9024	* header.) See maybe_emit_lscache_headers() for the paired LSCache
1310	9025	* stand-down that stops LiteSpeed's own module from shadowing the
1311	9026	* drop-in.
	9027	+ *
	9028	+ * Opt-in (#509): `litespeed_static_rewrite` re-enables the fast path on
	9029	+ * LiteSpeed for users who value raw TTFB over hit accounting. The trade
	9030	+ * is stated in the setting's copy: statically served hits carry no
	9031	+ * X-XSpeed-Cache header and are not counted (LiteSpeed logs the
	9032	+ * original request line, so even the access-log scan cannot see
	9033	+ * them — see Hit_Counter::collect_server_log_hits()). The drop-in
	9034	+ * default above stays — nobody is surprised into an unverifiable cache.
1312	9035	*/
1313	9036	public static function static_rewrite_allowed(): bool {
1314		- // LiteSpeed: drop-in serves hits (visible + counted) — see docblock.
	9037	+ // Stored read — reached from boot(); see stored_cache_opts().
	9038	+ $opts = self::stored_cache_opts();
	9039	+ // LiteSpeed: drop-in serves hits (visible + counted) unless the user
	9040	+ // explicitly opted into the static fast path — see docblock.
	9041	+ if ( Server::LITESPEED === Server::type()
	9042	+ && ! self::litespeed_optin_enabled( $opts['litespeed_static_rewrite'] ?? false ) ) {
	9043	+ return false;
	9044	+ }
	9045	+ // Apache without mod_headers is in EXACTLY the position LiteSpeed
	9046	+ // is in above: it can run the RewriteRule and serve the static
	9047	+ // file, but it cannot stamp `X-XSpeed-Cache` on the response, so
	9048	+ // the hit is invisible to the user and uncountable by
	9049	+ // Hit_Counter. The docblock above used to assert Apache "honors
	9050	+ // mod_headers" and left it on the fast path unconditionally —
	9051	+ // true only when the module is actually loaded. Fall back to the
	9052	+ // drop-in when it isn't, trading ~10ms of TTFB for a hit that
	9053	+ // shows up in the header and the ratio. (Field report: hit ratio
	9054	+ // pinned at 0% on a working Apache cache.)
	9055	+ if ( Server::APACHE === Server::type() && ! Server::apache_has_mod_headers() ) {
	9056	+ return false;
	9057	+ }
	9058	+ return empty( $opts['mobile_separate'] );
	9059	+ }
	9060	+
	9061	+ /**
	9062	+ * Why the device-blind static rewrite is NOT installed, when it isn't.
	9063	+ * Returns 'mobile_separate' when Separate Mobile Cache is the blocker
	9064	+ * (the static file is one-per-URL, so it can't coexist with per-device
	9065	+ * buckets), 'no_mod_headers' when Apache can't stamp the HIT header,
	9066	+ * '' otherwise. Lets the dashboard explain the slow path instead of
	9067	+ * silently falling back to PHP serving. (FBS-83145)
	9068	+ *
	9069	+ * Every refusal in static_rewrite_allowed() that is NOT self-explanatory
	9070	+ * must have a branch here. Otherwise the Health card falls through to
	9071	+ * "Block missing — toggle Enable Cache off and on to reinstall it",
	9072	+ * advice that cannot work: the same condition that suppressed the write
	9073	+ * suppresses the reinstall, and auto_heal() strips the block again on
	9074	+ * the next admin page load. (Field report: Apache host with mod_headers
	9075	+ * unloaded sat on the slow path with no way to find out why.)
	9076	+ */
	9077	+ /**
	9078	+ * Qualify a raw probe result with what we already KNOW about config.
	9079	+ *
	9080	+ * probe_static_rewrite() writes its own file under the static-cache tree
	9081	+ * and fetches that, which succeeds whenever the web server can serve a
	9082	+ * static file at all — including when static_rewrite_allowed() is false
	9083	+ * and no real page is on the static path. So `active: true` on its own is
	9084	+ * not evidence that pages are being served statically.
	9085	+ *
	9086	+ * The reachable case is nginx with Separate Mobile Cache on: the snippet
	9087	+ * lives in the server block and we cannot remove it, pages are
	9088	+ * deliberately routed to the PHP drop-in, but the probe file is still
	9089	+ * served directly.
	9090	+ *
	9091	+ * The Health panel learned this in 88b4b50; the CLI, REST and MCP paths
	9092	+ * did not, so they kept reporting "active" in exactly that configuration.
	9093	+ * Rather than repeat the reasoning at each call site, they now all come
	9094	+ * through here.
	9095	+ *
	9096	+ * Deliberately does NOT consult rewrite_installed(): on nginx the fast
	9097	+ * path is the pasted snippet and there is no .htaccess marker to find, so
	9098	+ * requiring one would report every correctly-configured nginx site as
	9099	+ * broken.
	9100	+ *
	9101	+ * Carries `rules` through as well. The dashboard bootstrap builds its own
	9102	+ * payload and so had it; every other caller — POST /cache/recheck-rewrite,
	9103	+ * `wp xspeed cache recheck-rewrite`, the recheck_rewrite_rules MCP tool —
	9104	+ * came through here and got four keys, so the one surface a user reaches
	9105	+ * AFTER pasting the block could not tell them whether the block took. An
	9106	+ * agent driving the same fix could not read it at all.
	9107	+ *
	9108	+ * @param array $probe Raw result from probe_static_rewrite().
	9109	+ * @return array{active:bool,inconclusive:bool,reason:string,block_reason:string,rules:array}
	9110	+ */
	9111	+ public static function qualify_rewrite_probe( array $probe ): array {
	9112	+ $active = (bool) ( $probe['active'] ?? false );
	9113	+ $inconclusive = (bool) ( $probe['inconclusive'] ?? false );
	9114	+ $reason = (string) ( $probe['reason'] ?? '' );
	9115	+ $block_reason = self::static_rewrite_block_reason();
	9116	+ $rules = self::rules_state( $probe );
	9117	+
	9118	+ // Same observed-refusal check Health makes. This is the shared path for
	9119	+ // `wp xspeed cache recheck-rewrite` and POST /cache/recheck-rewrite —
	9120	+ // and, because a CLI command is automatically an MCP tool, for the
	9121	+ // AI-facing surface too. Leaving it out would have fixed the dashboard
	9122	+ // while the CLI kept answering that the fast path was active. (#372)
	9123	+ if ( '' === $block_reason ) {
	9124	+ $skip = self::last_static_skip();
	9125	+ if ( ! empty( $skip['reason'] ) ) {
	9126	+ $block_reason = 'skipped_' . (string) $skip['reason'];
	9127	+ }
	9128	+ }
	9129	+
	9130	+ // With page caching off there is nothing to serve, so `active` can
	9131	+ // never be true here whatever the raw probe says. probe_static_rewrite()
	9132	+ // writes its OWN file under the static tree and fetches that, which
	9133	+ // succeeds whenever the server can serve a static file at all — and on
	9134	+ // nginx the snippet is server-level, so it keeps succeeding after the
	9135	+ // cache is switched off.
	9136	+ //
	9137	+ // block_reason() used to carry this meaning by accident: it returned
	9138	+ // 'mobile_separate' with caching off, and the refusal branch below
	9139	+ // forced active=false. Now that it correctly reports '' (nothing can
	9140	+ // block a fast path that isn't in use), this consumer has to state the
	9141	+ // condition itself — otherwise `wp xspeed cache recheck-rewrite` and
	9142	+ // POST /cache/recheck-rewrite claim "the web server is serving cache
	9143	+ // hits directly" on a site with no cache. That is a positive false
	9144	+ // claim rather than a nag, i.e. worse than the bug being fixed.
	9145	+ $cache_opts = Settings::get();
	9146	+ if ( empty( $cache_opts['cache_enabled'] ) ) {
	9147	+ return array(
	9148	+ 'active' => false,
	9149	+ 'inconclusive' => false,
	9150	+ 'reason' => 'Page caching is off, so there is no cache for the web server to serve.',
	9151	+ 'block_reason' => '',
	9152	+ 'rules' => $rules,
	9153	+ );
	9154	+ }
	9155	+
	9156	+ // A known refusal outranks the probe, and also outranks
	9157	+ // "inconclusive" — a blocked rewrite whose probe merely failed to
	9158	+ // complete is still definitely blocked.
	9159	+ if ( '' !== $block_reason ) {
	9160	+ $active = false;
	9161	+ $inconclusive = false;
	9162	+ $reason = self::block_reason_text( $block_reason );
	9163	+ }
	9164	+
	9165	+ return array(
	9166	+ 'active' => $active,
	9167	+ 'inconclusive' => $inconclusive,
	9168	+ 'reason' => $reason,
	9169	+ 'block_reason' => $block_reason,
	9170	+ 'rules' => $rules,
	9171	+ );
	9172	+ }
	9173	+
	9174	+ /**
	9175	+ * Human-readable explanation for a static_rewrite_block_reason() code.
	9176	+ *
	9177	+ * Each one has to say what to DO about it: "mobile_separate" alone tells
	9178	+ * a user nothing, and the whole point of surfacing a refusal instead of
	9179	+ * the probe verdict is that it is actionable.
	9180	+ */
	9181	+ public static function block_reason_text( string $code ): string {
	9182	+ switch ( $code ) {
	9183	+ case 'mobile_separate':
	9184	+ return 'Separate Mobile Cache is on, which disables the device-blind static rewrite. Cache hits are served by PHP instead. If your site serves the same HTML to every device, turn it off in Cache settings for much faster hits.';
	9185	+ case 'no_mod_headers':
	9186	+ return "Apache's mod_headers is not loaded, so the static rewrite cannot mark its responses as cache hits. Enable mod_headers, or leave hits on the PHP path.";
	9187	+ case 'litespeed_dropin':
	9188	+ return 'On LiteSpeed, cache hits are served by the PHP drop-in so every hit is tagged X-XSpeed-Cache and counted in the hit ratio — LiteSpeed\'s .htaccess engine cannot do either for statically served files. If raw TTFB matters more to you than hit accounting, turn on LiteSpeed Static Fast Path in Cache settings to serve hits straight from the web server.';
	9189	+ case 'skipped_nonce':
	9190	+ return 'The server config is correct, but pages are not reaching the static cache because they contain nonces, so hits are served by PHP instead. A static file is served with no PHP, so a nonce baked into one could never be refreshed and every anonymous form on the page would break once it expired — keeping these pages on PHP is deliberate. Nonces usually come from plugin widgets; disabling the ones the site does not use lets its pages be served statically again.';
	9191	+ default:
	9192	+ return sprintf( 'The static rewrite is disabled (%s).', $code );
	9193	+ }
	9194	+ }
	9195	+
	9196	+ public static function static_rewrite_block_reason(): string {
	9197	+ // Nothing can be blocking the fast path when there is no cache to
	9198	+ // serve from it. Without this the dashboard told users with page
	9199	+ // caching switched OFF that Separate Mobile Cache "is disabling
	9200	+ // faster static serving" — a fast path they were not using, about a
	9201	+ // cache that did not exist. Every caller of this is a user-facing
	9202	+ // explanation of why the rewrite is off, so "the cache is off" is
	9203	+ // the honest answer, and it is silence. (#108)
	9204	+ $opts = Settings::get();
	9205	+ if ( empty( $opts['cache_enabled'] ) ) {
	9206	+ return '';
	9207	+ }
1315	9208	if ( Server::LITESPEED === Server::type() ) {
	9209	+ // The opt-in is read RAW (stored_cache_opts), not through
	9210	+ // Settings_Manager::get(): the schema's bool coercion is a PHP
	9211	+ // cast, and (bool) "false" is true — so a junk string stored on
	9212	+ // another server (where the key bypasses the schema) would come
	9213	+ // back from the coercion layer as an ENABLE. Raw + the strict
	9214	+ // parse below is the same read static_rewrite_allowed() makes,
	9215	+ // so the two can't disagree either. (QA on #513)
	9216	+ $stored = self::stored_cache_opts();
	9217	+ // The intended default — but no longer silent: with the opt-in
	9218	+ // off, Health must be able to explain the PHP path and point at
	9219	+ // the toggle instead of falling through to "reinstall the block"
	9220	+ // advice that cannot work here. (#509)
	9221	+ if ( ! self::litespeed_optin_enabled( $stored['litespeed_static_rewrite'] ?? false ) ) {
	9222	+ return 'litespeed_dropin';
	9223	+ }
	9224	+ $cache_opts = Settings_Manager::get( 'cache' );
	9225	+ return ! empty( $cache_opts['mobile_separate'] ) ? 'mobile_separate' : '';
	9226	+ }
	9227	+ if ( Server::APACHE === Server::type() && ! Server::apache_has_mod_headers() ) {
	9228	+ return 'no_mod_headers';
	9229	+ }
	9230	+ $cache_opts = Settings_Manager::get( 'cache' );
	9231	+ return ! empty( $cache_opts['mobile_separate'] ) ? 'mobile_separate' : '';
	9232	+ }
	9233	+
	9234	+ /**
	9235	+ * Whether migration flagged Separate Mobile Cache for user review. Set by
	9236	+ * Migration::map_mobile_separate() when a source plugin (WP Rocket / WP
	9237	+ * Super Cache / LiteSpeed) had its "separate mobile cache" option on: we
	9238	+ * import it as OFF (to keep the device-blind static fast path) but record
	9239	+ * this flag so the dashboard can invite the user to turn it back on only
	9240	+ * if their site genuinely serves different HTML per device. (FBS-83145)
	9241	+ */
	9242	+ public static function mobile_separate_needs_review(): bool {
	9243	+ // Same reasoning as static_rewrite_block_reason(): the invitation is
	9244	+ // "turn this back on if your site needs it, to regain the fast path",
	9245	+ // which is meaningless with page caching off — there is no fast path
	9246	+ // to regain, and the equality probe behind the prompt would fetch
	9247	+ // pages that aren't being cached. Gated here rather than at the two
	9248	+ // payload call sites (Admin + Rest_Api) so `enabled`, `blocking` and
	9249	+ // `needs_review` are consistently gated on the same condition. (#108)
	9250	+ $opts = Settings::get();
	9251	+ if ( empty( $opts['cache_enabled'] ) ) {
1316	9252	return false;
1317	9253	}
1318		- $opts = Settings_Manager::get( 'cache' );
1319		- return empty( $opts['mobile_separate'] );
	9254	+ $cache_opts = Settings_Manager::get( 'cache' );
	9255	+ return ! empty( $cache_opts['mobile_separate_review'] );
1320	9256	}
1321	9257
	9258	+ /**
	9259	+ * Clear the review flag — called when the user has acted on the prompt
	9260	+ * (dismissed it, or turned Separate Mobile Cache on/off deliberately) so
	9261	+ * the dashboard callout doesn't nag forever. Writes the option directly
	9262	+ * (bypassing Settings_Manager) so it never touches schema fields.
