← All changes | includes/class-cache.php +7950 -213 1.0.4 → 1.3.6 View file →

		@@ -19,19 +19,341 @@
19	19	* @var int|null
20	20	*/
21	21	private static $buffer_level = null;
22	22
	23	+ /**
	24	+ * Bytes freed by the current sweep, accumulated by sweep_delete().
	25	+ *
	26	+ * A counter rather than a return value because the two sweeps that free
	27	+ * the bytes — the flat glob loop and the recursive static walk — already
	28	+ * report a FILE count, and `wp xspeed purge` needs both numbers from a
	29	+ * single pass. Re-walking the tree to size it would double the I/O on
	30	+ * exactly the caches large enough for the number to matter.
	31	+ *
	32	+ * @var int
	33	+ */
	34	+ private static $sweep_bytes = 0;
	35	+
	36	+ /**
	37	+ * The `X-XSpeed-Cache` value decided for this request, and — when the
	38	+ * decision was BYPASS — the slug of the gate that made it.
	39	+ *
	40	+ * Recorded as well as sent so unit tests (CLI SAPI, where header() is a
	41	+ * no-op and headers_sent() is meaningless) can assert on the decision.
	42	+ *
	43	+ * @var string
	44	+ */
	45	+ private static $status_header = '';
	46	+ private static $bypass_reason = '';
	47	+
	48	+ /**
	49	+ * Edge/CDN headers decided for this request, after sanitising.
	50	+ *
	51	+ * Same reason as $status_header: header() cannot be observed from the CLI
	52	+ * SAPI, so the pairs we sent are recorded here too.
	53	+ *
	54	+ * @var array<string,string>
	55	+ */
	56	+ private static $edge_headers = array();
	57	+
	58	+ /**
	59	+ * This entry's edge headers when they differ from the site-wide bake,
	60	+ * resolved once per store. Null until asked.
	61	+ *
	62	+ * @var array<string,string>|null
	63	+ */
	64	+ private static $per_entry_edge = null;
	65	+
	66	+ /**
	67	+ * Cache key whose write was deferred to shutdown because a render-time
	68	+ * translation plugin's buffer wraps ours. Null on every ordinary request.
	69	+ *
	70	+ * @var string|null
	71	+ */
	72	+ private static $deferred_key = null;
	73	+
	74	+ /**
	75	+ * Translated page HTML captured by the outer buffer, for the deferred
	76	+ * write. Only populated when a translation plugin is active.
	77	+ *
	78	+ * @var string
	79	+ */
	80	+ private static $translated_output = '';
	81	+
	82	+ /**
	83	+ * Did finalize_buffer() run to completion on this request?
	84	+ *
	85	+ * The deferred translated write runs as a PHP shutdown function, which
	86	+ * fires after a `wp_die()` or a bare `exit()` exactly as it does after a
	87	+ * clean render. Only finalize_buffer() sets this, and only at the point
	88	+ * where it has the full buffer in hand — so an aborted render leaves it
	89	+ * false and the writer declines rather than caching a truncated page
	90	+ * under the real key.
	91	+ *
	92	+ * @var bool
	93	+ */
	94	+ private static $render_completed = false;
	95	+
	96	+ /**
	97	+ * Hooks that get an argument-aware handler instead of a blanket purge.
	98	+ *
	99	+ * Each fires on an ordinary visitor action — an order, a review, a
	100	+ * registration — where purge_all() cannot see WHAT changed and so wiped
	101	+ * the whole cache on every one. They are re-bound further down to
	102	+ * handlers that inspect the payload first.
	103	+ *
	104	+ * Listed here so the generic invalidation loop skips them. It binds a
	105	+ * closure (to name the cause), and a closure cannot be unbound by the
	106	+ * remove_action() pairs below — binding one would leave the coarse purge
	107	+ * running alongside its replacement and silently undo #243.
	108	+ */
	109	+ private const TARGETED_INVALIDATION_HOOKS = array(
	110	+ 'save_post',
	111	+ 'before_delete_post',
	112	+ 'trashed_post',
	113	+ 'comment_post',
	114	+ 'wp_set_comment_status',
	115	+ 'user_register',
	116	+ 'profile_update',
	117	+ );
	118	+
23	119	public function __construct() {
24		- add_action( 'template_redirect', array( $this, 'maybe_start_cache' ), 0 );
	120	+ /**
	121	+ * When the page-cache output buffer opens.
	122	+ *
	123	+ * Filterable because buffer ORDER decides what gets cached. PHP's
	124	+ * output buffers are LIFO: the last one opened is innermost, and its
	125	+ * callback runs first. A render-time translation plugin that opens
	126	+ * an outer buffer therefore translates AFTER we have already captured
	127	+ * and cached the raw HTML — see translation_buffer_compat().
	128	+ *
	129	+ * @param string $hook Hook to open the buffer on.
	130	+ * @param int $priority Priority for that hook.
	131	+ */
	132	+ $hook = (string) apply_filters( 'xspeed_cache_buffer_hook', 'template_redirect' );
	133	+ $priority = (int) apply_filters( 'xspeed_cache_buffer_priority', 0 );
	134	+ add_action( $hook, array( $this, 'maybe_start_cache' ), $priority );
25	135
26		- $invalidate_hooks = array( 'save_post', 'deleted_post', 'trashed_post', 'comment_post', 'wp_set_comment_status', 'switch_theme', 'activated_plugin', 'deactivated_plugin' );
	136	+ // When a render-time translation plugin is present, open one extra
	137	+ // buffer OUTSIDE its own so we can capture post-translation HTML.
	138	+ // TranslatePress opens on `init` priority 0, so we take a negative
	139	+ // priority to land outside it. This buffer only collects bytes for
	140	+ // the deferred cache write — it never modifies the response.
	141	+ add_action(
	142	+ 'init',
	143	+ static function () {
	144	+ if ( ! self::translation_plugin_active() ) {
	145	+ return;
	146	+ }
	147	+ // `init` fires on EVERY request type, and
	148	+ // translation_plugin_active() is a class_exists() check that
	149	+ // is true site-wide — so without this guard the buffer opened
	150	+ // on REST, admin-ajax, cron and WP-CLI too. None of those
	151	+ // reach template_redirect, so $deferred_key stays null and
	152	+ // the collected bytes are never released: a long-running
	153	+ // WP-CLI command copied every byte of its output into a
	154	+ // string that grew for the life of the process.
	155	+ if ( is_admin()
	156	+ || wp_doing_ajax()
	157	+ || wp_doing_cron()
	158	+ || ( defined( 'REST_REQUEST' ) && REST_REQUEST )
	159	+ || ( defined( 'WP_CLI' ) && WP_CLI )
	160	+ || ( defined( 'XMLRPC_REQUEST' ) && XMLRPC_REQUEST ) ) {
	161	+ return;
	162	+ }
	163	+ ob_start(
	164	+ static function ( $chunk ) {
	165	+ self::$translated_output .= $chunk;
	166	+ return $chunk;
	167	+ }
	168	+ );
	169	+ },
	170	+ (int) apply_filters( 'xspeed_translation_outer_buffer_priority', -100 )
	171	+ );
	172	+
	173	+ // Events that should invalidate cached output. Beyond posts/comments,
	174	+ // this covers user and term changes — the REST cache can serve
	175	+ // /wp/v2/users, /wp/v2/categories, /wp/v2/tags, and these also affect
	176	+ // rendered author bylines / term-archive pages. Without them, an edit
	177	+ // left the matching endpoint (and archives) stale for the full TTL.
	178	+ // (FBS-82408)
	179	+ $invalidate_hooks = array(
	180	+ 'save_post', 'before_delete_post', 'trashed_post',
	181	+ 'comment_post', 'wp_set_comment_status',
	182	+ 'switch_theme', 'activated_plugin', 'deactivated_plugin',
	183	+ // Users → /wp/v2/users + author archives.
	184	+ 'profile_update', 'user_register', 'deleted_user',
	185	+ // Terms → /wp/v2/{taxonomy} + term archives.
	186	+ 'created_term', 'edited_term', 'delete_term',
	187	+ // Menu structure changes (reorder, rename, assign to a location)
	188	+ // fire only here — the per-item `nav_menu_item` save_post does
	189	+ // not cover them. (#270 regression)
	190	+ 'wp_update_nav_menu',
	191	+ );
27	192	foreach ( $invalidate_hooks as $hook ) {
28		- add_action( $hook, array( __CLASS__, 'purge_all' ) );
	193	+ // Name the hook in the cause rather than binding purge_all bare.
	194	+ // Bound bare, WordPress passes the action's own first argument
	195	+ // into $cause — a term id, a user id, a menu id — so the activity
	196	+ // feed read "Cache purged (12)" and told the user nothing about
	197	+ // what happened. (#270 QA round 2)
	198	+ //
	199	+ // The four hooks that get an argument-aware handler below
	200	+ // (save_post, comment_post, user_register, profile_update) are
	201	+ // deliberately NOT wired here: a closure cannot be unbound by
	202	+ // remove_action(), so binding one would leave the coarse purge in
	203	+ // place alongside its replacement and silently undo #243. Skipping
	204	+ // them is equivalent — each is re-added with its own handler, and
	205	+ // each of those names its own cause.
	206	+ if ( in_array( $hook, self::TARGETED_INVALIDATION_HOOKS, true ) ) {
	207	+ continue;
	208	+ }
	209	+ add_action(
	210	+ $hook,
	211	+ static function () use ( $hook ): void {
	212	+ self::purge_all(
	213	+ 'hook:' . $hook,
	214	+ null,
	215	+ self::invalidation_for_hook( $hook )
	216	+ );
	217	+ }
	218	+ );
29	219	add_action( $hook, array( 'XSpeed\\Minifier', 'purge_minified' ) );
30	220	}
31	221
	222	+ // Updating a plugin, theme or core changes the markup and the assets
	223	+ // a page is built from, but fires NONE of the hooks above: WordPress
	224	+ // does not deactivate and reactivate a plugin to update it, so
	225	+ // `activated_plugin` never runs and the cached HTML survives the
	226	+ // update untouched for the whole TTL — up to 7 days on the Aggressive
	227	+ // preset, 30 at the maximum.
	228	+ //
	229	+ // The stale copy is not merely old, it is wrong in a way the user
	230	+ // cannot see the cause of: they update a plugin to get a fix, the
	231	+ // cache keeps serving the pre-fix HTML, and the update looks like it
	232	+ // did nothing. Minified assets do regenerate on their own (their key
	233	+ // includes the source filemtime), which makes it worse rather than
	234	+ // better — the cached pages still link the PREVIOUS hashes.
	235	+ //
	236	+ // Purge unconditionally on any completed update. Scoping it to
	237	+ // "plugins that enqueue front-end assets" is not knowable here, and a
	238	+ // cold cache after an update is the cheaper mistake. (#269)
	239	+ add_action( 'upgrader_process_complete', array( __CLASS__, 'purge_after_upgrade' ), 10, 2 );
	240	+ // The replacement signal has to outlive OUR listener: add-ons read it
	241	+ // through upgrade_replaced_code() from their own priority-10 callbacks,
	242	+ // and consuming it inside purge_after_upgrade() meant whoever
	243	+ // registered second saw false. Cleared at the END of the dispatch
	244	+ // instead, once every listener has had its turn.
	245	+ //
	246	+ // Depth-counted, because this action NESTS. Core hangs
	247	+ // Language_Pack_Upgrader::async_upgrade() on it at priority 20
	248	+ // (wp-admin/includes/admin-filters.php), and that runs a whole
	249	+ // upgrader of its own, which fires this same action again. A flat
	250	+ // reset therefore fired while the OUTER dispatch was still running —
	251	+ // on any site with pending translations — and every listener after
	252	+ // priority 20 read the cleared signal as false. Which is the bug this
	253	+ // pair exists to fix, back again and harder to see. (#303)
	254	+ add_action( 'upgrader_process_complete', array( __CLASS__, 'note_upgrade_dispatch' ), PHP_INT_MIN );
	255	+ add_action( 'upgrader_process_complete', array( __CLASS__, 'forget_cleared_destination' ), PHP_INT_MAX );
	256	+ // WordPress labels an upload-and-replace as an INSTALL, so the action
	257	+ // alone cannot tell "added beside nothing" from "replaced live code".
	258	+ // This filter fires only when the upgrader removed an existing copy,
	259	+ // which is exactly the difference. Registered as a filter listener
	260	+ // that returns its input untouched. (#303)
	261	+ add_filter( 'upgrader_clear_destination', array( __CLASS__, 'note_cleared_destination' ), 10, 1 );
	262	+ // Unattended auto-updates are the case that matters most here: they
	263	+ // land overnight with nobody around to purge by hand, which is the
	264	+ // exact scenario the stale cache goes undiagnosed in. WordPress fires
	265	+ // this INSTEAD of a per-item upgrader_process_complete for some
	266	+ // background runs. Its payload is a results array keyed by type
	267	+ // rather than a hook_extra, so it needs its own handler — passing it
	268	+ // to purge_after_upgrade() landed it in the unused $upgrader slot and
	269	+ // left $type empty, which read as "invalidating" and purged the whole
	270	+ // cache for a language-pack-only run. Matches what LiteSpeed binds.
	271	+ // (#298)
	272	+ add_action( 'automatic_updates_complete', array( __CLASS__, 'purge_after_auto_updates' ), 10, 1 );
	273	+ // …except the four hooks above that fire on ordinary visitor actions.
	274	+ // Attached bare, purge_all() can't see WHAT changed, so on a store
	275	+ // every order, every product review and every checkout
	276	+ // account-creation wiped 100% of the cache — all anonymous happy-path
	277	+ // actions, so the cache never reached steady state (#243). Measured:
	278	+ // 3 orders across 36 pageviews took the hit rate from 83% to 50% and
	279	+ // the average response from 23ms to 57ms.
	280	+ //
	281	+ // HPOS does NOT help: WooCommerce still writes a
	282	+ // `shop_order_placehold` row into wp_posts to reserve the order ID,
	283	+ // so save_post fires either way. The gate therefore keys on POST-TYPE
	284	+ // VIEWABILITY, not on storage mode — which fixes both modes at once,
	285	+ // and generalises to Flamingo (#229) and Tutor LMS (#231) too.
	286	+ remove_action( 'save_post', array( __CLASS__, 'purge_all' ) );
	287	+ remove_action( 'save_post', array( 'XSpeed\\Minifier', 'purge_minified' ) );
	288	+ add_action( 'save_post', array( __CLASS__, 'on_save_post' ), 10, 2 );
	289	+ add_action( 'before_delete_post', array( __CLASS__, 'on_post_removed' ), 10, 2 );
	290	+ add_action( 'trashed_post', array( __CLASS__, 'on_post_removed' ), 10, 2 );
	291	+ // wp_delete_post() hands an attachment to wp_delete_attachment() and
	292	+ // returns BEFORE before_delete_post fires, so deleting media reached
	293	+ // neither hook above. Attachment pages are public and media appears in
	294	+ // galleries, so that left cached pages showing a file that is gone.
	295	+ // (dev caught this via `deleted_post`, which this branch replaced.)
	296	+ add_action( 'delete_attachment', array( __CLASS__, 'on_post_removed' ), 10, 2 );
	297	+
	298	+ remove_action( 'comment_post', array( __CLASS__, 'purge_all' ) );
	299	+ remove_action( 'comment_post', array( 'XSpeed\\Minifier', 'purge_minified' ) );
	300	+ add_action( 'comment_post', array( __CLASS__, 'on_comment_post' ), 10, 3 );
	301	+ add_action( 'wp_set_comment_status', array( __CLASS__, 'on_comment_status' ), 10, 2 );
	302	+
	303	+ remove_action( 'user_register', array( __CLASS__, 'purge_all' ) );
	304	+ remove_action( 'user_register', array( 'XSpeed\\Minifier', 'purge_minified' ) );
	305	+ add_action( 'user_register', array( __CLASS__, 'on_user_change' ) );
	306	+
	307	+ remove_action( 'profile_update', array( __CLASS__, 'purge_all' ) );
	308	+ remove_action( 'profile_update', array( 'XSpeed\\Minifier', 'purge_minified' ) );
	309	+ add_action( 'profile_update', array( __CLASS__, 'on_user_change' ) );
	310	+
	311	+ // Product data lives in post meta and lookup tables, NOT in wp_posts,
	312	+ // so WC_Product_Data_Store_CPT::update() takes a direct $wpdb->update()
	313	+ // branch and save_post never fires. Anchoring invalidation on
	314	+ // save_post therefore missed 100% of commerce-relevant mutations: a
	315	+ // REST price change, wc_update_product_stock(), a CLI ->save(), and
	316	+ // every scheduled sale start/end left the product page, the shop and
	317	+ // the category archives serving the old price and stock for the full
	318	+ // lifetime — the store quoting one price and charging another (#242).
	319	+ //
	320	+ // This MUST ship with the gate above: once orders stop purging
	321	+ // everything, the accidental invalidation that was masking this
	322	+ // disappears, and an order that reduces stock would leave the product
	323	+ // page stale.
	324	+ if ( class_exists( 'WooCommerce' ) ) {
	325	+ foreach ( array( 'woocommerce_update_product', 'woocommerce_new_product' ) as $wc_hook ) {
	326	+ add_action( $wc_hook, array( __CLASS__, 'purge_product' ) );
	327	+ }
	328	+ // Direct stock writes bypass the CRUD entirely.
	329	+ add_action( 'woocommerce_product_set_stock', array( __CLASS__, 'purge_product_object' ) );
	330	+ add_action( 'woocommerce_variation_set_stock', array( __CLASS__, 'purge_product_object' ) );
	331	+ add_action( 'woocommerce_product_set_stock_status', array( __CLASS__, 'purge_product' ) );
	332	+ add_action( 'woocommerce_variation_set_stock_status', array( __CLASS__, 'purge_product' ) );
	333	+ }
	334	+
32	335	add_action( 'update_option_xspeed_options', array( __CLASS__, 'on_settings_change' ), 10, 2 );
33	336
	337	+ // …and the same for every PER-MODULE option. The handler above only
	338	+ // ever watched the legacy `xspeed_options` blob, but every module has
	339	+ // since migrated to its own `xspeed_module_<slug>` option and no hook
	340	+ // followed — so changing Minify HTML, Lazy Load, Remove Query Strings
	341	+ // etc. left the cached HTML untouched until the TTL expired (24h by
	342	+ // default) and the feature read as broken. (#205)
	343	+ //
	344	+ // One central listener rather than a hook per module: it covers Pro
	345	+ // modules with no cross-repo change, and a new module can't forget to
	346	+ // wire it up.
	347	+ add_action( 'updated_option', array( __CLASS__, 'on_module_settings_change' ), 10, 1 );
	348	+ // `added_option` matters as much as `updated_option`: on a fresh install
	349	+ // a module's option doesn't exist yet, so the FIRST save of every panel
	350	+ // goes through add_option() and would otherwise skip the purge — the
	351	+ // original bug surviving one save per module. `deleted_option` covers a
	352	+ // reset-to-defaults, which changes rendered HTML just as much. (#205)
	353	+ add_action( 'added_option', array( __CLASS__, 'on_module_settings_change' ), 10, 1 );
	354	+ add_action( 'deleted_option', array( __CLASS__, 'on_module_settings_change' ), 10, 1 );
	355	+
34	356	add_action( 'admin_bar_menu', array( $this, 'admin_bar_purge' ), 100 );
35	357	add_action( 'admin_post_xspeed_purge', array( $this, 'handle_admin_bar_purge' ) );
36	358	}
37	359
		@@ -47,35 +369,921 @@
47	369	self::purge_all( 'settings change' );
48	370	Minifier::purge_minified();
49	371	}
50	372
	373	+ /**
	374	+ * Modules whose settings cannot change rendered HTML, so a write to them
	375	+ * doesn't warrant throwing away the page cache.
	376	+ *
	377	+ * The safe default is to purge: a module is listed here only when it is
	378	+ * clearly incapable of altering front-end output (diagnostics, the MCP
	379	+ * server, licensing/telemetry surfaces). When in doubt, leave it off the
	380	+ * list — a needless purge costs a re-render, a missed one makes the
	381	+ * feature look broken. (#205)
	382	+ *
	383	+ * @return string[] Module slugs.
	384	+ */
	385	+ public static function non_rendering_modules(): array {
	386	+ return (array) apply_filters(
	387	+ 'xspeed_non_rendering_modules',
	388	+ array(
	389	+ 'mcp', // AI endpoint — no front-end output.
	390	+ 'health', // diagnostics only.
	391	+ 'support', // support snapshot.
	392	+ 'score', // PageSpeed/GTmetrix runner.
	393	+ 'migration', // one-shot importer.
	394	+ 'settings', // import/export surface.
	395	+ 'cache-coverage', // read-only reporting.
	396	+ 'ai-privacy', // consent flags for AI surfaces.
	397	+ 'database', // DB cleanup schedule — no HTML impact.
	398	+ // Pro slugs — listed by name rather than by asking Pro, so
	399	+ // Free stays unaware of it. A Pro module absent here simply
	400	+ // purges, which is the safe default.
	401	+ 'license',
	402	+ 'pro_status',
	403	+ 'analytics',
	404	+ 'performance-health',
	405	+ 'recommendations',
	406	+ 'ai-provider',
	407	+ 'migration-pro',
	408	+ )
	409	+ );
	410	+ }
	411	+
	412	+ /**
	413	+ * Purge when ANY module's settings option is written. (#205)
	414	+ *
	415	+ * Bound to `updated_option`, `added_option` and `deleted_option` — all three
	416	+ * fire for every option on the site, so the prefix test comes first and is
	417	+ * the cheap path for the ~99% of writes that aren't ours. All three pass the
	418	+ * option name first, which is why this can't hook purge_all() directly:
	419	+ * that takes $cause first, so every purge would be filed under a cause
	420	+ * literally named "xspeed_module_minify".
	421	+ *
	422	+ * @param string $option Option name that was just written or removed.
	423	+ */
	424	+ public static function on_module_settings_change( $option ): void {
	425	+ $option = (string) $option;
	426	+ $prefix = Settings_Manager::OPTION_PREFIX;
	427	+ if ( 0 !== strpos( $option, $prefix ) ) {
	428	+ return;
	429	+ }
	430	+
	431	+ $slug = substr( $option, strlen( $prefix ) );
	432	+ if ( '' === $slug || in_array( $slug, self::non_rendering_modules(), true ) ) {
	433	+ return;
	434	+ }
	435	+
	436	+ // Guard against re-entry: purge_all() and purge_minified() can write
	437	+ // options of their own (stats, timestamps), and a nested purge would
	438	+ // both waste work and risk recursing through this same hook.
	439	+ static $purging = false;
	440	+ if ( $purging ) {
	441	+ return;
	442	+ }
	443	+ $purging = true;
	444	+
	445	+ self::purge_all( 'settings change' );
	446	+ Minifier::purge_minified();
	447	+
	448	+ $purging = false;
	449	+ }
	450	+
	451	+ /**
	452	+ * Stamp the request's cache decision on the response.
	453	+ *
	454	+ * `X-XSpeed-Cache` was only ever written on the serve-from-cache paths,
	455	+ * so a miss and a deliberate bypass both came back with no header at all
	456	+ * — indistinguishable from a `curl -I`, the first thing anyone reaches
	457	+ * for when a site "isn't caching" (issue #10). The reason slug rides
	458	+ * along on `X-XSpeed-Reason`, but only under WP_DEBUG so production
	459	+ * responses stay clean. Slugs are fixed per gate — never the matched
	460	+ * pattern, cookie or user-agent, which would echo request input back.
	461	+ *
	462	+ * @param string $value HIT (php) | MISS | BYPASS.
	463	+ * @param string $reason Fixed slug naming the gate, for BYPASS only.
	464	+ */
	465	+ private static function mark( string $value, string $reason = '' ): void {
	466	+ self::$status_header = $value;
	467	+ self::$bypass_reason = $reason;
	468	+
	469	+ // Every status, not just a HIT. A page we declined to cache is the
	470	+ // one an edge most needs telling about: it goes out naked today, and
	471	+ // a CDN that stores HTML by default keeps somebody's cart.
	472	+ //
	473	+ // Resolved before the headers_sent() guard so the decision is
	474	+ // recorded (and observable in tests) even on a request that can no
	475	+ // longer send headers; only the emission below is conditional.
	476	+ self::$edge_headers = self::edge_headers_for( self::edge_status( $value ), 'request', $reason );
	477	+
	478	+ if ( headers_sent() ) {
	479	+ return;
	480	+ }
	481	+ header( 'X-XSpeed-Cache: ' . $value );
	482	+ if ( '' !== $reason && defined( 'WP_DEBUG' ) && WP_DEBUG ) {
	483	+ header( 'X-XSpeed-Reason: ' . $reason );
	484	+ }
	485	+ foreach ( self::$edge_headers as $name => $val ) {
	486	+ header( $name . ': ' . $val );
	487	+ }
	488	+ }
	489	+
	490	+ /**
	491	+ * Normalize an `X-XSpeed-Cache` value to the vocabulary the edge seam
	492	+ * speaks.
	493	+ *
	494	+ * The header value carries which layer served the page (`HIT (php)`,
	495	+ * `HIT (nginx)`, `HIT (static)`); nothing deciding what to tell a CDN
	496	+ * cares, and making a caller match on three spellings of one outcome is
	497	+ * how a rule ends up applied on two paths out of three.
	498	+ */
	499	+ private static function edge_status( string $value ): string {
	500	+ return 0 === strpos( $value, 'HIT' ) ? 'HIT' : $value;
	501	+ }
	502	+
	503	+ /** Record a bypass gate and answer "don't cache" in one statement. */
	504	+ private static function bypass( string $reason ): bool {
	505	+ self::mark( 'BYPASS', $reason );
	506	+ return false;
	507	+ }
	508	+
	509	+ /** The X-XSpeed-Cache value decided for this request ('' if none yet). */
	510	+ public static function status_header(): string {
	511	+ return self::$status_header;
	512	+ }
	513	+
	514	+ /** The bypass gate slug for this request ('' unless BYPASS). */
	515	+ public static function bypass_reason(): string {
	516	+ return self::$bypass_reason;
	517	+ }
	518	+
	519	+ /**
	520	+ * The edge/CDN pairs sent on this request ('' if none were).
	521	+ *
	522	+ * @return array<string,string>
	523	+ */
	524	+ public static function edge_headers(): array {
	525	+ return self::$edge_headers;
	526	+ }
	527	+
	528	+ /**
	529	+ * Bypass gates that do NOT ask a cache in front of us to stand down.
	530	+ *
	531	+ * Every other slug does. The split is the reason this reads the gate
	532	+ * rather than the status: a bypass usually means "this response is
	533	+ * personal, or someone decided this page is never stored", and an edge
	534	+ * holding one of those does precisely what we refused to do. These two
	535	+ * mean something else.
	536	+ *
	537	+ * `cache-disabled` is the user switching OUR page cache off. Nothing
	538	+ * about the page became personal. Sending `no-store` on every page of a
	539	+ * site whose owner chose a different cache would make a local toggle a
	540	+ * site-wide side effect on infrastructure we do not own.
	541	+ *
	542	+ * `non-frontend` is admin, REST, cron and AJAX. Not ours to describe:
	543	+ * WordPress already nocaches admin, and a REST caller sets its own
	544	+ * policy.
	545	+ */
	546	+ private const HOLD_EXEMPT_BYPASS = array( 'cache-disabled', 'non-frontend' );
	547	+
	548	+ /**
	549	+ * Bypass gates that describe the SHAPE of the request rather than the
	550	+ * visitor or the page.
	551	+ *
	552	+ * These still hold, but only once we have evidence of an edge — the same
	553	+ * bar a MISS has to clear. The difference matters because the default
	554	+ * excluded-URL list contains `/feed/`, the sitemap and `/wp-json/`, and
	555	+ * `query-param` catches `?lang=fr`, `?paged=2`, and every page of a
	556	+ * plain-permalink site.
	557	+ *
	558	+ * xSpeed refuses those because IT cannot key on a query string, not
	559	+ * because the response is private. A CDN keys on the full URL and caches
	560	+ * them correctly. Holding them unconditionally would have meant every
	561	+ * default install stopped its feed and sitemap being edge-cached — a
	562	+ * performance regression shipped to sites that never had a CDN in the
	563	+ * first place, in the name of protecting them from one.
	564	+ *
	565	+ * The gates left out of this list are about the visitor (`logged-in`,
	566	+ * `excluded-cookie`) or are somebody stating outright that this page is
	567	+ * never to be stored (`donotcachepage`, `post-excluded`, `filtered`).
	568	+ * Those hold whether or not we can see an edge.
	569	+ */
	570	+ private const REQUEST_SHAPE_BYPASS = array( 'query-param', 'non-get', 'user-agent' );
	571	+
	572	+ /**
	573	+ * Default exclusions that are about the site's plumbing, not its content.
	574	+ *
	575	+ * `excluded-url` covers two unlike things. The default list carries
	576	+ * `/cart`, `/checkout`, `/my-account` and `/wp-login` — personal pages,
	577	+ * and the reason this feature exists. It also carries the entries below:
	578	+ * feeds, sitemaps, the REST root, the front controller. Those are public,
	579	+ * cacheable, and hammered by pollers; a CDN keys on the full URL and
	580	+ * serves them correctly, so telling it to stop is a cost with no benefit.
	581	+ *
	582	+ * Matched as exact strings against the stored list, never as patterns
	583	+ * against the path. Three bugs came out of doing it the other way round:
	584	+ * `strpos( $uri, '/feed' )` matched `/my-account/feedback/`, reading the
	585	+ * whole URI let `/cart/?utm_source=/feed/` disguise a cart as a feed, and
	586	+ * a bare `index.php` — which is in this list, and which every URL contains
	587	+ * on an "almost pretty" permalink site — made every page on such a site
	588	+ * look personal. Comparing the LIST ENTRY rather than the path cannot make
	589	+ * any of those mistakes, and it keeps a pattern the site owner added
	590	+ * themselves on the personal side where it belongs.
	591	+ */
	592	+ private const STRUCTURAL_EXCLUSIONS = array(
	593	+ '/wp-json/',
	594	+ '/xmlrpc.php',
	595	+ '~wp-.*\.php',
	596	+ '/feed/',
	597	+ 'index.php',
	598	+ '/robots.txt',
	599	+ // Both spellings, and no entry here is ever retired. This is a
	600	+ // RECOGNITION list, not a source of truth: it is matched against
	601	+ // whatever the site has STORED, and a site that saved its settings
	602	+ // before `~sitemap(_index)?\.xml` was widened to `sitemaps?` (for
	603	+ // SEOPress, which ships sitemaps.xml) still has the old string in
	604	+ // its option row. Dropping the old spelling when the default moved
	605	+ // would read every upgraded site's sitemap exclusion as somebody's
	606	+ // personal data and hold sitemaps off the CDN — the bug this whole
	607	+ // predicate exists to prevent, reintroduced by a rename.
	608	+ '~sitemaps?(_index)?\.xml',
	609	+ '~sitemap(_index)?\.xml',
	610	+ );
	611	+ /**
	612	+ * Header names no edge instruction may ever carry.
	613	+ *
	614	+ * These describe the transfer, not the caching policy, and one wrong
	615	+ * value from a settings field is a white screen rather than a missing
	616	+ * optimization.
	617	+ */
	618	+ private const NEVER_AN_EDGE_HEADER = array(
	619	+ 'content-length',
	620	+ 'content-encoding',
	621	+ 'content-type',
	622	+ 'transfer-encoding',
	623	+ 'set-cookie',
	624	+ 'location',
	625	+ 'x-xspeed-cache',
	626	+ 'x-xspeed-edge-hold',
	627	+ );
	628	+
	629	+ /**
	630	+ * Reasons that hold the edge off even when we detected nothing in front.
	631	+ *
	632	+ * `none` confidence means no evidence of a proxy, which is not proof
	633	+ * there is none — a transparent proxy and a host page cache both leave
	634	+ * the request untouched. So the question is what a wasted header costs
	635	+ * against what a missed one does, and the answer differs by reason.
	636	+ *
	637	+ * These two are correctness failures. A cart page stored by something we
	638	+ * could not see is the defect this exists to fix, and a mobile-split page
	639	+ * served to the wrong device is a wrong page rather than a slow one.
	640	+ * Ninety bytes on a response that was never cacheable is a cheap premium.
	641	+ *
	642	+ * `miss` and `pending` are performance hedges, and a hedge against a
	643	+ * cache that does not exist is noise on every first render. Skipping them
	644	+ * has a second benefit: because per_entry_edge_headers() compares `store`
	645	+ * against `bake`, a `pending` hold that never fires leaves the two
	646	+ * agreeing, which keeps the page on the static tree.
	647	+ */
	648	+ private const HOLD_WITHOUT_EVIDENCE = array( 'bypass', 'mobile-split' );
	649	+
	650	+ /**
	651	+ * Is a module still going to change this page after this response?
	652	+ *
	653	+ * Free itself never says yes — nothing in Free defers work past the
	654	+ * request. Minification and combining write their file and return its URL
	655	+ * inside the same render; the LCP preload is chosen by parsing the HTML
	656	+ * being sent. It is the question that matters to anything caching in
	657	+ * front of us, so Free asks it on their behalf and lets whoever owns the
	658	+ * deferred work answer.
	659	+ *
	660	+ * Answer TRUE while the work is outstanding for the page being served.
	661	+ * The cost of a false yes is one extra origin hit; the cost of a false no
	662	+ * is an un-optimized page pinned at the edge for the full lifetime, which
	663	+ * is the failure this exists to prevent — so when in doubt, say yes.
	664	+ *
	665	+ * Asked on a `request` only, and that boundary is the whole safety of it.
	666	+ *
	667	+ * A `bake` is generated once, in an admin or CLI request, and serves every
	668	+ * static HIT on the site; a per-page answer frozen into it would be wrong
	669	+ * for every other page.
	670	+ *
	671	+ * A `store` is worse, and cost a live site an afternoon. The pairs written
	672	+ * at store time go into the `.meta` sidecar, which the drop-in replays on
	673	+ * every later HIT — before plugins load, so nothing can re-ask this
	674	+ * question. A hold written there therefore outlives the state that caused
	675	+ * it, and the only thing that clears it is the page being stored again. On
	676	+ * a site where the deferred work never completes, every re-store re-pins
	677	+ * it, and the page is never edge-cacheable again. The symptom is a cache
	678	+ * HIT carrying `no-store` and `X-XSpeed-Edge-Hold: pending` on a page
	679	+ * whose deferred work finished long ago — the sidecar answering with
	680	+ * state nothing can re-ask.
	681	+ *
	682	+ * Holding the MISS is what this is for, and it is enough: that response is
	683	+ * the un-optimized one. The copy we then store is what an edge should
	684	+ * mirror, and when the work does land the module purges the page, which
	685	+ * reaches the edge. The purge is the correctness mechanism; this is only
	686	+ * meant to cover the single render before it.
	687	+ *
	688	+ * @param string $context `request`, `store` or `bake`.
	689	+ */
	690	+ public static function edge_optimization_pending( string $context = 'request' ): bool {
	691	+ if ( 'request' !== $context ) {
	692	+ return false;
	693	+ }
	694	+
	695	+ /**
	696	+ * Filter: xspeed_edge_optimization_pending
	697	+ *
	698	+ * @param bool $pending Whether deferred work will still change this page.
	699	+ */
	700	+ return (bool) apply_filters( 'xspeed_edge_optimization_pending', false );
	701	+ }
	702	+
	703	+ /**
	704	+ * Does mobile cache split this URL into two renders?
	705	+ *
	706	+ * With `mobile_separate` on, Free keys its cache on device and serves a
	707	+ * different page to a phone than to a desktop at the SAME url. No CDN
	708	+ * varies on User-Agent, so an edge holding one of those renders serves it
	709	+ * to everyone: whichever device asked first decides what the other sees,
	710	+ * for the whole lifetime. A wrong page, not a slow one.
	711	+ *
	712	+ * Read from the stored option rather than through Settings_Manager: this
	713	+ * is consulted from the serve path, where the module registry may not
	714	+ * have run.
	715	+ */
	716	+ private static function mobile_cache_splits_html(): bool {
	717	+ $stored = self::stored_cache_opts();
	718	+ return ! empty( $stored['mobile_separate'] );
	719	+ }
	720	+
	721	+ /**
	722	+ * Why, if at all, a cache in front of us should refuse to store this.
	723	+ *
	724	+ * @param string $status `HIT`, `MISS` or `BYPASS`.
	725	+ * @param string $context `request`, `store` or `bake`.
	726	+ * @param string $bypass_reason The gate slug, for BYPASS only.
	727	+ * @return string '' or one of bypass|bypass-shape|miss|mobile-split|pending.
	728	+ */
	729	+ private static function edge_hold_reason( string $status, string $context, string $bypass_reason ): string {
	730	+ $reason = '';
	731	+
	732	+ // The two exempt gates are answered before anything else, or a site
	733	+ // with Separate Mobile Cache on would keep holding after the page
	734	+ // cache was switched off — which is exactly the "a local toggle must
	735	+ // not become a site-wide side effect on infrastructure we do not own"
	736	+ // rule below, defeated by the ordering rather than by the logic.
	737	+ if ( 'BYPASS' === $status && in_array( $bypass_reason, self::HOLD_EXEMPT_BYPASS, true ) ) {
	738	+ /** This filter is documented below. */
	739	+ return (string) apply_filters( 'xspeed_edge_hold_reason', '', $status, $context, $bypass_reason );
	740	+ }
	741	+
	742	+ // First, because it is the only reason true in every context: the
	743	+ // setting is a property of the site, not of one request, so it is the
	744	+ // one thing a baked artifact can honestly assert.
	745	+ //
	746	+ // It is also the only reason that holds a HIT — a response we DID
	747	+ // cache — and that is deliberate rather than an artefact of the
	748	+ // ordering. With mobile_separate on we key the cache by device and
	749	+ // serve different HTML to a phone than to a desktop at the same URL.
	750	+ // No CDN varies on User-Agent, so an edge holding one of those
	751	+ // renders serves it to everyone and whichever device asked first
	752	+ // decides what the other sees. Our copy is fine; theirs would be a
	753	+ // wrong page. The static path is switched off in this mode anyway
	754	+ // (static_rewrite_allowed()), so these hits come from the drop-in,
	755	+ // which carries the same baked answer.
	756	+ if ( self::mobile_cache_splits_html() ) {
	757	+ $reason = 'mobile-split';
	758	+ } elseif ( 'BYPASS' === $status ) {
	759	+ $shaped = in_array( $bypass_reason, array( 'excluded-url', 'query-param' ), true )
	760	+ ? ! self::path_is_a_personal_exclusion( $bypass_reason )
	761	+ : in_array( $bypass_reason, self::REQUEST_SHAPE_BYPASS, true );
	762	+ $reason = $shaped ? 'bypass-shape' : 'bypass';
	763	+ } elseif ( self::edge_optimization_pending( $context ) ) {
	764	+ $reason = 'pending';
	765	+ } elseif ( 'MISS' === $status ) {
	766	+ $reason = 'miss';
	767	+ }
	768	+
	769	+ /**
	770	+ * Filter: xspeed_edge_hold_reason
	771	+ *
	772	+ * Return '' to veto a hold, or a reason string to force one.
	773	+ *
	774	+ * @param string $reason '' or bypass|bypass-shape|miss|mobile-split|pending.
	775	+ * @param string $status `HIT`, `MISS` or `BYPASS`.
	776	+ * @param string $context `request`, `store` or `bake`.
	777	+ * @param string $bypass_reason The gate slug, for BYPASS only.
	778	+ */
	779	+ return (string) apply_filters( 'xspeed_edge_hold_reason', $reason, $status, $context, $bypass_reason );
	780	+ }
	781	+
	782	+ /**
	783	+ * Was this page excluded because it is personal, or because it is
	784	+ * plumbing we cannot key a cache entry on?
	785	+ *
	786	+ * Answers by removing the structural defaults from the site's own
	787	+ * exclusion list and asking whether anything is left that matches. So a
	788	+ * feed matches only `/feed/` and comes back false; `/my-account/feedback/`
	789	+ * matches `/my-account` and comes back true; and on an "almost pretty"
	790	+ * permalink site, where every path contains `index.php`, an ordinary page
	791	+ * matches nothing else and is correctly treated as public.
	792	+ *
	793	+ * The path only, never the query string — a visitor writes that, and
	794	+ * `/cart/?utm_source=/feed/` must not be able to talk a cart out of its
	795	+ * hold. It is also what `should_cache()` matches the list against.
	796	+ *
	797	+ * Asked for a `query-param` bypass too, because the query gate runs
	798	+ * BEFORE the URL gate, so `/cart/?add-to-cart=12` reports `query-param`
	799	+ * and never reaches `excluded-url` at all. Which gate fired first says
	800	+ * nothing about whose data is on the page.
	801	+ */
	802	+ private static function path_is_a_personal_exclusion( string $bypass_reason ): bool {
	803	+ // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- reading the path of the request being served; there is no form here to nonce.
	804	+ $uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
	805	+ $path = (string) strtok( $uri, '?' );
	806	+ if ( '' === $path ) {
	807	+ return false;
	808	+ }
	809	+
	810	+ // Through Settings_Manager, not the raw option, because the schema's
	811	+ // default IS the structural list and a fresh install has never
	812	+ // written the option. Read raw, every site that has not visited the
	813	+ // settings screen looks like a site with no exclusions at all, takes
	814	+ // the contradiction branch below, and reports its feeds as personal.
	815	+ //
	816	+ // Safe here where `mobile_cache_splits_html()` is not: we are only
	817	+ // ever called with a bypass reason, and those come from
	818	+ // `should_cache()`, which resolved the same settings through
	819	+ // `Settings_Manager::get()` to produce them.
	820	+ $opts = Settings_Manager::get( 'cache' );
	821	+ $excluded = is_array( $opts['excluded_urls'] ?? null ) ? $opts['excluded_urls'] : array();
	822	+ if ( array() === $excluded ) {
	823	+ // An `excluded-url` bypass with no exclusion list is a
	824	+ // contradiction — something excluded the request and the list
	825	+ // cannot say what — so assume personal, because a wasted header
	826	+ // costs a little origin traffic while a missing one serves
	827	+ // somebody's basket to a stranger. A `query-param` bypass with an
	828	+ // empty list is just an ordinary page carrying a parameter, and
	829	+ // says nothing about the path at all.
	830	+ return 'excluded-url' === $bypass_reason;
	831	+ }
	832	+
	833	+ $personal = array_values(
	834	+ array_filter(
	835	+ $excluded,
	836	+ static fn ( $pattern ) => ! in_array( (string) $pattern, self::STRUCTURAL_EXCLUSIONS, true )
	837	+ )
	838	+ );
	839	+
	840	+ return array() !== $personal && Glob_Matcher::any_match( $personal, $path );
	841	+ }
	842	+
	843	+ /**
	844	+ * The edge/CDN headers to send on a response with this cache status.
	845	+ *
	846	+ * @param string $status `HIT`, `MISS` or `BYPASS`.
	847	+ * @param string $context `request` when resolved per request on the
	848	+ * PHP serve path, `store` when resolved for
	849	+ * one entry's sidecar, `bake` when resolved
	850	+ * once and frozen into an artifact.
	851	+ * @param string $bypass_reason The gate slug, for BYPASS only.
	852	+ * @return array<string,string>
	853	+ */
	854	+ public static function edge_headers_for( string $status, string $context = 'request', string $bypass_reason = '' ): array {
	855	+ $base = array();
	856	+ if ( 'HIT' === $status ) {
	857	+ /**
	858	+ * Filter: xspeed_edge_cache_headers
	859	+ *
	860	+ * Response headers to add to a cached HTML response. A HIT-only
	861	+ * contract: a lifetime is a promise that this copy is worth
	862	+ * keeping, and neither a first render nor a page we refused to
	863	+ * cache is one.
	864	+ *
	865	+ * The same filter feeds three regimes and `$context` says which.
	866	+ * On the PHP serve path it runs per request (`request`); at store
	867	+ * time it runs for one entry (`store`); when the drop-in or a
	868	+ * server rule is generated it runs once (`bake`) and the result
	869	+ * answers for every static HIT on the site. Anything per-page — a
	870	+ * post id in a cache tag, say — must be skipped under `bake`.
	871	+ *
	872	+ * @param array<string,string> $headers Header name => value.
	873	+ * @param string $status Always `HIT` here.
	874	+ * @param string $context `request`, `store` or `bake`.
	875	+ */
	876	+ $base = self::sanitize_edge_headers( (array) apply_filters( 'xspeed_edge_cache_headers', array(), 'HIT', $context ) );
	877	+ }
	878	+
	879	+ $reason = self::edge_hold_reason( $status, $context, $bypass_reason );
	880	+ if ( '' === $reason ) {
	881	+ return $base;
	882	+ }
	883	+ $detected = Edge_Provider::detect( $context );
	884	+ if ( Edge_Provider::is_off( $detected ) ) {
	885	+ return $base;
	886	+ }
	887	+ if ( Edge_Provider::NONE === $detected['confidence']
	888	+ && ! in_array( $reason, self::HOLD_WITHOUT_EVIDENCE, true ) ) {
	889	+ return $base;
	890	+ }
	891	+
	892	+ $hold = Edge_Provider::hold_headers( $detected['provider'] );
	893	+
	894	+ /**
	895	+ * Filter: xspeed_edge_hold_headers
	896	+ *
	897	+ * The last word on what a hold INSTRUCTS. Runs before sanitising, so
	898	+ * a value that cannot be sent as a header is still dropped, and
	899	+ * before `X-XSpeed-Edge-Hold` is added, so it cannot rewrite the
	900	+ * reason xSpeed held the page for — that is a diagnosis, not an
	901	+ * instruction, and a forged one sends a reader after the wrong
	902	+ * module.
	903	+ *
	904	+ * @param array<string,string> $hold Header name => value.
	905	+ * @param array<string,string> $detected Provider, confidence, source.
	906	+ * @param string $reason Why the hold fired.
	907	+ * @param string $context `request`, `store` or `bake`.
	908	+ */
	909	+ $hold = (array) apply_filters( 'xspeed_edge_hold_headers', $hold, $detected, $reason, $context );
	910	+
	911	+ // A hold replaces the lifetime rather than sitting beside it: the two
	912	+ // describe the same response and would contradict each other. The
	913	+ // cache tag survives, because a later purge still has to be able to
	914	+ // name whatever the edge picked up on its own terms.
	915	+ if ( isset( $base['Cache-Tag'] ) ) {
	916	+ $hold['Cache-Tag'] = $base['Cache-Tag'];
	917	+ }
	918	+
	919	+ // Never argue with a stronger answer WordPress already gave. It sends
	920	+ // `no-store, private` of its own accord on a logged-in, 404 or
	921	+ // password-protected response, from WP::send_headers() — which runs
	922	+ // before template_redirect, so it is already on the wire by the time
	923	+ // we get here. Ours is the weaker statement of the two; replacing it
	924	+ // would be a downgrade dressed as a fix. Only meaningful per request:
	925	+ // a bake has no response to inspect.
	926	+ if ( 'request' === $context && isset( $hold['Cache-Control'] ) && self::cache_control_already_stronger() ) {
	927	+ unset( $hold['Cache-Control'] );
	928	+ }
	929	+
	930	+ // A page we refused to cache must not carry a validator either. A
	931	+ // `Last-Modified` left on it invites a conditional request, and a
	932	+ // shared cache that gets a 304 back serves the copy it should not
	933	+ // have stored. Only on a bypass, and only per request: a MISS is
	934	+ // about to be stored by us, so its validator is ours to keep.
	935	+ if ( 'request' === $context && 'bypass' === $reason && ! headers_sent() ) {
	936	+ header_remove( 'Last-Modified' );
	937	+ }
	938	+
	939	+ $hold = self::sanitize_edge_headers( $hold );
	940	+
	941	+ // Name the reason in the hold set itself, rather than sending it
	942	+ // separately from mark().
	943	+ //
	944	+ // "Why is my page not being cached at the edge?" is the question this
	945	+ // answers, and mark() could only answer it on the PHP serve path. The
	946	+ // other emitters send whatever this function returns and never ran
	947	+ // mark() at all — so the responses hardest to explain went out
	948	+ // carrying `no-store` with nothing beside it to say why. Chiefly the
	949	+ // drop-in, which serves from the `.meta` sidecar written under
	950	+ // `store` and from the literal baked under `bake`, before plugins
	951	+ // load and with no way to re-ask (the symptom
	952	+ // edge_optimization_pending() describes above).
	953	+ //
	954	+ // The nginx and Apache blocks are a third path in principle and
	955	+ // almost never in practice: they are only installed when
	956	+ // static_rewrite_allowed() is true, and the one reason a stock site
	957	+ // can hold under `bake` is `mobile-split`, which is exactly what
	958	+ // makes that false. They will carry it where a site forces a hold
	959	+ // through `xspeed_edge_hold_reason`, and otherwise have no hold to
	960	+ // carry.
	961	+ //
	962	+ // Added AFTER sanitising and banned in NEVER_AN_EDGE_HEADER, so
	963	+ // neither of the two filters above can forge a reason or suppress the
	964	+ // real one.
	965	+ //
	966	+ // Reduced to the slug CHARACTER CLASS, not checked against the five
	967	+ // slugs: `xspeed_edge_hold_reason` is documented as able to force a
	968	+ // reason, and a site that forces its own deserves to see it. What is
	969	+ // not negotiable is the shape, because this value reaches an
	970	+ // .htaccess and an nginx conf as well as a response header — so no
	971	+ // CR/LF, no `$`, no `%`, no `\`, and a length a config file can hold.
	972	+ $slug = preg_replace( '/[^a-z0-9-]/', '', strtolower( $reason ) );
	973	+ if ( is_string( $slug ) && '' !== $slug ) {
	974	+ $hold['X-XSpeed-Edge-Hold'] = substr( $slug, 0, 32 );
	975	+ }
	976	+
	977	+ return $hold;
	978	+ }
	979	+
	980	+ /** Has something already sent a Cache-Control at least as strict as ours? */
	981	+ private static function cache_control_already_stronger(): bool {
	982	+ foreach ( headers_list() as $line ) {
	983	+ if ( 0 !== stripos( $line, 'cache-control:' ) ) {
	984	+ continue;
	985	+ }
	986	+ if ( preg_match( '/\b(?:no-store|private)\b/i', $line ) ) {
	987	+ return true;
	988	+ }
	989	+ }
	990	+
	991	+ return false;
	992	+ }
	993	+
	994	+ /**
	995	+ * Edge headers that belong to THIS page rather than to every page.
	996	+ *
	997	+ * `edge_headers_for('HIT','bake')` is the answer frozen into the drop-in
	998	+ * and the server rules: one set, serving the whole site. But the answer
	999	+ * for one URL can legitimately differ — a page whose deferred work is
	1000	+ * still outstanding, say — and that answer has nowhere to live, because
	1001	+ * the baked set is all the fast paths know about.
	1002	+ *
	1003	+ * So ask again in a `store` context, with the request still in scope, and
	1004	+ * return the pairs only when they differ from the baked ones. Identical is
	1005	+ * the overwhelmingly common case and writes nothing: pages do not pay a
	1006	+ * sidecar for an answer the drop-in already has.
	1007	+ *
	1008	+ * Memoised because two callers ask within one store — the sidecar writer
	1009	+ * and the static-tree guard — and the filters behind it are not required
	1010	+ * to be cheap.
	1011	+ *
	1012	+ * @return array<string,string> Empty when this page needs no override.
	1013	+ */
	1014	+ private static function per_entry_edge_headers(): array {
	1015	+ if ( is_array( self::$per_entry_edge ) ) {
	1016	+ return self::$per_entry_edge;
	1017	+ }
	1018	+ $baked = self::edge_headers_for( 'HIT', 'bake' );
	1019	+ $request = self::edge_headers_for( 'HIT', 'store' );
	1020	+ self::$per_entry_edge = ( $request === $baked ) ? array() : $request;
	1021	+
	1022	+ return self::$per_entry_edge;
	1023	+ }
	1024	+
	1025	+ /**
	1026	+ * Render baked pairs as a PHP array literal for the drop-in.
	1027	+ *
	1028	+ * Single-quoted literals with quotes escaped, because the result is
	1029	+ * written into a PHP file that must still parse. Values reaching here
	1030	+ * have already been through sanitize_edge_headers(), so neither name nor
	1031	+ * value can carry a newline.
	1032	+ *
	1033	+ * @param array<string,string> $headers Name => value.
	1034	+ */
	1035	+ private static function edge_headers_literal( array $headers ): string {
	1036	+ if ( array() === $headers ) {
	1037	+ return 'array()';
	1038	+ }
	1039	+ // var_export(), not hand-rolled quoting. A single-quoted PHP string
	1040	+ // escapes BOTH `'` and `\\`, and escaping only the first is how a
	1041	+ // value ending in a backslash — `X-Foo: C:\path\` from the custom
	1042	+ // headers box — leaves the literal unterminated. That file is
	1043	+ // included on every request once WP_CACHE is on, so the result is a
	1044	+ // parse error on the front end AND in wp-admin, with no way back
	1045	+ // except deleting the file over SSH.
	1046	+ $parts = array();
	1047	+ foreach ( $headers as $name => $value ) {
	1048	+ $parts[] = var_export( (string) $name, true ) . ' => ' . var_export( (string) $value, true );
	1049	+ }
	1050	+
	1051	+ return 'array( ' . implode( ', ', $parts ) . ' )';
	1052	+ }
	1053	+
	1054	+ /**
	1055	+ * Quote a header value for an nginx / Apache directive.
	1056	+ *
	1057	+ * Both accept a double-quoted string with backslash escapes, and both
	1058	+ * refuse to load a config where the quoting is wrong — a mis-escaped
	1059	+ * value takes the whole vhost down, not just this header.
	1060	+ */
	1061	+ private static function quote_directive_value( string $value ): string {
	1062	+ return str_replace( array( '\\', '"' ), array( '\\\\', '\\"' ), $value );
	1063	+ }
	1064	+
	1065	+ /**
	1066	+ * The same directive twice — once per name Apache can expose the
	1067	+ * rewrite's environment variable under.
	1068	+ *
	1069	+ * `RewriteRule ... [E=XSPEED_STATIC_HIT:1]` in a per-directory context is
	1070	+ * an INTERNAL REDIRECT: Apache re-enters the request with the substituted
	1071	+ * path, and every variable set on the first pass is renamed with a
	1072	+ * `REDIRECT_` prefix for the second. `env=XSPEED_STATIC_HIT` is evaluated
	1073	+ * on that second pass, where nothing answers to that name any more, so
	1074	+ * the directive never fires — dropping the headers from precisely the
	1075	+ * responses they exist for.
	1076	+ *
	1077	+ * It cannot be written once: `env=` takes a single name with no
	1078	+ * alternation, and `expr=` — which could express both — is not dependable
	1079	+ * on LiteSpeed, which reads this same block. So both are emitted; the one
	1080	+ * whose variable is unset on a given pass does nothing.
	1081	+ *
	1082	+ * @param string $directive The directive, without its `env=` clause.
	1083	+ * @return string[]
	1084	+ */
	1085	+ private static function static_hit_directives( string $directive ): array {
	1086	+ return array(
	1087	+ $directive . ' env=XSPEED_STATIC_HIT',
	1088	+ $directive . ' env=REDIRECT_XSPEED_STATIC_HIT',
	1089	+ );
	1090	+ }
	1091	+
	1092	+ /**
	1093	+ * Keep only pairs that can be sent as a header verbatim.
	1094	+ *
	1095	+ * These values reach three different emitters — PHP's header(), an nginx
	1096	+ * `add_header` and an Apache `Header always set` — so a name with a space
	1097	+ * or a value carrying CR/LF is not merely malformed, it is a
	1098	+ * response-splitting vector in the first and a broken server config in
	1099	+ * the other two. Names must be token-shaped; values lose CR/LF and are
	1100	+ * dropped if nothing survives.
	1101	+ *
	1102	+ * @param array<mixed,mixed> $headers Raw pairs.
	1103	+ * @return array<string,string>
	1104	+ */
	1105	+ public static function sanitize_edge_headers( array $headers ): array {
	1106	+ $clean = array();
	1107	+ foreach ( $headers as $name => $value ) {
	1108	+ // Never let one of these through, whoever asked. They describe the
	1109	+ // transfer rather than the caching policy, and getting one wrong
	1110	+ // from a settings field is a white screen: `Content-Encoding: gzip`
	1111	+ // on an uncompressed body, a `Content-Length` that disagrees with
	1112	+ // the bytes. `X-XSpeed-Cache` is ours and a second copy would lie
	1113	+ // to whoever reads it.
	1114	+ if ( is_string( $name ) && in_array( strtolower( $name ), self::NEVER_AN_EDGE_HEADER, true ) ) {
	1115	+ continue;
	1116	+ }
	1117	+ // `\z`, not `$`: PCRE's `$` also matches immediately BEFORE a
	1118	+ // trailing newline, so "Cache-Tag\n" passes a `$` check and gets
	1119	+ // concatenated raw into the generated .htaccess — splitting one
	1120	+ // Header directive across two lines, which is a syntax error
	1121	+ // Apache reports as a 500 on every request while `httpd -t` stays
	1122	+ // green (.htaccess is parsed per request, not at load).
	1123	+ if ( ! is_string( $name ) || ! preg_match( '/^[A-Za-z0-9-]+\z/', $name ) ) {
	1124	+ continue;
	1125	+ }
	1126	+ if ( ! is_string( $value ) && ! is_numeric( $value ) ) {
	1127	+ continue;
	1128	+ }
	1129	+ $value = trim( str_replace( array( "\r", "\n" ), '', (string) $value ) );
	1130	+ if ( '' === $value ) {
	1131	+ continue;
	1132	+ }
	1133	+ // `$` is a variable reference in an nginx string and `%` is a
	1134	+ // format tag to Apache's mod_headers, which rejects an
	1135	+ // unrecognised one — in .htaccess that is a 500 on every request
	1136	+ // while `httpd -t` still reports OK, because .htaccess is parsed
	1137	+ // per request. `\` escapes the quote in the PHP literal baked into
	1138	+ // the drop-in. None of them can be escaped reliably in all three
	1139	+ // places at once, and nothing a cache reads needs any of them, so
	1140	+ // the value is dropped rather than mangled.
	1141	+ if ( preg_match( '/[$%\\\\]/', $value ) ) {
	1142	+ continue;
	1143	+ }
	1144	+ $clean[ $name ] = $value;
	1145	+ }
	1146	+
	1147	+ return $clean;
	1148	+ }
	1149	+
	1150	+ /**
	1151	+ * Bypass gates that describe THE VISITOR rather than THIS REQUEST.
	1152	+ *
	1153	+ * Only these may be recorded in the bypass cookie. A visitor-scoped
	1154	+ * verdict stays true for the visitor's next request — they are still
	1155	+ * logged in, still hold a cart cookie — so the web server can act on
	1156	+ * it without booting PHP.
	1157	+ *
	1158	+ * Every other gate describes the request in front of us: its method,
	1159	+ * its URL, its query string, the client's user agent. Persisting one
	1160	+ * of those pins a visitor to the uncached path over a property that
	1161	+ * was never theirs to begin with. (#218)
	1162	+ */
	1163	+ private const VISITOR_SCOPED_BYPASS = array( 'logged-in', 'excluded-cookie' );
	1164	+
	1165	+ /**
	1166	+ * Whether $reason describes the visitor (persist it) or merely this
	1167	+ * request (don't).
	1168	+ *
	1169	+ * Split out as a pure function because it is the whole decision behind
	1170	+ * the bypass cookie, and the cookie write itself (setcookie()) can't be
	1171	+ * asserted in a unit test.
	1172	+ */
	1173	+ public static function bypass_is_visitor_scoped( string $reason ): bool {
	1174	+ return in_array( $reason, self::VISITOR_SCOPED_BYPASS, true );
	1175	+ }
	1176	+
51	1177	public function maybe_start_cache() {
52	1178	if ( ! self::should_cache() ) {
	1179	+ // PHP has just evaluated the FULL exclusion rule list — including
	1180	+ // the `~regex` patterns the server config can't express — and
	1181	+ // decided this response must not be served from cache. Record that
	1182	+ // verdict in the conventional bypass cookie so the web server can
	1183	+ // enforce it on subsequent requests without starting PHP.
	1184	+ //
	1185	+ // This is what stops most settings changes from needing an nginx
	1186	+ // reload: the config tests one fixed cookie name forever, and the
	1187	+ // rule list behind it can change freely.
	1188	+ //
	1189	+ // But ONLY when the verdict is about the visitor. A request-shape
	1190	+ // gate — `non-get` above all — says nothing about who is asking,
	1191	+ // and persisting it pinned that visitor to the uncached path for
	1192	+ // the rest of their session: one search-form POST, one comment,
	1193	+ // one `curl -I` from an uptime monitor, and every later GET
	1194	+ // bypassed. It could not self-heal either, because the bypass
	1195	+ // cookie is itself in excluded_cookies, so the next GET bypassed
	1196	+ // with `excluded-cookie` and landed right back here, where
	1197	+ // sync_bypass_cookie()'s no-change short-circuit left the cookie
	1198	+ // exactly where it was. (#218)
	1199	+ if ( self::bypass_is_visitor_scoped( self::bypass_reason() ) ) {
	1200	+ self::sync_bypass_cookie( true );
	1201	+ }
53	1202	return;
54	1203	}
55	1204
	1205	+ // Cacheable: clear any stale bypass cookie, or a visitor who once
	1206	+ // had a cart would keep skipping the fast path long after checkout.
	1207	+ self::sync_bypass_cookie( false );
	1208	+
56	1209	$key = self::cache_key();
57	1210	$file = self::cache_file_for( $key );
58	1211
59	1212	if ( file_exists( $file ) && ! self::is_expired( $file ) ) {
60	1213	Hit_Counter::record_hit();
	1214	+ // Emit the HIT marker on THIS path too. The drop-in
	1215	+ // (advanced-cache.php) sends "HIT (php)" and the nginx static
	1216	+ // rewrite sends "HIT (nginx)", but this template_redirect
	1217	+ // serve path — the one that runs when the drop-in isn't loaded
	1218	+ // (e.g. WP_CACHE not true) — previously streamed the cached
	1219	+ // file with NO marker, so a genuine HIT looked like a MISS in
	1220	+ // the response headers. Same header + value as the drop-in.
	1221	+ self::mark( 'HIT (php)' );
	1222	+ // Replay stored response bits so the HIT matches the original:
	1223	+ // a non-HTML Content-Type (cached feeds, sitemaps) and a non-200
	1224	+ // status (a cached 404 must serve 404, not 200). No-op for
	1225	+ // ordinary pages, which write no .meta.
	1226	+ $meta = self::read_meta( $key );
	1227	+ if ( ! headers_sent() ) {
	1228	+ if ( ! empty( $meta['status'] ) && function_exists( 'http_response_code' ) ) {
	1229	+ http_response_code( (int) $meta['status'] );
	1230	+ }
	1231	+ if ( ! empty( $meta['content_type'] ) && is_string( $meta['content_type'] ) ) {
	1232	+ header( 'Content-Type: ' . $meta['content_type'] );
	1233	+ }
	1234	+ // Conditional GET: emit Last-Modified + ETag and answer a
	1235	+ // matching If-Modified-Since / If-None-Match with 304 so
	1236	+ // aggregators (and browsers) skip re-downloading an unchanged
	1237	+ // cached response — the bandwidth win feeds are about.
	1238	+ // (FBS-82407 #5)
	1239	+ if ( self::serve_not_modified( $file ) ) {
	1240	+ exit; // 304 sent, no body.
	1241	+ }
	1242	+ }
	1243	+ // Serve the precompressed Brotli sibling when the client accepts
	1244	+ // it (an add-on, the Pro Brotli module, wrote <file>.br). On this
	1245	+ // PHP serve path the web server never sees the .br, so without
	1246	+ // this a br-capable client got the plain .html — precompression
	1247	+ // did nothing here. Falls through to plain readfile otherwise.
	1248	+ $br = self::maybe_serve_brotli( $file );
	1249	+ if ( null !== $br ) {
	1250	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_readfile -- streaming a static cache file directly; WP_Filesystem would buffer through PHP memory and is not appropriate for response streaming.
	1251	+ readfile( $br );
	1252	+ exit;
	1253	+ }
61	1254	// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_readfile -- readfile is optimal for streaming a static cache file directly to the visitor; WP_Filesystem would buffer through PHP memory and is not appropriate for response streaming.
62	1255	readfile( $file );
63	1256	exit;
64	1257	}
65	1258
66		- // Cache miss → render fresh + write cache. On LiteSpeed servers
67		- // we also signal the server-level LSCache module to cache this
68		- // response, so subsequent requests skip PHP entirely (~5-15ms
69		- // TTFB vs. our PHP drop-in's ~30ms floor). Defers if the
70		- // LiteSpeed Cache plugin is active — that plugin owns its own
71		- // header emission and conflicts with ours.
	1259	+ // Cache miss → render fresh + write cache. On LiteSpeed we send an
	1260	+ // explicit "stand down" header so the server's LSCache module does
	1261	+ // NOT cache + shadow our response — xSpeed's own .htaccess static
	1262	+ // rewrite owns hit serving (and hit accounting) here, exactly as on
	1263	+ // Apache. See maybe_emit_lscache_headers() for the full rationale.
72	1264	self::maybe_emit_lscache_headers();
73	1265
74	1266	// We're about to render fresh + cache → miss for this request.
75		- Hit_Counter::record_miss();
	1267	+ // …UNLESS this request is a 404 or a known bot/scanner. Those reach the
	1268	+ // render path too, but counting them as cache misses makes the ratio
	1269	+ // meaningless — a wave of `/wp-x7.php` scanner 404s reads as a collapsing
	1270	+ // cache when nothing is wrong. Runs at template_redirect (priority 0), so
	1271	+ // is_404() is already resolved. Excluded requests are tallied separately
	1272	+ // for the "you absorbed N scanner hits" line, not dropped. (#118)
	1273	+ if ( self::miss_is_excluded() ) {
	1274	+ Hit_Counter::record_excluded();
	1275	+ } else {
	1276	+ Hit_Counter::record_miss();
	1277	+ }
76	1278
	1279	+ // Stamp it, so "eligible but not cached yet" is visibly different
	1280	+ // from "deliberately bypassed" (issue #10). Headers can't be sent
	1281	+ // after the body starts, so this has to happen here, not in
	1282	+ // finalize_buffer() — nothing has been output at template_redirect.
	1283	+ self::mark( 'MISS' );
77	1284
	1285	+
78	1286	// WP < 6.9 fallback: ob_start() with a callback, paired with an
79	1287	// explicit shutdown close so the buffer lifecycle is visible to
80	1288	// reviewers and Plugin Check, instead of relying on PHP's implicit
81	1289	// request-end flush. We record our nesting level so close_buffer()
		@@ -104,20 +1312,192 @@
104	1312	}
105	1313	self::$buffer_level = null;
106	1314	}
107	1315
	1316	+ /**
	1317	+ * Are we buffering this request?
	1318	+ *
	1319	+ * Asked by Css_Combine_Buffer, which needs the finished HTML but must not
	1320	+ * open a second buffer when this one is already going to hand it the page
	1321	+ * through `xspeed_cache_final_html`. False here means the request is not
	1322	+ * cacheable — cache off, excluded URL, logged in — and the combiner has to
	1323	+ * provide its own buffer or it silently stops working. (#195)
	1324	+ */
	1325	+ public static function is_buffering(): bool {
	1326	+ return null !== self::$buffer_level;
	1327	+ }
	1328	+
	1329	+ /**
	1330	+ * Is a render-time translation plugin going to wrap our output buffer?
	1331	+ *
	1332	+ * TranslatePress opens its translation buffer on `init` priority 0. We
	1333	+ * open ours on `template_redirect`, which runs much later, so ours nests
	1334	+ * INSIDE theirs. PHP unwinds output buffers LIFO — innermost callback
	1335	+ * first — so `finalize_buffer()` saw the raw, pre-translation HTML and
	1336	+ * cached that, while the live visitor still got the translated bytes from
	1337	+ * TRP's outer buffer.
	1338	+ *
	1339	+ * Result: the first (MISS) visitor to /fr/some-page/ got correct French;
	1340	+ * every visitor after got English body text under a `lang="fr-FR"`
	1341	+ * document, plus TRP's internal `#TRPLINKPROCESSED` link markers, which
	1342	+ * TRP strips at the very end of its own buffer and which therefore leak
	1343	+ * into anything captured from inside it.
	1344	+ *
	1345	+ * Note the ordering cannot be fixed from TRP's side: its
	1346	+ * `trp_start_output_buffer_priority` filter only moves the PRIORITY on
	1347	+ * `init`, and `init` always fires before `template_redirect` whatever the
	1348	+ * priority. The buffer that has to move is ours.
	1349	+ *
	1350	+ * Detected by main class rather than plugin path, so a renamed directory
	1351	+ * or a bundled copy still matches.
	1352	+ */
	1353	+ public static function translation_plugin_active(): bool {
	1354	+ $active = class_exists( 'TRP_Translate_Press' );
	1355	+
	1356	+ /**
	1357	+ * Whether to treat this request as wrapped by a translation buffer.
	1358	+ *
	1359	+ * Lets a site add another render-time translation plugin (or opt out)
	1360	+ * without patching the engine.
	1361	+ *
	1362	+ * @param bool $active
	1363	+ */
	1364	+ return (bool) apply_filters( 'xspeed_translation_plugin_active', $active );
	1365	+ }
	1366	+
	1367	+ /**
	1368	+ * Write the cache file for a request whose output was wrapped by a
	1369	+ * render-time translation plugin.
	1370	+ *
	1371	+ * Registered as a PHP shutdown function (not a WP `shutdown` action) so
	1372	+ * it runs after PHP has unwound the output-buffer stack — by which point
	1373	+ * the translation plugin's callback has transformed the bytes and its
	1374	+ * internal markers are gone.
	1375	+ *
	1376	+ * finalize_buffer() has already applied the status gate, the
	1377	+ * xspeed_cache_final_html filter and HTML minification to the
	1378	+ * untranslated copy and then declined to write it. Here we re-run only
	1379	+ * what's needed on the translated bytes: minify, write, and fire the
	1380	+ * same downstream hooks so Brotli / static-tree listeners behave
	1381	+ * identically to the ordinary path.
	1382	+ */
	1383	+ public static function write_deferred_translated_cache(): void {
	1384	+ $key = self::$deferred_key;
	1385	+ self::$deferred_key = null;
	1386	+
	1387	+ // Release the collected bytes BEFORE the early return, so the static
	1388	+ // is cleared on every path rather than only when a key survived.
	1389	+ $full = self::$translated_output;
	1390	+ self::$translated_output = '';
	1391	+
	1392	+ $completed = self::$render_completed;
	1393	+ self::$render_completed = false;
	1394	+
	1395	+ if ( null === $key ) {
	1396	+ return;
	1397	+ }
	1398	+
	1399	+ // Did the render actually finish?
	1400	+ //
	1401	+ // This runs as a PHP shutdown function, which fires after a wp_die()
	1402	+ // or a bare exit() just as readily as after a clean render — but in
	1403	+ // those cases finalize_buffer() never returned, so the bytes we hold
	1404	+ // are a page that was cut off partway through. The length and
	1405	+ // TRPLINKPROCESSED checks below don't catch that: a fatal after the
	1406	+ // footer's translated markup is both over 255 bytes and free of TRP
	1407	+ // markers, i.e. truncated but entirely plausible. Caching it would
	1408	+ // freeze a half-rendered page under the real key for the full TTL.
	1409	+ //
	1410	+ // Serving this one URL uncached is the cheap failure; the corrupt
	1411	+ // cache entry is the expensive one.
	1412	+ if ( ! $completed ) {
	1413	+ return;
	1414	+ }
	1415	+
	1416	+ if ( strlen( $full ) < 255 ) {
	1417	+ return;
	1418	+ }
	1419	+
	1420	+ // Refuse to cache a copy still carrying the translation plugin's
	1421	+ // internal link markers. TRP strips these at the very end of its own
	1422	+ // buffer, so their presence means we captured too early — and a
	1423	+ // cached page containing them is SEO-visible damage. Better to serve
	1424	+ // this URL uncached than to freeze broken markup for the full TTL.
	1425	+ if ( false !== strpos( $full, 'TRPLINKPROCESSED' ) ) {
	1426	+ return;
	1427	+ }
	1428	+
	1429	+ $minify_opts = Settings_Manager::get( 'minify' );
	1430	+ if ( ! empty( $minify_opts['minify_html'] ) ) {
	1431	+ $full = Minifier::minify_html( $full );
	1432	+ }
	1433	+ $full = self::signed( $full );
	1434	+
	1435	+ // Per-site directory: on multisite every blog shares this tree, so
	1436	+ // entries are bucketed by host to keep one site's purge from
	1437	+ // sweeping the whole network. (#6)
	1438	+ self::ensure_host_dir();
	1439	+
	1440	+ // Never author a cache entry from a request that carried a query
	1441	+ // string: cache_key() files it under the BARE url, so the params'
	1442	+ // render would be served to every clean-URL visitor (#241).
	1443	+ if ( self::query_string_blocks_write() ) {
	1444	+ return;
	1445	+ }
	1446	+
	1447	+ $file = self::cache_file_for( $key );
	1448	+ // 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.
	1449	+ file_put_contents( $file, $full, LOCK_EX );
	1450	+
	1451	+ /** This action is documented in includes/class-cache.php */
	1452	+ do_action( 'xspeed_flat_file_written', $file, $full );
	1453	+
	1454	+ self::write_meta( $key, $full );
	1455	+
	1456	+ // Static tree too, under the same gates finalize_buffer() applies —
	1457	+ // otherwise deferring the write would silently cost translated pages
	1458	+ // the web-server fast path and leave them on the slower drop-in.
	1459	+ // The static tree cannot replay a sidecar. A file served straight by
	1460	+ // the web server carries the headers baked into the rule that serves
	1461	+ // the whole site — the very answer this entry exists because it
	1462	+ // disagreed with. Same reasoning as the status and content-type
	1463	+ // cases: what the fast path cannot replay belongs on the drop-in path.
	1464	+ if ( self::static_rewrite_allowed()
	1465	+ && self::response_is_plain_html()
	1466	+ && array() === self::per_entry_edge_headers() ) {
	1467	+ self::store_static( $full );
	1468	+ }
	1469	+ }
	1470	+
108	1471	public static function should_cache() {
	1472	+ // Reset first: a single request only reaches this once (the sole
	1473	+ // caller is maybe_start_cache()), but tests and any future caller
	1474	+ // must never inherit the previous request's verdict.
	1475	+ self::$status_header = '';
	1476	+ self::$bypass_reason = '';
	1477	+ self::$edge_headers = array();
	1478	+ self::$per_entry_edge = null;
	1479	+ // Under PHP-FPM a process serves one request and this is moot. Under
	1480	+ // a persistent worker runtime it is not: without it, an answer
	1481	+ // resolved from one visitor's forgeable headers would be reused for
	1482	+ // every later request the worker handles.
	1483	+ Edge_Provider::forget();
	1484	+
109	1485	$opts = Settings::get();
110	1486	if ( empty( $opts['cache_enabled'] ) ) {
111		- return false;
	1487	+ return self::bypass( 'cache-disabled' );
112	1488	}
113	1489
114		- if ( is_user_logged_in() || is_admin() || ( defined( 'DOING_AJAX' ) && DOING_AJAX ) || ( defined( 'DOING_CRON' ) && DOING_CRON ) || ( defined( 'REST_REQUEST' ) && REST_REQUEST ) ) {
115		- return false;
	1490	+ if ( is_user_logged_in() ) {
	1491	+ return self::bypass( 'logged-in' );
116	1492	}
117	1493
	1494	+ if ( is_admin() || ( defined( 'DOING_AJAX' ) && DOING_AJAX ) || ( defined( 'DOING_CRON' ) && DOING_CRON ) || ( defined( 'REST_REQUEST' ) && REST_REQUEST ) ) {
	1495	+ return self::bypass( 'non-frontend' );
	1496	+ }
	1497	+
118	1498	if ( defined( 'DONOTCACHEPAGE' ) && DONOTCACHEPAGE ) {
119		- return false;
	1499	+ return self::bypass( 'donotcachepage' );
120	1500	}
121	1501
122	1502	// All exclusion knobs now owned by CacheModule.
123	1503	$cache_opts = Settings_Manager::get( 'cache' );
		@@ -123,22 +1503,81 @@
123	1503	$cache_opts = Settings_Manager::get( 'cache' );
124	1504
125	1505	$method = isset( $_SERVER['REQUEST_METHOD'] ) ? strtoupper( sanitize_text_field( wp_unslash( $_SERVER['REQUEST_METHOD'] ) ) ) : '';
126	1506	if ( 'GET' !== $method ) {
127		- return false;
	1507	+ return self::bypass( 'non-get' );
128	1508	}
129	1509
	1510	+ // Search-results requests carry a `s` query param, which the
	1511	+ // query-string gate below would normally reject as "dynamic". An
	1512	+ // add-on (xspeed-pro search cache) can opt them in: when this is a
	1513	+ // genuine is_search() and the filter returns true, the `s` param is
	1514	+ // treated as cacheable (the search term goes into the cache key so
	1515	+ // different searches stay distinct — see cache_key()).
	1516	+ $cache_search = self::should_cache_search();
	1517	+
	1518	+ // Feed opt-in is resolved BEFORE the query-string gate so query-form
	1519	+ // feeds (/?feed=rss2, used on plain-permalink sites) aren't rejected
	1520	+ // as "dynamic" by that gate — the `feed` param is then allowed through
	1521	+ // just like the search `s` param. Feeds are excluded by default (the
	1522	+ // `/feed/` pattern in excluded_urls); an add-on (xspeed-pro feed cache)
	1523	+ // opts them back in via the filter. (FBS-82407 #4)
	1524	+ $is_feed_request = function_exists( 'is_feed' ) && is_feed();
	1525	+ /**
	1526	+ * Whether to cache the current feed request.
	1527	+ *
	1528	+ * Default false → feeds fall through to the normal URL-exclusion
	1529	+ * rules (so `/feed/` keeps them out). A listener returning true
	1530	+ * opts this feed request into caching.
	1531	+ *
	1532	+ * @param bool $cache_feed Whether to cache this feed request.
	1533	+ */
	1534	+ $cache_feed = $is_feed_request && (bool) apply_filters( 'xspeed_should_cache_feed', false );
	1535	+
	1536	+ // WordPress's virtual robots.txt (and virtual favicon) are not HTML:
	1537	+ // caching one runs it through the whole HTML pipeline, which stamped
	1538	+ // the footer comment onto text/plain and let HTML minification
	1539	+ // collapse robots.txt to a single line — a line-based format, so
	1540	+ // every directive after the first was lost and crawlers read an
	1541	+ // invalid file. No opt-in filter here: there is no correct way to
	1542	+ // treat these as pages. (Reported live on a customer site.)
	1543	+ if ( ( function_exists( 'is_robots' ) && is_robots() )
	1544	+ || ( function_exists( 'is_favicon' ) && is_favicon() ) ) {
	1545	+ return self::bypass( 'non-html' );
	1546	+ }
	1547	+
130	1548	// Query string handling: anything OUTSIDE the ignored-params
131	1549	// allow-list (utm_*, fbclid, gclid by default) means a unique
132	1550	// request that we don't want to share with the canonical cache
133	1551	// entry. Skip cache rather than poison the key.
134		- $query_raw = isset( $_SERVER['QUERY_STRING'] ) ? sanitize_text_field( wp_unslash( $_SERVER['QUERY_STRING'] ) ) : '';
	1552	+ //
	1553	+ // Parse the RAW query string, NOT a sanitize_text_field() copy:
	1554	+ // that filter strips percent-encoded octets (%XX), so `?%73=…`
	1555	+ // would lose its `s` key here while WordPress still decodes it to
	1556	+ // a search request — the gate would wave the request through and
	1557	+ // cache_key() would file the search page under the bare URL,
	1558	+ // letting an attacker poison the homepage cache with `/?%73=<spam>`.
	1559	+ // parse_str() does its own urldecoding, matching WP's own parse, and
	1560	+ // only the KEYS are used below (fed to Glob_Matcher → preg_match,
	1561	+ // never echoed or executed), so no sanitization is needed here.
	1562	+ $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.
135	1563	if ( '' !== $query_raw ) {
136	1564	$ignored = is_array( $cache_opts['ignored_query_params'] ?? null ) ? $cache_opts['ignored_query_params'] : array();
137	1565	parse_str( $query_raw, $params );
138	1566	foreach ( $params as $key => $_ ) {
	1567	+ // Allow the search param through when search caching is on.
	1568	+ if ( $cache_search && 's' === $key ) {
	1569	+ continue;
	1570	+ }
	1571	+ // Allow query-form feed params through when feed caching opted
	1572	+ // this request in (?feed=rss2 / &withcomments=1 on feeds).
	1573	+ if ( $cache_feed && in_array( $key, array( 'feed', 'withcomments', 'withoutcomments' ), true ) ) {
	1574	+ continue;
	1575	+ }
139	1576	if ( ! self::query_key_is_ignored( (string) $key, $ignored ) ) {
140		- return false;
	1577	+ // Slug only — never the param name, which is attacker-
	1578	+ // controlled and would be reflected into a header.
	1579	+ return self::bypass( 'query-param' );
141	1580	}
142	1581	}
143	1582	}
144	1583
		@@ -145,10 +1584,10 @@
145	1584	$request_uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
146	1585	$path = (string) strtok( $request_uri, '?' );
147	1586
148	1587	$excluded_urls = is_array( $cache_opts['excluded_urls'] ?? null ) ? $cache_opts['excluded_urls'] : array();
149		- if ( Glob_Matcher::any_match( $excluded_urls, $path ) ) {
150		- return false;
	1588	+ if ( ! $cache_feed && Glob_Matcher::any_match( $excluded_urls, $path ) ) {
	1589	+ return self::bypass( 'excluded-url' );
151	1590	}
152	1591
153	1592	// Cookie-based exclusion. We only check cookie NAMES (matching
154	1593	// values would leak content-sensitive logic into the cache key
		@@ -155,10 +1594,21 @@
155	1594	// rules); presence of any matching cookie name skips cache.
156	1595	$excluded_cookies = is_array( $cache_opts['excluded_cookies'] ?? null ) ? $cache_opts['excluded_cookies'] : array();
157	1596	if ( ! empty( $excluded_cookies ) && ! empty( $_COOKIE ) ) {
158	1597	foreach ( array_keys( $_COOKIE ) as $cookie_name ) {
	1598	+ // Our own bypass cookie is a RECORD of a previous verdict, not
	1599	+ // evidence about this visitor, so it never gets a vote here.
	1600	+ // Letting it match made the verdict self-confirming: once set,
	1601	+ // it produced `excluded-cookie` forever, which re-set it, and
	1602	+ // no later request could ever re-evaluate the visitor on the
	1603	+ // rules that actually describe them. The web server still acts
	1604	+ // on the cookie without booting PHP; when PHP does boot it is
	1605	+ // authoritative and re-decides from scratch. (#218)
	1606	+ if ( Server_Rules::BYPASS_COOKIE === $cookie_name ) {
	1607	+ continue;
	1608	+ }
159	1609	if ( Glob_Matcher::any_match( $excluded_cookies, (string) $cookie_name ) ) {
160		- return false;
	1610	+ return self::bypass( 'excluded-cookie' );
161	1611	}
162	1612	}
163	1613	}
164	1614
		@@ -169,9 +1619,9 @@
169	1619	if ( ! empty( $bypass_uas ) ) {
170	1620	$ua = isset( $_SERVER['HTTP_USER_AGENT'] ) ? sanitize_text_field( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ) ) : '';
171	1621	foreach ( $bypass_uas as $needle ) {
172	1622	if ( '' !== $needle && false !== stripos( $ua, (string) $needle ) ) {
173		- return false;
	1623	+ return self::bypass( 'user-agent' );
174	1624	}
175	1625	}
176	1626	}
177	1627
		@@ -178,25 +1628,218 @@
178	1628	// Per-post override (Phase 3.4). Honored only on singular
179	1629	// post-context requests — archives / 404s / taxonomies use the
180	1630	// global policy above.
181	1631	if ( Cache_Rules::should_skip_for_post( Cache_Rules::current_post_id() ) ) {
	1632	+ return self::bypass( 'post-excluded' );
	1633	+ }
	1634	+
	1635	+ /**
	1636	+ * Final say on whether the current request is cacheable.
	1637	+ *
	1638	+ * Runs at template_redirect (full WP context), so listeners may use
	1639	+ * conditional tags (is_search(), is_feed(), is_404(),
	1640	+ * wp_is_maintenance_mode(), …). The core engine has already applied
	1641	+ * its own exclusion rules and reached `true`; a listener returning
	1642	+ * false vetoes caching for this request. This is the documented
	1643	+ * extension point add-ons (xspeed-pro) hook to add their own
	1644	+ * request-level cache policy without forking the engine.
	1645	+ *
	1646	+ * Note: this gates the WRITE side. The pre-WP drop-in
	1647	+ * (advanced-cache.php) cannot run PHP filters, so request types that
	1648	+ * must never be *served* from a stale file are handled by not
	1649	+ * writing them here and/or by purging — see the conflict notes in
	1650	+ * advanced-cache.php.
	1651	+ *
	1652	+ * @param bool $should_cache Whether to cache the current request.
	1653	+ */
	1654	+ if ( ! apply_filters( 'xspeed_should_cache', true ) ) {
	1655	+ // One slug for every listener — a third-party callback name is
	1656	+ // not ours to put in a response header. Which listener vetoed is
	1657	+ // a WP_DEBUG-level question the filter itself can answer.
	1658	+ return self::bypass( 'filtered' );
	1659	+ }
	1660	+
	1661	+ return true;
	1662	+ }
	1663	+
	1664	+ /**
	1665	+ * Whether the current request is a 404 we may cache.
	1666	+ *
	1667	+ * True only when: it's a genuine main-query is_404(), an add-on opted
	1668	+ * in via `xspeed_should_cache_404` (default false), and the request
	1669	+ * isn't a transient 404 we must never freeze — maintenance mode or a
	1670	+ * 404 emitted while the DB/site is in an error state. The xspeed-pro
	1671	+ * 404 cache flips the filter; Free never caches 404s on its own.
	1672	+ */
	1673	+ public static function should_cache_404(): bool {
	1674	+ if ( ! function_exists( 'is_404' ) || ! is_404() ) {
182	1675	return false;
183	1676	}
	1677	+ // Never cache a 404 served because the site is down for
	1678	+ // maintenance — that screen disappears the moment maintenance
	1679	+ // ends, and a cached copy would outlive it.