	9263	+ */
	9264	+ public static function clear_mobile_separate_review(): void {
	9265	+ $stored = get_option( 'xspeed_module_cache', array() );
	9266	+ if ( ! is_array( $stored ) || empty( $stored['mobile_separate_review'] ) ) {
	9267	+ return;
	9268	+ }
	9269	+ unset( $stored['mobile_separate_review'] );
	9270	+ update_option( 'xspeed_module_cache', $stored );
	9271	+ }
	9272	+
	9273	+ /**
	9274	+ * On-demand probe: does the homepage serve materially the same HTML to a
	9275	+ * desktop and a mobile browser? Fetches home_url() twice over loopback —
	9276	+ * once with a desktop User-Agent, once with a mobile one — strips
	9277	+ * per-request noise (nonces, CSRF tokens, session ids, inline timestamps),
	9278	+ * and compares. When identical, Separate Mobile Cache is almost certainly
	9279	+ * unnecessary and the user can turn it off to regain the static fast path.
	9280	+ *
	9281	+ * NEVER run automatically (no page-load cost) — only from the dashboard
	9282	+ * "Check now" button. Result is cached for 10 minutes so a double-click or
	9283	+ * a re-render doesn't fire two more self-requests. (FBS-83145)
	9284	+ *
	9285	+ * @return array{ identical:bool, checked:bool, reason?:string, desktop_bytes?:int, mobile_bytes?:int }
	9286	+ */
	9287	+ public static function probe_mobile_equality(): array {
	9288	+ $cached = get_transient( 'xspeed_mobile_equality_probe' );
	9289	+ if ( is_array( $cached ) ) {
	9290	+ return $cached;
	9291	+ }
	9292	+
	9293	+ $home = home_url( '/' );
	9294	+ $host = (string) wp_parse_url( $home, PHP_URL_HOST );
	9295	+ if ( '' === $host ) {
	9296	+ $result = array( 'identical' => false, 'checked' => false, 'reason' => 'home_url has no host' );
	9297	+ set_transient( 'xspeed_mobile_equality_probe', $result, MINUTE_IN_SECONDS );
	9298	+ return $result;
	9299	+ }
	9300	+
	9301	+ // Match WP core's own mobile detection (wp_is_mobile) so the probe
	9302	+ // reflects what the site would actually branch on. iPhone Safari for
	9303	+ // mobile; a current desktop Chrome UA for desktop.
	9304	+ $desktop_ua = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36';
	9305	+ $mobile_ua = 'Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Mobile/15E148 Safari/604.1';
	9306	+
	9307	+ $is_local = function_exists( 'wp_get_environment_type' )
	9308	+ && in_array( wp_get_environment_type(), array( 'local', 'development' ), true );
	9309	+
	9310	+ $fetch = static function ( string $ua ) use ( $home, $is_local ) {
	9311	+ $resp = wp_remote_get(
	9312	+ $home,
	9313	+ array(
	9314	+ 'timeout' => 5,
	9315	+ 'sslverify' => ! $is_local,
	9316	+ 'redirection' => 2,
	9317	+ // Bust any per-device cache so we compare freshly-rendered
	9318	+ // HTML, and pass the device UA the site would branch on.
	9319	+ 'user-agent' => $ua,
	9320	+ // A real device UA by design, so only the header marks
	9321	+ // this as ours to analytics and the hit ratio.
	9322	+ 'headers' => Self_Traffic::headers( array( 'Cache-Control' => 'no-cache' ) ),
	9323	+ )
	9324	+ );
	9325	+ if ( is_wp_error( $resp ) || 200 !== (int) wp_remote_retrieve_response_code( $resp ) ) {
	9326	+ return null;
	9327	+ }
	9328	+ return (string) wp_remote_retrieve_body( $resp );
	9329	+ };
	9330	+
	9331	+ $desktop = $fetch( $desktop_ua );
	9332	+ $mobile = $fetch( $mobile_ua );
	9333	+
	9334	+ if ( null === $desktop || null === $mobile ) {
	9335	+ $result = array( 'identical' => false, 'checked' => false, 'reason' => 'could not fetch homepage twice' );
	9336	+ set_transient( 'xspeed_mobile_equality_probe', $result, MINUTE_IN_SECONDS );
	9337	+ return $result;
	9338	+ }
	9339	+
	9340	+ $identical = self::normalize_html_for_diff( $desktop ) === self::normalize_html_for_diff( $mobile );
	9341	+
	9342	+ $result = array(
	9343	+ 'identical' => $identical,
	9344	+ 'checked' => true,
	9345	+ 'desktop_bytes' => strlen( $desktop ),
	9346	+ 'mobile_bytes' => strlen( $mobile ),
	9347	+ );
	9348	+ set_transient( 'xspeed_mobile_equality_probe', $result, 10 * MINUTE_IN_SECONDS );
	9349	+ return $result;
	9350	+ }
	9351	+
	9352	+ /**
	9353	+ * Strip per-request noise from HTML so a desktop-vs-mobile diff reflects
	9354	+ * real structural differences, not nonces / session ids / timestamps that
	9355	+ * change on every render. Deliberately conservative: it normalizes the
	9356	+ * handful of well-known noise sources and collapses whitespace, so a site
	9357	+ * that truly serves different markup per device still compares as different.
	9358	+ */
	9359	+ private static function normalize_html_for_diff( string $html ): string {
	9360	+ // Every rule here errs toward "they differ" being WRONG rather than
	9361	+ // "they match" being wrong: this check only ever tells a user it is
	9362	+ // SAFE to turn Separate Mobile Cache off, so a false "identical"
	9363	+ // would cost them device-specific output. The risk of being too
	9364	+ // conservative is milder but real — the useful answer never appears,
	9365	+ // and the feature's whole pitch ("we'll prove it's safe to turn
	9366	+ // off") silently never pays out. These close the gaps that made a
	9367	+ // mismatch effectively guaranteed on an ordinary WordPress site. (#108)
	9368	+ $patterns = array(
	9369	+ // WP nonces in attribute or JSON form: data-nonce="…",
	9370	+ // _wpnonce=…, "nonce":"…". The `[:=]` adjacency below misses
	9371	+ // wp_nonce_field()'s own markup — `name="_wpnonce" value="ab…"`
	9372	+ // puts `value=` between the key and the token — which is the
	9373	+ // single most common nonce shape in WordPress, so that form is
	9374	+ // matched explicitly first.
	9375	+ '/name=["\']?(_wpnonce|_ajax_nonce)["\']?\s+value=["\']?[a-z0-9]{8,}/i',
	9376	+ // CSP nonces on script/style tags. Base64, so uppercase and
	9377	+ // +/= appear — the hex-only rules below can never match one,
	9378	+ // and a CSP-enabled site therefore differed on every fetch.
	9379	+ // MUST precede the generic nonce rule: that one stops at the
	9380	+ // first non-alphanumeric, leaving the rest of the token behind
	9381	+ // and the two responses still unequal.
	9382	+ // The quotes are optional so HTML5's legal unquoted attribute
	9383	+ // form (`<script nonce=AbCd+q/r=>`) is covered too — without
	9384	+ // that it fell through to the generic rule, which is the exact
	9385	+ // failure this rule exists to remove.
	9386	+ '/\bnonce=(["\'])?[A-Za-z0-9+\/=_-]{8,}(?(1)\1)/',
	9387	+ '/(_wpnonce|nonce|_ajax_nonce)["\']?\s*[:=]\s*["\']?[a-z0-9]{8,}/i',
	9388	+ // Generic hex tokens: cache busters, session ids, md5/sha
	9389	+ // digests. Was 16+, which left an 11-15 char gap above the
	9390	+ // 10-char nonce rule.
	9391	+ //
	9392	+ // The token MUST contain at least one a-f letter. `[a-f0-9]`
	9393	+ // also matches every decimal digit, so a bare `{10,}` erased
	9394	+ // every 10+ digit INTEGER anywhere in the document — including
	9395	+ // visible body text. A page whose desktop and mobile HTML
	9396	+ // differed only by a per-device numeric id (an AdSense slot, an
	9397	+ // A/B bucket, an analytics property) then compared as identical,
	9398	+ // and the check told the user it was safe to switch off the very
	9399	+ // setting keeping that output correct — the one direction this
	9400	+ // function must never fail in. Decimal-only runs are left to the
	9401	+ // bounded epoch rule below, which is deliberately narrower.
	9402	+ //
	9403	+ // Known, accepted (QA R2): a token whose letters all fall in a-f
	9404	+ // reads as a digest, so a per-device `ABC1234567890` strips even
	9405	+ // though it is an id, not a hash. Deliberately left open — the
	9406	+ // alternatives all cost more than the bug:
	9407	+ //
	9408	+ // Token shape (lowercase-only, case-uniformity, a trailing
	9409	+ // letter) cannot separate it. `ABC1234567890` and
	9410	+ // `ABCDEF012345` — an uppercase digest this rule SHOULD strip —
	9411	+ // are both all-hex, uniformly cased, letters-then-digits.
	9412	+ // Each variant fixed the id only by sparing the digest.
	9413	+ //
	9414	+ // Letter density does separate them (23% letters vs 50%), but
	9415	+ // measured over 2000 md5/sha1/sha256 samples, requiring letters
	9416	+ // spread through the token leaves 21-67% of REAL digests
	9417	+ // unmatched depending on the window. Digest noise is most of
	9418	+ // what this function exists to remove, so that trade guts it.
	9419	+ //
	9420	+ // Context (protecting data-* attribute values from this rule)
	9421	+ // works for ids and still strips digests in URLs, classes and
	9422	+ // query strings — but regresses a CHANGING digest inside a
	9423	+ // non-nonce data-* attribute, and needs a two-pass
	9424	+ // hold/restore. Viable if R2 is ever worth pressing; its
	9425	+ // failure at least errs toward "differ".
	9426	+ //
	9427	+ // An A-F-only prefix on a per-device id is rare, and the earlier
	9428	+ // nonce rules already claim the data-nonce/_wpnonce shapes.
	9429	+ '/\b(?=[a-f0-9]{10,}\b)[0-9]*[a-f][a-f0-9]*\b/i',
	9430	+ // wp-generated unique ids (e.g. wp-block ids, aria ids).
	9431	+ '/(id|for|aria-[a-z]+)="[^"]*-[0-9]{3,}"/i',
	9432	+ // ISO-ish timestamps + epoch-looking numbers in query strings.
	9433	+ '/\?ver=[0-9.]+/',
	9434	+ '/[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9:.+Z-]+/',
	9435	+ // Our own signature's generation stamp. The two fetches are
	9436	+ // sequential and each writes its own entry, so this differs on
	9437	+ // essentially every comparison — and it is space-separated, so
	9438	+ // the ISO rule above (which requires a literal `T`) never
	9439	+ // touches it. Without this the probe reports "differ" for every
	9440	+ // site and the "safe to turn Separate Mobile Cache off" verdict
	9441	+ // can never appear.
	9442	+ '/generated [0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2} UTC/',
	9443	+ // Raw epoch seconds. The two fetches are sequential, so any
	9444	+ // template printing time() guaranteed a mismatch.
	9445	+ //
	9446	+ // This is the ONLY rule that may strip a decimal-only run, so
	9447	+ // its bound is load-bearing rather than decorative — every digit
	9448	+ // it gives away is a class of per-device id it silently erases.
	9449	+ // `1[0-9]{9}` was too loose: it claimed the whole
	9450	+ // 1000000000-1999999999 range (2001-2033) to cover timestamps
	9451	+ // nobody serves, and took every 10-digit AdSense slot, order id
	9452	+ // and SKU beginning with 1 along with it — reproducing the exact
	9453	+ // false-"identical" verdict the hex rule above was tightened to
	9454	+ // stop. `1[6-9]` covers 2020-2033, which is the only span a live
	9455	+ // site can actually print, and collides with roughly a tenth as
	9456	+ // many ids.
	9457	+ //
	9458	+ // Not airtight — an id beginning 16-19 still collides. Closing
	9459	+ // that properly means scoping this to places a timestamp really
	9460	+ // appears (an attribute value, a query parameter, a JSON value)
	9461	+ // rather than bare body text; the bound is the cheap 90% of it.
	9462	+ '/\b1[6-9][0-9]{8}\b/',
	9463	+ );
	9464	+ $html = (string) preg_replace( $patterns, 'X', $html );
	9465	+ // Collapse all whitespace so trivial formatting differences don't count.
	9466	+ return trim( (string) preg_replace( '/\s+/', ' ', $html ) );
	9467	+ }
	9468	+
1322	9469	public static function ensure_hits_log_file(): bool {
	9470	+ // TWO writers append to this log, and an earlier fix conflated them:
	9471	+ //
	9472	+ // 1. nginx, via the server-level `access_log` directive in
	9473	+ // nginx_snippet() — a DIFFERENT uid, which is why the file needs
	9474	+ // to be world-writable there.
	9475	+ // 2. the PHP drop-in (advanced-cache.php), on EVERY server. A hit it
	9476	+ // serves bypasses WordPress entirely, so it can't call
	9477	+ // Hit_Counter::record_hit() — appending here is the only way that
	9478	+ // hit is ever counted.
	9479	+ //
	9480	+ // The nginx-only early return that used to sit at the top of this
	9481	+ // method was fixing something real: chmod() on a file PHP doesn't own
	9482	+ // raises "Operation not permitted", and off nginx that chmod buys
	9483	+ // nothing. But it took directory creation with it, so on LiteSpeed
	9484	+ // (which always serves via the drop-in), on Apache without mod_headers,
	9485	+ // and anywhere mobile_separate forces the drop-in path, writer 2 was
	9486	+ // appending to a file whose parent directory did not exist. The append
	9487	+ // is @-suppressed and documented as non-fatal, so every one of those
	9488	+ // hits vanished and the dashboard ratio sat at 0% forever.
	9489	+ //
	9490	+ // So: create the dir + file everywhere, and keep only the chmod gated
	9491	+ // to nginx.
1323	9492	$dir = self::hits_log_dir();
1324	9493	if ( ! is_dir( $dir ) && ! wp_mkdir_p( $dir ) ) {
1325	9494	return false;
1326	9495	}
1327		- // Ensure the dir is traversable + writable by a different-uid nginx.
1328		- // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_chmod -- nginx (a separate uid in multi-container setups) must be able to create/append the log; WP_Filesystem layers ownership overrides that defeat that intent.
1329		- @chmod( $dir, 0777 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort; the access_log just stays empty if it fails.
	9496	+
	9497	+ $is_nginx = ( Server::NGINX === Server::type() );
	9498	+
	9499	+ if ( $is_nginx ) {
	9500	+ // Ensure the dir is traversable + writable by a different-uid nginx.
	9501	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_chmod -- nginx (a separate uid in multi-container setups) must be able to create/append the log; WP_Filesystem layers ownership overrides that defeat that intent.
	9502	+ @chmod( $dir, 0777 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort; the access_log just stays empty if it fails.
	9503	+ }
	9504	+
1330	9505	$path = self::hits_log_path();
1331	9506	if ( ! file_exists( $path ) ) {
1332	9507	// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_touch -- See docblock: must be a plain touch, not WP_Filesystem.
1333	9508	@touch( $path ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- non-fatal helper; failures already covered by the dir check.
1334	9509	}
1335		- // World-writable so a different-uid nginx can append HIT lines.
1336		- // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_chmod -- See docblock.
1337		- @chmod( $path, 0666 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort.
	9510	+
	9511	+ if ( $is_nginx ) {
	9512	+ // World-writable so a different-uid nginx can append HIT lines.
	9513	+ // Off nginx the drop-in appends as the same uid that owns the file,
	9514	+ // so this is unnecessary — and would emit the "Operation not
	9515	+ // permitted" warnings the old early return was added to silence.
	9516	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_chmod -- See docblock.
	9517	+ @chmod( $path, 0666 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort.
	9518	+ }
	9519	+
1338	9520	return file_exists( $path );
1339	9521	}
1340	9522
1341	9523	public static function nginx_snippet(): ?string {
		@@ -1399,9 +9581,55 @@
1399	9581	$lines[] = 'if ($http_host ~ "^([^:]+):(\\d+)$") { set $xspeed_host $1$2; }'; // host:port → hostport (matches PHP static_host())
1400	9582	$lines[] = 'set $xspeed_no_cache "no-cache";';
1401	9583	$lines[] = 'if ($request_method != GET) { set $xspeed_no_cache "$xspeed_no_cache-method"; }';
1402	9584	$lines[] = 'if ($args) { set $xspeed_no_cache "$xspeed_no_cache-args"; }';
1403		- $lines[] = 'if ($http_cookie ~* "(wordpress_logged_in|comment_author|wp-postpass_)") { set $xspeed_no_cache "$xspeed_no_cache-cookie"; }';
	9585	+ // Cookie + user-agent exclusions, generated from the user's actual
	9586	+ // settings rather than a hardcoded list. Before this, the rule
	9587	+ // tested three fixed cookie names and no user agent at all, so
	9588	+ // every excluded_cookies / bypass_user_agents entry applied only
	9589	+ // while a page was cold — on a warm page nginx served the shared
	9590	+ // anonymous copy to carts, members and bypassed bots alike. The
	9591	+ // three historical names survive as a floor inside cookie_rule().
	9592	+ // `~*` is case-insensitive, matching PHP's stripos()/glob checks.
	9593	+ // Stored read — reached from boot(); see stored_cache_opts(). The
	9594	+ // fallbacks below mirror the schema's own defaults, which a raw read
	9595	+ // does not apply.
	9596	+ $cache_opts = self::stored_cache_opts();
	9597	+ $cookie_rule = Server_Rules::cookie_rule(
	9598	+ is_array( $cache_opts['excluded_cookies'] ?? null )
	9599	+ ? $cache_opts['excluded_cookies']
	9600	+ : \XSpeed\Modules\Cache\CacheModule::DEFAULT_EXCLUDED_COOKIES
	9601	+ );
	9602	+ $lines[] = 'if ($http_cookie ~* "(' . $cookie_rule['regex'] . ')") { set $xspeed_no_cache "$xspeed_no_cache-cookie"; }';
	9603	+
	9604	+ $ua_rule = Server_Rules::user_agent_rule(
	9605	+ is_array( $cache_opts['bypass_user_agents'] ?? null ) ? $cache_opts['bypass_user_agents'] : array()
	9606	+ );
	9607	+ // Emitted only when the list is non-empty — an empty alternation
	9608	+ // would compile to `(...)` matching every request and disable the
	9609	+ // fast path entirely.
	9610	+ if ( '' !== $ua_rule['regex'] ) {
	9611	+ $lines[] = 'if ($http_user_agent ~* "(' . $ua_rule['regex'] . ')") { set $xspeed_no_cache "$xspeed_no_cache-ua"; }';
	9612	+ }
	9613	+
	9614	+ // URL exclusions. Without this an excluded URL was only excluded
	9615	+ // while its page was cold: PHP won't write a static file for one, so
	9616	+ // there is usually nothing to serve — but a page cached BEFORE the
	9617	+ // rule was added still has its file on disk, and nginx serves it
	9618	+ // without ever asking PHP. The exclusion then does nothing until the
	9619	+ // next purge. (#169)
	9620	+ //
	9621	+ // Matched against $uri, not $request_uri: $uri is the decoded path
	9622	+ // without the query string, which is what Cache::should_cache()
	9623	+ // tests. Using $request_uri would make `/cart` fail to match
	9624	+ // `/cart?x=1` inconsistently with PHP. Same empty-regex guard as the
	9625	+ // UA rule above — an empty alternation matches everything.
	9626	+ $url_rule = Server_Rules::url_rule(
	9627	+ is_array( $cache_opts['excluded_urls'] ?? null ) ? $cache_opts['excluded_urls'] : array()
	9628	+ );
	9629	+ if ( '' !== $url_rule['regex'] ) {
	9630	+ $lines[] = 'if ($uri ~* "(' . $url_rule['regex'] . ')") { set $xspeed_no_cache "$xspeed_no_cache-url"; }';
	9631	+ }
1404	9632	$lines[] = 'if (!-f "$document_root' . $rel . '/$xspeed_host$uri/index.html") { set $xspeed_no_cache "$xspeed_no_cache-nofile"; }';
1405	9633	// Neither `add_header` nor `access_log` is allowed inside an `if{}`
1406	9634	// at server level (nginx rejects with "directive is not allowed
1407	9635	// here"). The logging therefore lives in a `location` block that
		@@ -1431,10 +9659,41 @@
1431	9659	// missing. So: hits are logged, and a user deleting the log can't take
1432	9660	// nginx down.
1433	9661	$lines[] = ' access_log ' . $hits_abs . ' combined buffer=16k flush=5s;';
1434	9662	$lines[] = ' add_header X-XSpeed-Cache "HIT (nginx)" always;';
	9663	+ // Edge/CDN headers from the same seam the drop-in bakes. nginx serves
	9664	+ // this path without ever starting PHP, so the answer cannot be
	9665	+ // resolved per request — the pairs are resolved HERE, when the
	9666	+ // snippet is generated, and a change of answer needs the snippet
	9667	+ // regenerated and re-pasted to take effect.
	9668	+ //
	9669	+ // Skipped entirely when the static path is switched off. The only
	9670	+ // reason that can fire under `bake` is mobile-split, and mobile-split
	9671	+ // is also what switches the static path off — so the block would be
	9672	+ // baked with a hold it can never serve, and would start serving it
	9673	+ // the moment the setting is turned off and static files reappear,
	9674	+ // until somebody regenerates and re-pastes. A rule that can only be
	9675	+ // served once its premise is false is guaranteed to be stale.
	9676	+ foreach ( self::static_rewrite_allowed() ? self::edge_headers_for( 'HIT', 'rules' ) : array() as $name => $value ) {
	9677	+ $lines[] = ' add_header ' . $name . ' "' . self::quote_directive_value( $value ) . '" always;';
	9678	+ }
1435	9679	$lines[] = '}';
1436		- return implode( "\n", $lines );
	9680	+
	9681	+ // Stamp the block with a hash of itself. This is the only way to find
	9682	+ // out what a user actually pasted: the block lives in a server config
	9683	+ // WordPress cannot read, so until now the dashboard could not tell an
	9684	+ // up-to-date paste from one made three settings changes ago, and
	9685	+ // covered for that by telling everyone to re-paste after every save.
	9686	+ // A hit through this location now carries the version that served it
	9687	+ // and probe_static_rewrite() reads it back. See rules_state().
	9688	+ return implode(
	9689	+ "\n",
	9690	+ self::with_rules_marker(
	9691	+ $lines,
	9692	+ array( ' add_header ' . self::RULES_HEADER . ' "%s" always;' ),
	9693	+ count( $lines ) - 1
	9694	+ )
	9695	+ );
1437	9696	}
1438	9697
1439	9698	/**
1440	9699	* Aggregate every enabled module's nginx_directives() into one
		@@ -1515,8 +9774,62 @@
1515	9774	header( 'X-LiteSpeed-Cache-Control: no-cache' );
1516	9775	}
1517	9776
1518	9777	/**
	9778	+ * Restore the drop-in + WP_CACHE constant for a site that had caching
	9779	+ * ON before this activation — and ONLY for such a site.
	9780	+ *
	9781	+ * WordPress runs an upgrade as deactivate → wipe plugin files →
	9782	+ * install → activate. The wipe takes advanced-cache.php with it, so
	9783	+ * without this the site serves 100% uncached from the moment the
	9784	+ * update finishes until the next authenticated wp-admin page load
	9785	+ * (auto_heal() is on admin_init). On a site whose admin logs in
	9786	+ * rarely that window is hours or days of silent cache loss, while
	9787	+ * the dashboard still reports cache_enabled = true. (FBS field
	9788	+ * report against 1.1.2 / Pro 1.0.5.)
	9789	+ *
	9790	+ * The `cache_enabled` guard is the whole contract: a FRESH install
	9791	+ * has the option unset, so activation writes nothing and the user
	9792	+ * still opts in explicitly through Cache::toggle() via the
	9793	+ * /cache/toggle REST endpoint. We only ever put back state the user
	9794	+ * already chose — repair, never a new install path. This is what
	9795	+ * keeps us on the right side of the "don't create drop-ins the user
	9796	+ * didn't ask for" guideline while matching what WP Rocket, W3 Total
	9797	+ * Cache and WP Super Cache all do on activation.
	9798	+ *
	9799	+ * @return bool True when a restore was performed.
	9800	+ */
	9801	+ public static function restore_dropin_if_enabled(): bool {
	9802	+ if ( defined( 'WP_INSTALLING' ) && WP_INSTALLING ) {
	9803	+ return false;
	9804	+ }
	9805	+
	9806	+ // The user's saved choice. Absent/false on a fresh install => no
	9807	+ // drop-in is written and nothing touches wp-config.php.
	9808	+ $opts = get_option( 'xspeed_options', array() );
	9809	+ if ( empty( $opts['cache_enabled'] ) ) {
	9810	+ return false;
	9811	+ }
	9812	+
	9813	+ $state = self::toggle( true, false );
	9814	+ // A refusal reports whether the cache SERVES, which on this path can
	9815	+ // be true for reasons that have nothing to do with this call — so a
	9816	+ // refusal would otherwise log "drop-in restored" for a restore that
	9817	+ // was declined. Restored means the transaction went through.
	9818	+ $restored = empty( $state['blocked'] ) && ! empty( $state['enabled'] );
	9819	+
	9820	+ if ( $restored ) {
	9821	+ Activity_Log::record(
	9822	+ 'cache_dropin_restored',
	9823	+ 'Cache drop-in restored after a plugin update — caching was already enabled.',
	9824	+ Activity_Log::SUCCESS
	9825	+ );
	9826	+ }
	9827	+
	9828	+ return $restored;
	9829	+ }
	9830	+
	9831	+ /**
1519	9832	* Reconcile drop-in + WP_CACHE + rewrite block with the user's
1520	9833	* saved choice. Runs on admin_init. Cheap when nothing's wrong
1521	9834	* (one option read + a handful of file_exists / defined checks);
1522	9835	* writes only when state has drifted (typical cause: plugin
		@@ -1538,32 +9851,16 @@
1538	9851	if ( empty( $opts['cache_enabled'] ) ) {
1539	9852	return;
1540	9853	}
1541	9854
1542		- $dropin_target = WP_CONTENT_DIR . '/advanced-cache.php';
1543		- $dropin_ours = false;
1544		- $dropin_stale = false;
1545		- if ( file_exists( $dropin_target ) ) {
1546		- $contents = @file_get_contents( $dropin_target ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
1547		- $dropin_ours = is_string( $contents ) && false !== strpos( $contents, 'XSPEED_DROPIN' );
1548		- // Reinstall when OUR drop-in is an older version than the source —
1549		- // the marker alone can't distinguish an old copy from a new one, so
1550		- // a serve-logic change (e.g. the .meta read for 404s/feeds) would
1551		- // otherwise never reach existing cache-enabled sites until a manual
1552		- // cache toggle. (FBS-82406/82407)
1553		- if ( $dropin_ours ) {
1554		- $dropin_stale = self::dropin_version( (string) $contents ) < self::dropin_version( @file_get_contents( XSPEED_DIR . 'includes/advanced-cache.php' ) ?: '' ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
1555		- }
	9855	+ $state = self::toggle( true, false );
	9856	+ // A refusal means something else now owns the page-cache field, or
	9857	+ // the write could not be verified. Either way this is not the moment
	9858	+ // to go on maintaining our rewrite block and log file.
	9859	+ if ( ! empty( $state['blocked'] ) || empty( $state['enabled'] ) ) {
	9860	+ return;
1556	9861	}
1557	9862
1558		- if ( ! $dropin_ours || $dropin_stale ) {
1559		- self::install_dropin();
1560		- }
1561		-
1562		- if ( ! defined( 'WP_CACHE' ) || ! WP_CACHE ) {
1563		- self::set_wp_cache_constant( true );
1564		- }
1565		-
1566	9863	// Rewrite block goes last. It's what turns the static-cache
1567	9864	// tree into a PHP-bypass — every cache hit served by the web
1568	9865	// server directly. Without it we still cache, just at drop-in
1569	9866	// speed (~85ms TTFB) instead of static-file speed (~25-40ms).
		@@ -1588,8 +9885,54 @@
1588	9885	self::ensure_hits_log_file();
1589	9886	}
1590	9887
1591	9888	/**
	9889	+ * Keep the generic bypass cookie in sync with PHP's caching verdict.
	9890	+ *
	9891	+ * The server config tests exactly one cookie name (Server_Rules::
	9892	+ * BYPASS_COOKIE) forever, and PHP decides what that name means. Adding
	9893	+ * a new excluded cookie therefore needs no config change and no nginx
	9894	+ * reload — the reason this exists.
	9895	+ *
	9896	+ * Session cookie (expiry 0) so it dies with the browser session, and
	9897	+ * deliberately NOT HttpOnly-sensitive: it carries no identity, only the
	9898	+ * boolean "don't serve this visitor a shared cached page".
	9899	+ *
	9900	+ * Honest limit: this can only ever help a visitor PHP has already seen
	9901	+ * once. A bot's first request to a warm page never reaches PHP, which
	9902	+ * is why user-agent rules are still written into the server config
	9903	+ * rather than relying on this.
	9904	+ *
	9905	+ * @param bool $bypass Whether this visitor must skip the cache.
	9906	+ */
	9907	+ private static function sync_bypass_cookie( bool $bypass ): void {
	9908	+ if ( headers_sent() ) {
	9909	+ return;
	9910	+ }
	9911	+
	9912	+ $name = Server_Rules::BYPASS_COOKIE;
	9913	+ $has = isset( $_COOKIE[ $name ] );
	9914	+
	9915	+ // Only touch the header when the state actually changes — a
	9916	+ // Set-Cookie on every request would make the response uncacheable
	9917	+ // for intermediary caches and add noise to every hit.