	1680	+ if ( function_exists( 'wp_is_maintenance_mode' ) && wp_is_maintenance_mode() ) {
	1681	+ return false;
	1682	+ }
184	1683
	1684	+ /**
	1685	+ * Whether to cache the current 404 response.
	1686	+ *
	1687	+ * Default false. A listener returning true opts the (genuine)
	1688	+ * 404 into the page cache, served back for any unknown URL under
	1689	+ * one generic key. The 404 status is preserved on the HIT.
	1690	+ *
	1691	+ * @param bool $cache_404 Whether to cache this 404.
	1692	+ */
	1693	+ return (bool) apply_filters( 'xspeed_should_cache_404', false );
	1694	+ }
	1695	+
	1696	+ /**
	1697	+ * Whether the current request is an internal search-results page we
	1698	+ * may cache.
	1699	+ *
	1700	+ * True only when: it's a genuine main-query is_search() with a
	1701	+ * non-empty term, and an add-on opted in via `xspeed_should_cache_search`
	1702	+ * (default false). The search term is folded into the cache key (see
	1703	+ * search_term() / cache_key()) so different searches stay distinct.
	1704	+ * The xspeed-pro search cache flips the filter; Free never caches
	1705	+ * search results on its own.
	1706	+ */
	1707	+ /**
	1708	+ * Whether this response was rendered for a query string and therefore
	1709	+ * must not be STORED under the bare-URL key.
	1710	+ *
	1711	+ * should_cache() lets a request through when every key is on the
	1712	+ * `ignored_query_params` allow-list, and cache_key() then drops the
	1713	+ * query string so `/post` and `/post?utm_source=x` share one entry.
	1714	+ * Sharing on READ is the point of the allow-list and stays. Sharing on
	1715	+ * WRITE is a cache-poisoning vector: the response was rendered *with*
	1716	+ * those params, and WordPress reflects REQUEST_URI into form actions,
	1717	+ * share links, canonical helpers and plugin smart tags. One anonymous
	1718	+ * GET to a cold URL therefore freezes an attacker-chosen variant under
	1719	+ * the clean URL's key, served for the whole TTL by the drop-in and by
	1720	+ * the web server — neither of which runs these checks (issue #241).
	1721	+ *
	1722	+ * The allow-list keeps its benefit: a visitor arriving on
	1723	+ * `?utm_source=…` is still SERVED the canonical cached entry. Only the
	1724	+ * write is skipped, so the entry is authored by a clean request.
	1725	+ *
	1726	+ * This is the same reasoning as the `should_cache_search()` guard in
	1727	+ * store_static() (#191), generalised to the allow-listed params.
	1728	+ */
	1729	+ public static function request_has_query_string(): bool {
	1730	+ $query = isset( $_SERVER['QUERY_STRING'] )
	1731	+ ? (string) wp_unslash( $_SERVER['QUERY_STRING'] ) // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- only tested for emptiness; never echoed, stored or used as a path.
	1732	+ : '';
	1733	+
	1734	+ return '' !== trim( $query );
	1735	+ }
	1736	+
	1737	+ /**
	1738	+ * Would authoring a cache entry from THIS request file a query-string
	1739	+ * render under the bare URL?
	1740	+ *
	1741	+ * The one predicate both write sites ask, so they cannot drift.
	1742	+ *
	1743	+ * Two shapes are exempt because cache_key() does NOT drop their query —
	1744	+ * it folds the distinguishing part into the key, so each variant gets
	1745	+ * its own entry and none is filed under the bare URL:
	1746	+ *
	1747	+ * - searches, keyed by `|s=<term>` (#191)
	1748	+ * - feeds, keyed by `|feed=<type>` — `/?feed=rss2` is the ONLY feed URL
	1749	+ * core generates on plain permalinks, so treating it as poisonable
	1750	+ * made feed caching a no-op on exactly the sites that need it
	1751	+ *
	1752	+ * @return bool True when the write must be skipped.
	1753	+ */
	1754	+ public static function query_string_blocks_write(): bool {
	1755	+ if ( ! self::request_has_query_string() ) {
	1756	+ return false;
	1757	+ }
	1758	+
	1759	+ if ( self::should_cache_search() ) {
	1760	+ return false;
	1761	+ }
	1762	+
	1763	+ // Feed caching is opt-in, via the same filter should_cache() reads
	1764	+ // to admit the feed params in the first place.
	1765	+ if ( function_exists( 'is_feed' ) && is_feed()
	1766	+ && (bool) apply_filters( 'xspeed_should_cache_feed', false )
	1767	+ ) {
	1768	+ return false;
	1769	+ }
	1770	+
185	1771	return true;
186	1772	}
187	1773
	1774	+ public static function should_cache_search(): bool {
	1775	+ if ( ! function_exists( 'is_search' ) || ! is_search() ) {
	1776	+ return false;
	1777	+ }
	1778	+ // Empty search (`?s=`) renders the same as a normal archive and
	1779	+ // carries no term to key on — let it fall through to the usual
	1780	+ // rules rather than caching an ambiguous entry.
	1781	+ if ( '' === self::search_term() ) {
	1782	+ return false;
	1783	+ }
	1784	+
	1785	+ /**
	1786	+ * Whether to cache the current search-results request.
	1787	+ *
	1788	+ * Default false. A listener returning true opts the search page
	1789	+ * into the cache, keyed by the normalized search term.
	1790	+ *
	1791	+ * @param bool $cache_search Whether to cache this search request.
	1792	+ */
	1793	+ return (bool) apply_filters( 'xspeed_should_cache_search', false );
	1794	+ }
	1795	+
188	1796	/**
	1797	+ * The current request's normalized search term, or '' if none. Reads
	1798	+ * the raw `s` query param (works on the pre-WP drop-in path too, where
	1799	+ * get_search_query() isn't available), trims + lowercases so
	1800	+ * "WordPress" and "wordpress" share one entry, and collapses internal
	1801	+ * whitespace.
	1802	+ */
	1803	+ public static function search_term(): string {
	1804	+ $raw = isset( $_GET['s'] ) ? sanitize_text_field( wp_unslash( $_GET['s'] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- read-only cache-key derivation from a public search param; no state change.
	1805	+ $raw = trim( $raw );
	1806	+ if ( '' === $raw ) {
	1807	+ return '';
	1808	+ }
	1809	+ $raw = preg_replace( '/\s+/', ' ', $raw );
	1810	+ return function_exists( 'mb_strtolower' ) ? mb_strtolower( $raw ) : strtolower( $raw );
	1811	+ }
	1812	+
	1813	+ /**
189	1814	* Is this query-string key on the ignored-params allow-list? Supports
190		- * trailing-star globs (`utm_*` matches `utm_source`, `utm_medium`,
191		- * etc.) so users don't have to enumerate every UTM variant.
	1815	+ * globs (`utm_*` matches `utm_source`, `utm_medium`, etc.) so users
	1816	+ * don't have to enumerate every UTM variant, and `~regex`.
	1817	+ *
	1818	+ * Matching is whole-name, not "contains" — a param name is an
	1819	+ * identifier, not a path. Under the old contains match the shipped
	1820	+ * default `ref` also swallowed `preference`, `product_ref` and
	1821	+ * `referrer`: those params were dropped from the cache key, so
	1822	+ * `/shop?preference=1` was served — and, on a cold entry, WRITTEN as —
	1823	+ * `/shop`. Same for `_ga` vs `_gallery`, and for the unanchored
	1824	+ * `~utm_…` default vs `my_utm_source`. A param name that is genuinely
	1825	+ * unknown now bypasses the cache, which is the safe direction.
192	1826	*/
193	1827	private static function query_key_is_ignored( string $key, array $ignored ): bool {
194		- return Glob_Matcher::any_match( $ignored, $key );
	1828	+ return Glob_Matcher::any_match_name( $ignored, $key );
195	1829	}
196	1830
197	1831	public static function cache_key() {
198	1832	$host = isset( $_SERVER['HTTP_HOST'] ) ? sanitize_text_field( wp_unslash( $_SERVER['HTTP_HOST'] ) ) : 'default';
	1833	+
	1834	+ // Cacheable 404s share ONE generic per-host entry — keying them by
	1835	+ // URL would let a scanner flood (millions of random paths) bloat
	1836	+ // the cache with identical 404 bodies. Both the write and the HIT
	1837	+ // lookup run through here, so they agree on the key automatically.
	1838	+ if ( self::should_cache_404() ) {
	1839	+ return md5( $host . '|404' );
	1840	+ }
	1841	+
199	1842	$uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '/';
200	1843	// Strip the query string from the key so /post and /post?utm_*=…
201	1844	// share the same cache entry. should_cache() above already
202	1845	// rejected requests with non-ignored params, so by the time we
		@@ -212,9 +1855,27 @@
212	1855	if ( ! empty( $opts['mobile_separate'] ) ) {
213	1856	$device = self::is_mobile_request() ? '|m' : '|d';
214	1857	}
215	1858
216		- return md5( $host . $uri . $device );
	1859	+ // Search-results requests fold the normalized term into the key so
	1860	+ // /?s=foo and /?s=bar get distinct entries (the query string is
	1861	+ // otherwise stripped above). Only added when search caching opted
	1862	+ // in, so non-search URLs are unaffected.
	1863	+ $search = self::should_cache_search() ? '|s=' . self::search_term() : '';
	1864	+
	1865	+ // Query-form feeds (/?feed=rss2 vs /?feed=atom) share the same path
	1866	+ // once the query is stripped, so fold the feed type into the key to
	1867	+ // keep the flavors distinct. Pretty-permalink feeds (/feed/rss/) carry
	1868	+ // the type in $uri already and are unaffected. (FBS-82407 #4)
	1869	+ $feed = '';
	1870	+ if ( function_exists( 'is_feed' ) && is_feed() && function_exists( 'get_query_var' ) ) {
	1871	+ $feed_type = (string) get_query_var( 'feed' );
	1872	+ if ( '' !== $feed_type ) {
	1873	+ $feed = '|feed=' . preg_replace( '/[^a-z0-9]/i', '', $feed_type );
	1874	+ }
	1875	+ }
	1876	+
	1877	+ return md5( $host . $uri . $device . $search . $feed );
217	1878	}
218	1879
219	1880	/**
220	1881	* Server-side mobile detection. Prefers WordPress's `wp_is_mobile()`
		@@ -225,20 +1886,635 @@
225	1886	private static function is_mobile_request(): bool {
226	1887	if ( function_exists( 'wp_is_mobile' ) ) {
227	1888	return (bool) wp_is_mobile();
228	1889	}
	1890	+ // Fallback for the rare context where wp_is_mobile() isn't loaded.
	1891	+ // Mirrors core's wp_is_mobile() EXACTLY — including the
	1892	+ // Sec-CH-UA-Mobile client hint it checks *before* UA tokens — so the
	1893	+ // bucket this picks matches whatever the engine's primary path (and
	1894	+ // the drop-in's own copy of this logic) would pick for the same
	1895	+ // request. Drift here re-introduces the cross-path key mismatch.
	1896	+ if ( isset( $_SERVER['HTTP_SEC_CH_UA_MOBILE'] ) ) {
	1897	+ return '?1' === $_SERVER['HTTP_SEC_CH_UA_MOBILE'];
	1898	+ }
229	1899	$ua = isset( $_SERVER['HTTP_USER_AGENT'] ) ? sanitize_text_field( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ) ) : '';
230	1900	if ( '' === $ua ) {
231	1901	return false;
232	1902	}
233		- // Mirrors the token list wp_is_mobile() uses internally.
234	1903	return (bool) preg_match( '/(Mobile|Android|Silk\/|Kindle|BlackBerry|Opera Mini|Opera Mobi)/i', $ua );
235	1904	}
236	1905
	1906	+ /**
	1907	+ * Filesystem-safe directory name for a host, or '' when unusable.
	1908	+ *
	1909	+ * The charset MUST match the static tree (store_static()) and the
	1910	+ * drop-in's own copy, or the paths disagree about where an entry lives.
	1911	+ * The colon of `host:port` is stripped: it is legal in a Host header but
	1912	+ * not portable in a path.
	1913	+ *
	1914	+ * @param string $host Raw host, e.g. from HTTP_HOST.
	1915	+ * @return string Safe directory segment, or '' if nothing usable remains.
	1916	+ */
	1917	+ /**
	1918	+ * The host segment of the STATIC tree — `xspeed-static/<host>/…`, which
	1919	+ * the web server resolves without PHP.
	1920	+ *
	1921	+ * Different from host_dir(): here the port is folded INTO the segment
	1922	+ * (`localhost:8080` → `localhost8080`) rather than dropped, because the
	1923	+ * generated server rules have to reproduce this from their own variables
	1924	+ * and nginx's `$host` has no port to drop — see the `$xspeed_host`
	1925	+ * derivation in nginx_snippet(). Shared by the write and the purge so the
	1926	+ * two can't drift; when they did, purging a page on a ported host deleted
	1927	+ * nothing and the stale copy kept being served by the rewrite.
	1928	+ */
	1929	+ public static function static_host_dir( string $host ): string {
	1930	+ return (string) preg_replace( '/[^a-zA-Z0-9.\-]/', '', $host );
	1931	+ }
	1932	+
	1933	+ public static function host_dir( string $host ): string {
	1934	+ $host = str_replace( "\0", '', $host );
	1935	+ // Drop the port BEFORE filtering, or `example.com:8080` collapses to
	1936	+ // `example.com8080` — which both loses the boundary and could collide
	1937	+ // with a real host of that name.
	1938	+ $colon = strpos( $host, ':' );
	1939	+ if ( false !== $colon ) {
	1940	+ $host = substr( $host, 0, $colon );
	1941	+ }
	1942	+ $host = preg_replace( '/[^a-zA-Z0-9.\-]/', '', $host );
	1943	+ // Collapse any run of dots so no traversal sequence can survive the
	1944	+ // charset filter (`a/../b` would otherwise reduce to `a..b`).
	1945	+ $host = preg_replace( '/\.{2,}/', '.', (string) $host );
	1946	+ $host = trim( (string) $host, '.-' );
	1947	+ return '' === $host ? '' : $host;
	1948	+ }
	1949	+
	1950	+ /**
	1951	+ * The per-site bucket a cache entry belongs to: `<host>` on a single
	1952	+ * site, `<host>/<path-prefix>` for a subdirectory multisite blog.
	1953	+ *
	1954	+ * On multisite every blog shares one cache directory, and a flat md5
	1955	+ * filename carries no clue which site wrote it — so purging one subsite
	1956	+ * swept the whole network cold. (#6)
	1957	+ *
	1958	+ * Host alone is NOT enough: a subdirectory network (the common layout)
	1959	+ * puts every blog on the same host, so `example.com/` and
	1960	+ * `example.com/siteb/` would share a bucket and keep purging each other.
	1961	+ * The path prefix is what separates them, and it is derivable from the
	1962	+ * REQUEST_URI alone — which matters because the drop-in must compute
	1963	+ * this identical value before WordPress (and get_blog_details()) exist.
	1964	+ *
	1965	+ * Subdomain and domain-mapped networks differ by host already, so they
	1966	+ * get a bare host bucket and are unaffected.
	1967	+ *
	1968	+ * @param string $host Raw host.
	1969	+ * @param string $uri Raw REQUEST_URI (query string is ignored).
	1970	+ * @return string Bucket path, always non-empty.
	1971	+ */
	1972	+ public static function site_bucket( string $host, string $uri ): string {
	1973	+ $dir = self::host_dir( $host );
	1974	+ if ( '' === $dir ) {
	1975	+ $dir = 'default';
	1976	+ }
	1977	+
	1978	+ $prefix = self::site_path_prefix();
	1979	+ return '' === $prefix ? $dir : $dir . '/' . $prefix;
	1980	+ }
	1981	+
	1982	+ /**
	1983	+ * The current blog's path prefix as a single safe segment ('' for the
	1984	+ * root blog or a non-multisite install). `/siteb/` becomes `siteb`;
	1985	+ * a nested `/a/b/` becomes `a-b` so the bucket stays one level deep.
	1986	+ *
	1987	+ * Written to a sidecar for the drop-in by sync_site_paths().
	1988	+ */
	1989	+ public static function site_path_prefix(): string {
	1990	+ if ( ! function_exists( 'is_multisite' ) || ! is_multisite() ) {
	1991	+ return '';
	1992	+ }
	1993	+ if ( function_exists( 'is_subdomain_install' ) && is_subdomain_install() ) {
	1994	+ return ''; // Hosts already differ; no prefix needed.
	1995	+ }
	1996	+ $path = function_exists( 'get_blog_details' ) ? (string) get_blog_details()->path : '/';
	1997	+ return self::path_prefix_segment( $path );
	1998	+ }
	1999	+
	2000	+ /**
	2001	+ * The bucket an arbitrary URL's cache entry lives in.
	2002	+ *
	2003	+ * `site_bucket()` answers for the CURRENT request; this answers for a URL
	2004	+ * that may belong to another blog entirely — which is what a per-URL purge
	2005	+ * is usually doing (WP-CLI, cron, the MCP tool, a network-admin action).
	2006	+ *
	2007	+ * The blog is resolved from the URL itself: on a subdirectory network
	2008	+ * `get_blog_details()` is asked which blog owns `<host><path>`, and its
	2009	+ * registered path becomes the prefix. Deriving the prefix from the URL's
	2010	+ * first path segment directly would be wrong — `/shop/` on the main blog
	2011	+ * is a page, not a subsite, and would send the purge into a bucket that
	2012	+ * does not exist. (QA B2 on #166)
	2013	+ *
	2014	+ * @param string $host Host of the URL being purged.
	2015	+ * @param string $path Path of the URL being purged.
	2016	+ * @return string Bucket path, always non-empty.
	2017	+ */
	2018	+ public static function bucket_for_url( string $host, string $path ): string {
	2019	+ $dir = self::host_dir( $host );
	2020	+ if ( '' === $dir ) {
	2021	+ $dir = 'default';
	2022	+ }
	2023	+
	2024	+ if ( ! function_exists( 'is_multisite' ) || ! is_multisite() ) {
	2025	+ return $dir;
	2026	+ }
	2027	+ if ( function_exists( 'is_subdomain_install' ) && is_subdomain_install() ) {
	2028	+ return $dir; // Hosts already differ; no prefix.
	2029	+ }
	2030	+ if ( ! function_exists( 'get_blog_details' ) ) {
	2031	+ return $dir;
	2032	+ }
	2033	+
	2034	+ // Longest registered blog path that prefixes this URL wins, so
	2035	+ // `/one/2026/post/` resolves to blog `/one/` and not to the root blog.
	2036	+ $blog = self::blog_for_path( $host, $path );
	2037	+ if ( null === $blog ) {
	2038	+ return $dir;
	2039	+ }
	2040	+ $prefix = self::path_prefix_segment( (string) $blog );
	2041	+ return '' === $prefix ? $dir : $dir . '/' . $prefix;
	2042	+ }
	2043	+
	2044	+ /**
	2045	+ * The registered path of the blog that owns `<host><path>`, or null.
	2046	+ *
	2047	+ * Uses get_blog_details() with a domain/path pair rather than scanning
	2048	+ * every blog, so a large network costs one lookup per candidate segment
	2049	+ * instead of a full table read.
	2050	+ */
	2051	+ private static function blog_for_path( string $host, string $path ): ?string {
	2052	+ $segments = array_values( array_filter( explode( '/', trim( $path, '/' ) ) ) );
	2053	+
	2054	+ // Try the longest candidate first: /a/b/ before /a/ before /.
	2055	+ for ( $take = min( count( $segments ), 2 ); $take >= 1; $take-- ) {
	2056	+ $candidate = '/' . implode( '/', array_slice( $segments, 0, $take ) ) . '/';
	2057	+ $details = get_blog_details(
	2058	+ array(
	2059	+ 'domain' => $host,
	2060	+ 'path' => $candidate,
	2061	+ ),
	2062	+ false
	2063	+ );
	2064	+ if ( $details && ! empty( $details->path ) ) {
	2065	+ return (string) $details->path;
	2066	+ }
	2067	+ }
	2068	+ return null;
	2069	+ }
	2070	+
	2071	+ /**
	2072	+ * Normalise a blog path ('/', '/siteb/', '/a/b/') into a single
	2073	+ * filesystem-safe segment. Shared with the drop-in's copy.
	2074	+ */
	2075	+ public static function path_prefix_segment( string $path ): string {
	2076	+ $path = trim( str_replace( "\0", '', $path ), '/' );
	2077	+ if ( '' === $path ) {
	2078	+ return '';
	2079	+ }
	2080	+ $path = preg_replace( '/[^a-zA-Z0-9._\-\/]/', '', $path );
	2081	+ $path = str_replace( '/', '-', (string) $path );
	2082	+ return trim( (string) $path, '.-' );
	2083	+ }
	2084	+
	2085	+ /**
	2086	+ * The current blog's path as the static tree stores it — real slashes
	2087	+ * preserved, because that tree mirrors the URL
	2088	+ * (`xspeed-static/{host}{request_uri}/index.html`) rather than using a
	2089	+ * single flattened segment. '' for a root blog / single site.
	2090	+ */
	2091	+ public static function site_path_raw(): string {
	2092	+ if ( ! function_exists( 'is_multisite' ) || ! is_multisite() ) {
	2093	+ return '';
	2094	+ }
	2095	+ if ( function_exists( 'is_subdomain_install' ) && is_subdomain_install() ) {
	2096	+ return '';
	2097	+ }
	2098	+ $path = function_exists( 'get_blog_details' ) ? (string) get_blog_details()->path : '/';
	2099	+ $path = trim( str_replace( "\0", '', $path ), '/' );
	2100	+ if ( '' === $path ) {
	2101	+ return '';
	2102	+ }
	2103	+ $path = preg_replace( '#[^a-zA-Z0-9._\-/]#', '', $path );
	2104	+ return trim( (string) $path, '/' );
	2105	+ }
	2106	+
	2107	+ /**
	2108	+ * Static-tree root for the current site: `<host>` plus the blog's real
	2109	+ * path. Mirrors store_static()'s layout so a scoped purge deletes
	2110	+ * exactly this blog's pages.
	2111	+ */
	2112	+ public static function current_static_scope(): string {
	2113	+ // Same switch_to_blog() caveat as current_host_dir() — see current_host().
	2114	+ // Keep the port folded into the segment exactly as store_static() does.
	2115	+ $dir = self::static_host_dir( self::current_host() );
	2116	+ if ( '' === $dir ) {
	2117	+ $dir = 'default';
	2118	+ }
	2119	+ $path = self::site_path_raw();
	2120	+ return '' === $path ? $dir : $dir . '/' . $path;
	2121	+ }
	2122	+
	2123	+ /**
	2124	+ * The bucket for the CURRENT request. Never empty, so an entry is never
	2125	+ * written to the tree root (which is what the unscoped sweeps used to
	2126	+ * delete indiscriminately).
	2127	+ */
	2128	+ public static function current_host_dir(): string {
	2129	+ $host = self::current_host();
	2130	+ $uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '/';
	2131	+ return self::site_bucket( $host, $uri );
	2132	+ }
	2133	+
	2134	+ /**
	2135	+ * The host the CURRENT blog is served from.
	2136	+ *
	2137	+ * Deliberately NOT just $_SERVER['HTTP_HOST']: inside a
	2138	+ * switch_to_blog() the request header still names whichever site is
	2139	+ * serving the admin screen, while the cache entries we want belong to
	2140	+ * the switched-to blog. On a subdomain network the host IS the bucket,
	2141	+ * so reading the header there would make Pro's per-site "purge this
	2142	+ * site" button clear the network admin's own cache instead — the very
	2143	+ * bug this scoping exists to fix, surviving in one topology.
	2144	+ *
	2145	+ * get_blog_details() follows the switch, so prefer it whenever we are
	2146	+ * on multisite, and fall back to the request header otherwise.
	2147	+ */
	2148	+ public static function current_host(): string {
	2149	+ if ( function_exists( 'is_multisite' ) && is_multisite() && function_exists( 'get_blog_details' ) ) {
	2150	+ $details = get_blog_details();
	2151	+ if ( $details && ! empty( $details->domain ) ) {
	2152	+ return (string) $details->domain;
	2153	+ }
	2154	+ }
	2155	+
	2156	+ if ( isset( $_SERVER['HTTP_HOST'] ) ) {
	2157	+ return sanitize_text_field( wp_unslash( $_SERVER['HTTP_HOST'] ) );
	2158	+ }
	2159	+
	2160	+ /*
	2161	+ * No request header — WP-CLI, or WP-Cron driven by system cron.
	2162	+ *
	2163	+ * Returning '' here made the bucket resolve to the literal `default`
	2164	+ * while HTTP requests were writing to `<host>/`, so a scheduled purge
	2165	+ * swept an empty directory and reported success, and get_stats()
	2166	+ * reported 0 cached pages on a site with a full cache. That is the
	2167	+ * normal setup on any host running DISABLE_WP_CRON, which is most of
	2168	+ * them. Fall back to the site's own registered host. (QA D4 on #166)
	2169	+ */
	2170	+ if ( function_exists( 'home_url' ) ) {
	2171	+ $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.
	2172	+ if ( is_array( $parts ) && ! empty( $parts['host'] ) ) {
	2173	+ return (string) $parts['host'];
	2174	+ }
	2175	+ }
	2176	+
	2177	+ return '';
	2178	+ }
	2179	+
	2180	+ /**
	2181	+ * Ensure the current site's cache directory exists, with the silence
	2182	+ * index in both it and the shared root. Returns the directory.
	2183	+ */
	2184	+ public static function ensure_host_dir(): string {
	2185	+ $dir = XSPEED_CACHE_DIR . '/' . self::current_host_dir();
	2186	+ if ( ! file_exists( XSPEED_CACHE_DIR ) ) {
	2187	+ wp_mkdir_p( XSPEED_CACHE_DIR );
	2188	+ self::write_silence( XSPEED_CACHE_DIR );
	2189	+ }
	2190	+ if ( ! file_exists( $dir ) ) {
	2191	+ wp_mkdir_p( $dir );
	2192	+ self::write_silence( $dir );
	2193	+ }
	2194	+ return $dir;
	2195	+ }
	2196	+
237	2197	public static function cache_file_for( $key ) {
238		- return XSPEED_CACHE_DIR . '/' . $key . '.html';
	2198	+ return XSPEED_CACHE_DIR . '/' . self::current_host_dir() . '/' . $key . '.html';
239	2199	}
240	2200
	2201	+ /**
	2202	+ * If a precompressed Brotli sibling (`<file>.br`) exists and the client
	2203	+ * advertises `Accept-Encoding: br`, emit the Brotli response headers and
	2204	+ * return the `.br` path to stream. Returns null to fall through to the
	2205	+ * plain file. Keeps the PHP serve path in parity with the web server's
	2206	+ * static .br serving (mod_brotli / ngx_brotli rewrite).
	2207	+ *
	2208	+ * Free has no Brotli logic of its own — this only fires when an add-on
	2209	+ * (the Pro Brotli module) actually wrote the .br, so it's a safe no-op
	2210	+ * on Free-only installs.
	2211	+ *
	2212	+ * @param string $file Absolute path to the cached .html file.
	2213	+ * @return string|null The .br path to stream, or null to serve $file.
	2214	+ */
	2215	+ public static function maybe_serve_brotli( string $file ): ?string {
	2216	+ if ( headers_sent() ) {
	2217	+ return null;
	2218	+ }
	2219	+ $accept = isset( $_SERVER['HTTP_ACCEPT_ENCODING'] )
	2220	+ ? strtolower( sanitize_text_field( wp_unslash( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) )
	2221	+ : '';
	2222	+ // Match `br` as a token (comma/space delimited), not a substring, so
	2223	+ // a hypothetical "xbr" encoding can't false-positive.
	2224	+ if ( ! preg_match( '/(^|[\s,])br([\s,;]|$)/', $accept ) ) {
	2225	+ return null;
	2226	+ }
	2227	+ $br = $file . '.br';
	2228	+ if ( ! is_string( $br ) || ! file_exists( $br ) || ! is_readable( $br ) ) {
	2229	+ return null;
	2230	+ }
	2231	+ if ( ! self::brotli_sibling_is_usable( $file, $br ) ) {
	2232	+ return null; // fall through to the plain .html
	2233	+ }
	2234	+ header( 'Content-Encoding: br' );
	2235	+ header( 'Vary: Accept-Encoding', false );
	2236	+ // The byte length changes for the compressed body — drop any
	2237	+ // Content-Length the caller may have set so the stream isn't
	2238	+ // truncated/padded. readfile() lets the SAPI set the right length.
	2239	+ header_remove( 'Content-Length' );
	2240	+ return $br;
	2241	+ }
	2242	+
	2243	+ /**
	2244	+ * Is a precompressed `.br` sibling safe to serve?
	2245	+ *
	2246	+ * Existence is not enough. The sibling is written with a plain
	2247	+ * file_put_contents() — no atomic rename — so a crash, a full disk, or a
	2248	+ * read that races the write leaves a TRUNCATED file behind. Serving that
	2249	+ * with `Content-Encoding: br` hands the browser a stream it cannot
	2250	+ * inflate: it renders nothing at all (document.body is null) and the
	2251	+ * navigation can hang. A 16-byte .br for a 172KB page reproduces it
	2252	+ * exactly. (#286)
	2253	+ *
	2254	+ * Brotli has no magic number, and no byte-level marker distinguishes a
	2255	+ * truncated stream from a short valid one (the ISLAST bit is bit-packed,
	2256	+ * not byte-aligned). So this checks only what CAN be known by stat:
	2257	+ *
	2258	+ * - Not empty. A zero-byte sibling is unambiguously broken.
	2259	+ * - Not older than the HTML. A stale sibling would serve the PREVIOUS
	2260	+ * revision of the page under the current entry's ETag.
	2261	+ *
	2262	+ * A size-RATIO floor was tried here and removed. Brotli's ratio is
	2263	+ * unbounded on repetitive input: a ~1 MB page of table rows or a product
	2264	+ * grid — the ordinary shape of a big generated page — compresses to
	2265	+ * about 0.04%, so a 2% floor rejected a perfectly good sibling and sent
	2266	+ * visitors the uncompressed page instead, silently. Measured: 963 KB of
	2267	+ * repeated markup → 89 bytes at q5 (0.009%). No floor can separate
	2268	+ * "impossibly small" from "extremely compressible" for arbitrary HTML.
	2269	+ *
	2270	+ * Truncation is prevented at the WRITE side instead — see
	2271	+ * write_atomic(), which the Brotli writer uses so a partial file is
	2272	+ * never visible under the final name. Detection at read time cannot be
	2273	+ * made correct; not creating the bad file can.
	2274	+ *
	2275	+ * Anything suspicious returns false and the caller streams the plain
	2276	+ * .html — slower, always correct. Serving an uninflatable body is worse
	2277	+ * than serving no compression at all.
	2278	+ *
	2279	+ * @param string $file Absolute path to the .html cache file.
	2280	+ * @param string $br Absolute path to its .br sibling.
	2281	+ * @return bool True when the sibling may be served.
	2282	+ */
	2283	+ /**
	2284	+ * Write a cache sidecar so a partial file is never visible.
	2285	+ *
	2286	+ * `file_put_contents()` truncates the target and then fills it, so any
	2287	+ * reader arriving mid-write — or any crash, full disk, or killed worker
	2288	+ * — leaves a SHORT file under the real name. For HTML that degrades to a
	2289	+ * clipped page; for a `.br` sibling it is worse, because a truncated
	2290	+ * brotli stream is not a short page but an UNINFLATABLE one: the browser
	2291	+ * renders nothing at all and the navigation can hang.
	2292	+ *
	2293	+ * Writing to a unique temp file in the same directory and renaming is
	2294	+ * atomic on POSIX, so readers see either the previous complete file or
	2295	+ * the new complete file, never a partial one. This is the half of #286
	2296	+ * that is actually fixable — a read-time heuristic cannot tell a
	2297	+ * truncated brotli stream from a very small valid one, but a truncated
	2298	+ * file that never becomes visible needs no detection.
	2299	+ *
	2300	+ * @param string $path Absolute destination path.
	2301	+ * @param string $contents Bytes to write.
	2302	+ * @return bool True when the destination now holds exactly $contents.
	2303	+ */
	2304	+ public static function write_atomic( string $path, string $contents ): bool {
	2305	+ $dir = dirname( $path );
	2306	+ // 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.
	2307	+ if ( ! is_dir( $dir ) || ! is_writable( $dir ) ) {
	2308	+ return false;
	2309	+ }
	2310	+
	2311	+ // Same directory, so the rename stays on one filesystem — a rename
	2312	+ // across devices is a copy and loses atomicity.
	2313	+ $tmp = @tempnam( $dir, '.xspeed-tmp-' ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- a failure returns false and the caller skips the write.
	2314	+ if ( ! is_string( $tmp ) || '' === $tmp ) {
	2315	+ return false;
	2316	+ }
	2317	+
	2318	+ // 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.
	2319	+ $written = @file_put_contents( $tmp, $contents ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- handled by the length check below.
	2320	+
	2321	+ // A short write is exactly the failure this function exists to
	2322	+ // prevent, so verify the byte count before publishing the file.
	2323	+ if ( false === $written || $written !== strlen( $contents ) ) {
	2324	+ @unlink( $tmp ); // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort cleanup of our own temp file; non-fatal.
	2325	+ return false;
	2326	+ }
	2327	+
	2328	+ // tempnam() creates the file 0600; cache files must stay readable by
	2329	+ // the web server, which may run as a different user.
	2330	+ @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.
	2331	+
	2332	+ // 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.
	2333	+ if ( ! @rename( $tmp, $path ) ) {
	2334	+ @unlink( $tmp ); // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort cleanup; non-fatal.
	2335	+ return false;
	2336	+ }
	2337	+
	2338	+ return true;
	2339	+ }
	2340	+
	2341	+ public static function brotli_sibling_is_usable( string $file, string $br ): bool {
	2342	+ $br_size = (int) @filesize( $br ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- a stat failure means "don't serve it", handled by the <= 0 check.
	2343	+ if ( $br_size <= 0 ) {
	2344	+ return false;
	2345	+ }
	2346	+
	2347	+ $html_size = (int) @filesize( $file ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- as above.
	2348	+ if ( $html_size <= 0 ) {
	2349	+ return false;
	2350	+ }
	2351	+
	2352	+ // A sibling older than the page it compresses is stale.
	2353	+ $br_mtime = (int) @filemtime( $br ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- as above.
	2354	+ $html_mtime = (int) @filemtime( $file ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- as above.
	2355	+ if ( $br_mtime > 0 && $html_mtime > 0 && $br_mtime < $html_mtime ) {
	2356	+ return false;
	2357	+ }
	2358	+
	2359	+ // The writer recorded how many bytes it produced. Where that record
	2360	+ // exists, truncation is a certainty rather than an inference: a
	2361	+ // stream shorter than its own declared length cannot inflate, and
	2362	+ // one that matches was published whole. This is what a size ratio
	2363	+ // could never be — brotli's ratio is unbounded on repetitive input,
	2364	+ // so a 0.01% sibling of a generated page is genuinely valid.
	2365	+ //
	2366	+ // Absent for a sibling written before this version, or by an add-on
	2367	+ // that writes the file directly. That case keeps the checks above
	2368	+ // and no more, which is where a pre-existing truncated file on a
	2369	+ // live site still slips through — write_atomic() stops NEW ones,
	2370	+ // but it cannot retroactively vouch for what is already on disk.
	2371	+ $expected = self::brotli_expected_size( $br );
	2372	+ if ( $expected > 0 && $br_size !== $expected ) {
	2373	+ return false;
	2374	+ }
	2375	+
	2376	+ return true;
	2377	+ }
	2378	+
	2379	+ /**
	2380	+ * Path of the sidecar recording a `.br` sibling's complete byte count.
	2381	+ *
	2382	+ * Kept beside the sibling as `<file>.html.br.size` rather than folded
	2383	+ * into the entry's `.meta`: the static tree the web server serves has no
	2384	+ * `.meta` at all, and the two trees must answer this question the same
	2385	+ * way. Every path that deletes a `.br` deletes this with it.
	2386	+ *
	2387	+ * @param string $br Absolute path to the `.br` sibling.
	2388	+ * @return string Absolute path to its size sidecar.
	2389	+ */
	2390	+ public static function brotli_size_sidecar( string $br ): string {
	2391	+ return $br . '.size';
	2392	+ }
	2393	+
	2394	+ /**
	2395	+ * The byte count the writer recorded for a `.br` sibling, or 0 when no
	2396	+ * record exists (a sibling predating this version, or written by an
	2397	+ * add-on that bypassed write_brotli_sibling()).
	2398	+ *
	2399	+ * @param string $br Absolute path to the `.br` sibling.
	2400	+ * @return int Expected size in bytes, or 0 when unknown.
	2401	+ */
	2402	+ public static function brotli_expected_size( string $br ): int {
	2403	+ $sidecar = self::brotli_size_sidecar( $br );
	2404	+ if ( ! is_file( $sidecar ) ) {
	2405	+ return 0;
	2406	+ }
	2407	+ // 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.
	2408	+ $raw = @file_get_contents( $sidecar ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- an unreadable sidecar means "unknown", handled by the cast below.
	2409	+ return max( 0, (int) trim( (string) $raw ) );
	2410	+ }
	2411	+
	2412	+ /**
	2413	+ * Publish a `.br` sibling together with the record of its own length.
	2414	+ *
	2415	+ * The single writer every producer of a `.br` should route through — the
	2416	+ * Pro Brotli module included. Publishing the body atomically stops a
	2417	+ * truncated file from ever becoming visible; recording the byte count
	2418	+ * lets the serve path prove wholeness for the files that already exist
	2419	+ * on disk when this ships.
	2420	+ *
	2421	+ * Order matters: the size sidecar is removed first and written last, so
	2422	+ * a reader arriving mid-update sees "no record" (checks above still
	2423	+ * apply) rather than the previous body's length against the new body.
	2424	+ *
	2425	+ * @param string $br Absolute path to the `.br` sibling to write.
	2426	+ * @param string $contents Compressed bytes.
	2427	+ * @return bool True when both the sibling and its size record are in place.
	2428	+ */
	2429	+ public static function write_brotli_sibling( string $br, string $contents ): bool {
	2430	+ $sidecar = self::brotli_size_sidecar( $br );
	2431	+ if ( is_file( $sidecar ) ) {
	2432	+ wp_delete_file( $sidecar );
	2433	+ }
	2434	+
	2435	+ if ( ! self::write_atomic( $br, $contents ) ) {
	2436	+ return false;
	2437	+ }
	2438	+
	2439	+ if ( self::write_atomic( $sidecar, (string) strlen( $contents ) ) ) {
	2440	+ return true;
	2441	+ }
	2442	+
	2443	+ // The body landed but its length did not. That sibling is servable
	2444	+ // and unguarded — exactly the file this function exists to prevent —
	2445	+ // and the caller has no way to know. Withdraw it: a MISS costs one
	2446	+ // uncompressed response, where an unguarded sibling can cost a blank
	2447	+ // page for as long as the entry lives.
	2448	+ wp_delete_file( $br );
	2449	+ return false;
	2450	+ }
	2451	+
	2452	+ /**
	2453	+ * Sidecar metadata file for a cache entry. Holds response bits the HIT
	2454	+ * path must replay — Content-Type (cached feeds → application/rss+xml,
	2455	+ * sitemaps → text/xml) and status (a cached 404 must serve 404, not
	2456	+ * 200). JSON, one tiny file per entry, written only when there's
	2457	+ * something non-default to replay.
	2458	+ */
	2459	+ public static function cache_meta_for( $key ) {
	2460	+ return XSPEED_CACHE_DIR . '/' . self::current_host_dir() . '/' . $key . '.meta';
	2461	+ }
	2462	+
	2463	+ /**
	2464	+ * Read the .meta sidecar for a cache entry as an array, or [] if none.
	2465	+ * Keys: 'content_type' (string), 'status' (int), 'ttl' (int seconds).
	2466	+ * Used on the HIT path to replay content-type/status before streaming
	2467	+ * the file, and by Cache_GC to age an entry by its own TTL rather than
	2468	+ * the global one — hence public.
	2469	+ */
	2470	+ public static function read_meta( $key ): array {
	2471	+ $meta_file = self::cache_meta_for( $key );
	2472	+ if ( ! file_exists( $meta_file ) ) {
	2473	+ return array();
	2474	+ }
	2475	+ // 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.
	2476	+ $raw = file_get_contents( $meta_file );
	2477	+ $data = json_decode( (string) $raw, true );
	2478	+ return is_array( $data ) ? $data : array();
	2479	+ }
	2480	+
	2481	+ /**
	2482	+ * Conditional-GET support for a cache HIT. Emits Last-Modified + ETag
	2483	+ * derived from the cache file's mtime, and — when the request's
	2484	+ * If-Modified-Since / If-None-Match still match — sends 304 Not Modified
	2485	+ * and returns true (caller should exit without a body). Returns false to
	2486	+ * proceed with a normal 200 body. Lets aggregators/browsers skip
	2487	+ * re-downloading an unchanged cached response. (FBS-82407 #5)
	2488	+ *
	2489	+ * @param string $file Absolute path to the cache .html file.
	2490	+ * @return bool True when a 304 was sent.
	2491	+ */
	2492	+ public static function serve_not_modified( string $file ): bool {
	2493	+ $mtime = (int) filemtime( $file );
	2494	+ if ( $mtime <= 0 ) {
	2495	+ return false;
	2496	+ }
	2497	+ $last_modified = gmdate( 'D, d M Y H:i:s', $mtime ) . ' GMT';
	2498	+ $etag = '"' . md5( $file . '|' . $mtime ) . '"';
	2499	+ header( 'Last-Modified: ' . $last_modified );
	2500	+ header( 'ETag: ' . $etag );
	2501	+
	2502	+ $ims = isset( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ? trim( sanitize_text_field( wp_unslash( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) ) : '';
	2503	+ $inm = isset( $_SERVER['HTTP_IF_NONE_MATCH'] ) ? trim( sanitize_text_field( wp_unslash( $_SERVER['HTTP_IF_NONE_MATCH'] ) ) ) : '';
	2504	+
	2505	+ $etag_match = '' !== $inm && false !== strpos( $inm, $etag );
	2506	+ $time_match = '' !== $ims && ( strtotime( $ims ) >= $mtime );
	2507	+
	2508	+ if ( $etag_match || $time_match ) {
	2509	+ if ( function_exists( 'http_response_code' ) ) {
	2510	+ http_response_code( 304 );
	2511	+ }
	2512	+ return true;
	2513	+ }
	2514	+ return false;
	2515	+ }
	2516	+
241	2517	public static function is_expired( $file ) {
242	2518	// cache_expiry now owned by CacheModule; per-post override
243	2519	// (Phase 3.4) shrinks the TTL further when the editor set one.
244	2520	$opts = Settings_Manager::get( 'cache' );
		@@ -246,9 +2522,57 @@
246	2522	$post_override = Cache_Rules::expiry_override_seconds_for_post( Cache_Rules::current_post_id() );
247	2523	if ( null !== $post_override ) {
248	2524	$max_age = $post_override;
249	2525	}
250		- return ( time() - filemtime( $file ) ) > $max_age;
	2526	+
	2527	+ /**
	2528	+ * Filter the max-age (seconds) for the current cache entry.
	2529	+ *
	2530	+ * Lets an add-on apply a request-type-specific TTL — e.g. the
	2531	+ * xspeed-pro feed cache gives feeds a longer expiry than pages,
	2532	+ * since aggregators tolerate more staleness. Return seconds.
	2533	+ *
	2534	+ * @param int $max_age Computed max-age in seconds.
	2535	+ */
	2536	+ $max_age = (int) apply_filters( 'xspeed_cache_max_age', $max_age );
	2537	+
	2538	+ // Honour the per-entry TTL the .meta sidecar carries, when it is
	2539	+ // SHORTER than what we just resolved. The sidecar records the TTL
	2540	+ // this specific entry was written under — a nonce cap (#236), a Pro
	2541	+ // feed/404 expiry — and the drop-in already reads it. is_expired()
	2542	+ // did not, so on the engine path a capped entry was still served for
	2543	+ // the full configured lifetime: exactly the stale nonce the cap
	2544	+ // exists to prevent. Only ever shortens, so an entry can never be
	2545	+ // kept alive past the configured maximum by a stale sidecar.
	2546	+ // Derive the sidecar from the FILE we were handed rather than
	2547	+ // recomputing cache_key(): callers legitimately ask about an entry
	2548	+ // that isn't the current request's (Cache_GC sweeps, Pro's warmer),
	2549	+ // and cache_key() would answer for the wrong one — besides needing a
	2550	+ // request context this function has no business requiring.
	2551	+ $meta_file = preg_replace( '/\.html$/', '.meta', (string) $file );
	2552	+ if ( is_string( $meta_file ) && $meta_file !== $file && is_readable( $meta_file ) ) {
	2553	+ // 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.
	2554	+ $raw = file_get_contents( $meta_file );
	2555	+ $decoded = is_string( $raw ) ? json_decode( $raw, true ) : null;
	2556	+ if ( is_array( $decoded ) && isset( $decoded['ttl'] ) ) {
	2557	+ $entry_ttl = (int) $decoded['ttl'];
	2558	+ if ( $entry_ttl > 0 && ( $max_age < 1 || $entry_ttl < $max_age ) ) {
	2559	+ $max_age = $entry_ttl;
	2560	+ }
	2561	+ }
	2562	+ }
	2563	+
	2564	+ // A missing file is "expired" — the caller should re-render. Guard
	2565	+ // filemtime() rather than letting it warn: callers legitimately ask
	2566	+ // about a file that isn't there (Pro's predictive warmer probes for
	2567	+ // freshness, and Cache_GC can collect an entry between the check and
	2568	+ // the read), and on a site with WP_DEBUG the warning is noise.
	2569	+ $mtime = file_exists( $file ) ? filemtime( $file ) : false;
	2570	+ if ( false === $mtime ) {
	2571	+ return true;
	2572	+ }
	2573	+
	2574	+ return ( time() - (int) $mtime ) > $max_age;
251	2575	}
252	2576
253	2577	/**
254	2578	* Accumulator for the full response body across all output-handler phases.
		@@ -283,10 +2607,18 @@
283	2607	if ( strlen( $full ) < 255 ) {
284	2608	return $buffer;
285	2609	}
286	2610
287		- if ( function_exists( 'http_response_code' ) && 200 !== http_response_code() ) {
288		- return $buffer;
	2611	+ // Status gate. We cache 200 by default. A 404 may be cached too,
	2612	+ // but only when an add-on (xspeed-pro 404 cache) opts in for a
	2613	+ // genuine is_404() — never a transient 404 (maintenance screen,
	2614	+ // DB error, or a 404 emitted outside the main query), which would
	2615	+ // otherwise be frozen until purge. Any other status is skipped.
	2616	+ $status = function_exists( 'http_response_code' ) ? (int) http_response_code() : 200;
	2617	+ if ( 200 !== $status ) {
	2618	+ if ( 404 !== $status || ! self::should_cache_404() ) {
	2619	+ return $buffer;
	2620	+ }
289	2621	}
290	2622
291	2623	// If no mid-request flush happened, $buffer === $full and we can
292	2624	// safely minify the on-wire bytes too. Otherwise earlier chunks have
		@@ -294,8 +2626,28 @@
294	2626	// the first visitor sees unminified HTML, every cache hit after that
295	2627	// is minified.
296	2628	$single_chunk = ( $buffer === $full );
297	2629
	2630	+ /**
	2631	+ * Filter: xspeed_cache_final_html
	2632	+ *
	2633	+ * Last chance to transform the fully-rendered page HTML before it is
	2634	+ * minified and written to the cache file. Runs on cache MISS only, so
	2635	+ * whatever a listener injects here is baked into the cached HTML and
	2636	+ * replayed on every subsequent HIT (the drop-in short-circuits before
	2637	+ * PHP on a HIT — a wp_head hook would never fire there).
	2638	+ *
	2639	+ * The Preload module uses this to inject the LCP-image <link rel=preload>
	2640	+ * + preconnect hints and add fetchpriority="high" to the hero <img>.
	2641	+ * Keep listeners fast and idempotent; this is the on-wire body.
	2642	+ *
	2643	+ * @param string $full Complete page HTML.
	2644	+ */
	2645	+ $full = (string) apply_filters( 'xspeed_cache_final_html', $full );
	2646	+ if ( $single_chunk ) {
	2647	+ $buffer = $full;
	2648	+ }
	2649	+
298	2650	// minify_html now owned by the Minify module; read through the
299	2651	// module's storage so this stays consistent with the engine that
300	2652	// applies CSS/JS minification.
301	2653	$minify_opts = Settings_Manager::get( 'minify' );
		@@ -305,27 +2657,124 @@
305	2657	$buffer = $full;
306	2658	}
307	2659	}
308	2660
309		- if ( ! file_exists( XSPEED_CACHE_DIR ) ) {
310		- wp_mkdir_p( XSPEED_CACHE_DIR );
311		- self::write_silence( XSPEED_CACHE_DIR );
	2661	+ // AFTER minification on purpose — the HTML minifier strips comments,
	2662	+ // so signing earlier would erase the signature from every minified
	2663	+ // page. Baked into the cached bytes so all three serve paths (nginx
	2664	+ // static rewrite, .htaccess, the PHP drop-in) carry it identically.
	2665	+ $full = self::signed( $full );
	2666	+ if ( $single_chunk ) {
	2667	+ $buffer = $full;
312	2668	}
313	2669
314		- // Path safety: cache_file_for() builds `XSPEED_CACHE_DIR . '/' . $key . '.html'`
315		- // where $key comes from md5() — guaranteed to be exactly 32 lowercase
316		- // hex chars, so no traversal sequence ('..', '/', null byte, etc.)
317		- // can appear. The write is therefore always inside XSPEED_CACHE_DIR.
318		- $file = self::cache_file_for( self::cache_key() );
	2670	+ // Per-site directory — see ensure_host_dir(). (#6)
	2671	+ self::ensure_host_dir();
	2672	+
	2673	+ // Path safety: cache_file_for() builds
	2674	+ // `XSPEED_CACHE_DIR . '/' . <host> . '/' . $key . '.html'` where $key
	2675	+ // comes from md5() — guaranteed to be exactly 32 lowercase hex chars —
	2676	+ // and <host> is filtered by host_dir() to [A-Za-z0-9.-] with leading
	2677	+ // dots trimmed, so no traversal sequence ('..', '/', null byte, etc.)
	2678	+ // can appear in either segment. The write is therefore always inside
	2679	+ // XSPEED_CACHE_DIR.
	2680	+ $key = self::cache_key();
	2681	+
	2682	+ // Query-string gate. should_cache() waved this request through
	2683	+ // because every param is on the ignored_query_params allow-list, and
	2684	+ // cache_key() drops the query so reads share the canonical entry.
	2685	+ // That sharing is safe on READ but not on WRITE: this response was
	2686	+ // rendered WITH the params, and WordPress reflects REQUEST_URI into
	2687	+ // form actions, share links and plugin smart tags — so storing it
	2688	+ // would serve an attacker-chosen variant under the clean URL for the
	2689	+ // whole TTL (#241).
	2690	+ //
	2691	+ // This sits BELOW the transforms deliberately. Returning above them
	2692	+ // also skipped xspeed_cache_final_html, and every listener disables
	2693	+ // its own fallback ob_start() when the page cache is on precisely
	2694	+ // because that filter is the shared transport — so a visitor
	2695	+ // arriving on ?utm_source=… was served HTML with no LCP preload, no
	2696	+ // preconnect, no CDN rewrite, no CSS combine and no HTML minify.
	2697	+ // That is the ad-click and newsletter cohort getting the least
	2698	+ // optimised page on the site. Only the WRITE is skipped, which is
	2699	+ // what this fix was always meant to do — and it is where the
	2700	+ // deferred writer has always placed its own copy of the guard.
	2701	+ if ( self::query_string_blocks_write() ) {
	2702	+ return $buffer;
	2703	+ }
	2704	+ $file = self::cache_file_for( $key );
	2705	+
	2706	+ // A render-time translation plugin (TranslatePress) wraps our buffer,
	2707	+ // so the bytes we hold here are still UNTRANSLATED — its callback has
	2708	+ // not run yet, and writing now would cache English under a French URL
	2709	+ // and bake in its internal #TRPLINKPROCESSED markers. Hand off to
	2710	+ // shutdown, where the outer buffer has already translated, and let
	2711	+ // the pass-through below deliver this request untouched.
	2712	+ if ( self::translation_plugin_active() ) {
	2713	+ self::$deferred_key = $key;
	2714	+ // Reaching here means finalize_buffer() ran to completion: the
	2715	+ // status gate passed, should_cache() said yes, and PHP handed us
	2716	+ // the whole buffer. A wp_die() or exit() mid-render unwinds the
	2717	+ // buffer stack WITHOUT calling this callback, so the flag stays
	2718	+ // false and the shutdown writer declines — see the guard there.
	2719	+ self::$render_completed = true;
	2720	+ // A PHP shutdown function, not a WP `shutdown` action: this must
	2721	+ // run after the output-buffer stack has unwound, and WP's
	2722	+ // shutdown action fires while our outer buffer is still open.
	2723	+ register_shutdown_function( array( __CLASS__, 'write_deferred_translated_cache' ) );
	2724	+ return $buffer;
	2725	+ }
	2726	+
319	2727	// 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.
320	2728	file_put_contents( $file, $full, LOCK_EX );
321	2729
	2730	+ /**
	2731	+ * Fires after the flat hash cache file ({md5}.html) is written.
	2732	+ *
	2733	+ * Mirror of `xspeed_static_file_written` for the flat cache. The PHP
	2734	+ * serve path (Cache::maybe_serve_brotli / the drop-in) serves THIS
	2735	+ * file and looks for a `{md5}.html.br` sibling — which only the Pro
	2736	+ * Brotli listener on this hook writes. Without it the .br sibling was
	2737	+ * never created and the PHP path could never serve Brotli (FBS-83039,
	2738	+ * Blocker 2): the static-tree .br (written on xspeed_static_file_written)
	2739	+ * lives in a different cache layout the PHP path never reads.
	2740	+ *
	2741	+ * @param string $file Absolute path to the flat cache file just written.
	2742	+ * @param string $full The HTML written to it.
	2743	+ */
	2744	+ do_action( 'xspeed_flat_file_written', $file, $full );
	2745	+
	2746	+ // Persist a non-default Content-Type so the HIT path can replay it
	2747	+ // (cached feeds must serve application/rss+xml, not text/html).
	2748	+ // Only written when the response set a content-type other than
	2749	+ // the HTML default — pages don't pay for an extra file.
	2750	+ self::write_meta( $key, $full );
	2751	+
322	2752	// Static-cache tree (xspeed-static/{host}{path}/index.html). The
323	2753	// .htaccess rewrite block serves this file directly via the web
324	2754	// server, bypassing PHP for ~3-5× lower TTFB vs the drop-in path.
325	2755	// store_static() returns silently on any path/permission issue —
326	2756	// the drop-in remains the safety net.
327		- self::store_static( $full );
	2757	+ //
	2758	+ // Skip it entirely when mobile_separate is on: the rewrite is
	2759	+ // disabled in that mode (static_rewrite_allowed()), so a static file
	2760	+ // would only be dead weight — and a device-blind one at that.
	2761	+ // Skip the static-tree write for responses the web server can't replay
	2762	+ // correctly: a non-200 status (a cached 404 would be served as a soft
	2763	+ // 200, FBS-82406) or a non-HTML content-type (a cached feed would go
	2764	+ // out as text/html, FBS-82407). The web server serves these .html files
	2765	+ // directly with no PHP, so there's no .meta replay — keep them on the
	2766	+ // drop-in / PHP path instead, which DOES replay status + content-type.
	2767	+ // The static tree cannot replay a sidecar. A file served straight by
	2768	+ // the web server carries the headers baked into the rule that serves
	2769	+ // the whole site — the very answer this entry exists because it
	2770	+ // disagreed with. Same reasoning as the status and content-type
	2771	+ // cases: what the fast path cannot replay belongs on the drop-in path.
	2772	+ if ( self::static_rewrite_allowed()
	2773	+ && self::response_is_plain_html()
	2774	+ && array() === self::per_entry_edge_headers() ) {
	2775	+ self::store_static( $full );
	2776	+ }
328	2777
329	2778	return $buffer;
330	2779	}
331	2780
		@@ -339,13 +2788,149 @@
339	2788	* $uri has its query string stripped, null bytes removed, '..'
340	2789	* sequences collapsed, and after concatenation we verify the
341	2790	* resolved real path stays inside XSPEED_CACHE_STATIC_DIR before
342	2791	* any write. Anything off the happy path returns silently.
	2792	+ *
	2793	+ * INVARIANT — the static tree is keyed by `{host}{path}` and NOTHING
	2794	+ * else, and both generated rewrites refuse any request that carries a
	2795	+ * query string at all (`RewriteCond %{QUERY_STRING} ^$` on Apache,
	2796	+ * `if ($args)` in nginx_snippet()). So a response may only be stored
	2797	+ * here when cache_key() adds no discriminator beyond `{host}{path}`:
	2798	+ * a query-keyed entry can never be *served* from here, only mis-served
	2799	+ * as the bare path. Any future opt-in that folds a query param into the
	2800	+ * key needs a guard below, exactly like the search one.
343	2801	*/
	2802	+ /**
	2803	+ * Transient holding the most recent static-tree refusal.
	2804	+ *
	2805	+ * Short-lived on purpose: it describes what the last cacheable render
	2806	+ * actually did, so a stale entry would keep warning about a page whose
	2807	+ * nonces have since been removed. A site that still refuses simply
	2808	+ * rewrites it on the next render. (#372)
	2809	+ */
	2810	+ private const STATIC_SKIP_TRANSIENT = 'xspeed_static_skip';
	2811	+
	2812	+ /**
	2813	+ * Remember why a page was kept out of the static tree, for Health.
	2814	+ *
	2815	+ * Records the URL, the reason, and — for the nonce case — the distinct
	2816	+ * nonce KEYS found, which is what makes the finding actionable: the names
	2817	+ * (`eael_login_nonce`, `post_grid_pagination_nonce`, …) trace straight back
	2818	+ * to the plugin emitting them, and it is usually a widget the site does not
	2819	+ * use on that page. Only key names are kept, never the nonce values.
	2820	+ *
	2821	+ * @param string $reason Machine-readable refusal reason.
	2822	+ * @param string $html The response, for extracting the nonce keys.
	2823	+ */
	2824	+ private static function note_static_skip( string $reason, string $html = '' ): void {
	2825	+ if ( ! function_exists( 'set_transient' ) ) {
	2826	+ return;
	2827	+ }
	2828	+
	2829	+ $keys = array();
	2830	+ if ( 'nonce' === $reason && '' !== $html ) {
	2831	+ // Must recognise the SAME shapes response_has_nonce() refuses on,
	2832	+ // or a page is skipped and reported with no keys at all — which is
	2833	+ // most of them, since the plain `name="_wpnonce"` form field is the
	2834	+ // commonest shape by far and only the JSON one was handled here.
	2835	+ // The keys are the actionable half of the message, so a mismatch
	2836	+ // leaves the admin with bad news and nothing to act on.
	2837	+ //
	2838	+ // Both alternations capture the KEY only: each value pattern sits
	2839	+ // outside the capture group, so a nonce secret can never be stored.
	2840	+ $found = array();
	2841	+ if ( preg_match_all( '/name=["\']([a-z0-9_\-\[\]]*nonce[a-z0-9_\-\[\]]*)["\']/i', $html, $m ) ) {
	2842	+ $found = array_merge( $found, $m[1] );
	2843	+ }
	2844	+ if ( preg_match_all( '/["\']([a-z0-9_\-]*nonce[a-z0-9_\-]*)["\']\s*:\s*["\'][a-f0-9]{8,}["\']/i', $html, $m ) ) {
	2845	+ $found = array_merge( $found, $m[1] );
	2846	+ }
	2847	+ // The query-arg shape (`?_wpnonce=…`) has no key name to report
	2848	+ // beyond the literal, so name it explicitly rather than reporting
	2849	+ // nothing for a page that was genuinely refused.
	2850	+ if ( preg_match( '/[?&]_wpnonce=/i', $html ) ) {
	2851	+ $found[] = '_wpnonce';
	2852	+ }
	2853	+ $keys = array_slice( array_values( array_unique( $found ) ), 0, 10 );
	2854	+ }
	2855	+
	2856	+ $uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
	2857	+
	2858	+ set_transient(
	2859	+ self::STATIC_SKIP_TRANSIENT,
	2860	+ array(
	2861	+ 'reason' => $reason,
	2862	+ 'url' => (string) strtok( $uri, '?' ),
	2863	+ 'keys' => $keys,
	2864	+ 'at' => time(),
	2865	+ ),
	2866	+ HOUR_IN_SECONDS
	2867	+ );
	2868	+ }
	2869	+
	2870	+ /**
	2871	+ * The most recent static-tree refusal, or an empty array when there is none.
	2872	+ *
	2873	+ * @return array{reason:string,url:string,keys:string[],at:int}|array{}
	2874	+ */
	2875	+ public static function last_static_skip(): array {
	2876	+ $stored = function_exists( 'get_transient' ) ? get_transient( self::STATIC_SKIP_TRANSIENT ) : false;
	2877	+ return is_array( $stored ) && ! empty( $stored['reason'] ) ? $stored : array();
	2878	+ }
	2879	+
344	2880	private static function store_static( string $html ): void {
	2881	+ // Search results are keyed by term in cache_key() (`|s=<term>`) but
	2882	+ // carry the *path* of whatever URL was searched from — for the usual
	2883	+ // `/?s=<term>` that path is `/`. Writing them here would file the
	2884	+ // results page as `{host}/index.html` and the web server would serve
	2885	+ // it to every visitor as the homepage: an unauthenticated visitor
	2886	+ // poisons the front page with one request. Searches stay on the
	2887	+ // drop-in, which replays the term-keyed entry correctly. (#191)
	2888	+ //
	2889	+ // This is a superset of the query-string check the exclusion gate
	2890	+ // does: it also covers `/?%73=<term>`, which decodes to the same
	2891	+ // search (the shape #109 fixed on the gate side).
	2892	+ if ( self::should_cache_search() ) {
	2893	+ return;
	2894	+ }
	2895	+
	2896	+ // Same hazard for the allow-listed query params: store_static()
	2897	+ // strips the query and files the response under the bare path, which
	2898	+ // the web server then serves to every visitor of the clean URL with
	2899	+ // no PHP involved at all — so none of the engine's checks can catch
	2900	+ // it later (#241). The callers already gate on this, but the guard
	2901	+ // is repeated here because this tree is the most dangerous of the
	2902	+ // three write sites and must not depend on its callers.
	2903	+ if ( self::request_has_query_string() ) {
	2904	+ return;
	2905	+ }
	2906	+
	2907	+ // A nonce-bearing page is served here with NO PHP: no TTL check and
	2908	+ // no .meta replay, so the per-entry cap that keeps the drop-in honest
	2909	+ // (#236) cannot reach a file once it is written. Only Cache_GC removes
	2910	+ // it, and until it does the page hands every visitor the same nonce —
	2911	+ // which, once that nonce dies, breaks every anonymous form on it.
	2912	+ //
	2913	+ // Refusing outright was the safe answer, and it cost every
	2914	+ // nonce-bearing page the static tree entirely: a site whose homepage
	2915	+ // carries one unused login nonce ran PHP on every request forever.
	2916	+ // The nonce's own remaining life is the better gate — the page is
	2917	+ // written and its deadline recorded below for GC to enforce.
	2918	+ //
	2919	+ // A nonce we cannot put a clock on is still refused, and that refusal
	2920	+ // is still recorded: it stays completely silent otherwise, because the
	2921	+ // drop-in answers HIT while Health reports the fast path active from a
	2922	+ // probe that writes its OWN file and never proves real pages reach the
	2923	+ // tree. (#372)
	2924	+ $nonce_ttl = self::response_has_nonce( $html ) ? self::nonce_capped_ttl( $html, 0 ) : 0;
	2925	+ if ( self::response_has_nonce( $html ) && $nonce_ttl < 1 ) {
	2926	+ self::note_static_skip( 'nonce', $html );
	2927	+ return;
	2928	+ }
	2929	+
345	2930	$host = isset( $_SERVER['HTTP_HOST'] ) ? sanitize_text_field( wp_unslash( $_SERVER['HTTP_HOST'] ) ) : '';
346	2931	$uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
347		- $host = preg_replace( '/[^a-zA-Z0-9.\-]/', '', $host );
	2932	+ $host = self::static_host_dir( $host );
348	2933	$uri = str_replace( "\0", '', $uri );
349	2934	$uri = (string) strtok( $uri, '?' );
350	2935	if ( '' === $host || '' === $uri ) {
351	2936	return;
		@@ -374,36 +2959,1633 @@
374	2959	if ( ! is_dir( $dir ) ) {
375	2960	return;
376	2961	}
377	2962	// 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.
378		- file_put_contents( $file, $html, LOCK_EX );
	2963	+ $written = file_put_contents( $file, $html, LOCK_EX );
	2964	+
	2965	+ // A nonce-bearing page expires on the nonce's schedule, not the site's.
	2966	+ // Nothing reads this file at serve time — the web server hands over
	2967	+ // index.html without PHP — so the deadline is recorded beside it for
	2968	+ // GC, which is the only thing that can enforce it. Written before the
	2969	+ // action below so a listener that shells out cannot race the sweep.
	2970	+ if ( false !== $written && $nonce_ttl > 0 ) {
	2971	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- same rationale as the write above.
	2972	+ file_put_contents( $dir . '/.xspeed-expires', (string) ( time() + $nonce_ttl ), LOCK_EX );
	2973	+ }
	2974	+
	2975	+ if ( false !== $written ) {
	2976	+ /**
	2977	+ * Fires after a static cache file (index.html) is written.
	2978	+ *
	2979	+ * The extension point for serving pre-compressed siblings:
	2980	+ * the xspeed-pro Brotli module writes `index.html.br` next to
	2981	+ * the file here so the web server's static rewrite can serve a
	2982	+ * Brotli copy to clients that advertise `Accept-Encoding: br`,
	2983	+ * falling back to GZIP / the plain file otherwise. No core
	2984	+ * behavior depends on a listener being present.
	2985	+ *
	2986	+ * @param string $file Absolute path to the static cache file just written.
	2987	+ * @param string $html The HTML written to it.
	2988	+ */
	2989	+ do_action( 'xspeed_static_file_written', $file, $html );
	2990	+ }
379	2991	}
380	2992
381	2993	/**
	2994	+ * Write the .meta sidecar for a cache entry when the response carries
	2995	+ * anything the HIT path must replay beyond a plain 200 text/html:
	2996	+ * - a non-HTML Content-Type (cached feeds → application/rss+xml,
	2997	+ * sitemaps → text/xml, …), and/or
	2998	+ * - a non-200 status (a cached 404 must serve 404, not 200).
	2999	+ *
	3000	+ * Ordinary 200 text/html pages get NO .meta file, so the common path
	3001	+ * stays a single write.
	3002	+ *
	3003	+ * @param string $key Cache key for the current request.
	3004	+ */
	3005	+ /**
	3006	+ * True only for a plain 200 text/html response — the only kind the
	3007	+ * web-server static tree can serve correctly (it streams the .html with
	3008	+ * no PHP, so it can't replay a 404 status or a feed Content-Type). Used
	3009	+ * to gate store_static() so cached 404s / feeds stay on the replay-capable
	3010	+ * drop-in / PHP path. (FBS-82406, FBS-82407)
	3011	+ */
	3012	+ private static function response_is_plain_html(): bool {
	3013	+ $status = function_exists( 'http_response_code' ) ? (int) http_response_code() : 200;
	3014	+ if ( 200 !== $status && $status > 0 ) {
	3015	+ return false;
	3016	+ }
	3017	+ foreach ( headers_list() as $header ) {
	3018	+ if ( 0 === stripos( $header, 'content-type:' ) ) {
	3019	+ $ct = trim( substr( $header, strlen( 'content-type:' ) ) );
	3020	+ if ( '' !== $ct && false === stripos( $ct, 'text/html' ) ) {
	3021	+ return false;
	3022	+ }
	3023	+ }
	3024	+ }
	3025	+ return true;
	3026	+ }
	3027	+
	3028	+ /**
	3029	+ * Append the cache signature comment to a finished page.
	3030	+ *
	3031	+ * The plugin's one outward version signal: external scanners (the
	3032	+ * xspeedcache.com speed test among them) read it to detect xSpeed and
	3033	+ * its version on a cached page, the way other cache plugins sign their
	3034	+ * output. Callers apply it AFTER HTML minification — the minifier strips
	3035	+ * comments — and before every cache write, so all serve paths carry the
	3036	+ * same bytes.
	3037	+ *
	3038	+ * The generation time is baked in here, at write time, in UTC. It is the
	3039	+ * moment the cached bytes were produced — NOT the moment they were served
	3040	+ * — because all three serve paths replay the same stored file, and two of
	3041	+ * them (the nginx/`.htaccess` static rewrite) run no PHP at all and so
	3042	+ * could never stamp a serve-time value. Reading the age of a page is the
	3043	+ * point: `generated` plus the current clock tells you how stale it is.
	3044	+ * `gmdate()` (not `current_time()`) keeps the value comparable across
	3045	+ * sites regardless of the configured timezone.
	3046	+ *
	3047	+ * @param string $html Finished page HTML.
	3048	+ * @return string HTML with the signature appended (or unchanged when a
	3049	+ * filter removed it).
	3050	+ */
	3051	+ private static function signed( string $html ): string {
	3052	+ $version = defined( 'XSPEED_VERSION' ) ? XSPEED_VERSION : '';
	3053	+ $generated = gmdate( 'Y-m-d H:i:s' ) . ' UTC';
	3054	+ // The literal ' | xspeedcache.com' must survive intact, and what
	3055	+ // precedes it is where an edition suffix lands: Pro appends itself by
	3056	+ // str_replace()-ing on that exact token
	3057	+ // (Pro_Plugin::sign_cache_signature). So the stamp goes AFTER it —
	3058	+ // placed before, it sits between the version and the anchor and
	3059	+ // composes as "generated <date> + Pro v1.1.3".
	3060	+ $signature = sprintf(
	3061	+ '<!-- Page cached by xSpeed Cache v%s | xspeedcache.com | generated %s -->',
	3062	+ $version,
	3063	+ $generated
	3064	+ );
	3065	+
	3066	+ /**
	3067	+ * Filter: xspeed_cache_signature
	3068	+ *
	3069	+ * The HTML comment appended to every cached page. Add-ons append
	3070	+ * their own edition/version here; white-label setups return '' to
	3071	+ * remove the comment entirely. Must remain a valid HTML comment (or
	3072	+ * an empty string) — it ships inside the cached body.
	3073	+ *
	3074	+ * @param string $signature The signature comment.
	3075	+ * @param string $version The plugin version baked into it.
	3076	+ * @param string $generated The write-time timestamp baked into it,
	3077	+ * formatted `Y-m-d H:i:s UTC`.
	3078	+ */
	3079	+ $signature = (string) apply_filters( 'xspeed_cache_signature', $signature, $version, $generated );
	3080	+ if ( '' === trim( $signature ) ) {
	3081	+ return $html;
	3082	+ }
	3083	+ return $html . "\n" . $signature;
	3084	+ }
	3085	+
	3086	+ /**
	3087	+ * Does this response carry a WordPress nonce?
	3088	+ *
	3089	+ * Anonymous nonces depend only on the tick (user 0, empty session
	3090	+ * token), so they are identical for every visitor — which is exactly why
	3091	+ * they cache "successfully" and then fail silently once the tick moves.
	3092	+ *
	3093	+ * Matches any form field whose NAME contains "nonce" — `_wpnonce`,
	3094	+ * `_wpnonce_<action>`, Tutor's `_tutor_nonce`, CF7's `_wpcf7_nonce` and
	3095	+ * WooCommerce's `woocommerce-add-to-cart-nonce` (which does NOT start
	3096	+ * with an underscore, so a `_`-anchored pattern misses it) — plus the
	3097	+ * `_wpnonce=` form used in nonce-bearing URLs. Deliberately keyed on
	3098	+ * `name=` so prose, CSS classes and data attributes don't false-positive.
	3099	+ *
	3100	+ * @param string $html Rendered response body.
	3101	+ */
	3102	+ public static function response_has_nonce( string $html ): bool {
	3103	+ if ( '' === $html ) {
	3104	+ return false;
	3105	+ }
	3106	+
	3107	+ /*
	3108	+ * Three shapes, because a nonce reaches the page in three ways:
	3109	+ *
	3110	+ * 1. A form field name — `_wpnonce`, `woocommerce-login-nonce`, and
	3111	+ * the GROUPED names form builders emit (`data[_wpnonce]`,
	3112	+ * `frm[nonce]`). The character class deliberately allows `[` and
	3113	+ * `]` so grouping does not hide the field: form builders are
	3114	+ * exactly the kind of plugin #236 is about, and a missed page
	3115	+ * keeps the old broken behaviour silently.
	3116	+ * 2. A query argument (`?_wpnonce=`) on a link.
	3117	+ * 3. A nonce handed to the page's own scripts rather than placed in
	3118	+ * a visible form — `wp_localize_script()` output and inline JSON
	3119	+ * both land as a `"nonce":"…"`-shaped pair.
	3120	+ */
	3121	+ return 1 === preg_match(
	3122	+ '/(name=["\'][a-z0-9_\-\[\]]*nonce[a-z0-9_\-\[\]]*["\']'
	3123	+ . '|[?&]_wpnonce='
	3124	+ . '|["\'][a-z0-9_\-]*nonce[a-z0-9_\-]*["\']\s*:\s*["\'][a-f0-9]{8,}["\'])/i',
	3125	+ $html
	3126	+ );
	3127	+ }
	3128	+
	3129	+ /**
	3130	+ * The TTL (seconds) a response may be cached for, capped to the nonce
	3131	+ * lifetime when it carries one.
	3132	+ *
	3133	+ * WordPress nonces are valid for at most `nonce_life` — 24h by default —
	3134	+ * because wp_verify_nonce() accepts the current tick and the previous
	3135	+ * one. Our own lifetime maximum is 720h and the shipped Aggressive
	3136	+ * preset is 168h, so on any site configured above 24h every anonymous
	3137	+ * front-end form carried a DEAD nonce for the majority of the cache's
	3138	+ * life and every submission was rejected — with the other plugin's error
	3139	+ * string ("Nonce not matched"), so the report never reached us (#236).
	3140	+ *
	3141	+ * `nonce_life` is the MAXIMUM a nonce can live, not the minimum, so it
	3142	+ * is the wrong number to cap with. wp_nonce_tick() buckets time into
	3143	+ * `nonce_life / 2` slices; a nonce minted x seconds into its bucket is
	3144	+ * valid for `nonce_life - x`, where x can be as large as a full bucket.
	3145	+ * Capping the entry at `nonce_life` therefore still served a dead nonce
	3146	+ * for up to half of every entry's life — 0-12h of each 24h entry,
	3147	+ * averaging 6h, re-rolled by every purge so it reads as intermittent.
	3148	+ * Capping at the guaranteed-valid remainder closes the window at every
	3149	+ * tick phase, at the cost of caching nonce-bearing pages for 12h rather
	3150	+ * than 24h.
	3151	+ *
	3152	+ * Capping is per-entry, so only nonce-bearing pages pay for it; the rest
	3153	+ * of the site keeps the configured lifetime.
	3154	+ *
	3155	+ * @param string $html Rendered response body.
	3156	+ * @param int $ttl Otherwise-resolved TTL in seconds.
	3157	+ * @return int TTL to actually use.
	3158	+ */
	3159	+ /**
	3160	+ * The nonce lifetime to cap against, in seconds.
	3161	+ *
	3162	+ * `nonce_life` is a TWO-argument filter in core:
	3163	+ *
	3164	+ * $nonce_life = apply_filters( 'nonce_life', DAY_IN_SECONDS, $action );
	3165	+ *
	3166	+ * Applying it with one argument is not merely incomplete — a callback
	3167	+ * that declares both parameters as required (the documented shape, and
	3168	+ * what a site branching per action must write) raises ArgumentCountError
	3169	+ * the moment we call it. That fatal lands in the shutdown cache write,
	3170	+ * so the visitor still sees a perfectly normal page while the sidecar is
	3171	+ * never written: the entry then keeps the FULL configured lifetime
	3172	+ * carrying a dead nonce, which is precisely the bug #236 set out to fix.
	3173	+ * Worse, the entry stays that way until a purge, even after the site
	3174	+ * removes whatever customised the lifetime.
	3175	+ *
	3176	+ * We are inspecting rendered markup, so we cannot know which action
	3177	+ * minted the nonce we found. Two consequences:
	3178	+ *
	3179	+ * 1. We pass `''` as the action. A per-action callback therefore sees
	3180	+ * the same "unknown action" value core itself passes when a nonce is
	3181	+ * created with no action, and can branch on it deliberately.
	3182	+ * 2. A page may carry nonces from SEVERAL actions with different
	3183	+ * lifetimes. The entry can only have one TTL, so the safe choice is
	3184	+ * the SHORTEST lifetime any action on the site resolves to — capping
	3185	+ * to a longer one would serve a dead nonce for the shorter action.
	3186	+ * Sites can narrow this with `xspeed_cache_nonce_life_actions`.
	3187	+ *
	3188	+ * @param string $html Response body being cached.
	3189	+ * @return int Nonce lifetime in seconds (0 = do not cap).
	3190	+ */
	3191	+ private static function nonce_life_seconds( string $html ): int {
	3192	+ /**
	3193	+ * Filter the nonce actions whose lifetimes are consulted when
	3194	+ * capping a cache entry.
	3195	+ *
	3196	+ * The default `''` is the "action unknown" case — we are reading
	3197	+ * rendered HTML, not minting a nonce. A site whose `nonce_life`
	3198	+ * callback shortens specific actions can list them here so the cap
	3199	+ * accounts for the shortest one that could appear on the page.
	3200	+ *
	3201	+ * @since 1.1.8
	3202	+ * @param string[] $actions Nonce actions to resolve.
	3203	+ * @param string $html The response body being cached.
	3204	+ */
	3205	+ $actions = (array) apply_filters( 'xspeed_cache_nonce_life_actions', array( '' ), $html );
	3206	+ if ( empty( $actions ) ) {
	3207	+ $actions = array( '' );
	3208	+ }
	3209	+
	3210	+ $shortest = 0;
	3211	+ foreach ( $actions as $action ) {
	3212	+ // Both arguments, exactly as core passes them.
	3213	+ $life = (int) apply_filters( 'nonce_life', DAY_IN_SECONDS, (string) $action );
	3214	+ if ( $life < 1 ) {
	3215	+ continue;
	3216	+ }
	3217	+ if ( 0 === $shortest || $life < $shortest ) {
	3218	+ $shortest = $life;
	3219	+ }
	3220	+ }
	3221	+
	3222	+ return $shortest;
	3223	+ }
	3224	+
	3225	+ public static function nonce_capped_ttl( string $html, int $ttl ): int {
	3226	+ if ( ! self::response_has_nonce( $html ) ) {
	3227	+ return $ttl;
	3228	+ }
	3229	+
	3230	+ $nonce_life = self::nonce_life_seconds( $html );
	3231	+ if ( $nonce_life < 1 ) {
	3232	+ return $ttl;
	3233	+ }
	3234	+
	3235	+ // Half of nonce_life is the GUARANTEED-valid remainder — see above.
	3236	+ $guaranteed = max( 1, intdiv( $nonce_life, 2 ) );
	3237	+ $capped = ( $ttl > 0 ) ? min( $ttl, $guaranteed ) : $guaranteed;
	3238	+
	3239	+ /**
	3240	+ * Filter the nonce-capped TTL for a cache entry.
	3241	+ *
	3242	+ * Escape hatch for a site whose nonce-shaped markup is decorative —
	3243	+ * return the uncapped $ttl to keep the configured lifetime. Most
	3244	+ * sites should leave this alone: serving a dead nonce breaks every
	3245	+ * anonymous form on the page.
	3246	+ *
	3247	+ * @param int $capped TTL after the nonce cap (seconds).
	3248	+ * @param int $ttl TTL before the cap (seconds).
	3249	+ * @param int $nonce_life Current nonce lifetime (seconds).
	3250	+ * @param string $html The response body being cached.
	3251	+ */
	3252	+ return (int) apply_filters( 'xspeed_cache_nonce_ttl_cap', $capped, $ttl, $nonce_life, $html );
	3253	+ }
	3254	+
	3255	+ private static function write_meta( string $key, string $html = '' ): void {
	3256	+ $content_type = '';
	3257	+ foreach ( headers_list() as $header ) {
	3258	+ if ( 0 === stripos( $header, 'content-type:' ) ) {
	3259	+ $content_type = trim( substr( $header, strlen( 'content-type:' ) ) );
	3260	+ }
	3261	+ }
	3262	+ $status = function_exists( 'http_response_code' ) ? (int) http_response_code() : 200;
	3263	+
	3264	+ $meta = array();
	3265	+ $is_default_type = ( '' === $content_type || false !== stripos( $content_type, 'text/html' ) );
	3266	+ if ( ! $is_default_type ) {
	3267	+ $meta['content_type'] = $content_type;
	3268	+ }
	3269	+ if ( 200 !== $status && $status > 0 ) {
	3270	+ $meta['status'] = $status;
	3271	+ }
	3272	+
	3273	+ // Per-content TTL (seconds). The drop-in and static fast paths can't
	3274	+ // call is_expired() / the xspeed_cache_max_age filter (they run before
	3275	+ // WP), so persist the resolved max-age here whenever it differs from
	3276	+ // the plain page TTL — e.g. the Pro feed cache's 12h vs the 24h page
	3277	+ // default. The fast paths read this to expire correctly. (FBS-82407)
	3278	+ // This MUST resolve the TTL the same way is_expired() does, including
	3279	+ // the per-post override — the sidecar is the only channel that can
	3280	+ // carry a per-entry TTL into the pre-boot fast paths. Omitting the
	3281	+ // override here left an editor's "expire this post after 1h" visible
	3282	+ // to the engine but invisible to the drop-in, which kept serving the
	3283	+ // entry until the global lifetime elapsed (#240 AC#3). Handing the
	3284	+ // filter the same base as is_expired() also keeps a filter that
	3285	+ // SCALES its input (e.g. $max_age * 2) consistent between the two.
	3286	+ $opts = Settings_Manager::get( 'cache' );
	3287	+ $default_ttl = (int) $opts['cache_expiry'] * HOUR_IN_SECONDS;
	3288	+ $max_age = $default_ttl;
	3289	+ $post_override = Cache_Rules::expiry_override_seconds_for_post( Cache_Rules::current_post_id() );
	3290	+ if ( null !== $post_override ) {
	3291	+ $max_age = $post_override;
	3292	+ }
	3293	+ /** This filter is documented in includes/class-cache.php */
	3294	+ $ttl = (int) apply_filters( 'xspeed_cache_max_age', $max_age );
	3295	+
	3296	+ // A response carrying a nonce may not outlive that nonce, however
	3297	+ // long the site's configured lifetime is (#236). This runs AFTER the
	3298	+ // max-age filter so it caps whatever the filter resolved rather than
	3299	+ // being overridden by it — a Pro module lengthening the TTL must not
	3300	+ // be able to reintroduce a dead nonce.
	3301	+ $ttl = self::nonce_capped_ttl( $html, $ttl );
	3302	+
	3303	+ if ( $ttl > 0 && $ttl !== $default_ttl ) {
	3304	+ $meta['ttl'] = $ttl;
	3305	+ }
	3306	+
	3307	+ // This entry's edge headers, when they differ from the site-wide set
	3308	+ // baked into the drop-in. The sidecar is the only channel that can
	3309	+ // carry a per-page answer into the pre-boot fast path, and the drop-in
	3310	+ // REPLACES the baked set with it rather than merging: the two describe
	3311	+ // the same response, so merging would leave the baked lifetime in
	3312	+ // place beside the hold meant to overrule it.
	3313	+ $edge = self::per_entry_edge_headers();
	3314	+ if ( array() !== $edge ) {
	3315	+ $meta['edge_headers'] = $edge;
	3316	+ }
	3317	+
	3318	+ // Nothing to replay → no sidecar.
	3319	+ if ( empty( $meta ) ) {
	3320	+ return;
	3321	+ }
	3322	+
	3323	+ $payload = wp_json_encode( $meta );
	3324	+ if ( false === $payload ) {
	3325	+ return;
	3326	+ }
	3327	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- our own cache dir; WP_Filesystem needs admin creds unavailable on a frontend shutdown write.
	3328	+ file_put_contents( self::cache_meta_for( $key ), $payload, LOCK_EX );
	3329	+ }
	3330	+
	3331	+ /**
382	3332	* @param string $cause Free-form human reason. Recorded in the
383	3333	* Activity log to give users context (e.g.
384	3334	* 'post saved', 'settings change', 'manual',
385	3335	* 'theme switch').
386	3336	*/
387		- public static function purge_all( string $cause = 'manual' ) {
	3337	+ /**
	3338	+ * Purge the cache entries for ONE URL — every variant of it: the
	3339	+ * flat-hash entry (+ .meta / .html.br siblings), both device buckets
	3340	+ * (mobile_separate keys them separately), both trailing-slash forms,
	3341	+ * and the static-tree index.html (+ .br) the server rewrite serves.
	3342	+ * The rest of the cache is untouched — this is the surgical
	3343	+ * alternative to purge_all for "I just edited this one page".
	3344	+ *
	3345	+ * @param string $url Absolute URL, or site-relative path ("/about/").
	3346	+ * @param string $cause Who asked, for the purge log. See purge_all().
	3347	+ * @return int Number of cache files removed.
	3348	+ */
	3349	+ /**
	3350	+ * Post types that are not "viewable" but ARE the presentation layer.
	3351	+ *
	3352	+ * `is_post_type_viewable()` answers "does this type have a front end of
	3353	+ * its own?" — which is the right question for `shop_order`, but the
	3354	+ * wrong one for the types core uses to render every OTHER page. A
	3355	+ * template part, a global-styles record, a navigation or a synced
	3356	+ * pattern has no permalink, yet editing one changes how the whole site
	3357	+ * looks. Gating purges on viewability alone meant a Site Editor save
	3358	+ * invalidated nothing and visitors kept the old design for the full
	3359	+ * TTL — up to 30 days at the maximum lifetime. (#270 regression)
	3360	+ *
	3361	+ * @return string[]
	3362	+ */
	3363	+ /**
	3364	+ * Could this post change alter anything an anonymous visitor had cached?