	9918	+ if ( $bypass === $has ) {
	9919	+ return;
	9920	+ }
	9921	+
	9922	+ $path = defined( 'COOKIEPATH' ) && COOKIEPATH ? COOKIEPATH : '/';
	9923	+ $domain = defined( 'COOKIE_DOMAIN' ) ? COOKIE_DOMAIN : '';
	9924	+
	9925	+ if ( $bypass ) {
	9926	+ setcookie( $name, '1', 0, $path, (string) $domain, is_ssl(), false );
	9927	+ $_COOKIE[ $name ] = '1';
	9928	+ } else {
	9929	+ setcookie( $name, '', time() - 3600, $path, (string) $domain, is_ssl(), false );
	9930	+ unset( $_COOKIE[ $name ] );
	9931	+ }
	9932	+ }
	9933	+
	9934	+ /**
1592	9935	* Build the .htaccess rules that map cacheable requests to the
1593	9936	* static-cache tree. Conditions are deliberately strict: GET only,
1594	9937	* empty query string, no session/comment-author/post-password
1595	9938	* cookie, and the static file must exist on disk. Anything that
		@@ -1606,14 +9949,46 @@
1606	9949	$rel = str_replace( ABSPATH, '/', XSPEED_CACHE_STATIC_DIR );
1607	9950	$rel = '/' . ltrim( $rel, '/' );
1608	9951	$rel = rtrim( $rel, '/' );
1609	9952
1610		- return array(
	9953	+ // Cookie + user-agent exclusions generated from the live settings.
	9954	+ // See the matching block in nginx_snippet() — same generator, same
	9955	+ // floor, so both servers enforce an identical policy. Apache reads
	9956	+ // .htaccess on every request and we already self-heal this file, so
	9957	+ // Apache/LiteSpeed users get the fix on upgrade with no action.
	9958	+ $cache_opts = Settings_Manager::get( 'cache' );
	9959	+ $cookie_rule = Server_Rules::cookie_rule(
	9960	+ is_array( $cache_opts['excluded_cookies'] ?? null ) ? $cache_opts['excluded_cookies'] : array()
	9961	+ );
	9962	+ $ua_rule = Server_Rules::user_agent_rule(
	9963	+ is_array( $cache_opts['bypass_user_agents'] ?? null ) ? $cache_opts['bypass_user_agents'] : array()
	9964	+ );
	9965	+
	9966	+ $lines = array(
1611	9967	'<IfModule mod_rewrite.c>',
1612	9968	' RewriteEngine On',
1613	9969	' RewriteCond %{REQUEST_METHOD} ^GET$',
1614	9970	' RewriteCond %{QUERY_STRING} ^$',
1615		- ' RewriteCond %{HTTP_COOKIE} !(wordpress_logged_in|comment_author|wp-postpass_) [NC]',
	9971	+ ' RewriteCond %{HTTP_COOKIE} !(' . $cookie_rule['regex'] . ') [NC]',
	9972	+ );
	9973	+
	9974	+ // Only emit the UA condition when there's something to match —
	9975	+ // `!()` would negate an always-true empty match and refuse every
	9976	+ // request, silently disabling the static path.
	9977	+ if ( '' !== $ua_rule['regex'] ) {
	9978	+ // Quoted, because RewriteCond is whitespace-delimited and real
	9979	+ // user-agent fragments contain spaces ("Mozilla/5.0 (compatible").
	9980	+ // Unquoted, a space adds an argument and Apache answers every
	9981	+ // request with a 500 — and because .htaccess is parsed per
	9982	+ // request, `httpd -t` still reports Syntax OK. Server_Rules has
	9983	+ // already excluded quotes and backslashes from the alternation,
	9984	+ // so the closing quote here cannot be escaped away.
	9985	+ $lines[] = ' RewriteCond %{HTTP_USER_AGENT} "!(' . $ua_rule['regex'] . ')" [NC]';
	9986	+ }
	9987	+
	9988	+ $block = array_merge(
	9989	+ $lines,
	9990	+ array(
1616	9991	// Capture REQUEST_URI without its trailing slash into %1.
1617	9992	// store_static() writes `{host}{uri-without-trailing-slash}/index.html`,
1618	9993	// so this normalization lets `/blog/` and `/blog` both hit
1619	9994	// the same cache file without producing the double-slash
		@@ -1629,11 +10004,83 @@
1629	10004	// `^` matches the empty string AND any non-empty path, so it
1630	10005	// covers `/` and `/blog` alike. (Confirmed on OpenLiteSpeed
1631	10006	// 1.8: `.` → homepage served by PHP drop-in; `^` → served
1632	10007	// directly from the static file.)
1633		- ' RewriteRule ^ ' . $rel . '/%{HTTP_HOST}%1/index.html [L]',
	10008	+ // `E=` tags the request the rewrite just served from the cache
	10009	+ // tree. The edge headers below key off it instead of the file
	10010	+ // name: <FilesMatch "\.html$"> in a document-root .htaccess
	10011	+ // matches EVERY .html on the site — a hand-uploaded /promo.html,
	10012	+ // a static export — and telling a CDN to hold those for the page
	10013	+ // TTL would pin files xSpeed never wrote and cannot purge.
	10014	+ ' RewriteRule ^ ' . $rel . '/%{HTTP_HOST}%1/index.html [E=XSPEED_STATIC_HIT:1,L]',
1634	10015	'</IfModule>',
	10016	+ // Mark the statically-served response as a cache HIT.
	10017	+ //
	10018	+ // A file served by the rewrite above bypasses PHP entirely, so
	10019	+ // this directive is the ONLY thing that can identify it as
	10020	+ // cached — both for the user reading response headers and for
	10021	+ // Hit_Counter, which reconciles static hits from the access
	10022	+ // log. Without it the cache works perfectly and reports a 0%
	10023	+ // hit ratio, which reads as "the plugin is broken". (Field
	10024	+ // report against 1.1.2: homepage served byte-identical from
	10025	+ // the static tree, no X-XSpeed-Cache header on any response.)
	10026	+ //
	10027	+ // `always` so the header is set on the 200 from the rewritten
	10028	+ // file, not only on the successful-response table. The
	10029	+ // <IfModule> guard keeps a server without mod_headers from
	10030	+ // 500ing on an unknown directive — on such a host the header
	10031	+ // is silently dropped, which is exactly why
	10032	+ // static_rewrite_allowed() refuses the static path there and
	10033	+ // routes hits through the drop-in instead.
	10034	+ '<IfModule mod_headers.c>',
	10035	+ ' <FilesMatch "\\.html$">',
	10036	+ ' Header always set X-XSpeed-Cache "HIT (static)"',
	10037	+ ' </FilesMatch>',
	10038	+ )
1635	10039	);
	10040	+
	10041	+ // Edge/CDN headers from the same seam the drop-in bakes. Like the
	10042	+ // nginx snippet, the static rewrite answers without PHP, so the pairs
	10043	+ // are resolved when the block is GENERATED rather than per request.
	10044	+ //
	10045	+ // `env=` rather than the `<FilesMatch>` scoping above, because these
	10046	+ // must ride only on responses the rewrite produced. The X-XSpeed-Cache
	10047	+ // marker stays filename-scoped: it is inert, and narrowing it would
	10048	+ // change a header QA reads.
	10049	+ //
	10050	+ // Same reasoning as the nginx snippet: a bake hold can only come from
	10051	+ // mobile-split, and mobile-split is what turns this path off, so a
	10052	+ // hold baked here could only ever be served once its own premise had
	10053	+ // stopped being true.
	10054	+ $edge_lines = array();
	10055	+ foreach ( self::static_rewrite_allowed() ? self::edge_headers_for( 'HIT', 'rules' ) : array() as $edge_name => $edge_value ) {
	10056	+ $edge_lines = array_merge(
	10057	+ $edge_lines,
	10058	+ self::static_hit_directives(
	10059	+ ' Header always set ' . $edge_name . ' "' . self::quote_directive_value( $edge_value ) . '"'
	10060	+ )
	10061	+ );
	10062	+ }
	10063	+
	10064	+ $block = array_merge( $block, $edge_lines, array( '</IfModule>' ) );
	10065	+
	10066	+ // Same self-describing marker as the nginx snippet. Apache's block is
	10067	+ // written by us rather than pasted by hand, so it should never be out
	10068	+ // of date — but "should" is what refresh_rewrite_if_installed() not
	10069	+ // running looks like from the outside, and the probe can now say so
	10070	+ // instead of assuming. `env=` keeps it on responses the rewrite
	10071	+ // produced, so a hand-uploaded .html never claims to be our cache.
	10072	+ //
	10073	+ // Spliced in after the edge headers so the hash covers them: a
	10074	+ // changed edge answer has to make an installed block report itself
	10075	+ // stale, and a marker computed before they were appended would not
	10076	+ // move. The splice point steps back over them and `</IfModule>` to
	10077	+ // land inside `<FilesMatch>`, beside the X-XSpeed-Cache marker.
	10078	+ return self::with_rules_marker(
	10079	+ $block,
	10080	+ self::static_hit_directives( ' Header always set ' . self::RULES_HEADER . ' "%s"' ),
	10081	+ count( $block ) - count( $edge_lines ) - 2
	10082	+ );
1636	10083	}
1637	10084
1638	10085	/**
1639	10086	* Active probe that confirms the web-server static-rewrite path is
		@@ -1660,8 +10107,21 @@
1660	10107	* synchronously on every dashboard bootstrap, so a slow/timing-out
1661	10108	* loopback request added up to `timeout` seconds to admin page loads on
1662	10109	* hosts that block self-requests. (FBS-82142)
1663	10110	*/
	10111	+ /**
	10112	+ * Discard the cached probe result and run a fresh one.
	10113	+ *
	10114	+ * Without this there was no way to re-check: the result sat in a transient
	10115	+ * for five minutes and nothing ever deleted it, so a user who fixed their
	10116	+ * nginx config kept seeing "nginx detected — configure for max cache speed"
	10117	+ * with no means of confirming the fix worked. (FBS-84012)
	10118	+ */
	10119	+ public static function recheck_static_rewrite(): array {
	10120	+ delete_transient( 'xspeed_rewrite_probe' );
	10121	+ return self::probe_static_rewrite( true );
	10122	+ }
	10123	+
1664	10124	public static function probe_static_rewrite( bool $allow_probe = false ): array {
1665	10125	$cached = get_transient( 'xspeed_rewrite_probe' );
1666	10126	if ( is_array( $cached ) ) {
1667	10127	return $cached;
		@@ -1675,9 +10135,12 @@
1675	10135
1676	10136	$home = home_url( '/' );
1677	10137	$host = (string) wp_parse_url( $home, PHP_URL_HOST );
1678	10138	if ( '' === $host ) {
1679		- $result = array( 'active' => false, 'reason' => 'home_url has no host' );
	10139	+ // Environmental failure, not evidence the server config is wrong —
	10140	+ // mark it inconclusive so Health surfaces say "could not verify"
	10141	+ // instead of demanding a snippet paste. (#480)
	10142	+ $result = array( 'active' => false, 'inconclusive' => true, 'reason' => 'home_url has no host' );
1680	10143	set_transient( 'xspeed_rewrite_probe', $result, MINUTE_IN_SECONDS );
1681	10144	return $result;
1682	10145	}
1683	10146
		@@ -1694,9 +10157,12 @@
1694	10157	if ( ! file_exists( $probe_dir ) ) {
1695	10158	wp_mkdir_p( $probe_dir );
1696	10159	}
1697	10160	if ( ! is_dir( $probe_dir ) ) {
1698		- $result = array( 'active' => false, 'reason' => 'cannot create probe dir' );
	10161	+ // A cache-dir permissions problem — the probe never ran, so this
	10162	+ // says nothing about the nginx config. Inconclusive, not
	10163	+ // "required". (#480)
	10164	+ $result = array( 'active' => false, 'inconclusive' => true, 'reason' => 'cannot create probe dir' );
1699	10165	set_transient( 'xspeed_rewrite_probe', $result, MINUTE_IN_SECONDS );
1700	10166	return $result;
1701	10167	}
1702	10168	// phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- WP_Filesystem requires admin credentials we may not have here; the file is in our own cache dir.
		@@ -1716,9 +10182,9 @@
1716	10182	// don't repeat the wait every minute.
1717	10183	'timeout' => 3,
1718	10184	'sslverify' => ! $is_local,
1719	10185	'redirection' => 0,
1720		- 'headers' => array( 'Cache-Control' => 'no-cache' ),
	10186	+ 'headers' => Self_Traffic::headers( array( 'Cache-Control' => 'no-cache' ) ),
1721	10187	)
1722	10188	);
1723	10189
1724	10190	// Best-effort cleanup so we don't accumulate probe dirs even
		@@ -1733,8 +10199,14 @@
1733	10199
1734	10200	if ( is_wp_error( $resp ) ) {
1735	10201	$result = array(
1736	10202	'active' => false,
	10203	+ // The request never completed, so we learned NOTHING about the
	10204	+ // rewrite. Flagged inconclusive so the UI doesn't tell the user
	10205	+ // to configure a server that may already be configured — a
	10206	+ // blocked loopback, a self-signed cert, or a timeout is a probe
	10207	+ // failure, not a missing rewrite. (FBS-84012)
	10208	+ 'inconclusive' => true,
1737	10209	'reason' => 'http error: ' . $resp->get_error_message(),
1738	10210	);
1739	10211	// Cache the failure for the full 5 minutes (not 1) so a host that
1740	10212	// times out on the loopback probe isn't re-probed — and re-stalled
		@@ -1748,8 +10220,17 @@
1748	10220	$ua_php = '' !== (string) wp_remote_retrieve_header( $resp, 'x-powered-by' );
1749	10221	$has_etag = '' !== (string) wp_remote_retrieve_header( $resp, 'etag' )
1750	10222	|| '' !== (string) wp_remote_retrieve_header( $resp, 'last-modified' );
1751	10223	$match = trim( $body ) === $nonce;
	10224	+ // Which version of our generated rules answered, if any. Only the
	10225	+ // static path can set this — it is baked into the rules themselves —
	10226	+ // so its presence is direct evidence about what is installed, and its
	10227	+ // absence on a conclusive probe is evidence too. See rules_state().
	10228	+ // Validated to the shape we generate, so a proxy or another plugin
	10229	+ // sending something else under this name cannot be mistaken for a
	10230	+ // rules version and reported as "out of date".
	10231	+ $rules_raw = trim( (string) wp_remote_retrieve_header( $resp, strtolower( self::RULES_HEADER ) ) );
	10232	+ $rules = preg_match( '/^[0-9a-f]{8}\z/', $rules_raw ) ? $rules_raw : '';
1752	10233
1753	10234	// "Active" = the web server served our raw nonce bytes back
1754	10235	// AND emitted the static-serve markers (ETag / Last-Modified)
1755	10236	// AND didn't add an X-Powered-By: PHP header. All three are
		@@ -1755,25 +10236,42 @@
1755	10236	// AND didn't add an X-Powered-By: PHP header. All three are
1756	10237	// individually noisy; together they're conclusive.
1757	10238	$active = $match && $has_etag && ! $ua_php && 200 === $code;
1758	10239
	10240	+ /*
	10241	+ * `inconclusive` separates "we proved the rewrite isn't serving" from
	10242	+ * "the probe couldn't tell". Only the former should drive a
	10243	+ * configure-your-server banner; the latter previously rendered the
	10244	+ * same alarming copy at a user who had already configured nginx
	10245	+ * correctly, and there was no way to clear it. (FBS-84012)
	10246	+ */
	10247	+ $inconclusive = false;
1759	10248	if ( $active ) {
1760	10249	$reason = 'static-served';
1761	10250	} elseif ( 200 === $code && $match && $ua_php ) {
1762	10251	$reason = 'php served the file instead of nginx/Apache (rewrite block missing)';
1763	10252	} elseif ( 200 === $code && ! $match ) {
1764		- $reason = 'unexpected body (CDN cached an older response?)';
	10253	+ // Something answered 200 with content that isn't our nonce — a CDN,
	10254	+ // a proxy, a security plugin. That tells us nothing about the
	10255	+ // origin's rewrite.
	10256	+ $reason = 'unexpected body (CDN cached an older response?)';
	10257	+ $inconclusive = true;
1765	10258	} elseif ( 404 === $code ) {
1766	10259	$reason = 'probe URL returned 404 (rewrite block missing or wrong path)';
1767	10260	} else {
1768		- $reason = sprintf( 'unexpected response (HTTP %d, body %d B, php=%s)', $code, strlen( $body ), $ua_php ? 'yes' : 'no' );
	10261	+ // Redirects, 403s from a WAF, 5xx — the probe never reached a
	10262	+ // verdict about the rewrite itself.
	10263	+ $reason = sprintf( 'unexpected response (HTTP %d, body %d B, php=%s)', $code, strlen( $body ), $ua_php ? 'yes' : 'no' );
	10264	+ $inconclusive = true;
1769	10265	}
1770	10266
1771	10267	$result = array(
1772		- 'active' => $active,
1773		- 'reason' => $reason,
1774		- 'code' => $code,
1775		- 'php' => $ua_php,
	10268	+ 'active' => $active,
	10269	+ 'inconclusive' => $inconclusive,
	10270	+ 'reason' => $reason,
	10271	+ 'code' => $code,
	10272	+ 'php' => $ua_php,
	10273	+ 'rules' => $rules,
1776	10274	);
1777	10275	set_transient( 'xspeed_rewrite_probe', $result, 5 * MINUTE_IN_SECONDS );
1778	10276	return $result;
1779	10277	}
		@@ -1830,12 +10328,49 @@
1830	10328	$cleaned = self::strip_marker_block( $existing, 'xSpeed Static Cache' );
1831	10329	$block = self::marker_block( 'xSpeed Static Cache', self::rewrite_block_lines() );
1832	10330	$next = $block . ( '' === $cleaned ? '' : "\n" . $cleaned );
1833	10331
	10332	+ /*
	10333	+ * Nothing to change. auto_heal() runs the whole enable transaction on
	10334	+ * every admin_init and this is called unconditionally from it, so
	10335	+ * without this every wp-admin request truncated and rewrote .htaccess
	10336	+ * with byte-identical content. Apache reads that file without a lock,
	10337	+ * so the truncate window is a real 500 on a busy admin, and the churn
	10338	+ * trips host file-integrity monitors.
	10339	+ */
	10340	+ if ( $next === $existing ) {
	10341	+ return true;
	10342	+ }
	10343	+
1834	10344	// phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents, PluginCheck.CodeAnalysis.WriteFile.ABSPATHDetected -- WP_Filesystem requires admin credentials we don't have here; toggle() runs in a REST request authorized by manage_options nonce. The target is the site's .htaccess (configuration file managed by WP core itself), not user data — wp_upload_dir() doesn't apply.
1835	10345	return false !== file_put_contents( $htaccess, $next, LOCK_EX );
1836	10346	}
1837	10347
	10348	+ /**
	10349	+ * Rewrite the .htaccess block in place when — and only when — one is
	10350	+ * already installed.
	10351	+ *
	10352	+ * The block embeds the generated cookie / user-agent exclusion rules,
	10353	+ * so it goes stale the moment those settings change. install_rewrite()
	10354	+ * regenerates it from the live settings, but calling that unconditionally
	10355	+ * on every save would CREATE a block on sites that never enabled the
	10356	+ * static path — silently turning on server-level serving nobody asked
	10357	+ * for. So we refresh only what's already there.
	10358	+ *
	10359	+ * @return bool True when a block was present and rewritten.
	10360	+ */
	10361	+ public static function refresh_rewrite_if_installed(): bool {
	10362	+ $htaccess = ABSPATH . '.htaccess';
	10363	+ if ( ! file_exists( $htaccess ) ) {
	10364	+ return false;
	10365	+ }
	10366	+ $existing = @file_get_contents( $htaccess ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Best-effort read; an unreadable file simply means nothing to refresh.
	10367	+ if ( ! is_string( $existing ) || false === strpos( $existing, '# BEGIN xSpeed Static Cache' ) ) {
	10368	+ return false;
	10369	+ }
	10370	+ return self::install_rewrite();
	10371	+ }
	10372	+
1838	10373	public static function remove_rewrite(): bool {
1839	10374	$htaccess = ABSPATH . '.htaccess';
1840	10375	// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_is_writable -- See install_rewrite() rationale.
1841	10376	if ( ! file_exists( $htaccess ) || ! is_writable( $htaccess ) ) {
		@@ -1856,9 +10391,21 @@
1856	10391	* follows it. Idempotent — returns the input unchanged if the
1857	10392	* marker isn't present.
1858	10393	*/
1859	10394	private static function strip_marker_block( string $contents, string $marker ): string {
1860		- $pattern = '/# BEGIN ' . preg_quote( $marker, '/' ) . '\b.*?# END ' . preg_quote( $marker, '/' ) . "\b[^\n]*\n?\n?/s";
	10395	+ /*
	10396	+ * The body may not contain another BEGIN for this marker.
	10397	+ *
	10398	+ * `.*?` is non-greedy but still spans anything, so an ORPHANED
	10399	+ * `# BEGIN xSpeed Static Cache` — an END line lost to a hand edit or
	10400	+ * a partial write — paired with the END of the NEXT block and deleted
	10401	+ * everything between them. On a site where the orphan sits above
	10402	+ * `# BEGIN WordPress`, that takes WordPress's own rewrite rules with
	10403	+ * it and every permalink 404s. Refusing to cross a second BEGIN makes
	10404	+ * the orphan a no-op instead of a site-wide outage.
	10405	+ */
	10406	+ $begin = '# BEGIN ' . preg_quote( $marker, '/' ) . '\b';
	10407	+ $pattern = '/' . $begin . '(?:(?!' . $begin . ').)*?# END ' . preg_quote( $marker, '/' ) . "\b[^\n]*\n?\n?/s";
1861	10408	$out = preg_replace( $pattern, '', $contents );
1862	10409	return is_string( $out ) ? $out : $contents;
1863	10410	}
1864	10411
		@@ -1882,8 +10429,417 @@
1882	10429	}
1883	10430	return 0;
1884	10431	}
1885	10432
	10433	+ /** The advanced-cache.php drop-in is ours. */
	10434	+ public const DROPIN_XSPEED = 'xspeed';
	10435	+ /** Someone else's drop-in is installed. */
	10436	+ public const DROPIN_FOREIGN = 'foreign';
	10437	+ /** No drop-in installed. */
	10438	+ public const DROPIN_NONE = 'none';
	10439	+ /** A drop-in is installed and we could not read it. */
	10440	+ public const DROPIN_UNREADABLE = 'unreadable';
	10441	+ /**
	10442	+ * Present but holding nothing -- empty, or whitespace only. WP Rocket
	10443	+ * truncates advanced-cache.php to 0 bytes on deactivate, and calling that
	10444	+ * FOREIGN made it a permanent blocker with no owner to ask. (#391)
	10445	+ */
	10446	+ public const DROPIN_ABANDONED = 'abandoned';
	10447	+
	10448	+ /**
	10449	+ * Who owns wp-content/advanced-cache.php right now.
	10450	+ *
	10451	+ * WordPress gives every caching plugin the same single file to live in,
	10452	+ * so "is there a drop-in" and "is it ours" are completely different
	10453	+ * questions, and only the second one licenses a write. An unreadable
	10454	+ * drop-in is deliberately its own answer rather than folding into
	10455	+ * "foreign": we cannot even name what we would be destroying.
	10456	+ *
	10457	+ * @return string One of the DROPIN_* constants.
	10458	+ */
	10459	+ public static function dropin_owner(): string {
	10460	+ require_once XSPEED_DIR . 'includes/wp-cache-constant.php';
	10461	+ $target = WP_CONTENT_DIR . '/advanced-cache.php';
	10462	+ if ( ! file_exists( $target ) ) {
	10463	+ return self::DROPIN_NONE;
	10464	+ }
	10465	+
	10466	+ $contents = self::read_file( $target );
	10467	+ if ( null === $contents ) {
	10468	+ return self::DROPIN_UNREADABLE;
	10469	+ }
	10470	+
	10471	+ if ( xspeed_has_canonical_dropin_signature( $contents ) ) {
	10472	+ return self::DROPIN_XSPEED;
	10473	+ }
	10474	+
	10475	+ // Nothing in the file means nothing owns it. Kept distinct from
	10476	+ // FOREIGN so the acquisition gate can tell "someone else's cache" from
	10477	+ // "a husk the last plugin left behind". (#391)
	10478	+ if ( '' === trim( $contents ) ) {
	10479	+ return self::DROPIN_ABANDONED;
	10480	+ }
	10481	+
	10482	+ /*
	10483	+ * The other half of the same question, and it cannot be answered from
	10484	+ * the bytes: a file we cannot attribute is a COMPETITOR only while
	10485	+ * some page cache is actually running. With every candidate switched
	10486	+ * off it is abandoned -- a hosting company's own cache, a hand-rolled
	10487	+ * one, or a plugin that was deleted without cleaning up.
	10488	+ *
	10489	+ * Asking the detector rather than re-deriving it here is the point:
	10490	+ * these two answers disagreeing is a split brain with a bad ending --
	10491	+ * acquisition_blocker() opens the gate, install_dropin() then refuses
	10492	+ * on FOREIGN, and toggle() blames the filesystem for a write it never
	10493	+ * attempted. One question, one answer. (#391, #393)
	10494	+ */
	10495	+ if ( class_exists( __NAMESPACE__ . '\\Page_Cache_Detector' ) ) {
	10496	+ $owner = (string) ( Page_Cache_Detector::inspect()['dropin']['owner'] ?? '' );
	10497	+
	10498	+ // Attributable to a named plugin -> somebody's cache, whatever its
	10499	+ // activation state. Only a file NOBODY can be shown to own, with
	10500	+ // nothing running, is abandoned.
	10501	+ if ( Page_Cache_Detector::OWNER_UNKNOWN === $owner
	10502	+ && ! Page_Cache_Detector::another_page_cache_is_active() ) {
	10503	+ return self::DROPIN_ABANDONED;
	10504	+ }
	10505	+ }
	10506	+
	10507	+ return self::DROPIN_FOREIGN;
	10508	+ }
	10509	+
	10510	+ /**
	10511	+ * Why xSpeed must not install its page-cache artifacts right now, or null
	10512	+ * when it may.
	10513	+ *
	10514	+ * This is the single gate in front of every write that touches shared
	10515	+ * state — the drop-in and the WP_CACHE define. Both are single-occupancy:
	10516	+ * whatever is there belongs to exactly one plugin, and taking it silently
	10517	+ * breaks that plugin's caching with no way back.
	10518	+ *
	10519	+ * Returns a user-facing string, so a REST caller can hand it straight to
	10520	+ * the dashboard instead of reporting a bare failure.
	10521	+ */
	10522	+ public static function acquisition_blocker(): ?string {
	10523	+ Page_Cache_Detector::invalidate();
	10524	+ $verdict = Page_Cache_Detector::classify();
	10525	+ $owner = self::dropin_owner();
	10526	+ // The reason we refuse, whether that reason already names a plugin,
	10527	+ // and every other page cache the detector counted anywhere in the
	10528	+ // verdict. See the tail of this method for why all three are needed.
	10529	+ $primary = null;
	10530	+ $primary_names = false;
	10531	+ $named = array();
	10532	+ foreach ( $verdict['blockers'] as $blocker ) {
	10533	+ $code = (string) ( $blocker['code'] ?? '' );
	10534	+ // The shared detector quite correctly reports xSpeed itself as a
	10535	+ // page-cache owner. That is not a competitor to this transaction.
	10536	+ //
	10537	+ // Except when the two disagree about the DROP-IN. The detector
	10538	+ // accepts our marker anywhere in a file's header; this plugin's
	10539	+ // own check requires it to open the header, because only this
	10540	+ // side authorizes overwriting and deleting. A foreign drop-in
	10541	+ // that merely carries our marker further down its header is
	10542	+ // attributed to us by the detector, and skipping it here dropped
	10543	+ // the refusal entirely — the write then failed on the stricter
	10544	+ // check and the user was told to go and fix file permissions.
	10545	+ // Where they disagree, believe the stricter one.
	10546	+ if ( self::PLUGIN_FILE === ( $blocker['plugin'] ?? null ) ) {
	10547	+ $about_dropin = in_array(
	10548	+ $code,
	10549	+ array(
	10550	+ Page_Cache_Detector::BLOCKER_FOREIGN_DROPIN,
	10551	+ Page_Cache_Detector::BLOCKER_UNKNOWN_DROPIN,
	10552	+ ),
	10553	+ true
	10554	+ );
	10555	+ if ( ! $about_dropin || self::DROPIN_XSPEED === $owner ) {
	10556	+ continue;
	10557	+ }
	10558	+ }
	10559	+ if ( Page_Cache_Detector::BLOCKER_WP_CACHE_ORPHANED === $code && self::DROPIN_XSPEED === $owner ) {
	10560	+ continue;
	10561	+ }
	10562	+ /*
	10563	+ * Another plugin's drop-in is no longer a refusal.
	10564	+ *
	10565	+ * It used to be: whoever held advanced-cache.php kept it, and
	10566	+ * enabling was blocked with "deactivate its page cache first".
	10567	+ * That left a user who had asked for our cache with no way to get
	10568	+ * it — on a live site the only exit was deleting a file over SSH,
	10569	+ * and the message could not even say which of its two causes
	10570	+ * applied ("is active OR owns advanced-cache.php").
	10571	+ *
	10572	+ * Turning the page cache on is the instruction to serve pages
	10573	+ * from cache, and that is not possible without this file. So we
	10574	+ * take it, and the dashboard says whose file it is first —
	10575	+ * dropin_disclosure() names the owner, the user confirms, and
	10576	+ * install_dropin() writes ours over the top.
	10577	+ *
	10578	+ * A still-active competitor is deliberately NOT re-added as a
	10579	+ * blocker below: it is caught by `active_page_cache`, which the
	10580	+ * capability rule already downgrades to a note. Two page caches
	10581	+ * installed at once is the user's call to make, not ours to
	10582	+ * refuse — they just told us which one they want serving.