	3365	+ *
	3366	+ * Deleting one post fired a full purge for the post AND for every stored
	3367	+ * revision, because wp_delete_post() removes each revision through
	3368	+ * wp_delete_post() again and every one of those fires before_delete_post
	3369	+ * with post_type 'revision'. A post with six revisions cost seven whole-
	3370	+ * site sweeps, each one also announcing to LiteSpeed, purging the object
	3371	+ * cache network-wide on Redis, rewriting the stats option and running
	3372	+ * every xspeed_after_purge_all listener -- including Pro's Cloudflare
	3373	+ * purge, so seven API calls. Trashing cost two, via save_post and then
	3374	+ * trashed_post. (QA #348)
	3375	+ *
	3376	+ * The check lives here, ahead of purge_all(), so one early return covers
	3377	+ * the local sweep, the server-cache announcement and both action hooks.
	3378	+ * It deliberately does NOT live inside purge_all(): a manual, CLI or
	3379	+ * explicit caller asked for a purge and must get one.
	3380	+ *
	3381	+ * @param int $post_id Post being saved or removed.
	3382	+ * @param mixed $post Post object when the hook passed one.
	3383	+ * @param string $event 'save' or 'remove'.
	3384	+ */
	3385	+ private static function post_change_is_cacheable_content( $post_id, $post, string $event ): bool {
	3386	+ $post_id = (int) $post_id;
	3387	+
	3388	+ // Only `save_post` and `before_delete_post` hand over a post object.
	3389	+ // `trashed_post` passes ( $post_id, $previous_status ) -- a STRING --
	3390	+ // so reaching for ->post_status on the second argument finds nothing
	3391	+ // and the status rule below would never fire. Read the row instead.
	3392	+ if ( ! is_object( $post ) && function_exists( 'get_post' ) ) {
	3393	+ $post = get_post( $post_id );
	3394	+ }
	3395	+
	3396	+ $type = is_object( $post ) && isset( $post->post_type )
	3397	+ ? (string) $post->post_type
	3398	+ : (string) ( function_exists( 'get_post_type' ) ? get_post_type( $post_id ) : '' );
	3399	+ if ( '' === $type ) {
	3400	+ return false;
	3401	+ }
	3402	+
	3403	+ // A revision is a copy of content nobody can browse to.
	3404	+ if ( 'revision' === $type ) {
	3405	+ return false;
	3406	+ }
	3407	+ if ( function_exists( 'wp_is_post_revision' ) && wp_is_post_revision( $post_id ) ) {
	3408	+ return false;
	3409	+ }
	3410	+ if ( function_exists( 'wp_is_post_autosave' ) && wp_is_post_autosave( $post_id ) ) {
	3411	+ return false;
	3412	+ }
	3413	+
	3414	+ $status = is_object( $post ) && isset( $post->post_status ) ? (string) $post->post_status : '';
	3415	+
	3416	+ // Clicking "Add New" inserts an auto-draft and fires save_post. There
	3417	+ // is nothing cached of a post that has never existed publicly.
	3418	+ if ( 'auto-draft' === $status ) {
	3419	+ return false;
	3420	+ }
	3421	+
	3422	+ // Unknown/!viewable → nothing anonymous can see changed, UNLESS the
	3423	+ // type is itself part of how pages render (#270 regression).
	3424	+ if ( function_exists( 'is_post_type_viewable' )
	3425	+ && ! is_post_type_viewable( $type )
	3426	+ && ! in_array( $type, self::presentation_post_types(), true )
	3427	+ ) {
	3428	+ return false;
	3429	+ }
	3430	+
	3431	+ // Deleting something that was already invisible changes no cached
	3432	+ // page: the transition that hid it purged at the time. This is what
	3433	+ // makes emptying a trash of a hundred posts cost nothing rather than
	3434	+ // a hundred full sweeps.
	3435	+ //
	3436	+ // It also collapses trashing to a single purge: wp_trash_post() fires
	3437	+ // save_post first, where the post is genuinely disappearing from
	3438	+ // listings and SHOULD purge, then trashed_post, by which point the
	3439	+ // row reads 'trash' and is skipped. A status we cannot read, on a row
	3440	+ // that still reports a type, means assume viewable -- erring toward
	3441	+ // an extra purge, never toward serving a stale page. A row that is
	3442	+ // gone entirely reports no type either and was refused above.
	3443	+ // 'inherit' is an INTERNAL status in core, so is_post_status_viewable()
	3444	+ // says no -- but an attachment carrying it is genuinely public. Judge
	3445	+ // those on the post type alone, which is already checked above.
	3446	+ if ( 'remove' === $event && '' !== $status && 'inherit' !== $status
	3447	+ && function_exists( 'is_post_status_viewable' )
	3448	+ && ! is_post_status_viewable( $status )
	3449	+ ) {
	3450	+ return false;
	3451	+ }
	3452	+
	3453	+ return true;
	3454	+ }
	3455	+
	3456	+ public static function presentation_post_types(): array {
	3457	+ $types = array(
	3458	+ 'wp_template', // Site Editor templates.
	3459	+ 'wp_template_part', // Header / footer / reusable parts.
	3460	+ 'wp_global_styles', // Colours, typography, spacing.
	3461	+ 'wp_navigation', // Navigation block menus.
	3462	+ 'nav_menu_item', // Classic menus.
	3463	+ 'wp_block', // Synced patterns / reusable blocks.
	3464	+ );
	3465	+
	3466	+ /**
	3467	+ * Filter the non-viewable post types that still invalidate the cache.
	3468	+ *
	3469	+ * Add a type here when it has no front end of its own but changes
	3470	+ * how other pages render (a theme's own layout CPT, for example).
	3471	+ *
	3472	+ * @param string[] $types Post type slugs.
	3473	+ */
	3474	+ return (array) apply_filters( 'xspeed_presentation_post_types', $types );
	3475	+ }
	3476	+
	3477	+ /**
	3478	+ * Describe a broad hook invalidation for response-cache adapters.
	3479	+ *
	3480	+ * Term, menu, theme and plugin changes can alter navigation, archives or
	3481	+ * markup across the site, so they require a site response-cache purge.
	3482	+ * Content saves also require this scope while their local operation is a
	3483	+ * complete bucket sweep.
	3484	+ *
	3485	+ * A new term is `content`, not `presentation`. It has no posts yet, so no
	3486	+ * page renders it until a post is saved with it, and that save is its own
	3487	+ * content purge. Classed as presentation, it cleared the host's whole
	3488	+ * nginx cache every time a post was published with a tag that did not
	3489	+ * exist yet, which is most publishing. Renaming or deleting a term stays
	3490	+ * presentation: the new name shows on every post in the term, and Nginx
	3491	+ * Helper purges only the homepage for either. (QA #448)
	3492	+ *
	3493	+ * @return array{scope:string,intent:string,urls:array<int,string>}
	3494	+ */
	3495	+ private static function invalidation_for_hook( string $hook ): array {
	3496	+ $presentation = array(
	3497	+ 'switch_theme',
	3498	+ 'activated_plugin',
	3499	+ 'deactivated_plugin',
	3500	+ 'edited_term',
	3501	+ 'delete_term',
	3502	+ 'wp_update_nav_menu',
	3503	+ );
	3504	+
	3505	+ return array(
	3506	+ 'scope' => 'site',
	3507	+ 'intent' => in_array( $hook, $presentation, true ) ? 'presentation' : 'content',
	3508	+ 'urls' => array(),
	3509	+ );
	3510	+ }
	3511	+
	3512	+
	3513	+ /**
	3514	+ * save_post → purge only when the saved thing can appear on a cached page.
	3515	+ *
	3516	+ * Revisions and autosaves are never rendered. Non-viewable post types —
	3517	+ * WooCommerce's `shop_order` / `shop_order_placehold` / `shop_order_refund`
	3518	+ * / `shop_coupon`, Flamingo's `flamingo_inbound` (#229), Tutor's
	3519	+ * `tutor_enrolled` (#231) — are invisible to anonymous visitors, so
	3520	+ * writing one changes nothing that is cached. (#243)
	3521	+ *
	3522	+ * The exception is the presentation types above, which are non-viewable
	3523	+ * yet render every page — they are allow-listed BEFORE the viewability
	3524	+ * test. (#270 regression)
	3525	+ *
	3526	+ * @param int $post_id Saved post ID.
	3527	+ * @param \WP_Post $post Saved post object.
	3528	+ */
	3529	+ public static function on_save_post( $post_id, $post = null ): void {
	3530	+ if ( ! self::post_change_is_cacheable_content( $post_id, $post, 'save' ) ) {
	3531	+ return;
	3532	+ }
	3533	+
	3534	+ $post_type = is_object( $post ) && isset( $post->post_type )
	3535	+ ? (string) $post->post_type
	3536	+ : (string) get_post_type( $post_id );
	3537	+
	3538	+ // Name the trigger rather than logging a bare numeric id — the old
	3539	+ // wiring passed the post ID into $cause, so the log read
	3540	+ // "Cache purged (46)" with no indication of what caused it. (#243)
	3541	+ $presentation = in_array( $post_type, self::presentation_post_types(), true );
	3542	+ self::purge_all(
	3543	+ 'post:' . $post_type,
	3544	+ null,
	3545	+ array(
	3546	+ // purge_all() sweeps every local response in this site's bucket.
	3547	+ // Without dependency tracking, the server cache must match that
	3548	+ // same boundary or unrelated pages can remain stale there.
	3549	+ 'scope' => 'site',
	3550	+ 'intent' => $presentation ? 'presentation' : 'content',
	3551	+ 'urls' => array(),
	3552	+ )
	3553	+ );
	3554	+ if ( class_exists( '\XSpeed\Minifier' ) ) {
	3555	+ Minifier::purge_minified();
	3556	+ }
	3557	+ }
	3558	+
	3559	+ /**
	3560	+ * Delete/trash invalidation while the post type is still available.
	3561	+ * The local and server response-cache sweeps share the same site boundary.
	3562	+ *
	3563	+ * @param int $post_id Removed post ID.
	3564	+ * @param object|null $post Post object supplied by core when available.
	3565	+ */
	3566	+ public static function on_post_removed( $post_id, $post = null ): void {
	3567	+ if ( ! self::post_change_is_cacheable_content( $post_id, $post, 'remove' ) ) {
	3568	+ return;
	3569	+ }
	3570	+
	3571	+ $post_type = is_object( $post ) && isset( $post->post_type )
	3572	+ ? (string) $post->post_type
	3573	+ : (string) get_post_type( $post_id );
	3574	+
	3575	+ self::purge_all(
	3576	+ 'post-removed:' . $post_type,
	3577	+ null,
	3578	+ array(
	3579	+ 'scope' => 'site',
	3580	+ // Match on_save_post: a presentation type changes how pages
	3581	+ // render rather than what they say.
	3582	+ 'intent' => in_array( $post_type, self::presentation_post_types(), true )
	3583	+ ? 'presentation'
	3584	+ : 'content',
	3585	+ 'urls' => array(),
	3586	+ )
	3587	+ );
	3588	+ }
	3589	+
	3590	+ /** Purge site responses when moderation changes visible comments. */
	3591	+ public static function on_comment_status( $comment_id, $status = '' ): void {
	3592	+ $comment = function_exists( 'get_comment' ) ? get_comment( (int) $comment_id ) : null;
	3593	+ $post_id = is_object( $comment ) && isset( $comment->comment_post_ID ) ? (int) $comment->comment_post_ID : 0;
	3594	+ if ( $post_id < 1 || ! function_exists( 'get_permalink' ) ) {
	3595	+ return;
	3596	+ }
	3597	+ $url = get_permalink( $post_id );
	3598	+ if ( ! is_string( $url ) || '' === $url ) {
	3599	+ return;
	3600	+ }
	3601	+ self::purge_all(
	3602	+ 'comment-status:' . (string) $status,
	3603	+ null,
	3604	+ array(
	3605	+ 'scope' => 'site',
	3606	+ 'intent' => 'content',
	3607	+ 'urls' => array(),
	3608	+ )
	3609	+ );
	3610	+ }
	3611	+
	3612	+ /**
	3613	+ * comment_post → purge just the commented-on URL, and only once the
	3614	+ * comment is actually visible.
	3615	+ *
	3616	+ * A comment held for moderation changes nothing on the front end, and an
	3617	+ * approved one changes exactly one page — not the whole site. Product
	3618	+ * reviews are comments and guest reviews are on by default, so under the
	3619	+ * old wiring any visitor could flush a store's entire cache, repeatedly,
	3620	+ * with no account. (#243)
	3621	+ *
	3622	+ * @param int $comment_id New comment ID.
	3623	+ * @param int|string $approved 1 when approved, 0 when held, 'spam'.
	3624	+ * @param array $data Comment data.
	3625	+ */
	3626	+ public static function on_comment_post( $comment_id, $approved = 0, $data = array() ): void {
	3627	+ if ( 1 !== (int) $approved ) {
	3628	+ return;
	3629	+ }
	3630	+ $post_id = is_array( $data ) && isset( $data['comment_post_ID'] ) ? (int) $data['comment_post_ID'] : 0;
	3631	+ if ( $post_id < 1 ) {
	3632	+ return;
	3633	+ }
	3634	+ $url = get_permalink( $post_id );
	3635	+ if ( is_string( $url ) && '' !== $url ) {
	3636	+ self::purge_url( $url, 'comment' );
	3637	+ }
	3638	+ }
	3639	+
	3640	+ /**
	3641	+ * user_register / profile_update → purge only when the user can author
	3642	+ * content that appears on the front end.
	3643	+ *
	3644	+ * A customer registering at checkout changes no rendered page, and cannot
	3645	+ * change an enqueued asset — so it must not purge the cache, and must not
	3646	+ * rebuild the minified bundles. Checkout account-creation fired FOUR
	3647	+ * full-site purges plus four purge_minified() runs in a single request
	3648	+ * before this gate. (#243)
	3649	+ *
	3650	+ * @param int $user_id Affected user.
	3651	+ */
	3652	+ public static function on_user_change( $user_id ): void {
	3653	+ $user = function_exists( 'get_userdata' ) ? get_userdata( (int) $user_id ) : null;
	3654	+ if ( ! $user ) {
	3655	+ return;
	3656	+ }
	3657	+
	3658	+ // Only roles that can publish can change a rendered page. WooCommerce
	3659	+ // customers and WordPress subscribers cannot.
	3660	+ if ( ! user_can( $user, 'edit_posts' ) ) {
	3661	+ return;
	3662	+ }
	3663	+
	3664	+ $url = get_author_posts_url( (int) $user_id );
	3665	+ if ( is_string( $url ) && '' !== $url ) {
	3666	+ self::purge_url( $url, 'user' );
	3667	+ }
	3668	+ }
	3669	+
	3670	+ /**
	3671	+ * Purge everything a product's price / stock / sale state is rendered on.
	3672	+ *
	3673	+ * The product permalink is not enough: the shop archive and the product's
	3674	+ * category and tag archives render the same price and Sale! badge, and
	3675	+ * #242 reproduces all three going stale together.
	3676	+ *
	3677	+ * Accepts a product ID or a WC_Product. A variation resolves to its
	3678	+ * parent, which is the page that actually renders.
	3679	+ *
	3680	+ * @param int|object $product Product ID or WC_Product.
	3681	+ */
	3682	+ public static function purge_product( $product ): void {
	3683	+ $product_id = is_object( $product ) && method_exists( $product, 'get_id' )
	3684	+ ? (int) $product->get_id()
	3685	+ : (int) $product;
	3686	+ if ( $product_id < 1 ) {
	3687	+ return;
	3688	+ }
	3689	+
	3690	+ // Variations are never rendered on their own URL.
	3691	+ $parent = (int) wp_get_post_parent_id( $product_id );
	3692	+ if ( $parent > 0 ) {
	3693	+ $product_id = $parent;
	3694	+ }
	3695	+
	3696	+ $urls = array();
	3697	+
	3698	+ $permalink = get_permalink( $product_id );
	3699	+ if ( is_string( $permalink ) && '' !== $permalink ) {
	3700	+ $urls[] = $permalink;
	3701	+ }
	3702	+
	3703	+ // The shop archive.
	3704	+ if ( function_exists( 'wc_get_page_id' ) ) {
	3705	+ $shop_id = (int) wc_get_page_id( 'shop' );
	3706	+ if ( $shop_id > 0 ) {
	3707	+ $shop_url = get_permalink( $shop_id );
	3708	+ if ( is_string( $shop_url ) && '' !== $shop_url ) {
	3709	+ $urls[] = $shop_url;
	3710	+ }
	3711	+ }
	3712	+ }
	3713	+
	3714	+ // Every category / tag archive this product appears on.
	3715	+ foreach ( array( 'product_cat', 'product_tag' ) as $taxonomy ) {
	3716	+ $terms = get_the_terms( $product_id, $taxonomy );
	3717	+ if ( ! is_array( $terms ) ) {
	3718	+ continue;
	3719	+ }
	3720	+ foreach ( $terms as $term ) {
	3721	+ $term_url = get_term_link( $term );
	3722	+ if ( is_string( $term_url ) && '' !== $term_url ) {
	3723	+ $urls[] = $term_url;
	3724	+ }
	3725	+ }
	3726	+ }
	3727	+
	3728	+ // The front page, when it is not the shop page but still lists
	3729	+ // products (a block/shortcode storefront).
	3730	+ $front_id = (int) get_option( 'page_on_front' );
	3731	+ if ( $front_id > 0 ) {
	3732	+ $front_url = get_permalink( $front_id );
	3733	+ if ( is_string( $front_url ) && '' !== $front_url ) {
	3734	+ $urls[] = $front_url;
	3735	+ }
	3736	+ }
	3737	+
	3738	+ /**
	3739	+ * Filter the URLs purged when a product changes.
	3740	+ *
	3741	+ * A storefront that renders products somewhere else — a landing page,
	3742	+ * a custom archive — can add its URLs here rather than falling back
	3743	+ * to purging the whole site.
	3744	+ *
	3745	+ * @param string[] $urls URLs about to be purged.
	3746	+ * @param int $product_id The product that changed.
	3747	+ */
	3748	+ $urls = (array) apply_filters( 'xspeed_purge_product_urls', $urls, $product_id );
	3749	+
	3750	+ foreach ( array_unique( array_filter( $urls ) ) as $url ) {
	3751	+ self::purge_url( (string) $url, 'product' );
	3752	+ }
	3753	+ }
	3754	+
	3755	+ /**
	3756	+ * Adapter for the WooCommerce stock actions that pass a product OBJECT
	3757	+ * where the status actions pass an ID.
	3758	+ *
	3759	+ * @param object $product WC_Product (or variation).
	3760	+ */
	3761	+ public static function purge_product_object( $product ): void {
	3762	+ self::purge_product( $product );
	3763	+ }
	3764	+
	3765	+ /**
	3766	+ * Re-entry guard for the purge-event contract.
	3767	+ *
	3768	+ * A listener on `xspeed_after_purge_url` legitimately purges its own
	3769	+ * layer, and a server-cache or CDN adapter that calls back into xSpeed
	3770	+ * while doing so re-enters this method — unbounded, because each pass
	3771	+ * looks like a fresh purge.
	3772	+ *
	3773	+ * A single global flag stops too much: a nested purge of a DIFFERENT URL is
	3774	+ * a real purge whose listeners must hear about it. But a per-request
	3775	+ * "already published" set stops too much in the other direction — a
	3776	+ * network purge loops every blog in one request, and on a subdirectory
	3777	+ * network they share a host, so blogs 2..N would be silently skipped. It
	3778	+ * also grows for the life of the process.
	3779	+ *
	3780	+ * So the guard tracks what is IN FLIGHT, not what has been published: a
	3781	+ * target is marked while its own dispatch is on the stack and unmarked
	3782	+ * when it returns. Re-entering the same target recurses, so it is refused;
	3783	+ * purging the same URL again later is a new event and publishes. The set
	3784	+ * is bounded by call depth rather than by how many URLs a request touches.
	3785	+ *
	3786	+ * @var array<string,bool>
	3787	+ */
	3788	+ private static $purge_events_in_flight = array();
	3789	+
	3790	+ /** Monotonic count used to detect whether a delegated purge published. */
	3791	+ private static $purge_event_sequence = 0;
	3792	+
	3793	+ /**
	3794	+ * Publish a purge event exactly once, with bounded arguments.
	3795	+ *
	3796	+ * Deliberately carries only what an integration needs to invalidate its
	3797	+ * own copy: the canonical URL (or null for a full purge), the site host,
	3798	+ * the cause label, and how many files went. No filesystem paths, no cache
	3799	+ * contents, no request headers, no user data. The URL query and caller-
	3800	+ * supplied cause may nevertheless contain sensitive text, so listeners
	3801	+ * must redact them in logs or unrelated destinations that do not need the
	3802	+ * exact cache key.
	3803	+ *
	3804	+ * A listener that throws must not take the purge down with it: the files
	3805	+ * are already gone by the time we get here, and an integration's bad day
	3806	+ * is not a reason to report a failed purge to the caller.
	3807	+ *
	3808	+ * @param string $hook Hook name to emit.
	3809	+ * @param array<string,mixed> $context Bounded context, see above.
	3810	+ */
	3811	+ private static function dispatch_purge_event( string $hook, array $context ): void {
	3812	+ if ( ! function_exists( 'do_action' ) ) {
	3813	+ return;
	3814	+ }
	3815	+ $target = $hook . '|' . ( isset( $context['url'] ) ? (string) $context['url'] : '' )
	3816	+ . '|' . ( isset( $context['host'] ) ? (string) $context['host'] : '' );
	3817	+ if ( isset( self::$purge_events_in_flight[ $target ] ) ) {
	3818	+ return;
	3819	+ }
	3820	+ self::$purge_events_in_flight[ $target ] = true;
	3821	+ ++self::$purge_event_sequence;
	3822	+
	3823	+ // Our own integrations get their own try. Sharing one with the public
	3824	+ // action below meant a listener on the extension seam could throw and
	3825	+ // take the contract event down with it — the mirror of the failure
	3826	+ // this separation exists to prevent.
	3827	+ try {
	3828	+ // Built-in server-cache integrations run FIRST, and by a direct
	3829	+ // call rather than as listeners on the action below.
	3830	+ //
	3831	+ // WordPress stops dispatching an action's remaining callbacks when
	3832	+ // one of them throws. As a listener, our LiteSpeed forwarding
	3833	+ // would then be skipped by any unrelated third-party callback that
	3834	+ // happened to be registered earlier and blew up — and the visible
	3835	+ // result is the worst kind: xSpeed reports a successful purge while
	3836	+ // the server keeps serving stale HTML. Shipped behaviour must not
	3837	+ // be hostage to a listener's bug.
	3838	+ self::forward_to_server_caches( $context );
	3839	+ } catch ( \Throwable $e ) {
	3840	+ self::log_purge_listener_error( $hook, $e );
	3841	+ }
	3842	+
	3843	+ try {
	3844	+ self::do_action_isolated( $hook, $context );
	3845	+ } catch ( \Throwable $e ) { // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedCatch
	3846	+ // Swallow: see docblock. The purge succeeded regardless.
	3847	+ self::log_purge_listener_error( $hook, $e );
	3848	+ } finally {
	3849	+ unset( self::$purge_events_in_flight[ $target ] );
	3850	+ }
	3851	+ }
	3852	+
	3853	+ /**
	3854	+ * Run every listener on a purge hook, isolating each from the others.
	3855	+ *
	3856	+ * `do_action()` dispatches callbacks in one loop, so the first one to
	3857	+ * throw takes every LATER listener down with it. On a purge that meant a
	3858	+ * failing CDN integration silently cancelled the ones queued behind it —
	3859	+ * and because the throw was swallowed to keep the purge itself succeeding,
	3860	+ * the user was told the clear worked while two edges were never touched.
	3861	+ * Invisible unless WP_DEBUG happened to be on. (QA #348)
	3862	+ *
	3863	+ * Each callback gets its own try/catch here, so one integration's bad day
	3864	+ * costs only that integration. Priority order is preserved. Falls back to
	3865	+ * a plain `do_action()` when the filter registry is not the shape we
	3866	+ * expect, so an unusual environment degrades to the old behaviour rather
	3867	+ * than skipping listeners entirely.
	3868	+ *
	3869	+ * @param string $hook Hook name to emit.
	3870	+ * @param mixed $arg Single argument passed to each listener.
	3871	+ */
	3872	+ public static function do_action_isolated( string $hook, $arg ): void {
	3873	+ global $wp_filter;
	3874	+
	3875	+ // Walking $wp_filter by hand and calling each callback directly was the
	3876	+ // obvious way to do this, and it was wrong: it bypasses WordPress, so
	3877	+ // `current_filter()` came back empty, `did_action()` stayed at 0, the
	3878	+ // `all` hook never fired, and Query Monitor and Debug Bar could not see
	3879	+ // the very contract this class publishes. A shared handler branching on
	3880	+ // current_filter() picked the wrong branch. (QA #348 round 2, issue 3)
	3881	+ //
	3882	+ // So let do_action() dispatch — WordPress keeps its bookkeeping — and
	3883	+ // isolate one level down instead: each registered callback is swapped
	3884	+ // for a wrapper that runs it inside a try/catch. One listener throwing
	3885	+ // then costs only that listener, which is the whole point, without
	3886	+ // costing the hook its identity.
	3887	+ if ( ! isset( $wp_filter[ $hook ] ) || ! ( $wp_filter[ $hook ] instanceof \WP_Hook ) ) {
	3888	+ do_action( $hook, $arg );
	3889	+ return;
	3890	+ }
	3891	+
	3892	+ $hook_object = $wp_filter[ $hook ];
	3893	+ $original = $hook_object->callbacks;
	3894	+ if ( ! is_array( $original ) || array() === $original ) {
	3895	+ do_action( $hook, $arg );
	3896	+ return;
	3897	+ }
	3898	+
	3899	+ $wrapped = array();
	3900	+ $restorations = array();
	3901	+ foreach ( $original as $priority => $group ) {
	3902	+ if ( ! is_array( $group ) ) {
	3903	+ $wrapped[ $priority ] = $group;
	3904	+ continue;
	3905	+ }
	3906	+ foreach ( $group as $id => $registered ) {
	3907	+ if ( ! isset( $registered['function'] ) || ! is_callable( $registered['function'] ) ) {
	3908	+ $wrapped[ $priority ][ $id ] = $registered;
	3909	+ continue;
	3910	+ }
	3911	+ $callback = $registered['function'];
	3912	+ $wrapper = static function ( ...$args ) use ( $callback, $hook ) {
	3913	+ try {
	3914	+ return $callback( ...$args );
	3915	+ } catch ( \Throwable $e ) {
	3916	+ self::log_purge_listener_error( $hook, $e );
	3917	+ return null;
	3918	+ }
	3919	+ };
	3920	+ $wrapped[ $priority ][ $id ] = array(
	3921	+ // Keep accepted_args: a listener registered for 0 or 1
	3922	+ // arguments must still be called the way it asked.
	3923	+ 'accepted_args' => $registered['accepted_args'] ?? 1,
	3924	+ 'function' => $wrapper,
	3925	+ );
	3926	+ $restorations[ $priority ][ $id ] = array(
	3927	+ 'original' => $registered,
	3928	+ 'wrapper' => $wrapper,
	3929	+ );
	3930	+ }
	3931	+ }
	3932	+
	3933	+ $hook_object->callbacks = $wrapped;
	3934	+ try {
	3935	+ do_action( $hook, $arg );
	3936	+ } finally {
	3937	+ // Restore only wrappers still present. Native add/remove operations
	3938	+ // performed by listeners must survive this temporary substitution.
	3939	+ foreach ( $restorations as $priority => $group ) {
	3940	+ foreach ( $group as $id => $restore ) {
	3941	+ $current = $hook_object->callbacks[ $priority ][ $id ]['function'] ?? null;
	3942	+ if ( $current === $restore['wrapper'] ) {
	3943	+ $hook_object->callbacks[ $priority ][ $id ] = $restore['original'];
	3944	+ }
	3945	+ }
	3946	+ }
	3947	+ }
	3948	+ }
	3949	+
	3950	+ /**
	3951	+ * Name a listener that threw, under WP_DEBUG only.
	3952	+ *
	3953	+ * Gated like the rest of Free's diagnostics: a third-party listener
	3954	+ * throwing on every purge must not fill a production log.
	3955	+ */
	3956	+ private static function log_purge_listener_error( string $hook, \Throwable $e ): void {
	3957	+ // An \Error — a TypeError from one of OUR listeners, say — is a bug
	3958	+ // rather than a runtime condition a third party imposed on us, and
	3959	+ // swallowing it silently in production turns it into a purge that
	3960	+ // quietly stops working. Those are logged whatever WP_DEBUG says;
	3961	+ // third-party \Exceptions stay gated so a noisy integration cannot
	3962	+ // fill a production log.
	3963	+ $always = $e instanceof \Error;
	3964	+ if ( ( $always || ( defined( 'WP_DEBUG' ) && WP_DEBUG ) ) && function_exists( 'error_log' ) ) {
	3965	+ // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log -- names a third-party listener that threw during a purge.
	3966	+ error_log( '[xspeed] a ' . $hook . ' listener threw: ' . $e->getMessage() );
	3967	+ }
	3968	+ }
	3969	+
	3970	+ /** Test seam: clear the in-flight set left behind by an aborted dispatch. */
	3971	+ public static function reset_purge_events(): void {
	3972	+ self::$purge_events_in_flight = array();
	3973	+ self::$purge_event_sequence = 0;
	3974	+ }
	3975	+
	3976	+ /**
	3977	+ * Hand the purge to the caches we ship integrations for.
	3978	+ *
	3979	+ * Isolated from the public action on purpose — see dispatch_purge_event().
	3980	+ * Guarded so a missing class (a partial upgrade, a stripped build) cannot
	3981	+ * turn a working purge into a fatal.
	3982	+ *
	3983	+ * @param array<string,mixed> $context Bounded purge context.
	3984	+ */
	3985	+ private static function forward_to_server_caches( array $context ): void {
	3986	+ if ( class_exists( __NAMESPACE__ . '\\Server_Caches' ) ) {
	3987	+ Server_Caches::forward( $context );
	3988	+ }
	3989	+ }
	3990	+
	3991	+ /**
	3992	+ * `host[:port]` for a cache key, from a parsed URL.
	3993	+ *
	3994	+ * The port is kept, because `cache_key()` hashes the raw `HTTP_HOST` and
	3995	+ * that carries `:8080` on any install not served from 80/443 — dropping it
	3996	+ * computed a different md5, found no file, and reported "already cold"
	3997	+ * while the page kept serving HIT.
	3998	+ *
	3999	+ * A port that is the DEFAULT for the scheme is dropped, though, because
	4000	+ * `HTTP_HOST` does not carry one: a browser sends `Host: site.com` for
	4001	+ * `https://site.com:443/`. Keeping it hashed `site.com:443` against a file
	4002	+ * stored under `site.com` — the same silent no-op in the other direction,
	4003	+ * and the one QA hit passing a canonical URL with the port spelled out.
	4004	+ * (QA #348)
	4005	+ *
	4006	+ * @param array<string,mixed> $parts Output of wp_parse_url().
	4007	+ */
	4008	+ private static function host_port_of( array $parts ): string {
	4009	+ if ( ! isset( $parts['host'] ) ) {
	4010	+ return '';
	4011	+ }
	4012	+ $host = strtolower( (string) $parts['host'] );
	4013	+ if ( '' === $host || ! isset( $parts['port'] ) ) {
	4014	+ return $host;
	4015	+ }
	4016	+ $port = (int) $parts['port'];
	4017	+ $scheme = isset( $parts['scheme'] ) ? strtolower( (string) $parts['scheme'] ) : '';
	4018	+ if ( ( 'https' === $scheme && 443 === $port ) || ( 'http' === $scheme && 80 === $port ) ) {
	4019	+ return $host;
	4020	+ }
	4021	+ return $host . ':' . $port;
	4022	+ }
	4023	+
	4024	+ public static function purge_url( string $url, string $cause = 'manual' ): int {
	4025	+ // A URL that names nothing is not a purge of everything. An empty or
	4026	+ // blank string used to fall through to the home_url() default below
	4027	+ // and clear the HOMEPAGE — so a third party calling
	4028	+ // `purge_url( get_permalink( $id ) )` on a post whose permalink came
	4029	+ // back empty silently purged the front page instead of nothing. The
	4030	+ // CLI and the MCP tool reject empties before reaching this, so only
	4031	+ // direct API callers were exposed, but they are exactly the audience
	4032	+ // this public contract is for. (QA #348)
	4033	+ if ( '' === trim( $url ) ) {
	4034	+ return 0;
	4035	+ }
	4036	+ $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.
	4037	+ if ( ! is_array( $parts ) ) {
	4038	+ return 0;
	4039	+ }
	4040	+ // Absolute URLs are accepted only for HTTP response caches. Schemes such
	4041	+ // as ftp:, file: and javascript: can parse cleanly but do not name a page
	4042	+ // xSpeed or a server response cache can invalidate. A leading-slash path
	4043	+ // remains a supported site-relative target.
	4044	+ if ( isset( $parts['scheme'] ) && ! in_array( strtolower( (string) $parts['scheme'] ), array( 'http', 'https' ), true ) ) {
	4045	+ return 0;
	4046	+ }
	4047	+ if ( isset( $parts['scheme'] ) && empty( $parts['host'] ) ) {
	4048	+ return 0;
	4049	+ }
	4050	+ // Reject a string that parsed but is not a URL we can act on: no
	4051	+ // scheme AND no host AND no leading-slash path means something like
	4052	+ // `ht!tp://[[[` or a bare word, which parse_url() hands back as a
	4053	+ // relative "path". Forwarding that produced `purge_url(/ht!tp://[[[)`
	4054	+ // — a nonsense tag sent to LiteSpeed for every malformed call.
	4055	+ if ( ! isset( $parts['scheme'] ) && ! isset( $parts['host'] ) ) {
	4056	+ $raw = isset( $parts['path'] ) ? (string) $parts['path'] : '';
	4057	+ if ( '' === $raw || '/' !== $raw[0] ) {
	4058	+ return 0;
	4059	+ }
	4060	+ }
	4061	+ // Keep the port. `cache_key()` hashes the raw `HTTP_HOST`, which
	4062	+ // carries `:8080` on any install not served from 80/443 — while
	4063	+ // parse_url() splits the port into its own component, so a purge that
	4064	+ // used the bare host computed a different md5, found no file, and
	4065	+ // reported "already cold". A silent no-op: the page kept serving HIT
	4066	+ // until its TTL ran out. Intranet installs, panel hosts on :8443 and
	4067	+ // proxies that forward `Host: site.com:8080` all hit this.
	4068	+ // A scheme-less `site.test:443/page/` is a supported explicit-host
	4069	+ // target. Infer a scheme only when it names THIS site's hostname: then
	4070	+ // its explicit default port is the same origin and the same local cache
	4071	+ // key. Never apply this to another host or to a non-default port.
	4072	+ if ( ! isset( $parts['scheme'] ) && isset( $parts['host'], $parts['port'] ) && function_exists( 'home_url' ) ) {
	4073	+ $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.
	4074	+ if ( is_array( $home ) && ! empty( $home['host'] ) && ! empty( $home['scheme'] )
	4075	+ && strtolower( (string) $home['host'] ) === strtolower( (string) $parts['host'] )
	4076	+ ) {
	4077	+ $home_scheme = strtolower( (string) $home['scheme'] );
	4078	+ $port = (int) $parts['port'];
	4079	+ $home_port = isset( $home['port'] )
	4080	+ ? (int) $home['port']
	4081	+ : ( 'https' === $home_scheme ? 443 : ( 'http' === $home_scheme ? 80 : 0 ) );
	4082	+ if ( $home_port === $port
	4083	+ && ( ( 'https' === $home_scheme && 443 === $port ) || ( 'http' === $home_scheme && 80 === $port ) )
	4084	+ ) {
	4085	+ $parts['scheme'] = $home_scheme;
	4086	+ }
	4087	+ }
	4088	+ }
	4089	+ $host = self::host_port_of( $parts );
	4090	+ if ( '' === $host && function_exists( 'home_url' ) ) {
	4091	+ $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.
	4092	+ if ( is_array( $home ) ) {
	4093	+ $host = self::host_port_of( $home );
	4094	+ }
	4095	+ }
	4096	+ if ( '' === $host ) {
	4097	+ return 0;
	4098	+ }
	4099	+ $path = isset( $parts['path'] ) ? (string) $parts['path'] : '/';
	4100	+ $path = '/' . ltrim( $path, '/' );
	4101	+ if ( false !== strpos( $path, '..' ) ) {
	4102	+ return 0;
	4103	+ }
	4104	+
	4105	+ // The cache key preserves REQUEST_URI's trailing-slash form, so
	4106	+ // purge both. Root stays a single '/'.
	4107	+ $forms = array( $path );
	4108	+ if ( '/' !== $path ) {
	4109	+ $forms[] = rtrim( $path, '/' );
	4110	+ $forms[] = rtrim( $path, '/' ) . '/';
	4111	+ }
	4112	+ $forms = array_unique( $forms );
	4113	+
	4114	+ /*
	4115	+ * Entries live under the bucket they were written for, and this URL's
	4116	+ * site may not be the one serving THIS request (a cross-site purge on
	4117	+ * multisite, WP-CLI, or cron). Build the directory from the URL's own
	4118	+ * host AND path. (#6)
	4119	+ *
	4120	+ * Host alone is wrong on a subdirectory network: `store()` wrote to
	4121	+ * `<host>/<prefix>/`, so looking in `<host>/` found nothing and the
	4122	+ * call reported "already cold" while the page kept serving HIT — a
	4123	+ * false success, which is worse than an error. The prefix has to come
	4124	+ * from the URL being purged rather than from the current blog, because
	4125	+ * the caller is usually purging some OTHER site. (QA B2 on #166)
	4126	+ */
	4127	+ $base = XSPEED_CACHE_DIR . '/' . self::bucket_for_url( $host, $path );
	4128	+
388	4129	$count = 0;
	4130	+ foreach ( $forms as $uri ) {
	4131	+ // '' = mobile_separate off; '|m' / '|d' = the device buckets.
	4132	+ foreach ( array( '', '|m', '|d' ) as $device ) {
	4133	+ $key = md5( $host . $uri . $device );
	4134	+ $file = $base . '/' . $key . '.html';
	4135	+ if ( is_file( $file ) ) {
	4136	+ wp_delete_file( $file );
	4137	+ ++$count;
	4138	+ }
	4139	+ foreach ( array( $base . '/' . $key . '.meta', $file . '.br', self::brotli_size_sidecar( $file . '.br' ) ) as $sidecar ) {
	4140	+ if ( is_file( $sidecar ) ) {
	4141	+ wp_delete_file( $sidecar );
	4142	+ }
	4143	+ }
	4144	+ }
	4145	+ }
	4146	+
	4147	+ // Static tree (served directly by the nginx/.htaccess rewrite).
	4148	+ if ( defined( 'XSPEED_CACHE_STATIC_DIR' ) ) {
	4149	+ // Same transform the write used — `localhost:8080` files under
	4150	+ // `localhost8080`, so the bare host found nothing here either.
	4151	+ $dir = rtrim( XSPEED_CACHE_STATIC_DIR, '/' ) . '/' . self::static_host_dir( $host ) . ( '/' === $path ? '' : rtrim( $path, '/' ) );
	4152	+ $file = $dir . '/index.html';
	4153	+ if ( is_file( $file ) ) {
	4154	+ wp_delete_file( $file );
	4155	+ ++$count;
	4156	+ }
	4157	+ foreach ( array( $file . '.br', self::brotli_size_sidecar( $file . '.br' ) ) as $sidecar ) {
	4158	+ if ( is_file( $sidecar ) ) {
	4159	+ wp_delete_file( $sidecar );
	4160	+ }
	4161	+ }
	4162	+ }
	4163	+
	4164	+ if ( $count > 0 ) {
	4165	+ Cache_Inventory::invalidate();
	4166	+ Activity_Log::record(
	4167	+ 'cache_purge_url',
	4168	+ sprintf(
	4169	+ /* translators: 1: cause of the purge, 2: URL or path, 3: number of files removed. */
	4170	+ __( 'Purged one URL (%1$s) — %2$s, %3$d file(s) removed', 'xspeed' ),
	4171	+ $cause,
	4172	+ $host . $path,
	4173	+ $count
	4174	+ ),
	4175	+ Activity_Log::INFO
	4176	+ );
	4177	+ }
	4178	+
	4179	+ /**
	4180	+ * Fires after one URL's cached copy has been purged.
	4181	+ *
	4182	+ * The single-URL counterpart to `xspeed_after_purge_all`. Subscribe
	4183	+ * here to invalidate a cache xSpeed does not own — a server-level
	4184	+ * cache such as LiteSpeed's LSCache, a reverse proxy, or a CDN — for
	4185	+ * the same URL.
	4186	+ *
	4187	+ * Only fires when the purge actually ran. A malformed URL, a URL with
	4188	+ * no resolvable host, or a traversal attempt returns earlier and
	4189	+ * publishes nothing, so a listener can treat this as "xSpeed purged
	4190	+ * this URL" rather than "xSpeed was asked to". `removed` may legitimately
	4191	+ * be 0: the URL was not in xSpeed's cache, which says nothing about
	4192	+ * whether it is in yours.
	4193	+ *
	4194	+ * Fires at most once per purge. A listener that calls back into
	4195	+ * xSpeed's purge API will not re-enter this event.
	4196	+ *
	4197	+ * @since 1.2.3
	4198	+ *
	4199	+ * @param array $context {
	4200	+ * Bounded description of the purge. URL queries and caller-supplied
	4201	+ * causes can contain sensitive values and are not logging fields.
	4202	+ *
	4203	+ * @type string $url Canonical scheme://host/path[?query] of the purged URL.
	4204	+ * The query is preserved because caches in front
	4205	+ * commonly key on it; xSpeed's own sweep is
	4206	+ * path-based, so `removed` describes that.
	4207	+ * @type string $host Host (with port when non-standard).
	4208	+ * @type string $path Path component, leading slash.
	4209	+ * @type string $cause Short label for who asked. See purge_all().
	4210	+ * @type int $removed Number of cache files removed.
	4211	+ * @type string $scope Actionable adapter scope: `urls`.
	4212	+ * @type string $intent Why responses changed: `content`.
	4213	+ * @type string[] $urls Exact response URLs to invalidate.
	4214	+ * }
	4215	+ */
	4216	+ $canonical_url = self::canonical_purge_url(
	4217	+ $host,
	4218	+ $path,
	4219	+ isset( $parts['query'] ) ? (string) $parts['query'] : '',
	4220	+ isset( $parts['scheme'] ) ? strtolower( (string) $parts['scheme'] ) : ''
	4221	+ );
	4222	+ self::dispatch_purge_event(
	4223	+ 'xspeed_after_purge_url',
	4224	+ array(
	4225	+ 'url' => $canonical_url,
	4226	+ 'host' => $host,
	4227	+ 'path' => $path,
	4228	+ 'cause' => $cause,
	4229	+ 'removed' => $count,
	4230	+ 'scope' => 'urls',
	4231	+ 'intent' => 'content',
	4232	+ 'urls' => array( $canonical_url ),
	4233	+ )
	4234	+ );
	4235	+
	4236	+ return $count;
	4237	+ }
	4238	+
	4239	+ /** Host this site's purge is scoped to, for the purge-event context. */
	4240	+ private static function current_purge_host(): string {
	4241	+ if ( ! function_exists( 'home_url' ) ) {
	4242	+ return '';
	4243	+ }
	4244	+ $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.