	10583	+ *
	10584	+ * UNREADABLE is the exception and stays a refusal: we cannot name
	10585	+ * what we would destroy, and install_dropin() refuses it too, so
	10586	+ * opening the gate here would only produce a failed write.
	10587	+ */
	10588	+ $about_dropin_owner = in_array(
	10589	+ $code,
	10590	+ array(
	10591	+ Page_Cache_Detector::BLOCKER_FOREIGN_DROPIN,
	10592	+ Page_Cache_Detector::BLOCKER_UNKNOWN_DROPIN,
	10593	+ ),
	10594	+ true
	10595	+ );
	10596	+ if ( $about_dropin_owner && self::DROPIN_UNREADABLE !== $owner ) {
	10597	+ continue;
	10598	+ }
	10599	+ /*
	10600	+ * Capability is not possession. `active_page_cache` and
	10601	+ * `multiple_page_caches` both fire on a plugin that merely CAN
	10602	+ * cache pages — the detector cannot prove a competitor's page
	10603	+ * cache is off, so it counts it. As a warning that is right. As
	10604	+ * a gate it refuses a write that takes nothing from anyone.
	10605	+ *
	10606	+ * This gate guards exactly two files: advanced-cache.php and the
	10607	+ * WP_CACHE define that loads it. A plugin that does not hold the
	10608	+ * drop-in has nothing here for us to overwrite, and one that does
	10609	+ * is already refused by `foreign_dropin` / `unknown_dropin` a few
	10610	+ * lines up. So when the field is ours or empty, an active
	10611	+ * competitor is a note, not a refusal.
	10612	+ *
	10613	+ * QA found this on a live OpenLiteSpeed site keeping LiteSpeed
	10614	+ * Cache for images and CDN with its page cache off, while xSpeed
	10615	+ * served the pages. One click of the off switch and it could not
	10616	+ * be turned back on: the only way out was deactivating LiteSpeed
	10617	+ * entirely, and the message told them to "deactivate its page
	10618	+ * cache" — which they already had.
	10619	+ */
	10620	+ $about_capability = in_array(
	10621	+ $code,
	10622	+ array(
	10623	+ Page_Cache_Detector::BLOCKER_ACTIVE_PAGE_CACHE,
	10624	+ Page_Cache_Detector::BLOCKER_MULTIPLE_PAGE_CACHES,
	10625	+ ),
	10626	+ true
	10627	+ );
	10628	+ /*
	10629	+ * FOREIGN belongs in this list now, and it is the whole point.
	10630	+ *
	10631	+ * The rule is still "capability is not possession": these two
	10632	+ * blockers fire on any plugin that CAN cache pages, which the
	10633	+ * detector cannot prove is switched off. What changed is that a
	10634	+ * competitor holding the drop-in no longer stops us either — we
	10635	+ * take the file, having said whose it is. So there is nothing
	10636	+ * left for a merely-installed competitor to protect, and keeping
	10637	+ * the refusal here would put back the dead end by another route:
	10638	+ * "another page cache is active" on a site where the user has
	10639	+ * just told us, by name, which cache they want serving.
	10640	+ *
	10641	+ * UNREADABLE is deliberately still absent — that one refuses.
	10642	+ */
	10643	+ if ( $about_capability
	10644	+ && in_array( $owner, array( self::DROPIN_XSPEED, self::DROPIN_NONE, self::DROPIN_FOREIGN, self::DROPIN_ABANDONED ), true ) ) {
	10645	+ continue;
	10646	+ }
	10647	+ if ( Page_Cache_Detector::BLOCKER_MULTIPLE_PAGE_CACHES === $code ) {
	10648	+ $others = self::other_page_cache_names( $blocker );
	10649	+ if ( array() === $others ) {
	10650	+ // We were the only owner counted — nothing to refuse —
	10651	+ // unless the list is missing entirely, which is an older
	10652	+ // detector copy we still must not talk past.
	10653	+ if ( null === $primary && array() === (array) ( $blocker['plugins'] ?? array() ) ) {
	10654	+ $primary = self::ownership_blocker_message( '', '' );
	10655	+ }
	10656	+ continue;
	10657	+ }
	10658	+ $named = array_values( array_unique( array_merge( $named, $others ) ) );
	10659	+ if ( null === $primary ) {
	10660	+ $primary = self::multiple_page_caches_message( $others );
	10661	+ $primary_names = true;
	10662	+ }
	10663	+ continue;
	10664	+ }
	10665	+ if ( null === $primary ) {
	10666	+ $label = (string) ( $blocker['label'] ?? '' );
	10667	+ $primary = self::ownership_blocker_message( $code, $label );
	10668	+ $primary_names = '' !== $label;
	10669	+ }
	10670	+ }
	10671	+
	10672	+ if ( null === $primary ) {
	10673	+ return null;
	10674	+ }
	10675	+ /*
	10676	+ * The first blocker decides WHY we refuse; it does not always know
	10677	+ * WHO. The detector can only attribute a drop-in it recognises, and
	10678	+ * an unrecognised one produces "its owner cannot be proved" — the
	10679	+ * sentence a W3 Total Cache site used to get while a later blocker in
	10680	+ * the same verdict was holding the name "W3 Total Cache".
	10681	+ *
	10682	+ * So keep the reason and add the names, rather than swapping one for
	10683	+ * the other: the plugin the user must deal with is not necessarily
	10684	+ * the owner of the file we could not identify, and promoting the
	10685	+ * named blocker would have told them to deactivate a plugin that is
	10686	+ * not what is in their way.
	10687	+ */
	10688	+ if ( $primary_names || array() === $named ) {
	10689	+ return $primary;
	10690	+ }
	10691	+ if ( 1 === count( $named ) ) {
	10692	+ return sprintf(
	10693	+ /* translators: 1: the refusal reason, 2: a page-caching plugin's name. */
	10694	+ __( '%1$s %2$s is also active on this site — deactivate its page cache before enabling xSpeed.', 'xspeed' ),
	10695	+ $primary,
	10696	+ $named[0]
	10697	+ );
	10698	+ }
	10699	+ return sprintf(
	10700	+ /* translators: 1: the refusal reason, 2: comma-separated page-caching plugin names. */
	10701	+ __( '%1$s These page caches are also active on this site: %2$s. Deactivate them before enabling xSpeed.', 'xspeed' ),
	10702	+ $primary,
	10703	+ implode( ', ', $named )
	10704	+ );
	10705	+ }
	10706	+
	10707	+ /** How xSpeed's own plugin file appears in the detector's catalog. */
	10708	+ private const PLUGIN_FILE = 'xspeed/xspeed.php';
	10709	+
	10710	+ /**
	10711	+ * Name the OTHER page caches behind a `multiple_page_caches` refusal.
	10712	+ *
	10713	+ * This blocker has no single owner, so the detector leaves `plugin` and
	10714	+ * `label` null and hands over the full list instead. Left unhandled it
	10715	+ * fell through to the anonymous fallback sentence — and it is the blocker
	10716	+ * an ordinary site hits most: xSpeed counts toward "multiple", so the
	10717	+ * count reaches two the moment one other page-cache plugin is activated,
	10718	+ * even one that has not written a drop-in. A site running our cache that
	10719	+ * activated LiteSpeed could not re-enable it and was told only that "the
	10720	+ * page-cache field is occupied".
	10721	+ *
	10722	+ * Returns an empty list when xSpeed was the only owner counted, or when
	10723	+ * an older detector copy sent no list at all — the caller distinguishes
	10724	+ * the two by looking at `plugins`.
	10725	+ *
	10726	+ * @param array<string,mixed> $blocker One entry from Detector::classify().
	10727	+ * @return string[]
	10728	+ */
	10729	+ private static function other_page_cache_names( array $blocker ): array {
	10730	+ $plugins = array_values( (array) ( $blocker['plugins'] ?? array() ) );
	10731	+ $labels = array_values( (array) ( $blocker['labels'] ?? array() ) );
	10732	+
	10733	+ $others = array();
	10734	+ foreach ( $plugins as $i => $plugin ) {
	10735	+ if ( self::PLUGIN_FILE === $plugin ) {
	10736	+ continue;
	10737	+ }
	10738	+ $others[] = isset( $labels[ $i ] ) && '' !== (string) $labels[ $i ]
	10739	+ ? (string) $labels[ $i ]
	10740	+ : (string) $plugin;
	10741	+ }
	10742	+ return array_values( array_unique( $others ) );
	10743	+ }
	10744	+
	10745	+ /**
	10746	+ * The refusal sentence for a `multiple_page_caches` blocker.
	10747	+ *
	10748	+ * @param string[] $others Page caches other than xSpeed. Never empty.
	10749	+ */
	10750	+ private static function multiple_page_caches_message( array $others ): string {
	10751	+ if ( 1 === count( $others ) ) {
	10752	+ return self::ownership_blocker_message( Page_Cache_Detector::BLOCKER_ACTIVE_PAGE_CACHE, $others[0] );
	10753	+ }
	10754	+ return sprintf(
	10755	+ /* translators: %s: comma-separated list of page-caching plugin names. */
	10756	+ __( 'More than one page cache is active on this site (%s). Turn off the other page caches before enabling xSpeed.', 'xspeed' ),
	10757	+ implode( ', ', $others )
	10758	+ );
	10759	+ }
	10760	+
	10761	+ private static function ownership_blocker_message( string $code, string $label ): string {
	10762	+ if ( '' !== $label ) {
	10763	+ return sprintf( __( '%s is active or owns advanced-cache.php. Deactivate its page cache before enabling xSpeed.', 'xspeed' ), $label );
	10764	+ }
	10765	+ $messages = array(
	10766	+ 'wp_cache_orphaned' => __( 'WP_CACHE is true but no page-cache drop-in owner can be proved. xSpeed will not claim it.', 'xspeed' ),
	10767	+ 'wp_cache_duplicate' => __( 'wp-config.php defines WP_CACHE more than once. Remove the duplicate before enabling the cache.', 'xspeed' ),
	10768	+ 'wp_cache_dynamic' => __( 'WP_CACHE is set from an expression in wp-config.php. xSpeed will not rewrite it.', 'xspeed' ),
	10769	+ 'wp_cache_conditional' => __( 'WP_CACHE is defined inside a conditional in wp-config.php, so xSpeed cannot tell what it will be. Move it to a plain define before enabling the cache.', 'xspeed' ),
	10770	+ 'wp_config_unreadable' => __( 'wp-config.php cannot be read, so xSpeed cannot safely change page-cache ownership.', 'xspeed' ),
	10771	+ 'unknown_dropin' => __( 'advanced-cache.php is occupied but its owner cannot be proved. xSpeed will not replace it.', 'xspeed' ),
	10772	+ 'unreadable_dropin' => __( 'advanced-cache.php cannot be read, so xSpeed cannot prove its owner.', 'xspeed' ),
	10773	+ );
	10774	+ return $messages[ $code ] ?? __( 'The page-cache field is occupied or cannot be verified. xSpeed will not change it.', 'xspeed' );
	10775	+ }
	10776	+
	10777	+ /**
	10778	+ * How WP_CACHE is written in wp-config.php, as opposed to what it
	10779	+ * evaluates to at runtime.
	10780	+ *
	10781	+ * The literal is what matters to a writer: a value behind an expression,
	10782	+ * or two competing defines, cannot be rewritten by a regex without
	10783	+ * guessing — and a wrong guess silently disables page caching (ours or
	10784	+ * someone else's) with no error anywhere.
	10785	+ *
	10786	+ * @return string undefined | true | false | duplicate | dynamic | conditional | unreadable
	10787	+ */
	10788	+ public static function wp_cache_define_state(): string {
	10789	+ $path = self::wp_config_path();
	10790	+ if ( '' === $path ) {
	10791	+ return 'unreadable';
	10792	+ }
	10793	+
	10794	+ $config = self::read_file( $path );
	10795	+ if ( null === $config ) {
	10796	+ return 'unreadable';
	10797	+ }
	10798	+
	10799	+ require_once XSPEED_DIR . 'includes/wp-cache-constant.php';
	10800	+ $parsed = \xspeed_parse_wp_cache_defines( $config );
	10801	+ return $parsed['state'];
	10802	+ }
	10803	+
	10804	+ /**
	10805	+ * Classify the captured right-hand side of a WP_CACHE define.
	10806	+ *
	10807	+ * Hosts and older tutorials write the value several ways —
	10808	+ * `1`, `'1'`, `TRUE` — and all of them are literals a rewrite can safely
	10809	+ * replace. Only a value we cannot evaluate by looking at it (a variable, a
	10810	+ * function call, a ternary) counts as dynamic, because that is the case
	10811	+ * where rewriting means guessing.
	10812	+ *
	10813	+ * @return string true | false | dynamic
	10814	+ */
	10815	+ private static function classify_wp_cache_literal( string $raw ): string {
	10816	+ $literal = strtolower( trim( $raw ) );
	10817	+ $literal = trim( $literal, "'\"" );
	10818	+
	10819	+ if ( in_array( $literal, array( 'true', '1' ), true ) ) {
	10820	+ return 'true';
	10821	+ }
	10822	+ if ( in_array( $literal, array( 'false', '0', '', 'null' ), true ) ) {
	10823	+ return 'false';
	10824	+ }
	10825	+ return 'dynamic';
	10826	+ }
	10827	+
	10828	+ /**
	10829	+ * Read a file for an ownership decision. Null on any failure — callers
	10830	+ * treat null as "unknown", never as "empty", because an empty string
	10831	+ * would read as "no marker found" and license an overwrite.
	10832	+ */
	10833	+ private static function read_file( string $path ): ?string {
	10834	+ if ( ! is_readable( $path ) ) {
	10835	+ return null;
	10836	+ }
	10837	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- Ownership check on a local file; WP_Filesystem would need credentials we must not prompt for here.
	10838	+ $contents = @file_get_contents( $path ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- A failed read is a valid answer ("unknown"), not an error to surface.
	10839	+ return is_string( $contents ) ? $contents : null;
	10840	+ }
	10841	+
1886	10842	public static function install_dropin() {
1887	10843	$source = XSPEED_DIR . 'includes/advanced-cache.php';
1888	10844	$target = WP_CONTENT_DIR . '/advanced-cache.php';
1889	10845	if ( ! file_exists( $source ) ) {
		@@ -1889,8 +10845,26 @@
1889	10845	if ( ! file_exists( $source ) ) {
1890	10846	return false;
1891	10847	}
1892	10848
	10849	+ /*
	10850	+ * A drop-in we cannot READ is the one thing still refused here. Not
	10851	+ * because of who owns it — we no longer refuse on ownership — but
	10852	+ * because an unreadable file is usually a permissions problem, and
	10853	+ * writing over it would fail anyway or destroy something we were
	10854	+ * never able to look at.
	10855	+ *
	10856	+ * Everything else is ours to take. Enabling the page cache IS the
	10857	+ * user's instruction to serve the cache, and serving it means holding
	10858	+ * advanced-cache.php; the dashboard says whose file it is replacing
	10859	+ * before the click (Page_Cache_Detector::dropin_disclosure()), so the
	10860	+ * takeover is consented rather than silent.