	4245	+ if ( ! is_array( $home ) || empty( $home['host'] ) ) {
	4246	+ return '';
	4247	+ }
	4248	+ // Same default-port normalisation as purge_url(): a site whose
	4249	+ // home_url() carries `:443` (normal behind a proxy) otherwise stamps
	4250	+ // every full-purge event with a host that matches none of its own
	4251	+ // URLs, so the LiteSpeed forward stood down site-wide. (QA #348)
	4252	+ return self::host_port_of( $home );
	4253	+ }
	4254	+
	4255	+ /**
	4256	+ * Rebuild the canonical URL a purge applied to.
	4257	+ *
	4258	+ * Built from the parts the purge itself used, so a listener is told the
	4259	+ * URL we acted on rather than the string the caller happened to pass —
	4260	+ * those differ whenever the caller supplied a site-relative path, a
	4261	+ * different scheme, or a query string the cache key ignores.
	4262	+ */
	4263	+ private static function canonical_purge_url( string $host, string $path, string $query = '', string $url_scheme = '' ): string {
	4264	+ // The purged URL's own scheme wins. purge_url() explicitly supports
	4265	+ // cross-site purges (multisite, WP-CLI, cron), where composing the
	4266	+ // current site's scheme onto another site's host builds a URL that was
	4267	+ // never served — and a CDN listener then purges the wrong key and
	4268	+ // reports success.
	4269	+ if ( '' !== $url_scheme ) {
	4270	+ return $url_scheme . '://' . $host . $path . ( '' !== $query ? '?' . $query : '' );
	4271	+ }
	4272	+ $scheme = function_exists( 'is_ssl' ) && is_ssl() ? 'https' : 'http';
	4273	+ if ( function_exists( 'home_url' ) ) {
	4274	+ $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.
	4275	+ if ( is_array( $home ) && ! empty( $home['scheme'] ) ) {
	4276	+ $scheme = (string) $home['scheme'];
	4277	+ }
	4278	+ }
	4279	+ // The query is carried even though OUR sweep above is path-based.
	4280	+ // Caches in front commonly key on the full request line — LiteSpeed
	4281	+ // tags `/shop/?page=2` separately from `/shop/` — so publishing the
	4282	+ // bare path would have a listener confidently purge the wrong entry
	4283	+ // and report success. Telling it exactly what was asked for lets it
	4284	+ // act correctly; `removed` still describes only what WE removed.
	4285	+ return $scheme . '://' . $host . $path . ( '' !== $query ? '?' . $query : '' );
	4286	+ }
	4287	+
	4288	+ /**
	4289	+ * Sweep this site's cache files.
	4290	+ *
	4291	+ * On multisite every blog shares one cache directory, so an unscoped
	4292	+ * sweep here took the whole network cold — one subsite's settings save
	4293	+ * or post publish rebuilt every other site from PHP. Entries are stored
	4294	+ * per host (see host_dir()), and the sweep is scoped to match, so a
	4295	+ * purge originating on site-a leaves site-b's cache warm. (#6)
	4296	+ *
	4297	+ * Clears the files only: the flat tree, the static tree, the REST
	4298	+ * responses and the minified assets. The object-cache flush, the stats
	4299	+ * update, `xspeed_after_purge_all`, the `xspeed_after_purge` contract
	4300	+ * event and the log entry live in purge_all(), which is still the entry
	4301	+ * point for every existing caller. Split out so `wp xspeed purge` can
	4302	+ * report the local sweep as one line item and the object cache as
	4303	+ * another, each with its own status — see Purge_Runner.
	4304	+ *
	4305	+ * @param string|null $host Host to purge. Defaults to the current site.
	4306	+ * Pass '*' to sweep the ENTIRE tree — network
	4307	+ * admin's "purge all sites", and the migration
	4308	+ * of pre-#6 entries that sit in the tree root.
	4309	+ * @return array{pages:int,rest:int,assets:int,bytes:int} Entries removed
	4310	+ * per store, and the bytes freed by the two file sweeps
	4311	+ * that measure themselves.
	4312	+ */
	4313	+ public static function purge_local( ?string $host = null ): array {
	4314	+ $network_wide = ( '*' === $host );
	4315	+ self::$sweep_bytes = 0;
	4316	+ // The flat tree buckets by a flattened segment (host/a-b) while the
	4317	+ // static tree mirrors the URL (host/a/b), so they need separate
	4318	+ // scopes — see current_host_dir() vs current_static_scope().
	4319	+ $static_scope = '';
	4320	+ if ( null === $host || $network_wide ) {
	4321	+ $scope = $network_wide ? '' : self::current_host_dir();
	4322	+ $static_scope = $network_wide ? '' : self::current_static_scope();
	4323	+ } else {
	4324	+ $dir = self::host_dir( $host );
	4325	+ $scope = '' === $dir ? 'default' : $dir;
	4326	+ $static_dir = self::static_host_dir( $host );
	4327	+ $static_scope = '' === $static_dir ? 'default' : $static_dir;
	4328	+ }
	4329	+
	4330	+ $count = 0;
389	4331	if ( is_dir( XSPEED_CACHE_DIR ) ) {
390		- $files = glob( XSPEED_CACHE_DIR . '/*.html' );
391		- if ( $files ) {
392		- $count = count( $files );
393		- foreach ( $files as $f ) {
394		- wp_delete_file( $f );
	4332	+ // Scoped to one host directory, or the whole tree (including the
	4333	+ // legacy top-level entries written before #6) when network-wide.
	4334	+ /*
	4335	+ * Network-wide sweeps go TWO levels deep, not one. A subdirectory
	4336	+ * subsite's bucket is `<host>/<prefix>/`, so globbing only
	4337	+ * `<cache>/*` reached the main site and left every subsite's
	4338	+ * entries in place. (QA D5 on #166)
	4339	+ *
	4340	+ * A scoped purge also has to cover its own nested buckets: when
	4341	+ * the main blog of a subdirectory network purges, `<host>/` is its
	4342	+ * bucket and `<host>/one/` belongs to another blog — so the scoped
	4343	+ * branch deliberately does NOT descend, which is what keeps
	4344	+ * site-level purges isolated.
	4345	+ */
	4346	+ $roots = $network_wide
	4347	+ ? array_merge(
	4348	+ array( XSPEED_CACHE_DIR ),
	4349	+ array_filter( (array) glob( XSPEED_CACHE_DIR . '/*', GLOB_ONLYDIR ) ),
	4350	+ array_filter( (array) glob( XSPEED_CACHE_DIR . '/*/*', GLOB_ONLYDIR ) )
	4351	+ )
	4352	+ : array( XSPEED_CACHE_DIR . '/' . $scope );
	4353	+
	4354	+ foreach ( $roots as $root ) {
	4355	+ /*
	4356	+ * min/ and rest/ are swept by their own purgers below; never
	4357	+ * treat them as host buckets.
	4358	+ *
	4359	+ * Checked on every path SEGMENT, not just the basename: now
	4360	+ * that the network-wide glob descends two levels it can reach
	4361	+ * `min/combined`, whose basename is `combined` and would sail
	4362	+ * past a basename-only test — deleting the combined
	4363	+ * stylesheets out from under the pages that link them.
	4364	+ */
	4365	+ if ( ! $network_wide || XSPEED_CACHE_DIR !== $root ) {
	4366	+ $relative = trim( str_replace( XSPEED_CACHE_DIR, '', (string) $root ), '/' );
	4367	+ $segments = '' === $relative ? array() : explode( '/', $relative );
	4368	+ if ( array_intersect( $segments, array( 'min', 'rest' ) ) ) {
	4369	+ continue;
	4370	+ }
395	4371	}
	4372	+ if ( ! is_dir( $root ) ) {
	4373	+ continue;
	4374	+ }
	4375	+ $files = glob( $root . '/*.html' );
	4376	+ if ( $files ) {
	4377	+ $count += count( $files );
	4378	+ foreach ( $files as $f ) {
	4379	+ self::sweep_delete( $f );
	4380	+ }
	4381	+ }
	4382	+ // Remove the .meta sidecars (content-type for feeds/sitemaps)
	4383	+ // alongside their .html entries. Not counted — they're not
	4384	+ // cache "pages", just per-entry metadata.
	4385	+ $meta = glob( $root . '/*.meta' );
	4386	+ if ( $meta ) {
	4387	+ foreach ( $meta as $m ) {
	4388	+ self::sweep_delete( $m );
	4389	+ }
	4390	+ }
	4391	+ // Remove precompressed siblings (e.g. <key>.html.br from the Pro
	4392	+ // Brotli module). Not counted — same as .meta. Without this a
	4393	+ // purge leaves stale .br bodies behind: disk bloat, and a
	4394	+ // staleness window if precompression is later disabled.
	4395	+ $br = glob( $root . '/*.br' );
	4396	+ if ( $br ) {
	4397	+ foreach ( $br as $b ) {
	4398	+ self::sweep_delete( $b );
	4399	+ }
	4400	+ }
	4401	+ // `*.br` does not match `*.br.size` — same reason as the flat-root
	4402	+ // sweep above: a size record outliving its body would later be
	4403	+ // read against a different sibling's bytes.
	4404	+ $br_size = glob( $root . '/*.br.size' );
	4405	+ if ( $br_size ) {
	4406	+ foreach ( $br_size as $b ) {
	4407	+ self::sweep_delete( $b );
	4408	+ }
	4409	+ }
396	4410	}
397	4411	}
398	4412	// Static-cache tree purge — recursive because the layout is
399	4413	// xspeed-static/{host}/{path}/index.html, so a flat glob can't
400		- // reach everything.
	4414	+ // reach everything. Already host-segmented, so scoping is just a
	4415	+ // matter of starting one level down.
401	4416	if ( is_dir( XSPEED_CACHE_STATIC_DIR ) ) {
402		- $count += self::rmtree_html( XSPEED_CACHE_STATIC_DIR );
	4417	+ $static_root = $network_wide
	4418	+ ? XSPEED_CACHE_STATIC_DIR
	4419	+ : XSPEED_CACHE_STATIC_DIR . '/' . $static_scope;
	4420	+ if ( is_dir( $static_root ) ) {
	4421	+ $count += self::rmtree_html( $static_root );
	4422	+ }
403	4423	}
	4424	+ // REST response cache (cache/xspeed/rest/*.json) — same purge
	4425	+ // triggers (publish, settings change) invalidate it too.
	4426	+ $rest = Rest_Cache::purge();
	4427	+ $count += $rest;
	4428	+
	4429	+ // Minified + combined CSS/JS (cache/xspeed/min/ and min/combined/).
	4430	+ // purge_all is a full filesystem sweep and must clear these too, even
	4431	+ // when the Minify module is currently disabled — orphaned min/ files
	4432	+ // from a feature the user later turned off must still be removed, and
	4433	+ // a stale combined-<hash>.css that the regenerated page no longer
	4434	+ // references otherwise 404s and breaks the frontend. (FBS-83114/83116)
	4435	+ $assets = class_exists( '\\XSpeed\\Minifier' ) ? Minifier::purge_minified() : 0;
	4436	+
	4437	+ return array(
	4438	+ 'pages' => $count - $rest,
	4439	+ 'rest' => $rest,
	4440	+ 'assets' => $assets,
	4441	+ 'bytes' => self::$sweep_bytes,
	4442	+ );
	4443	+ }
	4444	+
	4445	+ /**
	4446	+ * Flush the persistent object cache (Redis / Memcached).
	4447	+ *
	4448	+ * Runs regardless of whether the Object Cache module is currently
	4449	+ * enabled — a drop-in installed earlier keeps serving until flushed.
	4450	+ *
	4451	+ * @param bool $network_wide Flush every blog's entries. wp_cache_flush()
	4452	+ * is NETWORK-global, so on multisite the
	4453	+ * default prefers the blog-scoped group flush
	4454	+ * (WP 6.1+) — otherwise one site's purge drops
	4455	+ * every other site's object cache, the same bug
	4456	+ * #6 fixed for the page cache.
	4457	+ * @return bool Whether a flush was actually performed.
	4458	+ */
	4459	+ public static function flush_object_cache( bool $network_wide = false ): bool {
	4460	+ if ( ! $network_wide && is_multisite() && function_exists( 'wp_cache_flush_group' ) && function_exists( 'wp_cache_supports' ) && wp_cache_supports( 'flush_group' ) ) {
	4461	+ // Blog-scoped groups only; a shared/global group (site options,
	4462	+ // user meta) is intentionally left alone.
	4463	+ foreach ( array( 'options', 'posts', 'terms', 'post_meta', 'comment' ) as $group ) {
	4464	+ wp_cache_flush_group( $group );
	4465	+ }
	4466	+ return true;
	4467	+ }
	4468	+ if ( function_exists( 'wp_cache_flush' ) ) {
	4469	+ return (bool) wp_cache_flush();
	4470	+ }
	4471	+ return false;
	4472	+ }
	4473	+
	4474	+ /**
	4475	+ * Purge this site's cache: the local sweep, then the object cache, then
	4476	+ * the bookkeeping every caller expects (stats, `xspeed_after_purge_all`,
	4477	+ * inventory invalidation, purge log).
	4478	+ *
	4479	+ * @param string $cause Who asked, for the purge log.
	4480	+ * @param string|null $host See purge_local().
	4481	+ * @param array<string,mixed> $invalidation Public adapter policy. `scope`
	4482	+ * is urls/site/network/none,
	4483	+ * `intent` explains why, and
	4484	+ * `urls` supplies exact targets.
	4485	+ * @return int Page + REST entries removed.
	4486	+ */
	4487	+ public static function purge_all( string $cause = 'manual', ?string $host = null, array $invalidation = array() ) {
	4488	+ $network_wide = ( '*' === $host );
	4489	+ $adapter_scope = isset( $invalidation['scope'] ) && is_string( $invalidation['scope'] )
	4490	+ ? $invalidation['scope']
	4491	+ : ( $network_wide ? 'network' : 'site' );
	4492	+ if ( ! in_array( $adapter_scope, array( 'urls', 'site', 'network', 'none' ), true ) ) {
	4493	+ $adapter_scope = $network_wide ? 'network' : 'site';
	4494	+ }
	4495	+ if ( $network_wide ) {
	4496	+ $adapter_scope = 'network';
	4497	+ }
	4498	+ $intent = isset( $invalidation['intent'] ) && is_string( $invalidation['intent'] ) && '' !== $invalidation['intent']
	4499	+ ? $invalidation['intent']
	4500	+ : 'complete';
	4501	+ $urls = isset( $invalidation['urls'] ) && is_array( $invalidation['urls'] )
	4502	+ ? array_values( array_unique( array_filter( $invalidation['urls'], 'is_string' ) ) )
	4503	+ : array();
	4504	+ // This method always sweeps a complete local bucket. A narrower adapter
	4505	+ // announcement would claim unrelated local pages stayed warm when they
	4506	+ // did not, leaving their server copies stale. Until purge_all() gains
	4507	+ // dependency-aware local deletion, its response scope cannot be `urls`.
	4508	+ if ( 'urls' === $adapter_scope ) {
	4509	+ $adapter_scope = $network_wide ? 'network' : 'site';
	4510	+ }
	4511	+ if ( 'site' === $adapter_scope || 'network' === $adapter_scope || 'none' === $adapter_scope ) {
	4512	+ $urls = array();
	4513	+ }
	4514	+
	4515	+ $removed = self::purge_local( $host );
	4516	+ $count = $removed['pages'] + $removed['rest'];
	4517	+
	4518	+ self::flush_object_cache( $network_wide );
	4519	+
404	4520	self::update_stats( array( 'last_purge' => time() ) );
405	4521
	4522	+ // Fire AFTER the local sweep so module listeners (Critical CSS,
	4523	+ // Unused CSS, Cloudflare edge purge) run — this action had three
	4524	+ // registered listeners but was never emitted. Treat it as additive
	4525	+ // (CDN / edge invalidation), not the mechanism for clearing local
	4526	+ // files. (FBS-83114)
	4527	+ // Wrapped: this action predates the purge-event contract and has its
	4528	+ // own third-party listeners. One of them throwing used to abort
	4529	+ // purge_all() here, which now also means the contract event below
	4530	+ // never fires and a server cache keeps serving stale HTML. The local
	4531	+ // sweep is already done by this point, so swallowing is strictly safer
	4532	+ // than letting a listener decide the rest of the method runs.
	4533	+ try {
	4534	+ // Isolated per listener: one throwing used to cancel every
	4535	+ // listener queued behind it — Critical CSS, Unused CSS and the
	4536	+ // Cloudflare edge purge all hang off this hook. (QA #348)
	4537	+ self::do_action_isolated( 'xspeed_after_purge_all', $cause );
	4538	+ } catch ( \Throwable $e ) {
	4539	+ self::log_purge_listener_error( 'xspeed_after_purge_all', $e );
	4540	+ }
	4541	+
	4542	+ /**
	4543	+ * Fires after a full purge, with the same bounded context shape as
	4544	+ * `xspeed_after_purge_url`.
	4545	+ *
	4546	+ * Distinct from `xspeed_after_purge_all` on purpose. That action is
	4547	+ * the long-standing internal signal — it passes a bare `$cause` string
	4548	+ * and Free's own modules use it for local bookkeeping. This one is the
	4549	+ * documented contract for OUTSIDE integrations: same argument shape as
	4550	+ * the per-URL event, so a server-cache or CDN adapter can subscribe to
	4551	+ * both with one handler and branch on a null `url`.
	4552	+ *
	4553	+ * Fires at most once per purge, and not at all when a listener's own
	4554	+ * purge re-enters xSpeed.
	4555	+ *
	4556	+ * @since 1.2.3
	4557	+ *
	4558	+ * @param array $context {
	4559	+ * @type null $url Always null — a full purge has no single URL.
	4560	+ * @type string $host Host swept, or '*' for the entire tree.
	4561	+ * @type null $path Always null.
	4562	+ * @type string $cause Short label for who asked.
	4563	+ * @type int $removed Number of cache files removed.
	4564	+ * @type string $scope Adapter action: urls/site/network/none.
	4565	+ * @type string $intent content/presentation/complete or a caller-defined intent.
	4566	+ * @type string[] $urls Exact targets when scope is urls.
	4567	+ * }
	4568	+ */
	4569	+ self::dispatch_purge_event(
	4570	+ 'xspeed_after_purge',
	4571	+ array(
	4572	+ 'url' => null,
	4573	+ 'host' => null === $host ? self::current_purge_host() : (string) $host,
	4574	+ 'path' => null,
	4575	+ 'cause' => $cause,
	4576	+ 'removed' => $count,
	4577	+ 'scope' => $adapter_scope,
	4578	+ 'intent' => $intent,
	4579	+ 'urls' => $urls,
	4580	+ )
	4581	+ );
	4582	+
	4583	+ // The list behind the "Cached pages" card is memoized for a minute;
	4584	+ // a purge has to drop it or the drill-down shows pages that no
	4585	+ // longer exist.
	4586	+ Cache_Inventory::invalidate();
	4587	+
406	4588	// Trigger of WP_CLI / hook / admin-bar purges all hit the same
407	4589	// path. Record once with the supplied cause so the dashboard
408	4590	// activity feed reads naturally.
409	4591	Activity_Log::record(
		@@ -410,16 +4592,853 @@
410	4592	'cache_purged',
411	4593	sprintf( 'Cache purged (%s) — %d file%s removed', $cause, $count, 1 === $count ? '' : 's' ),
412	4594	Activity_Log::INFO
413	4595	);
	4596	+
	4597	+ return $count;
414	4598	}
415	4599
416	4600	/**
417		- * Recursively delete every `index.html` and empty directory inside
418		- * the static-cache tree. Used by purge_all(). Returns the number of
419		- * .html files removed so purge stats stay accurate across the flat
420		- * + static caches.
	4601	+ * Purge everything after a plugin / theme / core update completes.
	4602	+ *
	4603	+ * Bound to `upgrader_process_complete`, which is the only hook an update
	4604	+ * fires — no activation hook runs, so without this the cached HTML (and
	4605	+ * the asset URLs baked into it) outlives the code that produced it.
	4606	+ *
	4607	+ * Runs for plugin, theme and core updates alike, including bulk runs and
	4608	+ * auto-updates, and purges the WHOLE network rather than the current
	4609	+ * site — see the call below. Translation updates are skipped: they
	4610	+ * change no markup a cached page depends on, and language packs update
	4611	+ * often enough that purging on them would keep a multilingual site
	4612	+ * permanently cold.
	4613	+ *
	4614	+ * Note this cannot be folded into the `$invalidate_hooks` loop above:
	4615	+ * that binds `purge_all` directly, and `purge_all( string $cause )` would
	4616	+ * then receive the WP_Upgrader instance as its cause.
	4617	+ *
	4618	+ * @param mixed $upgrader WP_Upgrader instance (unused).
	4619	+ * @param array $hook_extra Context for the completed operation.
	4620	+ * @return void
421	4621	*/
	4622	+ public static function purge_after_upgrade( $upgrader = null, $hook_extra = array() ) {
	4623	+ $cleared = self::$upgrade_cleared_destination;
	4624	+
	4625	+ if ( ! self::upgrade_produced_something( $upgrader ) ) {
	4626	+ return;
	4627	+ }
	4628	+
	4629	+ if ( ! self::upgrade_should_purge( is_array( $hook_extra ) ? $hook_extra : array(), $cleared ) ) {
	4630	+ return;
	4631	+ }
	4632	+
	4633	+ self::purge_for_upgrade();
	4634	+ }
	4635	+
	4636	+ /**
	4637	+ * Whether this request's upgrader removed an existing copy.
	4638	+ *
	4639	+ * @var bool
	4640	+ */
	4641	+ private static $upgrade_cleared_destination = false;
	4642	+
	4643	+ /**
	4644	+ * How many `upgrader_process_complete` dispatches are on the stack.
	4645	+ *
	4646	+ * @var int
	4647	+ */
	4648	+ private static $upgrade_dispatch_depth = 0;
	4649	+
	4650	+ /**
	4651	+ * Enter an `upgrader_process_complete` dispatch.
	4652	+ *
	4653	+ * Bound at PHP_INT_MIN, so it runs before any listener that might read
	4654	+ * the replacement signal. Public because it is a hook target.
	4655	+ *
	4656	+ * @return void
	4657	+ */
	4658	+ public static function note_upgrade_dispatch(): void {
	4659	+ ++self::$upgrade_dispatch_depth;
	4660	+ }
	4661	+
	4662	+ /**
	4663	+ * Drop the replacement signal once every listener has read it.
	4664	+ *
	4665	+ * Bound at PHP_INT_MAX so a second upgrade in the same request starts
	4666	+ * clean, without taking the answer away from the add-on callbacks that
	4667	+ * run at the same priority as ours.
	4668	+ *
	4669	+ * Only the OUTERMOST dispatch clears it. A nested run — core's language
	4670	+ * pack upgrader, or any add-on that installs something from this hook —
	4671	+ * fires the action again, and clearing there would answer for a run that
	4672	+ * has not finished. Called directly (no dispatch on the stack) it still
	4673	+ * clears, which is what a test wants.
	4674	+ *
	4675	+ * Known limit: a nested run INHERITS the outer run's signal, because the
	4676	+ * only evidence we get is a filter that fires before the nested dispatch
	4677	+ * begins and carries no upgrader identity. So a fresh install performed
	4678	+ * from inside a replacement run reads as a replacement and purges once
	4679	+ * more than it needs to. A cold cache is the cheap direction, and the
	4680	+ * alternative — scoping the signal per upgrader — is not knowable from
	4681	+ * `upgrader_clear_destination`.
	4682	+ *
	4683	+ * @return void
	4684	+ */
	4685	+ public static function forget_cleared_destination(): void {
	4686	+ if ( self::$upgrade_dispatch_depth > 0 ) {
	4687	+ --self::$upgrade_dispatch_depth;
	4688	+ }
	4689	+
	4690	+ if ( 0 === self::$upgrade_dispatch_depth ) {
	4691	+ self::$upgrade_cleared_destination = false;
	4692	+ }
	4693	+ }
	4694	+
	4695	+ /**
	4696	+ * Record that the upgrader cleared an existing destination.
	4697	+ *
	4698	+ * A pass-through listener on `upgrader_clear_destination`: WordPress only
	4699	+ * fires it when `clear_destination` was set AND something was there to
	4700	+ * remove, which is the one signal that separates an upload-and-replace
	4701	+ * from a first-time install. The filtered value is returned untouched.
	4702	+ *
	4703	+ * @param true|\WP_Error $removed Whether the destination was cleared.
	4704	+ * @return true|\WP_Error
	4705	+ */
	4706	+ public static function note_cleared_destination( $removed ) {
	4707	+ if ( ! is_wp_error( $removed ) ) {
	4708	+ self::$upgrade_cleared_destination = true;
	4709	+ }
	4710	+
	4711	+ return $removed;
	4712	+ }
	4713	+
	4714	+ /**
	4715	+ * Did the completed run actually replace anything?
	4716	+ *
	4717	+ * `upgrader_process_complete` fires whether the run succeeded or failed —
	4718	+ * the failure branch in WP_Upgrader::run() only feeds the skin before the
	4719	+ * action fires. A run that installed nothing changed no markup, so purging
	4720	+ * for it is a cold cache bought for nothing.
	4721	+ *
	4722	+ * Deliberately conservative: this returns false ONLY when every result we
	4723	+ * can see is an error. An upgrader we cannot read, a mixed bulk run, or a
	4724	+ * missing result all fall through to purging, which is the safe direction
	4725	+ * everywhere else in this handler.
	4726	+ *
	4727	+ * @param mixed $upgrader WP_Upgrader instance, or anything else.
	4728	+ * @return bool
	4729	+ */
	4730	+ public static function upgrade_produced_something( $upgrader ): bool {
	4731	+ if ( ! is_object( $upgrader ) ) {
	4732	+ return true;
	4733	+ }
	4734	+
	4735	+ // A bulk run collects one entry per item; `result` alone would only
	4736	+ // describe the last of them.
	4737	+ if ( isset( $upgrader->results ) && is_array( $upgrader->results ) && ! empty( $upgrader->results ) ) {
	4738	+ foreach ( $upgrader->results as $result ) {
	4739	+ if ( ! is_wp_error( $result ) && ! empty( $result ) ) {
	4740	+ return true;
	4741	+ }
	4742	+ }
	4743	+ return false;
	4744	+ }
	4745	+
	4746	+ if ( ! property_exists( $upgrader, 'result' ) ) {
	4747	+ return true;
	4748	+ }
	4749	+
	4750	+ return ! is_wp_error( $upgrader->result ) && ! empty( $upgrader->result );
	4751	+ }
	4752	+
	4753	+ /**
	4754	+ * Decide whether a completed operation invalidates the cache.
	4755	+ *
	4756	+ * Split out from the handler so the decision is testable on its own:
	4757	+ * purge_all() reaches straight for glob() and unlink(), which a unit test
	4758	+ * cannot observe honestly, while every rule that matters lives here.
	4759	+ *
	4760	+ * @param array $hook_extra Context for the completed operation.
	4761	+ * @return bool
	4762	+ */
	4763	+ public static function upgrade_should_purge( array $hook_extra, bool $destination_cleared = false ): bool {
	4764	+ if ( ! self::upgrade_replaced_code( $hook_extra, $destination_cleared ) ) {
	4765	+ return false;
	4766	+ }
	4767	+
	4768	+ // An update to xSpeed ITSELF always purges, whatever the setting says.
	4769	+ // This plugin's own code is what rendered every cached page — the
	4770	+ // minifier, lazy-loader, resource hints and CDN rewriter all changed
	4771	+ // underneath it — so serving that HTML after an update means serving
	4772	+ // output from a version that no longer exists. Minified assets make it
	4773	+ // concrete rather than theoretical: their filenames are keyed on the
	4774	+ // source filemtime, so they regenerate under NEW hashes while the
	4775	+ // cached pages still link the old ones, and the page requests files
	4776	+ // that are no longer on disk. Offering an opt-out for that would be
	4777	+ // offering a broken site.
	4778	+ return self::upgrade_touches_xspeed( $hook_extra ) || self::purge_on_upgrade_enabled();
	4779	+ }
	4780	+
	4781	+ /**
	4782	+ * Did this completed run replace code that renders pages?
	4783	+ *
	4784	+ * The half of the decision that has nothing to do with our settings: it
	4785	+ * asks only whether live code changed underneath the output we cached.
	4786	+ * Add-ons that keep their own derived artifacts — generated CSS, captured
	4787	+ * selectors, fingerprints — need the same answer and must not have to
	4788	+ * rebuild these rules, or they drift apart. Call it with the hook's own
	4789	+ * `$hook_extra`; the upload-and-replace signal is read from this request.
	4790	+ *
	4791	+ * Deliberately independent of the "Purge After Updates" setting. That
	4792	+ * setting governs the page cache, not whether an add-on's derived data is
	4793	+ * still valid.
	4794	+ *
	4795	+ * @param array $hook_extra Context for the completed operation.
	4796	+ * @param bool|null $destination_cleared Override the recorded signal; null reads this request's.
	4797	+ * @return bool
	4798	+ */
	4799	+ public static function upgrade_replaced_code( array $hook_extra, ?bool $destination_cleared = null ): bool {
	4800	+ $cleared = null === $destination_cleared ? self::$upgrade_cleared_destination : $destination_cleared;
	4801	+
	4802	+ $type = isset( $hook_extra['type'] ) ? (string) $hook_extra['type'] : '';
	4803	+ $action = isset( $hook_extra['action'] ) ? (string) $hook_extra['action'] : '';
	4804	+
	4805	+ // `upgrader_process_complete` fires for INSTALLS as well as updates.
	4806	+ // A freshly installed plugin is inactive and a freshly installed theme
	4807	+ // is not the active one, so neither can change a single rendered page
	4808	+ // — but the first cut of this handler purged the whole tree anyway, so
	4809	+ // evaluating three plugins in a row emptied the cache three times.
	4810	+ //
	4811	+ // 'install' alone is NOT enough to skip on, because WordPress reports
	4812	+ // an upload-and-replace as an install: `Plugin_Upgrader::install()`
	4813	+ // hardcodes `action => install` and `overwrite_package` does not change
	4814	+ // it, so "Replace current with uploaded" and `wp plugin install <zip>
	4815	+ // --force` both arrive here labelled install while genuinely replacing
	4816	+ // live code. That is how a plugin distributed as a zip is updated, and
	4817	+ // skipping it put back the stale markup this handler exists to clear.
	4818	+ //
	4819	+ // The distinguishing signal is whether the destination was cleared:
	4820	+ // WP_Upgrader only fires `upgrader_clear_destination` when it removed
	4821	+ // something that was already there. Installing beside nothing does not.
	4822	+ if ( 'install' === $action && ! $cleared ) {
	4823	+ return false;
	4824	+ }
	4825	+
	4826	+ // 'translation' is the one update type that cannot change rendered
	4827	+ // markup. Anything else — including an empty type from a custom
	4828	+ // updater — is treated as cache-invalidating, because guessing wrong
	4829	+ // in that direction only costs a cold cache.
	4830	+ if ( 'translation' === $type ) {
	4831	+ return false;
	4832	+ }
	4833	+
	4834	+ return true;
	4835	+ }
	4836	+
	4837	+ /**
	4838	+ * Purge everything an update can invalidate.
	4839	+ *
	4840	+ * Network-wide ('*'), not the calling site's bucket. A plugin, theme or
	4841	+ * core update replaces code shared by EVERY site on the network, so a
	4842	+ * scoped purge would clear the site that happened to run the updater and
	4843	+ * leave every other subsite serving pre-update HTML for the whole TTL —
	4844	+ * the very bug this handler exists to fix, one level down. On single-site
	4845	+ * this is identical to the scoped call, since there is only ever one
	4846	+ * bucket.
	4847	+ *
	4848	+ * @return void
	4849	+ */
	4850	+ private static function purge_for_upgrade(): void {
	4851	+ self::purge_all( 'upgrade', '*' );
	4852	+ Minifier::purge_minified();
	4853	+ }
	4854	+
	4855	+ /**
	4856	+ * Purge after an unattended background update run.
	4857	+ *
	4858	+ * `automatic_updates_complete` passes ONE argument, and it is not a
	4859	+ * hook_extra: it is WordPress's results array, keyed by what was updated
	4860	+ * ('core', 'plugin', 'theme', 'translation'). Handing it to
	4861	+ * purge_after_upgrade() put it in the unused $upgrader slot and left the
	4862	+ * type empty, so a night on which only a language pack updated purged
	4863	+ * every cached page — the exact case the translation exemption exists to
	4864	+ * prevent, and WordPress auto-updates language packs by default.
	4865	+ *
	4866	+ * @param array $results Update results, keyed by type.
	4867	+ * @return void
	4868	+ */
	4869	+ public static function purge_after_auto_updates( $results = array() ): void {
	4870	+ if ( ! self::auto_updates_should_purge( is_array( $results ) ? $results : array() ) ) {
	4871	+ return;
	4872	+ }
	4873	+
	4874	+ self::purge_for_upgrade();
	4875	+ }
	4876	+
	4877	+ /**
	4878	+ * Decide whether a background update run invalidates the cache.
	4879	+ *
	4880	+ * @param array $results Update results, keyed by type.
	4881	+ * @return bool
	4882	+ */
	4883	+ public static function auto_updates_should_purge( array $results ): bool {
	4884	+ // An unrecognisable payload is treated as invalidating, the same
	4885	+ // direction every other unknown takes here.
	4886	+ if ( empty( $results ) ) {
	4887	+ return true;
	4888	+ }
	4889	+
	4890	+ // Failed items are listed alongside successful ones — WP_Automatic_Updater
	4891	+ // appends an entry whatever the outcome — and a night on which every
	4892	+ // update failed replaced no code, so it invalidates nothing.
	4893	+ $updated = array();
	4894	+ foreach ( $results as $type => $items ) {
	4895	+ if ( ! is_array( $items ) ) {
	4896	+ continue;
	4897	+ }
	4898	+ foreach ( $items as $item ) {
	4899	+ $result = is_object( $item ) && isset( $item->result ) ? $item->result : true;
	4900	+ if ( ! is_wp_error( $result ) && ! empty( $result ) ) {
	4901	+ $updated[] = (string) $type;
	4902	+ break;
	4903	+ }
	4904	+ }
	4905	+ }
	4906	+
	4907	+ if ( empty( $updated ) ) {
	4908	+ return false;
	4909	+ }
	4910	+
	4911	+ // Nothing but language packs: a language pack changes no markup a
	4912	+ // cached page depends on, and purging on one would keep a multilingual
	4913	+ // site permanently cold.
	4914	+ if ( array( 'translation' ) === array_values( array_unique( $updated ) ) ) {
	4915	+ return false;
	4916	+ }
	4917	+
	4918	+ return self::auto_updates_touch_xspeed( $results ) || self::purge_on_upgrade_enabled();
	4919	+ }
	4920	+
	4921	+ /**
	4922	+ * Does a background run include one of our own plugins?
	4923	+ *
	4924	+ * Same rule as a foreground self-update, read out of the results array's
	4925	+ * shape instead of a hook_extra: each plugin entry carries the update
	4926	+ * object on `->item->plugin`.
	4927	+ *
	4928	+ * @param array $results Update results, keyed by type.
	4929	+ * @return bool
	4930	+ */
	4931	+ private static function auto_updates_touch_xspeed( array $results ): bool {
	4932	+ if ( empty( $results['plugin'] ) || ! is_array( $results['plugin'] ) ) {
	4933	+ return false;
	4934	+ }
	4935	+
	4936	+ $ours = self::self_update_plugins();
	4937	+ foreach ( $results['plugin'] as $entry ) {
	4938	+ $item = is_object( $entry ) && isset( $entry->item ) ? $entry->item : null;
	4939	+ $file = is_object( $item ) && isset( $item->plugin ) ? (string) $item->plugin : '';
	4940	+ if ( '' !== $file && in_array( $file, $ours, true ) ) {
	4941	+ return true;
	4942	+ }
	4943	+ }
	4944	+
	4945	+ return false;
	4946	+ }
	4947	+
	4948	+ /**
	4949	+ * Is the "Purge After Updates" setting on?
	4950	+ *
	4951	+ * Gates THIRD-PARTY updates only — an xSpeed self-update ignores it, see
	4952	+ * purge_after_upgrade(). Defaults to true when the option has never been
	4953	+ * written, matching the schema default in CacheModule: an unset value on
	4954	+ * an existing install must not read as "the user turned this off".
	4955	+ *
	4956	+ * Unlike LiteSpeed, which ships the equivalent toggle OFF, this defaults
	4957	+ * ON — a cold cache costs one slow request, whereas stale HTML is a wrong
	4958	+ * page for up to the full TTL and the site owner has no way to tell why.
	4959	+ *
	4960	+ * @return bool
	4961	+ */
	4962	+ private static function purge_on_upgrade_enabled(): bool {
	4963	+ $opts = Settings_Manager::get( 'cache' );
	4964	+ return ! array_key_exists( 'purge_on_upgrade', $opts ) || ! empty( $opts['purge_on_upgrade'] );
	4965	+ }
	4966	+
	4967	+ /**
	4968	+ * Does this completed update include xSpeed itself?
	4969	+ *
	4970	+ * Mirrors the payload shapes Plugin::maybe_restore_after_update() reads:
	4971	+ * a single update carries 'plugin', a bulk run carries 'plugins'.
	4972	+ *
	4973	+ * @param array $hook_extra Context for the completed operation.
	4974	+ * @return bool
	4975	+ */
	4976	+ private static function upgrade_touches_xspeed( array $hook_extra ): bool {
	4977	+ if ( ! isset( $hook_extra['type'] ) || 'plugin' !== $hook_extra['type'] ) {
	4978	+ return false;
	4979	+ }
	4980	+
	4981	+ $updated = array();
	4982	+ if ( isset( $hook_extra['plugins'] ) && is_array( $hook_extra['plugins'] ) ) {
	4983	+ // Strings only: array_intersect() stringifies what it is given, so
	4984	+ // an object without __toString in a custom updater's payload would
	4985	+ // be a fatal rather than a miss.
	4986	+ $updated = array_filter( $hook_extra['plugins'], 'is_string' );
	4987	+ } elseif ( isset( $hook_extra['plugin'] ) && is_string( $hook_extra['plugin'] ) ) {
	4988	+ $updated = array( $hook_extra['plugin'] );
	4989	+ }
	4990	+
	4991	+ return (bool) array_intersect( self::self_update_plugins(), $updated );
	4992	+ }
	4993	+
	4994	+ /**
	4995	+ * Plugin files whose update counts as an update to us.
	4996	+ *
	4997	+ * The self-update rule is "our own code rendered this cached HTML, so it
	4998	+ * must not survive the code being replaced". That is true of any add-on
	4999	+ * that writes into the same page: an add-on inlines critical CSS, rewrites
	5000	+ * stylesheet links and image URLs, and produces the compressed and static
	5001	+ * copies, so its update leaves exactly the stale markup this rule exists
	5002	+ * to clear. Free cannot name an add-on, so it asks instead.
	5003	+ *
	5004	+ * Filter: xspeed_self_update_plugins
	5005	+ *
	5006	+ * Add-ons add their own `plugin_basename( __FILE__ )`. Entries are matched
	5007	+ * against the plugin files WordPress reports for the completed update, so
	5008	+ * a value that is not a `dir/file.php` basename simply never matches.
	5009	+ *
	5010	+ * @param string[] $plugins Plugin basenames treated as our own.
	5011	+ * @return string[]
	5012	+ */
	5013	+ private static function self_update_plugins(): array {
	5014	+ $ours = array( plugin_basename( XSPEED_FILE ) );
	5015	+
	5016	+ /** This filter is documented above. */
	5017	+ $filtered = apply_filters( 'xspeed_self_update_plugins', $ours );
	5018	+
	5019	+ // Our own file is merged back afterwards rather than trusted to survive
	5020	+ // the round trip. A listener that returns null, a bare string, or a
	5021	+ // list it built from scratch would otherwise drop it, and the plugin
	5022	+ // would quietly stop exempting its OWN update from the setting — a
	5023	+ // failure no add-on author would think to test for.
	5024	+ $claimed = array_filter( is_array( $filtered ) ? $filtered : array(), 'is_string' );
	5025	+
	5026	+ return array_values( array_unique( array_merge( $ours, array_filter( $claimed ) ) ) );
	5027	+ }
	5028	+
	5029	+ /**
	5030	+ * Invalidate caches of RENDERED output owned by other plugins.
	5031	+ *
	5032	+ * purge_all() sweeps only what xSpeed wrote. A page builder that stores
	5033	+ * rendered HTML or generated CSS of its own — Elementor's element cache
	5034	+ * and `uploads/elementor/css/`, and the equivalents in Beaver / Divi /
	5035	+ * Bricks / Oxygen — keeps whatever asset URLs were current when it was
	5036	+ * written, and no xSpeed purge has ever reached it.
	5037	+ *
	5038	+ * That only matters for rewrites that happen DURING render rather than on
	5039	+ * the finished page. Minify, combine, lazy-load and resource hints all run
	5040	+ * on `xspeed_cache_final_html` or a `template_redirect` buffer — after the
	5041	+ * builder has already stored its copy — so nothing they emit can leak.
	5042	+ * The CDN module's `wp_get_attachment_url` filter is the one that can.
	5043	+ *
	5044	+ * Called ONLY from purges where asset URLs themselves can have changed
	5045	+ * (a CDN settings write, an explicit Purge All). NOT from purge_all(),
	5046	+ * which also runs on every post publish — regenerating every builder CSS
	5047	+ * file that often would cost more than it saves, and the builder already
	5048	+ * invalidates its own copy for the post being saved.
	5049	+ *
	5050	+ * @param string $cause Who asked. Threaded through to the listeners and
	5051	+ * the activity log.
	5052	+ * @return string[] Labels of the caches that were actually cleared.
	5053	+ */
	5054	+ public static function purge_render_caches( string $cause = 'manual' ): array {
	5055	+ /**
	5056	+ * Clear render caches belonging to other plugins.
	5057	+ *
	5058	+ * A listener does its own work and appends a human-readable label for
	5059	+ * what it cleared, so the activity log can name it. Returning
	5060	+ * `$cleared` unchanged means "nothing of mine is installed" and is the
	5061	+ * correct no-op — never a failure.
	5062	+ *
	5063	+ * Detect the owning plugin by class or constant, not by an
	5064	+ * `is_plugin_active()` path check: a renamed plugin folder must not
	5065	+ * silently disable the integration.
	5066	+ *
	5067	+ * @param string[] $cleared Labels of caches cleared so far.
	5068	+ * @param string $cause Why the purge is happening.
	5069	+ */
	5070	+ $cleared = (array) apply_filters( 'xspeed_purge_third_party_render_caches', array(), $cause );
	5071	+
	5072	+ // Labels are strings destined for the activity feed. Anything else a
	5073	+ // third-party listener returns is dropped rather than coerced — a
	5074	+ // stray `0` or `null` in the log reads as a cache we cleared.