	10861	+ */
	10862	+ $owner = self::dropin_owner();
	10863	+ if ( self::DROPIN_UNREADABLE === $owner ) {
	10864	+ return false;
	10865	+ }
	10866	+
1893	10867	global $wp_filesystem;
1894	10868	if ( ! function_exists( 'WP_Filesystem' ) ) {
1895	10869	require_once ABSPATH . 'wp-admin/includes/file.php';
1896	10870	}
		@@ -1914,38 +10888,144 @@
1914	10888	str_replace( "'", "\\'", self::hits_log_path() ),
1915	10889	$source_contents
1916	10890	);
1917	10891
	10892	+ // Bake the cookie + user-agent exclusion rules in too. The drop-in
	10893	+ // runs before WordPress loads, so it cannot read the settings — and
	10894	+ // without them it served the shared anonymous page to any visitor
	10895	+ // PHP had not yet seen (a first-time cart visitor, a bypassed bot).
	10896	+ // The generic bypass cookie only covers repeat visitors; these two
	10897	+ // regexes are what make the FIRST request correct.
	10898	+ //
	10899	+ // Both are already fully escaped by Server_Rules, and each is
	10900	+ // embedded as a single-quoted PHP literal, so a settings value can
	10901	+ // neither break the drop-in's syntax nor execute.
	10902	+ $cache_opts = Settings_Manager::get( 'cache' );
	10903	+ $cookie_rule = Server_Rules::cookie_rule(
	10904	+ is_array( $cache_opts['excluded_cookies'] ?? null ) ? $cache_opts['excluded_cookies'] : array()
	10905	+ );
	10906	+ $ua_rule = Server_Rules::user_agent_rule(
	10907	+ is_array( $cache_opts['bypass_user_agents'] ?? null ) ? $cache_opts['bypass_user_agents'] : array()
	10908	+ );
	10909	+
	10910	+ $source_contents = str_replace(
	10911	+ '@@XSPEED_COOKIE_RE@@',
	10912	+ str_replace( "'", "\\'", $cookie_rule['regex'] ),
	10913	+ $source_contents
	10914	+ );
	10915	+ $source_contents = str_replace(
	10916	+ '@@XSPEED_UA_RE@@',
	10917	+ str_replace( "'", "\\'", $ua_rule['regex'] ),
	10918	+ $source_contents
	10919	+ );
	10920	+ // Which user agents must not count toward the hit ratio. Built here
	10921	+ // because `xspeed_self_user_agents` is a filter the drop-in cannot
	10922	+ // call. A renamed warmer is caught by Self_Traffic::HEADER instead.
	10923	+ $source_contents = str_replace(
	10924	+ '@@XSPEED_HIT_EXCLUDE_RE@@',
	10925	+ str_replace( "'", "\\'", Hit_Counter::excluded_ua_regex() ),
	10926	+ $source_contents
	10927	+ );
	10928	+
	10929	+ /*
	10930	+ * Ours or absent — the ownership gate at the top of this method ruled
	10931	+ * out everything else. The old code path that moved a foreign drop-in
	10932	+ * into uploads/xspeed-backups and wrote ours on top is gone: it
	10933	+ * disabled the other plugin's page cache the moment an xSpeed install
	10934	+ * ran, with nothing in its own UI to explain why.
	10935	+ */
	10936	+
	10937	+ // Bake the configured cache lifetime in. The drop-in runs before
	10938	+ // WordPress loads, so it cannot read the option — it previously fell
	10939	+ // back to a hardcoded 86400 for every ordinary page, because
	10940	+ // write_meta() only emits a `ttl` sidecar when the value DIFFERS from
	10941	+ // the page default. That made the admin's "1 to 720 hours" control a
	10942	+ // no-op at the layer that actually answers the request: 12h served
	10943	+ // stale for up to 2x the configured lifetime, and 168h lost the fast
	10944	+ // path for 6 of every 7 days (issue #240).
	10945	+ //
	10946	+ // This is re-baked on every cache settings save (see CacheModule::boot),
	10947	+ // exactly like the cookie / user-agent rules above.
	10948	+ $expiry_hours = isset( $cache_opts['cache_expiry'] ) ? (int) $cache_opts['cache_expiry'] : 24;
	10949	+ if ( $expiry_hours < 1 || $expiry_hours > 720 ) {
	10950	+ $expiry_hours = 24;
	10951	+ }
	10952	+ $source_contents = str_replace(
	10953	+ '@@XSPEED_DEFAULT_TTL@@',
	10954	+ (string) ( $expiry_hours * HOUR_IN_SECONDS ),
	10955	+ $source_contents
	10956	+ );
	10957	+
	10958	+ // Bake the site-wide edge answer in. Resolved in a `bake` context, so
	10959	+ // nothing per-page and nothing a request header vouched for can reach
	10960	+ // it: a bake runs once, in an admin or CLI request, and answers for
	10961	+ // every page on the site. A page that disagrees gets a sidecar
	10962	+ // instead — see per_entry_edge_headers().
	10963	+ //
	10964	+ // Re-baked on every cache settings save (see CacheModule::boot),
	10965	+ // exactly like the cookie, user-agent and lifetime rules above.
	10966	+ $source_contents = str_replace(
	10967	+ "'@@XSPEED_EDGE_HEADERS@@'",
	10968	+ self::edge_headers_literal( self::edge_headers_for( 'HIT', 'bake' ) ),
	10969	+ $source_contents
	10970	+ );
	10971	+
	10972	+ // And the answer for the same HIT served for a URL with an ignored
	10973	+ // param in it, which the drop-in sends instead of the one above. An
	10974	+ // empty array means the two agree. See query_variant_edge_headers().
	10975	+ $source_contents = str_replace(
	10976	+ "'@@XSPEED_EDGE_QUERY_HOLD@@'",
	10977	+ self::edge_headers_literal( self::query_variant_edge_headers() ),
	10978	+ $source_contents
	10979	+ );
	10980	+
1918	10981	if ( file_exists( $target ) ) {
1919	10982	$existing = $wp_filesystem->get_contents( $target );
1920		- $is_xspeed = is_string( $existing ) && false !== strpos( $existing, 'XSPEED_DROPIN' );
	10983	+ if ( is_string( $existing ) && $existing === $source_contents ) {
	10984	+ return true;
	10985	+ }
	10986	+ }
1921	10987
1922		- if ( $is_xspeed ) {
1923		- if ( $existing === $source_contents ) {
1924		- return true;
1925		- }
1926		- return (bool) $wp_filesystem->put_contents( $target, $source_contents, FS_CHMOD_FILE );
1927		- }
	10988	+ $written = (bool) $wp_filesystem->put_contents( $target, $source_contents, FS_CHMOD_FILE );
	10989	+ if ( $written ) {
	10990	+ self::forget_compiled_dropin( $target );
	10991	+ }
	10992	+ return $written;
	10993	+ }
1928	10994
1929		- // Foreign drop-in (e.g. left over from another cache plugin) — back it up
1930		- // before overwriting so the user can recover if needed. Uploads dir
1931		- // (not wp-content root) keeps the backup out of WordPress's reserved
1932		- // drop-in location.
1933		- $upload = wp_upload_dir( null, false );
1934		- $basedir = isset( $upload['basedir'] ) ? trailingslashit( $upload['basedir'] ) . 'xspeed-backups' : false;
1935		- if ( $basedir ) {
1936		- if ( ! file_exists( $basedir ) ) {
1937		- wp_mkdir_p( $basedir );
1938		- self::write_silence( $basedir );
1939		- }
1940		- $backup = $basedir . '/advanced-cache.foreign-' . gmdate( 'Ymd-His' ) . '.php.bak';
1941		- $wp_filesystem->move( $target, $backup, true );
1942		- } else {
1943		- $wp_filesystem->delete( $target );
	10995	+ /**
	10996	+ * Callable that drops a script's compiled copy. Replaced by tests only;
	10997	+ * opcache_invalidate() is a PHP internal that cannot be stubbed.
	10998	+ *
	10999	+ * @var callable|null
	11000	+ */
	11001	+ private static $opcache_invalidate = null;
	11002	+
	11003	+ /**
	11004	+ * Make PHP compile the new drop-in on the next request.
	11005	+ *
	11006	+ * opcache keeps the compiled drop-in and checks the file's timestamp at
	11007	+ * most every `opcache.revalidate_freq` seconds (60 on lenzora.site), or
	11008	+ * never with `validate_timestamps` off. So a re-bake, such as the one
	11009	+ * that follows a change to "CDN or proxy in front", kept serving the old
	11010	+ * edge headers for up to a minute, or until PHP restarted.
	11011	+ *
	11012	+ * This reaches the opcache of the PHP process doing the write, which is
	11013	+ * the web server's own when the bake runs in a page or REST request. A
	11014	+ * WP-CLI bake has its own opcache, so the web server still waits for its
	11015	+ * next timestamp check there.
	11016	+ *
	11017	+ * @param string $target Absolute path of the drop-in just written.
	11018	+ */
	11019	+ private static function forget_compiled_dropin( string $target ): void {
	11020	+ $invalidate = self::$opcache_invalidate;
	11021	+ if ( null === $invalidate ) {
	11022	+ if ( ! function_exists( 'opcache_invalidate' ) ) {
	11023	+ return;
1944	11024	}
	11025	+ $invalidate = 'opcache_invalidate';
1945	11026	}
1946		-
1947		- return (bool) $wp_filesystem->put_contents( $target, $source_contents, FS_CHMOD_FILE );
	11027	+ @call_user_func( $invalidate, $target, true ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- opcache may be disabled or restricted (opcache.restrict_api); nothing to do either way.
1948	11028	}
1949	11029
1950	11030	public static function remove_dropin() {
1951	11031	$target = WP_CONTENT_DIR . '/advanced-cache.php';
		@@ -1962,61 +11042,374 @@
1962	11042	return;
1963	11043	}
1964	11044
1965	11045	$contents = $wp_filesystem->get_contents( $target );
1966		- if ( is_string( $contents ) && false !== strpos( $contents, 'XSPEED_DROPIN' ) ) {
	11046	+ if ( is_string( $contents ) && xspeed_has_canonical_dropin_signature( $contents ) ) {
1967	11047	wp_delete_file( $target );
1968	11048	}
1969	11049	}
1970	11050
	11051	+ /**
	11052	+ * Where wp-config.php actually is.
	11053	+ *
	11054	+ * WordPress core supports the file one directory ABOVE ABSPATH, and
	11055	+ * plenty of installs use that layout. This used to look only in ABSPATH
	11056	+ * and bail, so on those sites the constant could never be written — while
	11057	+ * Health, which did fall back to the parent, reported the file writable
	11058	+ * and told the user to toggle the cache off and on. The advice could
	11059	+ * never work, and its fallback hint ("another plugin left WP_CACHE false
	11060	+ * behind") was wrong too: there was no define at all. (#19, QA on #174)
	11061	+ *
	11062	+ * Returns '' when no wp-config.php can be found in either location.
	11063	+ */
	11064	+ public static function wp_config_path(): string {
	11065	+ $candidates = array( ABSPATH . 'wp-config.php', dirname( ABSPATH ) . '/wp-config.php' );
	11066	+ foreach ( $candidates as $path ) {
	11067	+ if ( file_exists( $path ) ) {
	11068	+ return $path;
	11069	+ }
	11070	+ }
	11071	+ return '';
	11072	+ }
	11073	+
	11074	+ /**
	11075	+ * Can we actually write the constant right now?
	11076	+ *
	11077	+ * This is the single oracle for that question — Health asks THIS rather
	11078	+ * than running its own `wp_is_writable()` test, so the message a user
	11079	+ * reads can never disagree with what the plugin will do. The two differed
	11080	+ * in both directions: on the path (above) and on the test itself, since
	11081	+ * an FTP/SSH WP_Filesystem transport can refuse a file that
	11082	+ * `wp_is_writable()` reports as writable. (#19, QA on #174)
	11083	+ */
	11084	+ public static function can_write_wp_config(): bool {
	11085	+ $wp_config = self::wp_config_path();
	11086	+ if ( '' === $wp_config ) {
	11087	+ return false;
	11088	+ }
	11089	+
	11090	+ global $wp_filesystem;
	11091	+ if ( ! function_exists( 'WP_Filesystem' ) ) {
	11092	+ require_once ABSPATH . 'wp-admin/includes/file.php';
	11093	+ }
	11094	+ WP_Filesystem();
	11095	+ return (bool) ( $wp_filesystem && $wp_filesystem->is_writable( $wp_config ) );
	11096	+ }
	11097	+
1971	11098	public static function set_wp_cache_constant( $enable ) {
1972		- $wp_config = ABSPATH . 'wp-config.php';
1973		- if ( ! file_exists( $wp_config ) ) {
	11099	+ $wp_config = self::wp_config_path();
	11100	+ if ( '' === $wp_config ) {
1974	11101	return false;
1975	11102	}
1976	11103
	11104	+ /*
	11105	+ * WP_CACHE belongs to whoever owns the drop-in — it is the switch that
	11106	+ * makes core load that one file. Editing it while someone else's
	11107	+ * drop-in is installed either turns THEIR cache on or off; either way
	11108	+ * it is a write to another plugin's state. So: no ownership, no edit.
	11109	+ */
	11110	+ $owner = self::dropin_owner();
	11111	+ if ( self::DROPIN_FOREIGN === $owner || self::DROPIN_UNREADABLE === $owner ) {
	11112	+ return false;
	11113	+ }
	11114	+
	11115	+ $state = self::wp_cache_define_state();
	11116	+ if ( 'duplicate' === $state || 'dynamic' === $state ) {
	11117	+ // Two competing defines, or a value behind an expression. A regex
	11118	+ // rewrite here is a guess, and a wrong guess silently kills page
	11119	+ // caching with no error anywhere.
	11120	+ return false;
	11121	+ }
1977	11122	global $wp_filesystem;
1978	11123	if ( ! function_exists( 'WP_Filesystem' ) ) {
1979	11124	require_once ABSPATH . 'wp-admin/includes/file.php';
1980	11125	}
1981	11126	WP_Filesystem();
1982		- if ( ! $wp_filesystem || ! $wp_filesystem->is_writable( $wp_config ) ) {
	11127	+ if ( ! $wp_filesystem ) {
1983	11128	return false;
1984	11129	}
1985	11130
1986	11131	$config = $wp_filesystem->get_contents( $wp_config );
	11132	+ if ( ! is_string( $config ) ) {
	11133	+ return false;
	11134	+ }
	11135	+ require_once XSPEED_DIR . 'includes/wp-cache-constant.php';
	11136	+ $marker = $enable ? self::wp_cache_receipt() : '';
	11137	+ $updated = xspeed_rewrite_wp_cache_define( $config, (bool) $enable, $marker );
	11138	+ if ( ! is_string( $updated ) ) {
	11139	+ return false;
	11140	+ }
1987	11141
1988		- if ( $enable ) {
1989		- if ( strpos( $config, "define( 'WP_CACHE'" ) !== false || strpos( $config, "define('WP_CACHE'" ) !== false ) {
1990		- return true;
	11142	+ /*
	11143	+ * Removing a WP_CACHE line we cannot prove we wrote is somebody else's
	11144	+ * configuration, so a disable needs either our drop-in or our receipt.
	11145	+ *
	11146	+ * The test is on the REWRITE, not on the request: it used to run
	11147	+ * before the rewrite and refuse a disable that had nothing to remove.
	11148	+ * An ordinary site with no drop-in and no define — every fresh
	11149	+ * install — therefore failed to turn page caching off, so the
	11150	+ * onboarding wizard reported "setup needs attention" to every user who
	11151	+ * declined it and Migration reported the cache import as failed.
	11152	+ */
	11153	+ if ( ! $enable && $updated !== $config
	11154	+ && self::DROPIN_XSPEED !== $owner
	11155	+ && ! self::wp_cache_receipt_matches_source( $config ) ) {
	11156	+ return false;
	11157	+ }
	11158	+
	11159	+ /*
	11160	+ * Nothing to write. auto_heal() runs the whole enable transaction on
	11161	+ * every admin_init, so without this every wp-admin request rewrote
	11162	+ * wp-config.php with byte-identical content: pointless disk churn
	11163	+ * that trips host file-integrity monitors and widens the window for
	11164	+ * a concurrent write on a busy admin.
	11165	+ *
	11166	+ * It is also what makes a correct WP_CACHE on a read-only
	11167	+ * wp-config.php succeed. A managed host that ships the file
	11168	+ * unwritable, on a site where the user already pasted the define,
	11169	+ * is in the state we wanted — the writability test below is about
	11170	+ * whether we can CHANGE the file, and there is nothing to change.
	11171	+ */
	11172	+ if ( $updated === $config ) {
	11173	+ if ( ! $enable ) {
	11174	+ // Our line is not in the file, so the receipt that proved we
	11175	+ // wrote it is stale — drop it on the same terms as a real
	11176	+ // removal, or uninstall keeps a claim on nothing.
	11177	+ delete_option( 'xspeed_page_cache_ownership_receipt' );
1991	11178	}
1992		- $config = preg_replace( '/(<\?php)/', "$1\ndefine( 'WP_CACHE', true );", $config, 1 );
1993		- } else {
1994		- $config = preg_replace( "/define\\(\\s*['\"]WP_CACHE['\"]\\s*,\\s*true\\s*\\);\\s*\\n?/", '', $config );
	11179	+ return true;
1995	11180	}
1996	11181
1997		- return (bool) $wp_filesystem->put_contents( $wp_config, $config, FS_CHMOD_FILE );
	11182	+ if ( ! $wp_filesystem->is_writable( $wp_config ) ) {
	11183	+ return false;
	11184	+ }
	11185	+ $written = (bool) $wp_filesystem->put_contents( $wp_config, $updated, FS_CHMOD_FILE );
	11186	+ if ( $written && ! $enable ) {
	11187	+ delete_option( 'xspeed_page_cache_ownership_receipt' );
	11188	+ }
	11189	+ return $written;
1998	11190	}
1999	11191
	11192	+ private static function wp_cache_receipt(): string {
	11193	+ $receipt = get_option( 'xspeed_page_cache_ownership_receipt', '' );
	11194	+ if ( is_string( $receipt ) && preg_match( '/^[a-f0-9]{32}$/', $receipt ) ) {
	11195	+ return $receipt;
	11196	+ }
	11197	+ $receipt = substr( hash( 'sha256', XSPEED_DIR . microtime( true ) . mt_rand() ), 0, 32 );
	11198	+ update_option( 'xspeed_page_cache_ownership_receipt', $receipt, false );
	11199	+ return $receipt;
	11200	+ }
	11201	+
	11202	+ /**
	11203	+ * Is the WP_CACHE line in wp-config.php ours to REMOVE?
	11204	+ *
	11205	+ * Two different questions live here and only one of them matters. "Did we
	11206	+ * write it" is answered by our drop-in on disk or by our receipt comment
	11207	+ * beside the define. "Is it ours to remove" also asks what the line does
	11208	+ * NOW — and once a competitor owns advanced-cache.php, a line we wrote
	11209	+ * ourselves is the switch that loads THEIR drop-in. They had no reason to
	11210	+ * touch an already-true define, so our receipt is still sitting on it.
	11211	+ * Removing it there would stop their live page cache.
	11212	+ *
	11213	+ * So a foreign or unreadable owner is never ours to remove, whatever the
	11214	+ * receipt says, and the caller treats that as a reason to leave the line
	11215	+ * and get on with disabling our own cache — not as a reason to refuse.
	11216	+ */
	11217	+ private static function wp_cache_define_is_ours_to_remove( string $owner ): bool {
	11218	+ if ( self::DROPIN_FOREIGN === $owner || self::DROPIN_UNREADABLE === $owner ) {
	11219	+ return false;
	11220	+ }
	11221	+ if ( self::DROPIN_XSPEED === $owner ) {
	11222	+ return true;
	11223	+ }
	11224	+ $path = self::wp_config_path();
	11225	+ if ( '' === $path ) {
	11226	+ return false;
	11227	+ }
	11228	+ $config = self::read_file( $path );
	11229	+ return is_string( $config ) && self::wp_cache_receipt_matches_source( $config );
	11230	+ }
	11231	+
	11232	+ private static function wp_cache_receipt_matches_source( string $source ): bool {
	11233	+ $receipt = get_option( 'xspeed_page_cache_ownership_receipt', '' );
	11234	+ require_once XSPEED_DIR . 'includes/wp-cache-constant.php';
	11235	+ return xspeed_wp_cache_receipt_matches( $source, $receipt );
	11236	+ }
	11237	+
	11238	+ /**
	11239	+ * Admin-bar purge menu — a parent node plus one child per visible cache
	11240	+ * type (LiteSpeed-style), instead of a single "Purge All" link. Each
	11241	+ * child posts to the same admin-post handler with its type slug. The
	11242	+ * per-type items only appear for active/licensed modules; "Purge All"
	11243	+ * always shows and always sweeps everything. (FBS-83114)
	11244	+ *
	11245	+ * The parent node links to the settings page rather than a purge URL —
	11246	+ * clicking the top-level item used to wipe the whole cache instantly with
	11247	+ * no confirmation, which is far too destructive for a stray click. Purging
	11248	+ * stays available (and explicit) through the child items. (FBS-84068)
	11249	+ */
2000	11250	public function admin_bar_purge( $wp_admin_bar ) {
2001	11251	if ( ! current_user_can( 'manage_options' ) ) {
2002	11252	return;
2003	11253	}
	11254	+
2004	11255	$wp_admin_bar->add_node(
2005	11256	array(
2006	11257	'id' => 'xspeed-purge',
2007		- 'title' => __( 'Purge xSpeed Cache', 'xspeed' ),
2008		- 'href' => wp_nonce_url( admin_url( 'admin-post.php?action=xspeed_purge' ), 'xspeed_purge' ),
	11258	+ 'title' => __( 'xSpeed Cache', 'xspeed' ),
	11259	+ 'href' => admin_url( 'admin.php?page=' . Admin::PAGE_SLUG ),
2009	11260	)
2010	11261	);
	11262	+
	11263	+ // Settings first, then the two whole-errand actions (Purge All,
	11264	+ // Purge this URL), then the per-type items. The order is the one WP
	11265	+ // Rocket uses, and it front-loads what people open this menu for:
	11266	+ // nobody reaches for "Purge Object Cache" as often as they reach for
	11267	+ // the page they are looking at.
	11268	+ $wp_admin_bar->add_node(
	11269	+ array(
	11270	+ 'id' => 'xspeed-purge-settings',
	11271	+ 'parent' => 'xspeed-purge',
	11272	+ 'title' => esc_html__( 'Settings', 'xspeed' ),
	11273	+ 'href' => admin_url( 'admin.php?page=' . Admin::PAGE_SLUG ),
	11274	+ )
	11275	+ );
	11276	+
	11277	+ $types = self::purge_types();
	11278	+
	11279	+ // 'all' is rendered out of band so the single-URL item can sit
	11280	+ // directly under it. A filter that reorders or drops it is honoured:
	11281	+ // the loop below skips whatever was emitted here.
	11282	+ $emitted = array();
	11283	+ if ( ! empty( $types['all']['visible'] ) ) {
	11284	+ $wp_admin_bar->add_node(
	11285	+ array(
	11286	+ 'id' => 'xspeed-purge-all',
	11287	+ 'parent' => 'xspeed-purge',
	11288	+ 'title' => esc_html( $types['all']['label'] ),
	11289	+ 'href' => self::purge_type_url( 'all' ),
	11290	+ )
	11291	+ );
	11292	+ $emitted['all'] = true;
	11293	+ }
	11294	+
	11295	+ // Only when the current screen is about one thing — a front-end view,
	11296	+ // or a published post's edit screen. On a list table or a settings
	11297	+ // page there is nothing for "this" to mean, so the item stays hidden
	11298	+ // rather than silently targeting the dashboard. Purge_Ui decides both
	11299	+ // the label and the scope, which differ between the two contexts.
	11300	+ $context = Purge_Ui::context_node();
	11301	+ if ( null !== $context ) {
	11302	+ $wp_admin_bar->add_node(
	11303	+ array(
	11304	+ 'id' => 'xspeed-purge-this-url',
	11305	+ 'parent' => 'xspeed-purge',
	11306	+ 'title' => esc_html( $context['title'] ),
	11307	+ 'href' => $context['href'],
	11308	+ )
	11309	+ );
	11310	+ }
	11311	+
	11312	+ foreach ( $types as $slug => $type ) {
	11313	+ if ( empty( $type['visible'] ) || isset( $emitted[ $slug ] ) ) {
	11314	+ continue;
	11315	+ }
	11316	+ $wp_admin_bar->add_node(
	11317	+ array(
	11318	+ 'id' => 'xspeed-purge-' . $slug,
	11319	+ 'parent' => 'xspeed-purge',
	11320	+ 'title' => esc_html( $type['label'] ),
	11321	+ 'href' => self::purge_type_url( $slug ),
	11322	+ )
	11323	+ );
	11324	+ }
2011	11325	}
2012	11326
	11327	+ /**
	11328	+ * Nonce-protected admin-post URL for purging a single type. The nonce
	11329	+ * action is per-type so a leaked URL can't be replayed for a different
	11330	+ * scope.
	11331	+ */
	11332	+ private static function purge_type_url( string $type ): string {
	11333	+ return wp_nonce_url(
	11334	+ admin_url( 'admin-post.php?action=xspeed_purge&type=' . rawurlencode( $type ) ),
	11335	+ 'xspeed_purge_' . $type
	11336	+ );
	11337	+ }
	11338	+
2013	11339	public function handle_admin_bar_purge() {
2014	11340	if ( ! current_user_can( 'manage_options' ) ) {
2015	11341	wp_die( esc_html__( 'Unauthorized.', 'xspeed' ), 403 );
2016	11342	}
2017		- check_admin_referer( 'xspeed_purge' );
2018		- self::purge_all();
2019		- wp_safe_redirect( wp_get_referer() ?: admin_url() );
	11343	+ $type = isset( $_GET['type'] ) ? sanitize_key( wp_unslash( $_GET['type'] ) ) : 'all';
	11344	+ check_admin_referer( 'xspeed_purge_' . $type );
	11345	+
	11346	+ // Only honour known types; anything else falls back to a full purge.
	11347	+ if ( ! array_key_exists( $type, self::purge_types() ) ) {
	11348	+ $type = 'all';
	11349	+ }
	11350	+
	11351	+ // Answer the browser BEFORE purging. "Purge All" fans out to the local
	11352	+ // sweep, the object cache, CSS/edge listeners (outbound HTTP) and
	11353	+ // third-party render caches, all in this one request — on a large site
	11354	+ // that can outlive PHP-FPM's request_terminate_timeout, FPM kills the
	11355	+ // worker mid-purge, and nginx answers the admin's click with a 502.
	11356	+ // fastcgi_finish_request() exists on exactly those FPM setups: send
	11357	+ // the redirect, close the connection, then keep purging in the same
	11358	+ // process. Elsewhere (mod_php, CLI tests) fall back to purge-then-
	11359	+ // redirect as before.
	11360	+ $redirect = self::safe_purge_redirect( wp_get_referer() );
	11361	+ if ( function_exists( 'ignore_user_abort' ) ) {
	11362	+ ignore_user_abort( true );
	11363	+ }
	11364	+ if ( function_exists( 'set_time_limit' ) ) {
	11365	+ @set_time_limit( 300 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort under safe-mode-like restrictions.
	11366	+ }
	11367	+ if ( function_exists( 'fastcgi_finish_request' ) ) {
	11368	+ wp_safe_redirect( $redirect );
	11369	+ fastcgi_finish_request();
	11370	+ self::purge_type( $type );
	11371	+ exit;
	11372	+ }
	11373	+
	11374	+ self::purge_type( $type );
	11375	+ wp_safe_redirect( $redirect );
2020	11376	exit;
	11377	+ }
	11378	+
	11379	+ /**
	11380	+ * Resolve a safe redirect target for an admin-bar purge.
	11381	+ *
	11382	+ * The purge sends the admin back where they came from — but the referer
	11383	+ * can be a ONE-SHOT action URL (e.g. update.php?action=upload-plugin from
	11384	+ * installing a plugin zip, or any *.php?action=… that consumed a POST /
	11385	+ * temp upload). Redirecting there re-runs the action with nothing to act
	11386	+ * on, so WordPress dies — the classic "Please select a file" from
	11387	+ * File_Upload_Upgrader. Strip the transient action args so we return to a
	11388	+ * safe, re-GET-able view of the same page; fall back to the dashboard when
	11389	+ * there is no usable referer.
	11390	+ *
	11391	+ * @param string|false $referer Raw wp_get_referer() value.
	11392	+ * @return string Safe URL to redirect to.
	11393	+ */
	11394	+ public static function safe_purge_redirect( $referer ): string {
	11395	+ $referer = is_string( $referer ) ? $referer : '';
	11396	+ if ( '' === $referer ) {
	11397	+ return admin_url();
	11398	+ }
	11399	+
	11400	+ // A referer that lands on an action-processing endpoint (update.php,
	11401	+ // update-core.php, plugin/theme install/upload flows) can't be safely
	11402	+ // re-requested — send them to the dashboard instead of replaying it.
	11403	+ $path = (string) wp_parse_url( $referer, PHP_URL_PATH );
	11404	+ if ( preg_match( '#/wp-admin/(update|update-core)\.php$#', $path ) ) {
	11405	+ return admin_url();
	11406	+ }
	11407	+
	11408	+ // Otherwise keep them on the same page but drop the query args that
	11409	+ // would re-trigger a form action or upload on load.
	11410	+ return remove_query_arg(
	11411	+ array( 'action', 'action2', 'package', 'overwrite', 'plugin', 'theme', 'file', '_wpnonce', '_ajax_nonce' ),
	11412	+ $referer
	11413	+ );
2021	11414	}
2022	11415	}