	5075	+ $cleared = array_values(
	5076	+ array_filter(
	5077	+ $cleared,
	5078	+ static function ( $label ) {
	5079	+ return is_string( $label ) && '' !== trim( $label );
	5080	+ }
	5081	+ )
	5082	+ );
	5083	+
	5084	+ if ( ! $cleared ) {
	5085	+ return $cleared;
	5086	+ }
	5087	+
	5088	+ // Logged separately from the page-cache purge above it. "I turned the
	5089	+ // CDN off and the images are still wrong" is only diagnosable if the
	5090	+ // feed says which OTHER plugin's cache was regenerated and when.
	5091	+ Activity_Log::record(
	5092	+ 'cache_purged',
	5093	+ sprintf( 'Render caches cleared (%s) — %s', $cause, implode( ', ', $cleared ) ),
	5094	+ Activity_Log::INFO
	5095	+ );
	5096	+
	5097	+ return $cleared;
	5098	+ }
	5099	+
	5100	+ /**
	5101	+ * The per-type purge menu, LiteSpeed-style. Each entry is a cache type
	5102	+ * the user can purge individually from the admin-bar dropdown. `visible`
	5103	+ * controls whether the item shows (active + licensed module only) — it
	5104	+ * NEVER limits Purge All, which always sweeps everything on disk.
	5105	+ *
	5106	+ * Pro registers its own types (Critical CSS, Unused CSS, …) by filtering
	5107	+ * `xspeed_purge_types`, so Free degrades gracefully when Pro is absent.
	5108	+ *
	5109	+ * @return array<string,array{label:string,visible:bool}>
	5110	+ */
	5111	+ public static function purge_types(): array {
	5112	+ $minify_on = false;
	5113	+ if ( class_exists( '\\XSpeed\\Settings_Manager' ) ) {
	5114	+ $min = Settings_Manager::get( 'minify' );
	5115	+ $minify_on = ! empty( $min['minify_css'] ) || ! empty( $min['minify_js'] ) || ! empty( $min['combine_css'] ) || ! empty( $min['combine_js'] );
	5116	+ }
	5117	+ // Object cache is "active" when an external object-cache drop-in is in
	5118	+ // use — the canonical WP signal, independent of our settings option.
	5119	+ $oc_on = function_exists( 'wp_using_ext_object_cache' ) && wp_using_ext_object_cache();
	5120	+
	5121	+ $types = array(
	5122	+ 'all' => array(
	5123	+ 'label' => __( 'Purge All', 'xspeed' ),
	5124	+ 'visible' => true,
	5125	+ ),
	5126	+ 'page' => array(
	5127	+ 'label' => __( 'Purge Page / Static Cache', 'xspeed' ),
	5128	+ 'visible' => true,
	5129	+ ),
	5130	+ 'assets' => array(
	5131	+ 'label' => __( 'Purge CSS / JS Cache', 'xspeed' ),
	5132	+ 'visible' => $minify_on,
	5133	+ ),
	5134	+ 'object' => array(
	5135	+ 'label' => __( 'Purge Object Cache', 'xspeed' ),
	5136	+ 'visible' => $oc_on,
	5137	+ ),
	5138	+ 'rest' => array(
	5139	+ 'label' => __( 'Purge REST Cache', 'xspeed' ),
	5140	+ 'visible' => true,
	5141	+ ),
	5142	+ );
	5143	+
	5144	+ /**
	5145	+ * Filter the admin-bar purge-type menu. Pro modules add their own
	5146	+ * (Critical CSS, Unused CSS, CDN). Adding a type here only adds a
	5147	+ * MENU item — purge_type() must know how to handle the same slug.
	5148	+ *
	5149	+ * @param array $types Map of slug => [label, visible].
	5150	+ */
	5151	+ return (array) apply_filters( 'xspeed_purge_types', $types );
	5152	+ }
	5153	+
	5154	+ /**
	5155	+ * Purge a single cache type by slug. 'all' delegates to purge_all();
	5156	+ * every other slug clears just its own artifacts. Unknown slugs (e.g. a
	5157	+ * Pro type) fan out via the `xspeed_purge_type_{slug}` action so the
	5158	+ * owning module can handle it. Returns the number of items removed where
	5159	+ * countable.
	5160	+ *
	5161	+ * @param string $type Cache type slug.
	5162	+ * @param string $cause Who asked. Threaded through so the purge log can
	5163	+ * tell an AI assistant's purge apart from a click —
	5164	+ * "the cache cleared four times today" is only
	5165	+ * actionable once you know what kept clearing it.
	5166	+ */
	5167	+ public static function purge_type( string $type, string $cause = 'manual' ): int {
	5168	+ switch ( $type ) {
	5169	+ case 'all':
	5170	+ $count = self::purge_all( $cause );
	5171	+ // "Purge All" is the user saying they don't trust anything
	5172	+ // stored anywhere — the one purge that should also reach
	5173	+ // caches of rendered output we don't own. purge_all() itself
	5174	+ // deliberately does NOT, because it also runs on every post
	5175	+ // publish. (See Render_Caches.)
	5176	+ self::purge_render_caches( $cause );
	5177	+ return $count;
	5178	+
	5179	+ case 'page':
	5180	+ $count = self::purge_pages();
	5181	+ self::update_stats( array( 'last_purge' => time() ) );
	5182	+ Cache_Inventory::invalidate();
	5183	+ self::record_partial_purge( 'page', $cause, $count );
	5184	+ self::announce_purge( $cause, $count );
	5185	+ return $count;
	5186	+
	5187	+ case 'assets':
	5188	+ if ( class_exists( '\\XSpeed\\Minifier' ) ) {
	5189	+ Minifier::purge_minified();
	5190	+ }
	5191	+ // Deleting min/ without clearing the pages that link it left
	5192	+ // every cached page pointing at files that no longer exist.
	5193	+ // WordPress answers the missing asset by 301-ing to its
	5194	+ // pretty-permalink form and serving the 404 TEMPLATE as
	5195	+ // `HTTP 200 text/html`, which the browser accepts as a
	5196	+ // stylesheet and parses to zero rules — no console error, no
	5197	+ // network failure, no 4xx anywhere in devtools. The pages
	5198	+ // stayed broken for the rest of the TTL (7 days on
	5199	+ // Aggressive, up to 30), and the admin who clicked could not
	5200	+ // see it: they are logged in, so their own requests bypass
	5201	+ // the page cache and re-render, regenerating the assets as a
	5202	+ // side effect. Only anonymous visitors were served the stale
	5203	+ // HTML. (#244)
	5204	+ //
	5205	+ // The assets are the pages' dependency, so invalidating them
	5206	+ // invalidates the pages. Same invariant Cache_GC enforces
	5207	+ // with is_referenced(): never leave a cached page pointing at
	5208	+ // an asset that is gone.
	5209	+ $count = self::purge_pages();
	5210	+ self::update_stats( array( 'last_purge' => time() ) );
	5211	+ Cache_Inventory::invalidate();
	5212	+ self::record_partial_purge( 'assets', $cause, $count );
	5213	+ self::announce_purge( $cause, $count );
	5214	+ return $count;
	5215	+
	5216	+ case 'object':
	5217	+ if ( function_exists( 'wp_cache_flush' ) ) {
	5218	+ wp_cache_flush();
	5219	+ }
	5220	+ self::record_partial_purge( 'object cache', $cause, null );
	5221	+ return 0;
	5222	+
	5223	+ case 'rest':
	5224	+ $count = Rest_Cache::purge();
	5225	+ self::record_partial_purge( 'REST responses', $cause, $count );
	5226	+ self::announce_purge( $cause, $count );
	5227	+ return $count;
	5228	+
	5229	+ default:
	5230	+ return self::purge_type_unhandled( $type, $cause );
	5231	+ }
	5232	+ }
	5233	+
	5234	+ /**
	5235	+ * Delete this site's cached pages from both the flat and static trees.
	5236	+ *
	5237	+ * Extracted so the `assets` purge can reuse it: minified assets are a
	5238	+ * dependency of the cached HTML, so clearing them must clear the pages
	5239	+ * too or the pages are left referencing deleted files (#244).
	5240	+ *
	5241	+ * @return int Number of page entries removed.
	5242	+ */
	5243	+ private static function purge_pages(): int {
	5244	+ $count = 0;
	5245	+ // Scoped to this site — see purge_all(). (#6)
	5246	+ $scope = self::current_host_dir();
	5247	+ $flat_root = XSPEED_CACHE_DIR . '/' . $scope;
	5248	+ if ( is_dir( $flat_root ) ) {
	5249	+ foreach ( (array) glob( $flat_root . '/*.html' ) as $f ) {
	5250	+ wp_delete_file( $f );
	5251	+ ++$count;
	5252	+ }
	5253	+ foreach ( (array) glob( $flat_root . '/*.meta' ) as $m ) {
	5254	+ wp_delete_file( $m );
	5255	+ }
	5256	+ foreach ( (array) glob( $flat_root . '/*.br' ) as $b ) {
	5257	+ wp_delete_file( $b );
	5258	+ }
	5259	+ // `*.br` does not match `*.br.size`; a size record outliving its
	5260	+ // body would later be read against a DIFFERENT sibling's bytes.
	5261	+ foreach ( (array) glob( $flat_root . '/*.br.size' ) as $b ) {
	5262	+ wp_delete_file( $b );
	5263	+ }
	5264	+ }
	5265	+ $static_root = XSPEED_CACHE_STATIC_DIR . '/' . self::current_static_scope();
	5266	+ if ( is_dir( $static_root ) ) {
	5267	+ $count += self::rmtree_html( $static_root );
	5268	+ }
	5269	+
	5270	+ return $count;
	5271	+ }
	5272	+
	5273	+ /**
	5274	+ * A purge type this class does not own — a Pro or third-party module
	5275	+ * registered it via the `xspeed_purge_types` filter, so hand it off.
	5276	+ *
	5277	+ * @param string $type Purge-type slug.
	5278	+ * @param string $cause Who asked.
	5279	+ */
	5280	+ private static function purge_type_unhandled( string $type, string $cause ): int {
	5281	+ $event_sequence = self::$purge_event_sequence;
	5282	+ $hook = 'xspeed_purge_type_' . $type;
	5283	+ $has_handler = false !== has_action( $hook );
	5284	+ do_action( $hook );
	5285	+ self::record_partial_purge( $type, $cause, null );
	5286	+
	5287	+ // Announce, same as the types this class owns. Pro's "Purge Critical
	5288	+ // CSS" and "Purge Unused CSS" arrive here, and they change what a
	5289	+ // cached page CONTAINS — critical CSS is inlined into the HTML, so a
	5290	+ // server cache goes on serving pages with the old styles baked in.
	5291	+ // Fixing the three Free buttons and leaving these two silent left the
	5292	+ // same hole for the tier most likely to be using both plugins.
	5293	+ // (QA #348 round 2, issue 2)
	5294	+ //
	5295	+ // Unknown slugs must not turn into a site-wide purge merely because no
	5296	+ // handler exists. These are the response-changing Pro types Free knows;
	5297	+ // third parties can declare another through the filter. A registered
	5298	+ // handler plus this explicit response scope is the handled signal.
	5299	+ $scope = in_array( $type, array( 'critical-css', 'unused-css' ), true ) ? 'site' : 'none';
	5300	+ /**
	5301	+ * Declare whether a handled custom purge type changes cached responses.
	5302	+ *
	5303	+ * @since 1.2.3
	5304	+ * @param string $scope site/network/none.
	5305	+ * @param string $type Purge-type slug.
	5306	+ */
	5307	+ $scope = (string) apply_filters( 'xspeed_purge_type_response_scope', $scope, $type );
	5308	+ if ( $has_handler
	5309	+ && $event_sequence === self::$purge_event_sequence
	5310	+ && in_array( $scope, array( 'site', 'network' ), true )
	5311	+ ) {
	5312	+ self::announce_purge( $cause, 0, $scope, 'presentation' );
	5313	+ }
	5314	+
	5315	+ return 0;
	5316	+ }
	5317	+
	5318	+ /**
	5319	+ * Tell the server cache that a PARTIAL purge cleared cached responses.
	5320	+ *
	5321	+ * "Purge Page / Static Cache", "Purge CSS / JS Cache" and "Purge REST
	5322	+ * Cache" each delete cached RESPONSES for the whole site, so a cache in
	5323	+ * front of PHP is now serving copies xSpeed has just thrown away. Only
	5324	+ * "Purge All" announced itself, which left three of the four toolbar
	5325	+ * buttons doing exactly what this contract exists to prevent: clearing
	5326	+ * our copy while the server kept serving the stale one. The `assets` case
	5327	+ * was the sharpest — it deletes the minified bundles too, so LiteSpeed
	5328	+ * went on serving pages whose CSS and JS no longer exist. (QA #348)
	5329	+ *
	5330	+ * Sent as the full-purge shape (`url` null) because that is what happened:
	5331	+ * every cached page for this site went, not one address. `object` is not
	5332	+ * announced — flushing the object cache changes no rendered response a
	5333	+ * server cache could be holding.
	5334	+ *
	5335	+ * Public because Purge_Runner sweeps the local files itself, through
	5336	+ * purge_local(), rather than through purge_all() — so it has to announce
	5337	+ * on its own behalf or `wp xspeed purge` and the dashboard button clear
	5338	+ * our copy while LiteSpeed keeps serving the stale one.
	5339	+ *
	5340	+ * @param string $cause Who asked.
	5341	+ * @param int $removed Entries removed locally.
	5342	+ * @param string $scope Actionable adapter scope.
	5343	+ * @param string $intent Reason rendered responses changed.
	5344	+ */
	5345	+ public static function announce_purge( string $cause, int $removed, string $scope = 'site', string $intent = 'complete' ): void {
	5346	+ // Announcing is additive: the local sweep has already happened and
	5347	+ // succeeded. Notification must never be able to turn a working purge
	5348	+ // into a fatal, so anything the URL helpers do in an unusual context
	5349	+ // (early boot, a drop-in, a bare test harness) is contained here
	5350	+ // rather than propagating to the caller.
	5351	+ if ( ! function_exists( 'home_url' ) || ! function_exists( 'do_action' ) ) {
	5352	+ return;
	5353	+ }
	5354	+ try {
	5355	+ self::dispatch_purge_event(
	5356	+ 'xspeed_after_purge',
	5357	+ array(
	5358	+ 'url' => null,
	5359	+ 'host' => self::current_purge_host(),
	5360	+ 'path' => null,
	5361	+ 'cause' => $cause,
	5362	+ 'removed' => $removed,
	5363	+ 'scope' => $scope,
	5364	+ 'intent' => $intent,
	5365	+ 'urls' => array(),
	5366	+ )
	5367	+ );
	5368	+ } catch ( \Throwable $e ) {
	5369	+ self::log_purge_listener_error( 'xspeed_after_purge', $e );
	5370	+ }
	5371	+ }
	5372	+
	5373	+ /**
	5374	+ * Log a partial purge so the drill-down behind "Last purge" shows every
	5375	+ * clear, not only the full ones. Without this a site whose object cache
	5376	+ * is flushed on a schedule looks, from the log, like nothing happens.
	5377	+ *
	5378	+ * @param string $what Human label for the slice purged.
	5379	+ * @param string $cause Who asked.
	5380	+ * @param int|null $count Items removed, when countable.
	5381	+ */
	5382	+ private static function record_partial_purge( string $what, string $cause, ?int $count ): void {
	5383	+ $message = null === $count
	5384	+ ? sprintf(
	5385	+ /* translators: 1: what was purged, 2: cause of the purge. */
	5386	+ __( 'Purged %1$s (%2$s)', 'xspeed' ),
	5387	+ $what,
	5388	+ $cause
	5389	+ )
	5390	+ : sprintf(
	5391	+ /* translators: 1: what was purged, 2: cause of the purge, 3: number of files removed. */
	5392	+ __( 'Purged %1$s (%2$s) — %3$d file(s) removed', 'xspeed' ),
	5393	+ $what,
	5394	+ $cause,
	5395	+ $count
	5396	+ );
	5397	+
	5398	+ Activity_Log::record( 'cache_purged', $message, Activity_Log::INFO );
	5399	+ }
	5400	+
	5401	+ /**
	5402	+ * Clear the static tree only, leaving the flat cache in place.
	5403	+ *
	5404	+ * A narrower purge_all() for the case where only the web-server tree can
	5405	+ * be wrong: its files are keyed by `{host}{path}` and nothing else, so a
	5406	+ * response filed under the wrong path poisons it while the flat cache —
	5407	+ * keyed by cache_key(), discriminators included — stays correct. Avoids
	5408	+ * throwing away Critical CSS, minified bundles and the object cache to
	5409	+ * fix a static-only problem.
	5410	+ *
	5411	+ * @return int Number of index.html files removed.
	5412	+ */
	5413	+ public static function purge_static_tree(): int {
	5414	+ return self::rmtree_html( XSPEED_CACHE_STATIC_DIR );
	5415	+ }
	5416	+
	5417	+ /**
	5418	+ * Recursively delete every `index.html` (and its precompressed
	5419	+ * `index.html.br` sibling, if the Pro Brotli module wrote one) plus
	5420	+ * empty directories inside the static-cache tree. Used by purge_all().
	5421	+ * Returns the number of .html files removed so purge stats stay accurate
	5422	+ * across the flat + static caches — .br siblings are not counted
	5423	+ * (they're encodings of a page, not pages).
	5424	+ */
	5425	+ /**
	5426	+ * Delete a cache file, adding its size to the current sweep's byte
	5427	+ * total. filesize() is silenced and re-checked because the file can
	5428	+ * vanish between the glob and the unlink — a concurrent purge, or the
	5429	+ * cache GC — and a warning there would be noise, not news.
	5430	+ *
	5431	+ * @param string $file Absolute path inside the cache tree.
	5432	+ */
	5433	+ private static function sweep_delete( string $file ): void {
	5434	+ $size = @filesize( $file ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- the file may be gone already; see docblock.
	5435	+ if ( is_int( $size ) ) {
	5436	+ self::$sweep_bytes += $size;
	5437	+ }
	5438	+ wp_delete_file( $file );
	5439	+ }
	5440	+
422	5441	private static function rmtree_html( string $dir ): int {
423	5442	if ( ! is_dir( $dir ) ) {
424	5443	return 0;
425	5444	}
		@@ -443,10 +5462,16 @@
443	5462	@rmdir( $path );
444	5463	continue;
445	5464	}
446	5465	if ( substr( $entry, -5 ) === '.html' ) {
447		- wp_delete_file( $path );
	5466	+ self::sweep_delete( $path );
448	5467	++$removed;
	5468	+ } elseif ( substr( $entry, -3 ) === '.br' || substr( $entry, -8 ) === '.br.size' ) {
	5469	+ // Precompressed sibling (index.html.br) and the record of its
	5470	+ // length. Remove both so a purge doesn't orphan stale Brotli
	5471	+ // bodies, or a size record that would later be read against a
	5472	+ // different sibling's bytes. Not counted.
	5473	+ self::sweep_delete( $path );
449	5474	}
450	5475	}
451	5476	return $removed;
452	5477	}
		@@ -463,25 +5488,42 @@
463	5488	}
464	5489	}
465	5490
466	5491	/**
	5492	+ * The raw xspeed_stats option as an array. Keys currently in use:
	5493	+ * 'last_purge', 'last_gc', 'gc_removed', 'gc_removed_total'.
	5494	+ */
	5495	+ public static function get_stats_option(): array {
	5496	+ $stats = get_option( 'xspeed_stats', array() );
	5497	+ return is_array( $stats ) ? $stats : array();
	5498	+ }
	5499	+
	5500	+ /**
467	5501	* Persist stats with autoload disabled — stats are only read in admin
468	5502	* contexts, so there is no reason to inflate every frontend request's
469	5503	* `wp_load_alloptions()` payload.
	5504	+ *
	5505	+ * MERGES into whatever is already stored. It used to overwrite, which
	5506	+ * was harmless while `last_purge` was the only key — with the GC keys
	5507	+ * alongside it, a purge would have wiped the GC history and vice versa.
470	5508	*/
471		- private static function update_stats( array $stats ) {
472		- if ( false === get_option( 'xspeed_stats' ) ) {
	5509	+ public static function update_stats( array $stats ) {
	5510	+ if ( false === get_option( 'xspeed_stats', false ) ) {
473	5511	add_option( 'xspeed_stats', $stats, '', 'no' );
474	5512	return;
475	5513	}
476		- update_option( 'xspeed_stats', $stats );
	5514	+ update_option( 'xspeed_stats', array_merge( self::get_stats_option(), $stats ) );
477	5515	}
478	5516
479	5517	public static function get_stats() {
480	5518	$count = 0;
481	5519	$size = 0;
482		- if ( is_dir( XSPEED_CACHE_DIR ) ) {
483		- $files = glob( XSPEED_CACHE_DIR . '/*.html' );
	5520	+ // This site's entries only — on multisite the tree is shared, so an
	5521	+ // unscoped count reported the whole network's pages on every
	5522	+ // subsite's dashboard. (#6)
	5523	+ $flat_root = XSPEED_CACHE_DIR . '/' . self::current_host_dir();
	5524	+ if ( is_dir( $flat_root ) ) {
	5525	+ $files = glob( $flat_root . '/*.html' );
484	5526	if ( $files ) {
485	5527	$count = count( $files );
486	5528	foreach ( $files as $f ) {
487	5529	$size += filesize( $f );
		@@ -487,16 +5529,29 @@
487	5529	$size += filesize( $f );
488	5530	}
489	5531	}
490	5532	}
491		- // Drain the nginx HIT-log file written by the server-level
492		- // rewrite (see nginx_snippet()) BEFORE reading totals — otherwise
493		- // nginx-served HITs that never reach PHP go uncounted and the
494		- // dashboard reports 0% hit-ratio on a perfectly working cache.
	5533	+ // Drain the HIT-log file BEFORE reading totals. Two serve paths that
	5534	+ // bypass the normal in-PHP record_hit() append one line per HIT here:
	5535	+ // the nginx server-level rewrite (see nginx_snippet(), never reaches
	5536	+ // PHP) and the advanced-cache.php drop-in (runs pre-WordPress, can't
	5537	+ // reach Hit_Counter). Without this drain both look like a 0% hit-ratio
	5538	+ // on a perfectly working cache.
495	5539	Hit_Counter::collect_nginx_log_hits();
496	5540
	5541	+ // Apache/LiteSpeed static-rewrite HITs are served straight from disk
	5542	+ // by .htaccess and never reach PHP either — but there's no .htaccess
	5543	+ // equivalent of nginx's access_log directive, so we count them by
	5544	+ // scanning the web server's own access log incrementally. No-op when
	5545	+ // the log isn't readable (managed hosts) — see the method docblock.
	5546	+ Hit_Counter::collect_server_log_hits();
	5547	+
497	5548	$stats = get_option( 'xspeed_stats', array() );
498	5549	$totals = Hit_Counter::totals_24h();
	5550	+ // One read of the ground truth for both fields below: it costs a
	5551	+ // stat of advanced-cache.php and a tokenize of wp-config.php, and
	5552	+ // this runs on every dashboard poll.
	5553	+ $serving = self::page_cache_operational();
499	5554	return array(
500	5555	'cached_pages' => $count,
501	5556	'cache_size' => $size,
502	5557	'last_purge' => isset( $stats['last_purge'] ) ? (int) $stats['last_purge'] : 0,
		@@ -505,21 +5560,141 @@
505	5560	// CacheHero stat grid + the Health module's panel.
506	5561	'hits_24h' => $totals['hits'],
507	5562	'misses_24h' => $totals['misses'],
508	5563	'hit_ratio' => $totals['ratio'],
	5564	+ // Requests kept OUT of the ratio (404s + bots) — surfaced as its own
	5565	+ // "absorbed N scanner/bot requests" line rather than distorting the
	5566	+ // cache-performance number. (#118)
	5567	+ 'excluded_24h' => $totals['excluded'],
	5568	+ // True when an edge cache (Cloudflare) fronts the origin, so hits are
	5569	+ // absorbed before reaching PHP. The dashboard labels the ratio
	5570	+ // "origin-layer only" instead of implying it's the full picture. (#118)
	5571	+ 'edge_cache' => self::edge_cache_detected(),
	5572	+ // LiteSpeed Static Fast Path (#509): the web server serves hits
	5573	+ // with no PHP, no way to tag them, and no way to count them. The
	5574	+ // dashboard labels the ratio as PHP-layer only so a low number
	5575	+ // reads as the trade the user chose, not a fault.
	5576	+ //
	5577	+ // rewrite_installed() is part of the condition (QA on #513): when
	5578	+ // the .htaccess write failed (read-only file), hits still take
	5579	+ // the drop-in path and ARE counted — the disclosure would be the
	5580	+ // opposite of the truth. Health carries the "block missing"
	5581	+ // warning for that state; this flag only speaks when static
	5582	+ // serving is genuinely in effect.
	5583	+ 'static_hits_uncounted' => (
	5584	+ Server::LITESPEED === Server::type()
	5585	+ && ! empty( Settings::get()['cache_enabled'] )
	5586	+ && self::static_rewrite_allowed()
	5587	+ && self::rewrite_installed()
	5588	+ ),
	5589	+ /*
	5590	+ * Whether the page cache is actually SERVING, as opposed to
	5591	+ * switched on in settings. The hero read the setting alone and
	5592	+ * announced "Active — serving cached HTML"; a site whose
	5593	+ * advanced-cache.php had been taken over by another cache plugin
	5594	+ * got that line while every response carried
	5595	+ * `X-XSpeed-Cache: BYPASS`. The setting is the user's intent;
	5596	+ * this is the outcome, and the dashboard needs both to explain
	5597	+ * the difference.
	5598	+ */
	5599	+ 'page_cache_serving' => $serving,
	5600	+ /*
	5601	+ * Why not, when intent and outcome disagree. Only computed in
	5602	+ * that state — the detector sweep behind it is far more work than
	5603	+ * a stats call should do on an ordinary healthy site.
	5604	+ */
	5605	+ 'page_cache_blocked_reason' => ( ! $serving && ! empty( Settings::get()['cache_enabled'] ) )
	5606	+ ? ( self::acquisition_blocker() ?? self::not_serving_reason() )
	5607	+ : null,
509	5608	);
510	5609	}
511	5610
512	5611	/**
513		- * Apply the user's enable/disable choice. Called only from the REST
514		- * toggle endpoint, which is gated by current_user_can( 'manage_options' )
515		- * and a verified REST nonce. This is the only place the drop-in and
516		- * the WP_CACHE constant are written — they MUST NOT happen on
517		- * register_activation_hook (WordPress.org review requirement).
	5612	+ * Why the cache is not serving, when nothing REFUSES to enable it.
518	5613	*
	5614	+ * acquisition_blocker() answers "may we take the field", and since a
	5615	+ * foreign drop-in became takeable it answers null on a site where another
	5616	+ * plugin is nonetheless holding that file. Intent and outcome still
	5617	+ * disagree there, and the dashboard was left reporting the symptom -- not
	5618	+ * serving -- with no reason under it, which is exactly the state a user
	5619	+ * cannot act on.
	5620	+ *
	5621	+ * So this names the holder and says what to do: enabling takes it over.
	5622	+ */
	5623	+ private static function not_serving_reason(): ?string {
	5624	+ $owner = self::dropin_owner();
	5625	+ if ( self::DROPIN_FOREIGN !== $owner && self::DROPIN_UNREADABLE !== $owner ) {
	5626	+ return null;
	5627	+ }
	5628	+
	5629	+ if ( self::DROPIN_UNREADABLE === $owner ) {
	5630	+ return __( 'advanced-cache.php cannot be read, so xSpeed cannot tell whose page cache is installed.', 'xspeed' );
	5631	+ }
	5632	+
	5633	+ $label = Page_Cache_Detector::dropin_owner_label();
	5634	+ return $label
	5635	+ ? sprintf(
	5636	+ /* translators: %s: the page-caching plugin that owns advanced-cache.php. */
	5637	+ __( '%s is serving the page cache. Turn the xSpeed cache off and on again to take it over.', 'xspeed' ),
	5638	+ $label
	5639	+ )
	5640	+ : __( 'Another plugin is serving the page cache. Turn the xSpeed cache off and on again to take it over.', 'xspeed' );
	5641	+ }
	5642	+
	5643	+ /**
	5644	+ * Whether the current request should be kept OUT of the cache hit/miss
	5645	+ * ratio: a genuine 404, or a known bot / scanner. Runs at template_redirect
	5646	+ * time, so is_404() is resolved. (#118)
	5647	+ */
	5648	+ private static function miss_is_excluded(): bool {
	5649	+ if ( function_exists( 'is_404' ) && is_404() ) {
	5650	+ return true;
	5651	+ }
	5652	+ $ua = isset( $_SERVER['HTTP_USER_AGENT'] )
	5653	+ ? sanitize_text_field( wp_unslash( (string) $_SERVER['HTTP_USER_AGENT'] ) )
	5654	+ : '';
	5655	+ return Hit_Counter::is_bot_ua( $ua );
	5656	+ }
	5657	+
	5658	+ /**
	5659	+ * Whether an edge cache fronts this origin, so an unknown share of hits
	5660	+ * is served there and never counted here — which makes the origin ratio a
	5661	+ * partial view the dashboard has to label as such. (#118)
	5662	+ *
	5663	+ * This used to mean "the Cloudflare module is switched on", which answered
	5664	+ * no for every site fronted by anything else, and no for a site on
	5665	+ * Cloudflare that had never opened our Cloudflare panel. Both of those
	5666	+ * sites had their ratio presented as the whole story. Edge_Provider knows
	5667	+ * better and knows it per request, so ask it.
	5668	+ */
	5669	+ private static function edge_cache_detected(): bool {
	5670	+ return Edge_Provider::NONE !== Edge_Provider::detect()['confidence'];
	5671	+ }
	5672	+
	5673	+ /**
	5674	+ * Apply the user's enable/disable choice. Called from the REST toggle
	5675	+ * endpoint, which is gated by current_user_can( 'manage_options' ) and
	5676	+ * a verified REST nonce.
	5677	+ *
	5678	+ * This is the only path that ENABLES caching — a drop-in is never
	5679	+ * created for a user who hasn't opted in, which is the guideline that
	5680	+ * matters (a plugin must not install drop-ins or edit wp-config.php
	5681	+ * on a fresh activation). RESTORING the drop-in for a site that
	5682	+ * already has cache_enabled = true is a different act and is handled
	5683	+ * by restore_dropin_if_enabled() on activation and auto_heal() at
	5684	+ * runtime; without it every plugin update silently un-caches the site.
	5685	+ *
	5686	+ * Enabling is gated on acquisition_blocker(): if another plugin owns the
	5687	+ * drop-in, or WP_CACHE is written in a form we must not rewrite, nothing
	5688	+ * is written and the returned state carries `blocked` + a reason the
	5689	+ * caller can show. Callers must persist `cache_enabled` from the returned
	5690	+ * `enabled`, never from what they asked for.
	5691	+ *
519	5692	* @param bool $enable User's choice.
520	5693	* @return array{
521	5694	* enabled: bool,
	5695	+ * blocked: bool,
	5696	+ * blocked_reason: ?string,
522	5697	* dropin_installed: bool,
523	5698	* wp_cache_constant: bool,
524	5699	* wp_config_writable: bool,
525	5700	* manual_snippet: ?string
		@@ -524,28 +5699,228 @@
524	5699	* wp_config_writable: bool,
525	5700	* manual_snippet: ?string
526	5701	* }
527	5702	*/
528		- public static function toggle( $enable ) {
	5703	+ public static function toggle( $enable, bool $consented = true ) {
	5704	+ Page_Cache_Detector::invalidate();
	5705	+ $expected = Page_Cache_Detector::inspect()['revision'];
	5706	+ /** Diagnostic seam; changing the expected revision can only force a safe refusal. */
	5707	+ $expected = (string) apply_filters( 'xspeed_page_cache_expected_revision', $expected );
	5708	+ $lock = self::page_cache_lock();
	5709	+ if ( ! is_resource( $lock ) ) {
	5710	+ return self::blocked_toggle_state( __( 'Could not lock page-cache ownership. Try again.', 'xspeed' ) );
	5711	+ }
	5712	+ try {
	5713	+ Page_Cache_Detector::invalidate();
	5714	+ $fresh = Page_Cache_Detector::inspect()['revision'];
	5715	+ if ( ! hash_equals( (string) $expected, (string) $fresh ) ) {
	5716	+ return self::blocked_toggle_state( __( 'Page-cache ownership changed while xSpeed was checking it. Nothing was changed; try again.', 'xspeed' ) );
	5717	+ }
	5718	+ $state = self::toggle_unlocked( (bool) $enable, $consented );
	5719	+ return $state;
	5720	+ } finally {
	5721	+ flock( $lock, LOCK_UN );
	5722	+ fclose( $lock );
	5723	+ }
	5724	+ }
	5725	+
	5726	+ /** Run the page-cache mutation while toggle() owns the scoped lock. */
	5727	+ /**
	5728	+ * @param bool $consented The user asked for this in the dashboard, so a
	5729	+ * foreign drop-in may be taken over. False on the
	5730	+ * unattended paths, which stand down instead.
	5731	+ */
	5732	+ private static function toggle_unlocked( bool $enable, bool $consented = true ) {
529	5733	$enable = (bool) $enable;
530	5734
531	5735	if ( $enable ) {
532		- $dropin_ok = self::install_dropin();
533		- $wp_config_ok = self::set_wp_cache_constant( true );
	5736	+ /*
	5737	+ * Preflight. The drop-in and the WP_CACHE define are shared,
	5738	+ * single-occupancy state; if we do not own them, no part of this
	5739	+ * runs — not the drop-in, not wp-config.php, not the rewrite
	5740	+ * block. Refusing whole is the point: a partial enable leaves the
	5741	+ * site claiming a cache it cannot serve.
	5742	+ *
	5743	+ * Every caller routes through here (REST, onboarding, MCP, CLI,
	5744	+ * the optimize runner, Pro's migration), so the gate lives here
	5745	+ * rather than being re-implemented at each entry point.
	5746	+ *
	5747	+ * Except when there is nothing to acquire. A site where we
	5748	+ * already own the drop-in and are already serving is being asked
	5749	+ * to stay as it is, and the gate answers a different question —
	5750	+ * "is the field free to take" — which a merely ACTIVE competitor
	5751	+ * makes false. So "make sure caching is on", from an AI agent,
	5752	+ * the optimize runner or Pro's migration, came back as a refusal
	5753	+ * telling the user to deactivate a plugin on a site that was
	5754	+ * caching perfectly. The dashboard never saw it, because nobody
	5755	+ * presses Enable on a cache that is already enabled.
	5756	+ *
	5757	+ * Only the GATE is skipped. The writes below still run, and every
	5758	+ * one of them is individually idempotent — which matters, because
	5759	+ * this is the path CacheModule re-bakes the drop-in through when
	5760	+ * an exclusion rule or the TTL changes (#240, #251), and the path
	5761	+ * auto_heal() restores a stripped WP_CACHE through. Returning
	5762	+ * early here left both of those doing nothing at all, silently,
	5763	+ * on exactly the healthy sites this branch is about.
	5764	+ */
	5765	+ $reasserting = self::page_cache_operational() && self::DROPIN_XSPEED === self::dropin_owner();
	5766	+ $blocker = $reasserting ? null : self::acquisition_blocker();
	5767	+
	5768	+ /*
	5769	+ * Taking over another plugin's drop-in needs the user to have
	5770	+ * asked for it. On the dashboard they did -- they clicked the
	5771	+ * switch, having been told whose file it is. The UNATTENDED
	5772	+ * callers have no such click: restore_dropin_if_enabled() runs
	5773	+ * after a plugin update and auto_heal() on an admin page load,
	5774	+ * both from nothing more than `cache_enabled` still being true.
	5775	+ *
	5776	+ * A competitor installed since that flag was set would have its
	5777	+ * page cache seized by a background repair, which is the silent
	5778	+ * acquisition this plugin refuses to perform. So those callers
	5779	+ * pass $consented = false and stand down instead.
	5780	+ */
	5781	+ if ( null === $blocker && ! $consented && self::DROPIN_FOREIGN === self::dropin_owner() ) {
	5782	+ // Name the owner. This string is rendered by host plugins
	5783	+ // through Host::enable_page_cache(), and an unnamed refusal
	5784	+ // is what made every host invent its own explanation.
	5785	+ $owner_label = Page_Cache_Detector::dropin_owner_label();
	5786	+ return self::blocked_toggle_state(
	5787	+ $owner_label
	5788	+ ? sprintf(
	5789	+ /* translators: %s: the page-caching plugin that owns advanced-cache.php. */
	5790	+ __( '%s owns advanced-cache.php, so xSpeed left it alone. Enable the cache from the xSpeed dashboard to take it over.', 'xspeed' ),
	5791	+ $owner_label
	5792	+ )
	5793	+ : __( 'Another plugin owns advanced-cache.php, so xSpeed left it alone. Enable the cache from the xSpeed dashboard to take it over.', 'xspeed' )
	5794	+ );
	5795	+ }
	5796	+ if ( null !== $blocker ) {
	5797	+ Activity_Log::record(
	5798	+ 'cache_enable_blocked',
	5799	+ 'Cache not enabled — ' . $blocker,
	5800	+ Activity_Log::WARN
	5801	+ );
	5802	+
	5803	+ return self::blocked_toggle_state( $blocker );
	5804	+ }
	5805	+
	5806	+ $dropin_path = WP_CONTENT_DIR . '/advanced-cache.php';
	5807	+ $config_path = self::wp_config_path();
	5808	+ $dropin_before = file_exists( $dropin_path ) ? self::read_file( $dropin_path ) : null;
	5809	+ $config_before = '' !== $config_path ? self::read_file( $config_path ) : null;
	5810	+ $dropin_ok = self::install_dropin();
	5811	+ if ( ! $dropin_ok ) {
	5812	+ $partial = self::read_file( $dropin_path );
	5813	+ if ( is_string( $partial ) && xspeed_has_canonical_dropin_signature( $partial ) ) {
	5814	+ self::rollback_page_cache_artifacts( $dropin_path, $dropin_before, $partial, $config_path, $config_before, null );
	5815	+ }
	5816	+ /*
	5817	+ * Preflight said the field was clear, so this is a filesystem
	5818	+ * failure (or a drop-in that appeared in between). Without the
	5819	+ * drop-in there is no cache to enable, and persisting
	5820	+ * cache_enabled anyway is what produced sites reporting a
	5821	+ * healthy cache while serving every request uncached.
	5822	+ */
	5823	+ $reason = __( 'Could not write wp-content/advanced-cache.php. Check filesystem permissions.', 'xspeed' );
	5824	+ Activity_Log::record(
	5825	+ 'cache_enable_blocked',
	5826	+ 'Cache not enabled — ' . $reason,
	5827	+ Activity_Log::WARN
	5828	+ );
	5829	+
	5830	+ return array(
	5831	+ 'enabled' => false,
	5832	+ 'blocked' => true,
	5833	+ 'blocked_reason' => $reason,
	5834	+ 'dropin_installed' => false,
	5835	+ 'wp_cache_constant' => false,
	5836	+ 'rewrite_installed' => false,
	5837	+ 'wp_config_writable' => self::wp_config_writable(),
	5838	+ 'manual_snippet' => null,
	5839	+ 'nginx_snippet' => self::nginx_snippet(),
	5840	+ 'nginx_server_block' => self::full_nginx_server_block(),
	5841	+ );
	5842	+ }
	5843	+
	5844	+ $dropin_written = self::read_file( $dropin_path );
	5845	+ self::set_wp_cache_constant( true );
	5846	+ $config_written = '' !== $config_path ? self::read_file( $config_path ) : null;
	5847	+ Page_Cache_Detector::invalidate();
	5848	+ $dropin_ours = self::DROPIN_XSPEED === self::dropin_owner();
	5849	+ $constant_state = self::wp_cache_define_state();
	5850	+ $constant_ok = 'true' === $constant_state;
	5851	+
	5852	+ /*
	5853	+ * A wp-config.php we cannot write at all is a supported state, not
	5854	+ * a failed transaction. Plenty of managed hosts ship the file
	5855	+ * read-only; there the drop-in is ours and installed, the cache
	5856	+ * works the moment WP_CACHE exists, and the one line to paste
	5857	+ * comes back as `manual_snippet`. Rolling back instead left those
	5858	+ * hosts unable to turn the page cache on by any route — including
	5859	+ * when the user had already pasted the define, since the write
	5860	+ * fails on an unwritable file whatever value is already there.
	5861	+ *
	5862	+ * `undefined` ONLY. `false` looks eligible — this method would
	5863	+ * have rewritten it — but the snippet we hand back cannot work
	5864	+ * there: the file already says `define( 'WP_CACHE', false )`, the
	5865	+ * first define() call wins, and a user who pastes our line via
	5866	+ * FTP ends up with a cache that never serves AND a `duplicate`
	5867	+ * wp-config that blocks every future toggle in both directions.
	5868	+ * They have to edit the existing line, which means refusing here
	5869	+ * and saying so. `duplicate` and `dynamic` are refused by
	5870	+ * acquisition_blocker() before we get here, and if one appears in
	5871	+ * the race window it must still fail closed.
	5872	+ */
	5873	+ $manual_mode = ! $constant_ok
	5874	+ && 'undefined' === $constant_state
	5875	+ && ! self::can_write_wp_config();
	5876	+
	5877	+ if ( ! $dropin_ours || ( ! $constant_ok && ! $manual_mode ) ) {
	5878	+ if ( ! self::can_write_wp_config() ) {
	5879	+ $reason = 'false' === $constant_state
	5880	+ ? __( "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' )
	5881	+ : __( 'xSpeed could not verify the complete page-cache write, and wp-config.php is not writable. Its changes were rolled back.', 'xspeed' );
	5882	+ } else {
	5883	+ $reason = __( 'xSpeed could not verify the complete page-cache write. Its changes were rolled back.', 'xspeed' );
	5884	+ }
	5885	+ self::rollback_page_cache_artifacts( $dropin_path, $dropin_before, $dropin_written, $config_path, $config_before, $config_written );
	5886	+ return self::blocked_toggle_state( $reason );
	5887	+ }
	5888	+ $wp_config_ok = $constant_ok;
534	5889	$rewrite_ok = self::install_rewrite();
535	5890	self::ensure_hits_log_file();
	5891	+ self::sync_mobile_flag();
536	5892	$snippet = $wp_config_ok ? null : "define( 'WP_CACHE', true );";
	5893	+ Settings::update( array( 'cache_enabled' => true ) );
	5894	+ if ( empty( Settings::get()['cache_enabled'] ) ) {
	5895	+ self::remove_rewrite();
	5896	+ self::rollback_page_cache_artifacts( $dropin_path, $dropin_before, $dropin_written, $config_path, $config_before, $config_written );
	5897	+ delete_option( 'xspeed_page_cache_ownership_receipt' );
	5898	+ return self::blocked_toggle_state( __( 'xSpeed could not save the page-cache setting. Its file changes were rolled back.', 'xspeed' ) );
	5899	+ }
537	5900
538		- Activity_Log::record(
539		- 'cache_enabled_event',
540		- $wp_config_ok
541		- ? 'Cache enabled. Drop-in installed, WP_CACHE constant set.'
542		- : 'Cache enabled. Drop-in installed; wp-config.php not writable — add the WP_CACHE snippet manually.',
543		- $wp_config_ok ? Activity_Log::SUCCESS : Activity_Log::WARN
544		- );
	5901	+ /*
	5902	+ * Only when this call actually changed something. auto_heal() runs
	5903	+ * the enable transaction on every admin_init, and an unconditional
	5904	+ * entry filled the 50-slot log with identical "Cache enabled" lines
	5905	+ * within 50 wp-admin page loads, evicting every real event — plus
	5906	+ * an option write per admin request. The sentence is also false
	5907	+ * when nothing was installed.
	5908	+ */
	5909	+ if ( $dropin_written !== $dropin_before || $config_written !== $config_before ) {
	5910	+ Activity_Log::record(
	5911	+ 'cache_enabled_event',
	5912	+ $wp_config_ok
	5913	+ ? 'Cache enabled. Drop-in installed, WP_CACHE constant set.'
	5914	+ : 'Cache enabled. Drop-in installed; wp-config.php not writable — add the WP_CACHE snippet manually.',
	5915	+ $wp_config_ok ? Activity_Log::SUCCESS : Activity_Log::WARN
	5916	+ );
	5917	+ }
545	5918
546	5919	return array(
547	5920	'enabled' => true,
	5921	+ 'blocked' => false,
	5922	+ 'blocked_reason' => null,
548	5923	'dropin_installed' => (bool) $dropin_ok,
549	5924	'wp_cache_constant' => (bool) $wp_config_ok,
550	5925	'rewrite_installed' => (bool) $rewrite_ok,
551	5926	'wp_config_writable' => self::wp_config_writable(),
		@@ -550,33 +5925,310 @@
550	5925	'rewrite_installed' => (bool) $rewrite_ok,
551	5926	'wp_config_writable' => self::wp_config_writable(),
552	5927	'manual_snippet' => $snippet,
553	5928	'nginx_snippet' => self::nginx_snippet(),
	5929	+ // Unified server-block snippet aggregating every enabled
	5930	+ // module's directives — the same value the dashboard and
	5931	+ // Health insight render. The wizard shows this so all three
	5932	+ // surfaces stay in lockstep. Null on non-nginx hosts.
	5933	+ 'nginx_server_block' => self::full_nginx_server_block(),
554	5934	);
555	5935	}
556	5936
	5937	+ /*
	5938	+ * Whose advanced-cache.php is on disk decides how much of the disable
	5939	+ * below may run. Read it once, before anything is touched.
	5940	+ */
	5941	+ $owner = self::dropin_owner();
	5942	+ $not_ours = self::DROPIN_FOREIGN === $owner || self::DROPIN_UNREADABLE === $owner;
	5943	+ if ( ! self::set_wp_cache_constant( false ) ) {
	5944	+ /*
	5945	+ * The mirror of the enable path. A wp-config.php nobody can write
	5946	+ * does not trap the user in a cache they turned off: WP_CACHE on
	5947	+ * its own does nothing once advanced-cache.php is gone, and core
	5948	+ * simply skips the missing drop-in. Refusing here left the
	5949	+ * read-only managed hosts able to enable the page cache and never
	5950	+ * able to disable it again.
	5951	+ *
	5952	+ * A drop-in that is not ours reaches the same conclusion by a
	5953	+ * different road. WP_CACHE is then the switch for THEIR cache, so
	5954	+ * set_wp_cache_constant() refuses it — correctly, and permanently,
	5955	+ * because nothing the user does to xSpeed will make that file ours
	5956	+ * again. Treating that refusal as a failed disable was a trap with
	5957	+ * no exit: install any competing cache plugin while xSpeed's cache
	5958	+ * was on, and xSpeed's toggle could never be turned off again,
	5959	+ * while the dashboard went on claiming a cache that was serving
	5960	+ * nothing. Turning xSpeed off is entirely within our own state —
	5961	+ * our setting, our rewrite block — so it proceeds, and their
	5962	+ * constant and their file are left exactly as they are.
	5963	+ */
	5964	+ /*
	5965	+ * Every reason set_wp_cache_constant() refuses is structural
	5966	+ * except one, and the exception is the only one worth blocking
	5967	+ * on. It will not touch a constant it cannot prove is ours; it
	5968	+ * will not rewrite a define it cannot read as a literal —
	5969	+ * duplicate, dynamic, or inside a conditional; and it cannot
	5970	+ * write a file the filesystem will not let it write. None of
	5971	+ * those improve on a retry, and all of them leave a WP_CACHE
	5972	+ * that does nothing once our drop-in is gone. What is left — our
	5973	+ * own constant, in a shape we can rewrite, in a file we can
	5974	+ * write, and the write still failed — is a real I/O failure, and
	5975	+ * that one still refuses so the user is not told a cache was
	5976	+ * turned off while it goes on serving.
	5977	+ *
	5978	+ * The proof, not the drop-in, is the test. A user who pasted our
	5979	+ * manual snippet on a locked-down host has a WP_CACHE line with
	5980	+ * no receipt on it; if their drop-in later goes missing, we can
	5981	+ * never prove that line is ours, so refusing left the toggle
	5982	+ * stuck on with no way out but enabling first and disabling
	5983	+ * again. Nothing loads a drop-in that is not there, so the line
	5984	+ * is inert either way and the disable proceeds without it.
	5985	+ */
	5986	+ $leave_it = ! self::wp_cache_define_is_ours_to_remove( $owner )
	5987	+ || ! in_array( self::wp_cache_define_state(), array( 'true', 'false', 'undefined' ), true )
	5988	+ || ! self::can_write_wp_config();
	5989	+ if ( ! $leave_it ) {
	5990	+ return self::blocked_toggle_state( __( 'xSpeed could not safely remove its WP_CACHE setting. The cache remains enabled.', 'xspeed' ) );
	5991	+ }
	5992	+ }
557	5993	self::remove_dropin();
558		- self::set_wp_cache_constant( false );
	5994	+ if ( self::DROPIN_XSPEED === self::dropin_owner() ) {
	5995	+ // Put WP_CACHE back, and say so if we could not. Reporting a
	5996	+ // hardcoded `enabled: true` here claimed a working cache on a
	5997	+ // site whose constant we had just failed to restore.
	5998	+ // Put WP_CACHE back, then read the outcome off disk rather than
	5999	+ // trusting the write's return value — a write can report failure
	6000	+ // for a value that was already correct, and the question the
	6001	+ // caller needs answered is whether the cache serves.
	6002	+ self::set_wp_cache_constant( true );
	6003	+ return self::blocked_toggle_state(
	6004	+ self::page_cache_operational()
	6005	+ ? __( 'xSpeed could not remove its page-cache drop-in. The cache remains enabled.', 'xspeed' )
	6006	+ : __( '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' )
	6007	+ );
	6008	+ }
559	6009	self::remove_rewrite();
	6010	+ /*
	6011	+ * The .htaccess block serves cached HTML straight off disk without
	6012	+ * ever reaching PHP, so a block we failed to remove keeps answering
	6013	+ * requests from a cache the user just turned off — and nothing else
	6014	+ * in this method can stop it. remove_rewrite() also returns false
	6015	+ * when there is no .htaccess to clean, which is the ordinary case,
	6016	+ * so ask the file rather than trust the return value.
	6017	+ */
	6018	+ if ( self::rewrite_installed() ) {
	6019	+ if ( $not_ours ) {
	6020	+ // Nothing to roll back — under a foreign drop-in this method
	6021	+ // removed no drop-in and wrote no constant, and it could not
	6022	+ // put either back if it wanted to. Say what is actually left.
	6023	+ 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' ) );
	6024	+ }
	6025	+ /*
	6026	+ * Roll the disable back. Both calls can fail — a filesystem that
	6027	+ * would not let us remove the block may not let us write the
	6028	+ * drop-in either — and discarding their results reported an
	6029	+ * enabled cache over a site left with no drop-in and no
	6030	+ * constant. Fall through to the default state so the artifact
	6031	+ * fields are read from disk rather than asserted.
	6032	+ */
	6033	+ self::install_dropin();
	6034	+ self::set_wp_cache_constant( true );
	6035	+ // Both of those can fail — a filesystem that would not let us
	6036	+ // remove the block may not let us write the drop-in either — so
	6037	+ // the message follows what is on disk afterwards, not what the
	6038	+ // calls returned.
	6039	+ return self::blocked_toggle_state(
	6040	+ self::page_cache_operational()
	6041	+ ? __( 'xSpeed could not remove its rewrite rules from .htaccess, which would keep serving cached pages. The cache remains enabled.', 'xspeed' )
	6042	+ : __( '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' )
	6043	+ );
	6044	+ }
	6045	+ // Drop the device-bucket marker too — with the drop-in gone there's
	6046	+ // nothing left to read it, and leaving it behind would dirty a fresh
	6047	+ // re-enable (and leaks across test runs).
	6048	+ self::sync_mobile_flag( false );
	6049	+ Settings::update( array( 'cache_enabled' => false ) );
	6050	+ if ( ! empty( Settings::get()['cache_enabled'] ) ) {
	6051	+ if ( $not_ours ) {
	6052	+ // Same as above: there is nothing of ours on disk to restore.
	6053	+ return self::blocked_toggle_state( __( 'xSpeed could not save the disabled state.', 'xspeed' ) );
	6054	+ }
	6055	+ self::install_dropin();
	6056	+ self::set_wp_cache_constant( true );
	6057	+ return self::blocked_toggle_state( __( 'xSpeed could not save the disabled state. The page cache was restored.', 'xspeed' ) );
	6058	+ }
560	6059
	6060	+ // A WP_CACHE we could not remove because wp-config.php is read-only
	6061	+ // is left behind deliberately (see above) — say so rather than
	6062	+ // reporting a constant that is still in the file as gone.
	6063	+ $constant_left = 'true' === self::wp_cache_define_state();
	6064	+ /*
	6065	+ * Say why the constant is still there, because there are now three
	6066	+ * different reasons and they call for different advice. Keyed off the
	6067	+ * same facts $leave_it was, so the log cannot drift from the decision
	6068	+ * it is describing — it did, briefly, and reported a wp-config.php as
	6069	+ * unwritable when the real reason was that we could not prove the
	6070	+ * line was ours.
	6071	+ */
	6072	+ if ( self::DROPIN_UNREADABLE === $owner ) {
	6073	+ $log_message = 'Cache disabled. advanced-cache.php could not be read, so it and the WP_CACHE setting were left untouched.';
	6074	+ } elseif ( $not_ours ) {
	6075	+ $log_message = 'Cache disabled. Another plugin owns advanced-cache.php, so its drop-in and its WP_CACHE setting were left untouched.';
	6076	+ } elseif ( ! $constant_left ) {
	6077	+ $log_message = 'Cache disabled. Drop-in removed.';
	6078	+ } elseif ( ! self::wp_cache_define_is_ours_to_remove( $owner ) ) {
	6079	+ $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.';
	6080	+ } elseif ( ! self::can_write_wp_config() ) {
	6081	+ $log_message = 'Cache disabled. Drop-in removed; wp-config.php not writable, so WP_CACHE was left in place (harmless without the drop-in).';
	6082	+ } else {
	6083	+ $log_message = 'Cache disabled. Drop-in removed; WP_CACHE was left in place (harmless without the drop-in).';
	6084	+ }
561	6085	Activity_Log::record(
562	6086	'cache_disabled_event',
563		- 'Cache disabled. Drop-in removed.',
564		- Activity_Log::INFO
	6087	+ $log_message,
	6088	+ $constant_left ? Activity_Log::WARN : Activity_Log::INFO
565	6089	);
566	6090
567	6091	return array(
568	6092	'enabled' => false,
	6093	+ 'blocked' => false,
	6094	+ 'blocked_reason' => null,
569	6095	'dropin_installed' => false,
570		- 'wp_cache_constant' => false,
	6096	+ 'wp_cache_constant' => $constant_left,
571	6097	'rewrite_installed' => false,
572	6098	'wp_config_writable' => self::wp_config_writable(),
573	6099	'manual_snippet' => null,
574	6100	'nginx_snippet' => self::nginx_snippet(),
	6101	+ 'nginx_server_block' => self::full_nginx_server_block(),
575	6102	);
576	6103	}
577	6104
	6105	+ /** Acquire the local lock that serializes page-cache ownership changes. */
	6106	+ private static function page_cache_lock() {
	6107	+ $path = WP_CONTENT_DIR . '/.xspeed-page-cache.lock';
	6108	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fopen,WordPress.PHP.NoSilencedErrors.Discouraged -- flock requires a local handle; failure is a safe blocked result.
	6109	+ $lock = @fopen( $path, 'c+' );
	6110	+ if ( ! is_resource( $lock ) || ! flock( $lock, LOCK_EX ) ) {
	6111	+ return false;
	6112	+ }
	6113	+ return $lock;
	6114	+ }
	6115	+
578	6116	/**
	6117	+ * Build the stable response shape for a refused transaction.
	6118	+ *
	6119	+ * The artifact fields report what is ON DISK, not zeros. A refusal means
	6120	+ * xSpeed changed nothing — on a site already running our cache that is
	6121	+ * exactly the state where the drop-in and WP_CACHE are both still in
	6122	+ * place and still serving hits. Hardcoding false told the dashboard the
	6123	+ * cache had been dismantled every time a refusal was returned.
	6124	+ */
	6125	+ private static function blocked_toggle_state( string $reason ): array {
	6126	+ /*
	6127	+ * `enabled` answers ONE question: is the page cache operational right
	6128	+ * now. Not what was asked for, and not what the option says.
	6129	+ *
	6130	+ * WordPress loads advanced-cache.php only when WP_CACHE is truthy, so
	6131	+ * those two files together are the whole answer, and reading them is
	6132	+ * the only source that cannot go stale. Both of the alternatives were
	6133	+ * tried here and both produced wrong answers on real paths: a
	6134	+ * hardcoded false told a caller the cache had gone away on a site
	6135	+ * still serving hits, and the persisted setting told a caller the
	6136	+ * cache was healthy after a rollback had just removed the artifacts
	6137	+ * — the option is not written until the end of the transaction, so
	6138	+ * mid-transaction it is stale by construction.
	6139	+ *
	6140	+ * Deliberately not a parameter. Every branch that got to choose its
	6141	+ * own answer eventually chose wrong.
	6142	+ */
	6143	+ return array(
	6144	+ 'enabled' => self::page_cache_operational(),
	6145	+ 'blocked' => true,
	6146	+ 'blocked_reason' => $reason,
	6147	+ 'dropin_installed' => self::DROPIN_XSPEED === self::dropin_owner(),
	6148	+ 'wp_cache_constant' => 'true' === self::wp_cache_define_state(),
	6149	+ 'rewrite_installed' => self::rewrite_installed(),
	6150	+ 'wp_config_writable' => self::wp_config_writable(),
	6151	+ 'manual_snippet' => null,
	6152	+ 'nginx_snippet' => self::nginx_snippet(),
	6153	+ 'nginx_server_block' => self::full_nginx_server_block(),
	6154	+ );
	6155	+ }
	6156	+
	6157	+ /**
	6158	+ * The wp-config.php line a user must paste, or null when none is needed.
	6159	+ *
	6160	+ * Non-null only where the drop-in is ours and WP_CACHE is not set to true
	6161	+ * in a file we can write — the read-only managed host. Everywhere else the
	6162	+ * constant is ours to manage and there is nothing to ask for.
	6163	+ */
	6164	+ public static function manual_wp_cache_snippet(): ?string {
	6165	+ if ( self::DROPIN_XSPEED !== self::dropin_owner() ) {
	6166	+ return null;
	6167	+ }
	6168	+ if ( 'true' === self::wp_cache_define_state() ) {
	6169	+ return null;
	6170	+ }
	6171	+ return self::wp_config_writable() ? null : "define( 'WP_CACHE', true );";
	6172	+ }
	6173	+
	6174	+ /**
	6175	+ * Is the page cache serving right now?
	6176	+ *
	6177	+ * Two things decide it, and `WP_CACHE` is not one of them.
	6178	+ *
	6179	+ * xSpeed serves a cached page from `template_redirect` whenever the
	6180	+ * setting is on — see the `HIT (php)` mark on that path, which exists
	6181	+ * precisely for "the drop-in isn't loaded". `advanced-cache.php` and the
	6182	+ * `WP_CACHE` constant that loads it are the FAST path: they answer before
	6183	+ * WordPress boots, which is worth a lot of milliseconds and nothing at
	6184	+ * all to the question of whether pages are being served from cache.
	6185	+ *
	6186	+ * Conflating the two reported a dead cache over a live one. On a managed
	6187	+ * host with an unwritable wp-config.php — the exact case the manual
	6188	+ * snippet exists for — one card said "Your cache works on every request",
	6189	+ * "On, but not serving", "nothing will be cached until you add this line"
	6190	+ * and "hit ratio 67%", all at once, and told the user to edit a file they
	6191	+ * have no permission to write. The released 1.2.1 reported that site as
	6192	+ * active, correctly.
	6193	+ *
	6194	+ * So: the setting, and whether anyone else holds the drop-in. A foreign
	6195	+ * drop-in answers before WordPress loads us, so ours never runs and we
	6196	+ * genuinely are not serving. An unreadable one we must assume the same of.
	6197	+ * Everything else — our drop-in, or none at all — serves.
	6198	+ *
	6199	+ * Public because it is part of the host-plugin contract — see Host. A
	6200	+ * plugin that installed xSpeed needs to be able to say whether the cache
	6201	+ * it asked for is actually serving, and no combination of settings reads
	6202	+ * answers that.
	6203	+ */
	6204	+ public static function page_cache_operational(): bool {
	6205	+ $settings = Settings::get();
	6206	+ if ( empty( $settings['cache_enabled'] ) ) {
	6207	+ return false;
	6208	+ }
	6209	+ $owner = self::dropin_owner();
	6210	+ return self::DROPIN_FOREIGN !== $owner && self::DROPIN_UNREADABLE !== $owner;
	6211	+ }
	6212	+
	6213	+ /** Restore exact snapshots only while disk still matches our own write. */
	6214	+ 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 {
	6215	+ // Roll back only files that still carry xSpeed's just-written state.
	6216	+ if ( null !== $dropin_written && hash_equals( $dropin_written, (string) self::read_file( $dropin_path ) ) ) {
	6217	+ if ( null === $dropin_before ) {
	6218	+ wp_delete_file( $dropin_path );
	6219	+ } else {
	6220	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- Exact compare-and-swap rollback under the scoped lock.
	6221	+ file_put_contents( $dropin_path, $dropin_before );
	6222	+ }
	6223	+ }
	6224	+ 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 ) ) {
	6225	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- Exact compare-and-swap rollback under the scoped lock.
	6226	+ file_put_contents( $config_path, $config_before );
	6227	+ }
	6228	+ }
	6229	+
	6230	+ /**
579	6231	* Check wp-config.php writability via WP_Filesystem. Plugin Check flags
580	6232	* direct is_writable() under WordPress.WP.AlternativeFunctions.
581	6233	*/
582	6234	private static function wp_config_writable() {
		@@ -613,27 +6265,913 @@
613	6265	* they don't share a user at all. A default-umask 0644 file is then
614	6266	* unwritable by nginx, the access_log write silently fails, and the
615	6267	* dashboard shows a 0% hit ratio even though static HITs are serving.
616	6268	* So we widen the dir to 0777 and the file to 0666 — group/other write —
617		- * so whatever uid nginx runs as can append. (The file holds only HIT
618		- * request lines, no secrets.)
	6269	+ * so whatever uid nginx runs as can append. The file holds HIT request
	6270	+ * lines and must be protected like an access log: paths and queries can
	6271	+ * contain sensitive values.
619	6272	*/
	6273	+ /**
	6274	+ * Directory holding the nginx hit log. Lives under uploads/, NOT the
	6275	+ * cache dir — uninstall.php and a cache purge both delete the cache
	6276	+ * dir, which would orphan the pasted nginx `access_log` directive's
	6277	+ * parent directory and make `nginx -t` fail [emerg], taking down every
	6278	+ * vhost on the host (FBS-82478). uploads/ always exists, isn't a
	6279	+ * plugin-managed cache dir, and is never deleted on uninstall — so the
	6280	+ * directive's target dir survives both, and nginx (which creates a
	6281	+ * missing log FILE but not a missing DIR) can always open it.
	6282	+ *
	6283	+ * Falls back to the cache dir only if uploads is somehow unavailable.
	6284	+ */
	6285	+ public static function hits_log_dir(): string {
	6286	+ if ( function_exists( 'wp_upload_dir' ) ) {
	6287	+ $uploads = wp_upload_dir( null, false );
	6288	+ if ( is_array( $uploads ) && empty( $uploads['error'] ) && ! empty( $uploads['basedir'] ) ) {
	6289	+ return rtrim( (string) $uploads['basedir'], '/' ) . '/xspeed';
	6290	+ }
	6291	+ }
	6292	+ return XSPEED_CACHE_DIR;
	6293	+ }
	6294	+
	6295	+ /** Absolute path to the nginx hit log file. */
	6296	+ public static function hits_log_path(): string {
	6297	+ return self::hits_log_dir() . '/hits.log';
	6298	+ }
	6299	+
	6300	+ /**
	6301	+ * Sync the drop-in's mobile-bucket flag file with the `mobile_separate`
	6302	+ * setting. The drop-in (advanced-cache.php) runs before WordPress loads,
	6303	+ * so it can't read the option — instead it checks for a zero-byte
	6304	+ * `.mobile-separate` marker next to the cache files. When the setting is
	6305	+ * on we touch the marker; when off we remove it. The drop-in's cache_key
	6306	+ * computation keys off the marker's presence so its '|m'/'|d' device
	6307	+ * bucket stays in lockstep with Cache::cache_key().
	6308	+ *
	6309	+ * Without this, turning on mobile_separate made Cache::store() write keys
	6310	+ * with a '|d'/'|m' suffix the drop-in never reproduced — so the drop-in's
	6311	+ * file_exists() always missed, every HIT fell through to a full WP boot,
	6312	+ * and the fast pre-WP path was silently dead.
	6313	+ *
	6314	+ * @param bool|null $enabled Force a state; null reads the current setting.
	6315	+ */
	6316	+ /**
	6317	+ * Write the subdirectory-multisite path list the drop-in needs to work
	6318	+ * out which blog a request belongs to.
	6319	+ *
	6320	+ * The drop-in runs before WordPress, so it cannot call is_multisite()
	6321	+ * or get_blog_details(). It can only see REQUEST_URI — so we persist the
	6322	+ * network's blog paths (one per line, longest first) next to the cache
	6323	+ * files, exactly as sync_mobile_flag() persists the device flag. The
	6324	+ * drop-in prefix-matches the URI against that list to pick the same
	6325	+ * bucket Cache::current_host_dir() picks. (#6)
	6326	+ *
	6327	+ * No file is written for a single site or a subdomain network — there
	6328	+ * the host alone identifies the blog and the bucket carries no prefix.
	6329	+ */
	6330	+ public static function sync_site_paths(): void {
	6331	+ $file = XSPEED_CACHE_DIR . '/.site-paths';
	6332	+
	6333	+ $needed = function_exists( 'is_multisite' ) && is_multisite()
	6334	+ && ( ! function_exists( 'is_subdomain_install' ) || ! is_subdomain_install() );
	6335	+
	6336	+ if ( ! $needed ) {
	6337	+ if ( file_exists( $file ) ) {
	6338	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- plain marker removal; non-fatal.
	6339	+ @unlink( $file );
	6340	+ }
	6341	+ return;
	6342	+ }
	6343	+
	6344	+ if ( ! function_exists( 'get_sites' ) ) {
	6345	+ return;
	6346	+ }
	6347	+
	6348	+ $paths = array();
	6349	+ foreach ( get_sites( array( 'number' => 0 ) ) as $site ) {
	6350	+ $prefix = self::path_prefix_segment( (string) $site->path );
	6351	+ if ( '' !== $prefix ) {
	6352	+ // Store the raw path so the drop-in can prefix-match a URI,
	6353	+ // alongside the segment it maps to.
	6354	+ $paths[ trim( (string) $site->path, '/' ) ] = $prefix;
	6355	+ }
	6356	+ }
	6357	+
	6358	+ if ( empty( $paths ) ) {
	6359	+ if ( file_exists( $file ) ) {
	6360	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- see above.
	6361	+ @unlink( $file );
	6362	+ }
	6363	+ return;
	6364	+ }
	6365	+
	6366	+ // Longest path first so /a/b wins over /a.
	6367	+ uksort(
	6368	+ $paths,
	6369	+ static function ( $x, $y ) {
	6370	+ return strlen( (string) $y ) <=> strlen( (string) $x );
	6371	+ }
	6372	+ );
	6373	+
	6374	+ $lines = array();
	6375	+ foreach ( $paths as $raw => $segment ) {
	6376	+ $lines[] = $raw . '|' . $segment;
	6377	+ }
	6378	+
	6379	+ if ( ! is_dir( XSPEED_CACHE_DIR ) && ! wp_mkdir_p( XSPEED_CACHE_DIR ) ) {
	6380	+ return;
	6381	+ }
	6382	+ // 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.
	6383	+ file_put_contents( $file, implode( "\n", $lines ), LOCK_EX );
	6384	+ }
	6385	+
	6386	+ /**
	6387	+ * Compile `ignored_query_params` into a regex the DROP-IN can use.
	6388	+ *
	6389	+ * Tracking traffic was cached but never served fast. should_cache()
	6390	+ * learned to allow `?utm_source=…` through and cache_key() strips the
	6391	+ * query, so `/post` and `/post?utm_source=x` share one entry — but the
	6392	+ * drop-in still bailed on ANY query string, so every visitor from an
	6393	+ * email or ad campaign paid a full WordPress boot to be handed a file
	6394	+ * that was already on disk. On a marketing site that is most of the
	6395	+ * paid traffic taking the slowest path. (#13)
	6396	+ *
	6397	+ * The drop-in runs before WordPress, so it cannot read the option or
	6398	+ * call Glob_Matcher. It gets a precompiled alternation instead, written
	6399	+ * next to the cache files exactly as sync_mobile_flag() writes the
	6400	+ * device flag. Regenerated whenever cache settings are saved.
	6401	+ *
	6402	+ * Only the KEYS matter: a param whose name is on the list contributes
	6403	+ * nothing to the response, so the entry keyed without it is correct.
	6404	+ * Anything not on the list means the drop-in must stand down and let
	6405	+ * PHP decide — the file is deleted rather than left stale when the
	6406	+ * list is empty, so a missing sidecar always fails safe.
	6407	+ */
	6408	+ public static function sync_query_allowlist(): void {
	6409	+ $file = XSPEED_CACHE_DIR . '/.ignored-query-params';
	6410	+
	6411	+ /*
	6412	+ * Stored read, not Settings_Manager::get() — this runs from boot(),
	6413	+ * before translation is legal (see stored_cache_opts()).
	6414	+ *
	6415	+ * A raw read applies no schema defaults, and this field's default is a
	6416	+ * long tracking-parameter list, NOT empty. Falling back to array()
	6417	+ * would strip that whole allow-list from the drop-in on any install
	6418	+ * that has never saved the Cache panel. So fall back to the schema's
	6419	+ * own default, read from the module without building its labels.
	6420	+ */
	6421	+ $opts = self::stored_cache_opts();
	6422	+ $ignored = is_array( $opts['ignored_query_params'] ?? null )
	6423	+ ? $opts['ignored_query_params']
	6424	+ : \XSpeed\Modules\Cache\CacheModule::DEFAULT_IGNORED_QUERY_PARAMS;
	6425	+
	6426	+ $parts = array();
	6427	+ foreach ( $ignored as $pattern ) {
	6428	+ $pattern = trim( (string) $pattern );
	6429	+ if ( '' === $pattern ) {
	6430	+ continue;
	6431	+ }
	6432	+ if ( '~' === $pattern[0] ) {
	6433	+ // Raw regex, PHP-side dialect. Keep it — unlike a server
	6434	+ // config, the drop-in runs the same PCRE engine, so the
	6435	+ // pattern behaves identically. Anchored below with the rest.
	6436	+ $body = substr( $pattern, 1 );
	6437	+ if ( '' !== $body && false !== @preg_match( '#^(?:' . $body . ')$#', '' ) ) { // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- a malformed user pattern must be dropped, not fatal.
	6438	+ $parts[] = $body;
	6439	+ }
	6440	+ continue;
	6441	+ }
	6442	+ // Glob semantics, same as Glob_Matcher: * is any run, ? is one.
	6443	+ $esc = preg_quote( $pattern, '#' );
	6444	+ $esc = str_replace( array( '\*', '\?' ), array( '.*', '.' ), $esc );
	6445	+ $parts[] = $esc;
	6446	+ }
	6447	+
	6448	+ if ( empty( $parts ) ) {
	6449	+ if ( file_exists( $file ) ) {
	6450	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- plain marker removal; non-fatal.
	6451	+ @unlink( $file );
	6452	+ }
	6453	+ return;
	6454	+ }
	6455	+
	6456	+ if ( ! is_dir( XSPEED_CACHE_DIR ) && ! wp_mkdir_p( XSPEED_CACHE_DIR ) ) {
	6457	+ return;
	6458	+ }
	6459	+
	6460	+ $payload = '(?:' . implode( '|', array_unique( $parts ) ) . ')';
	6461	+
	6462	+ // Only write when the value actually changed. This runs from
	6463	+ // reconcile_mobile_separate() on CacheModule::boot(), so an
	6464	+ // unconditional write cost a file write and an exclusive lock on every
	6465	+ // request that boots WordPress — every MISS, every BYPASS, every admin
	6466	+ // screen, every REST call. sync_mobile_flag() below is the model: it
	6467	+ // touches the marker only when the setting flips.
	6468	+ // 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.
	6469	+ if ( is_readable( $file ) && (string) @file_get_contents( $file ) === $payload ) {
	6470	+ return;
	6471	+ }
	6472	+
	6473	+ // 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.
	6474	+ file_put_contents( $file, $payload, LOCK_EX );
	6475	+ }
	6476	+
	6477	+ /**
	6478	+ * CacheModule's STORED settings, read straight from the option.
	6479	+ *
	6480	+ * `Settings_Manager::get( 'cache' )` builds CacheModule's settings schema,
	6481	+ * whose labels are declared through `__()`. The reconcile chain below runs
	6482	+ * from `CacheModule::boot()` on `plugins_loaded` — before
	6483	+ * `after_setup_theme`, the point WordPress 6.7+ treats as safe to
	6484	+ * translate — so going through the schema there fires
	6485	+ * `_load_textdomain_just_in_time` on every request AND resolves the labels
	6486	+ * against a domain that is not loaded yet.
	6487	+ *
	6488	+ * The callers here need stored values, not schema metadata, so a raw read
	6489	+ * is equivalent. It applies NO defaults or coercion: read each key with a
	6490	+ * fallback matching the schema's own default.
	6491	+ *
	6492	+ * @return array<string,mixed>
	6493	+ */
	6494	+ private static function stored_cache_opts(): array {
	6495	+ $stored = get_option( Settings_Manager::OPTION_PREFIX . 'cache', array() );
	6496	+ return is_array( $stored ) ? $stored : array();
	6497	+ }
	6498	+
	6499	+ /**
	6500	+ * Strict truthiness for the LiteSpeed Static Fast Path opt-in.
	6501	+ *
	6502	+ * On non-LiteSpeed servers the key is out of the schema and carried by
	6503	+ * preserved_keys(), so a REST/MCP write lands VERBATIM — QA on #513
	6504	+ * stored the string "false" on Apache and the fast path installed
	6505	+ * itself the moment the site moved to LiteSpeed, because
	6506	+ * empty("false") is false. Only an explicit, unambiguous "yes" may
	6507	+ * enable a path that trades away hit tagging; any other value —
	6508	+ * "false", "no", arbitrary junk — stays OFF, which is the default the
	6509	+ * user never left.
	6510	+ */
	6511	+ private static function litespeed_optin_enabled( $value ): bool {
	6512	+ if ( true === $value || 1 === $value ) {
	6513	+ return true;
	6514	+ }
	6515	+ return is_string( $value )
	6516	+ && in_array( strtolower( trim( $value ) ), array( '1', 'true', 'on', 'yes' ), true );
	6517	+ }
	6518	+
	6519	+ public static function sync_mobile_flag( $enabled = null ): void {
	6520	+ if ( null === $enabled ) {
	6521	+ $stored = self::stored_cache_opts();
	6522	+ $enabled = ! empty( $stored['mobile_separate'] );
	6523	+ }
	6524	+ $dir = XSPEED_CACHE_DIR;
	6525	+ $flag = $dir . '/.mobile-separate';
	6526	+ if ( $enabled ) {
	6527	+ if ( ! is_dir( $dir ) && ! wp_mkdir_p( $dir ) ) {
	6528	+ return;
	6529	+ }
	6530	+ if ( ! file_exists( $flag ) ) {
	6531	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_touch, WordPress.PHP.NoSilencedErrors.Discouraged -- read by the pre-WP drop-in via file_exists(); must be a plain marker, not WP_Filesystem.
	6532	+ @touch( $flag );
	6533	+ }
	6534	+ return;
	6535	+ }
	6536	+ if ( file_exists( $flag ) ) {
	6537	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- plain marker removal; non-fatal.
	6538	+ @unlink( $flag );
	6539	+ }
	6540	+ }
	6541	+
	6542	+ /**
	6543	+ * Write / remove the `.maintenance-active` sentinel next to the cache
	6544	+ * files. The pre-WP drop-in checks for this marker and bails when present,
	6545	+ * so a page cached while the site was live is NOT served during
	6546	+ * maintenance / coming-soon mode — WordPress loads and renders the
	6547	+ * maintenance screen instead. The Pro Maintenance-Cache module drives this
	6548	+ * on the maintenance on/off transition. (FBS-82409 B1)
	6549	+ *
	6550	+ * @param bool $active True to arm the sentinel (entering maintenance),
	6551	+ * false to clear it (site recovered).
	6552	+ */
	6553	+ public static function sync_maintenance_flag( bool $active ): void {
	6554	+ $dir = XSPEED_CACHE_DIR;
	6555	+ $flag = $dir . '/.maintenance-active';
	6556	+ if ( $active ) {
	6557	+ if ( ! is_dir( $dir ) && ! wp_mkdir_p( $dir ) ) {
	6558	+ return;
	6559	+ }
	6560	+ if ( ! file_exists( $flag ) ) {
	6561	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_touch, WordPress.PHP.NoSilencedErrors.Discouraged -- read by the pre-WP drop-in via file_exists(); must be a plain marker, not WP_Filesystem.
	6562	+ @touch( $flag );
	6563	+ }
	6564	+ return;
	6565	+ }
	6566	+ if ( file_exists( $flag ) ) {
	6567	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink, WordPress.PHP.NoSilencedErrors.Discouraged -- plain marker removal; non-fatal.
	6568	+ @unlink( $flag );
	6569	+ }
	6570	+ }
	6571	+
	6572	+ /**
	6573	+ * Reconcile every mobile_separate-dependent artifact to the current
	6574	+ * setting. Called on boot and whenever the cache settings are saved, so
	6575	+ * flipping mobile_separate at runtime can't leave the install in a
	6576	+ * half-converted state.
	6577	+ *
	6578	+ * Three things must agree with the setting:
	6579	+ * 1. the drop-in's `.mobile-separate` flag (sync_mobile_flag()),
	6580	+ * 2. the device-blind server rewrite — present only when OFF
	6581	+ * (static_rewrite_allowed()),
	6582	+ * 3. the now-stale static-cache tree + page cache, which were keyed
	6583	+ * under the old scheme and would serve wrong-device HTML.
	6584	+ *
	6585	+ * No-ops when the cache is disabled — there's nothing installed to
	6586	+ * reconcile, and toggle() handles install/teardown itself.
	6587	+ */
	6588	+ public static function reconcile_mobile_separate(): void {
	6589	+ self::sync_mobile_flag();
	6590	+ if ( defined( 'XSPEED_CACHE_DIR' ) ) {
	6591	+ // Keep the drop-in's view of the network's blog paths current — a
	6592	+ // site added or removed changes which bucket its URLs belong to. (#6)
	6593	+ self::sync_site_paths();
	6594	+ // Keep the drop-in's copy of the query allow-list current — a param
	6595	+ // added in settings must reach the fast path too. (#13)
	6596	+ self::sync_query_allowlist();
	6597	+ }
	6598	+
	6599	+ // The rewrite/static reconciliation below needs the plugin's path
	6600	+ // constants. They're absent in early-boot / unit-test contexts where
	6601	+ // only the drop-in flag matters — bail to the flag-only behavior then.
	6602	+ if ( ! defined( 'XSPEED_CACHE_STATIC_DIR' ) ) {
	6603	+ return;
	6604	+ }
	6605	+
	6606	+ // Only touch the rewrite + caches when caching is actually on.
	6607	+ $opts = get_option( 'xspeed_options', array() );
	6608	+ if ( empty( $opts['cache_enabled'] ) ) {
	6609	+ return;
	6610	+ }
	6611	+
	6612	+ $rewrite_present = self::rewrite_installed();
	6613	+ $rewrite_wanted = self::static_rewrite_allowed();
	6614	+
	6615	+ // Did the thing that actually invalidates cache KEYS change?
	6616	+ // mobile_separate buckets entries as |d / |m, so flipping it makes
	6617	+ // stored entries mis-bucketed and they must go. A rewrite-state
	6618	+ // mismatch from anything else (e.g. mod_headers detection, a hand-
	6619	+ // edited .htaccess) changes no key at all — the same files are still
	6620	+ // valid, they're just served by PHP instead of by the web server.
	6621	+ // Purging there is what let one WP-CLI call wipe the whole cache on
	6622	+ // every bootstrap. (#138)
	6623	+ //
	6624	+ // Read the setting from the SAME place static_rewrite_allowed() and
	6625	+ // sync_mobile_flag() do — the cache module's settings, not the
	6626	+ // top-level xspeed_options — or this marker would track a key that
	6627	+ // never changes and a real flip would go unnoticed.
	6628	+ // Stored read — this runs from boot(); see stored_cache_opts().
	6629	+ $cache_opts = self::stored_cache_opts();
	6630	+ $mobile_now = ! empty( $cache_opts['mobile_separate'] );
	6631	+ $mobile_last = get_option( 'xspeed_last_mobile_separate', null );
	6632	+ $mobile_flipped = ( null !== $mobile_last && (bool) (int) $mobile_last !== $mobile_now );
	6633	+
	6634	+ if ( (string) (int) $mobile_now !== (string) $mobile_last ) {
	6635	+ update_option( 'xspeed_last_mobile_separate', $mobile_now ? '1' : '0', false );
	6636	+ }
	6637	+
	6638	+ if ( $rewrite_present === $rewrite_wanted ) {
	6639	+ // Already consistent — nothing flipped, leave caches intact so a
	6640	+ // plain settings save (e.g. expiry change) doesn't blow the cache.
	6641	+ return;
	6642	+ }
	6643	+
	6644	+ // Bring the rewrite into line with what this server actually supports.
	6645	+ if ( $rewrite_wanted ) {
	6646	+ self::install_rewrite();
	6647	+ } else {
	6648	+ self::remove_rewrite();
	6649	+ }
	6650	+
	6651	+ // Only discard cache contents when the device bucketing changed.
	6652	+ if ( $mobile_flipped ) {
	6653	+ self::purge_all( 'mobile_separate changed' );
	6654	+ }
	6655	+ }
	6656	+
	6657	+ /**
	6658	+ * Whether the server-level static-rewrite fast path may be used.
	6659	+ *
	6660	+ * The rewrite serves `{host}{path}/index.html` straight from the web
	6661	+ * server, keyed only by host + path — it has no way to run our PHP
	6662	+ * device detection, so it can't tell mobile from desktop. When
	6663	+ * `mobile_separate` is on, a single static file would be shared across
	6664	+ * devices and whoever primed it wins (mobile visitors could get desktop
	6665	+ * HTML, or vice-versa). Rather than duplicate a wp_is_mobile()-equivalent
	6666	+ * UA matcher into .htaccess AND the nginx snippet (three copies that
	6667	+ * would inevitably drift), we simply DON'T engage the static rewrite when
	6668	+ * mobile_separate is on. Requests then fall through to the PHP drop-in,
	6669	+ * which buckets correctly — a small TTFB cost (~85ms vs ~30ms) paid only
	6670	+ * on mobile-separate sites, in exchange for guaranteed correctness.
	6671	+ *
	6672	+ * LiteSpeed exclusion (2026-06-16): on LiteSpeed — OpenLiteSpeed in
	6673	+ * particular — `.htaccess` CAN run our RewriteRule to serve the static
	6674	+ * file, but its `.htaccess` engine ignores `mod_headers`, so we cannot
	6675	+ * stamp the served response with `X-XSpeed-Cache: HIT`, AND there is no
	6676	+ * `.htaccess` equivalent of nginx's per-location `access_log` to record
	6677	+ * the hit. The result was a cache that worked but was invisible: no HIT
	6678	+ * header and a hit-ratio frozen near 0%. Every OTHER server gives the
	6679	+ * user a visible HIT header + a counted hit (nginx via add_header +
	6680	+ * access_log in its snippet; Apache via the `<IfModule mod_headers.c>`
	6681	+ * block in rewrite_block_lines(), WHEN that module is loaded — when it is
	6682	+ * not, Apache takes this same drop-in fallback). To keep LiteSpeed
	6683	+ * CONSISTENT with the rest, we route its hits
	6684	+ * through the PHP drop-in instead — the drop-in emits
	6685	+ * `X-XSpeed-Cache: HIT (php)` and calls Hit_Counter inline, exactly the
	6686	+ * observable behavior the other servers get. The cost is the drop-in's
	6687	+ * ~30ms TTFB vs the static path's ~10ms, paid only on LiteSpeed; in
	6688	+ * exchange the dashboard hit-ratio and the response header finally tell
	6689	+ * the truth there. (Apache keeps the static fast path — it honors the
	6690	+ * header.) See maybe_emit_lscache_headers() for the paired LSCache
	6691	+ * stand-down that stops LiteSpeed's own module from shadowing the
	6692	+ * drop-in.
	6693	+ *
	6694	+ * Opt-in (#509): `litespeed_static_rewrite` re-enables the fast path on
	6695	+ * LiteSpeed for users who value raw TTFB over hit accounting. The trade
	6696	+ * is stated in the setting's copy: statically served hits carry no
	6697	+ * X-XSpeed-Cache header and are not counted (LiteSpeed logs the
	6698	+ * original request line, so even the access-log scan cannot see
	6699	+ * them — see Hit_Counter::collect_server_log_hits()). The drop-in
	6700	+ * default above stays — nobody is surprised into an unverifiable cache.
	6701	+ */
	6702	+ public static function static_rewrite_allowed(): bool {
	6703	+ // Stored read — reached from boot(); see stored_cache_opts().
	6704	+ $opts = self::stored_cache_opts();
	6705	+ // LiteSpeed: drop-in serves hits (visible + counted) unless the user
	6706	+ // explicitly opted into the static fast path — see docblock.
	6707	+ if ( Server::LITESPEED === Server::type()
	6708	+ && ! self::litespeed_optin_enabled( $opts['litespeed_static_rewrite'] ?? false ) ) {
	6709	+ return false;
	6710	+ }
	6711	+ // Apache without mod_headers is in EXACTLY the position LiteSpeed
	6712	+ // is in above: it can run the RewriteRule and serve the static
	6713	+ // file, but it cannot stamp `X-XSpeed-Cache` on the response, so
	6714	+ // the hit is invisible to the user and uncountable by
	6715	+ // Hit_Counter. The docblock above used to assert Apache "honors
	6716	+ // mod_headers" and left it on the fast path unconditionally —
	6717	+ // true only when the module is actually loaded. Fall back to the
	6718	+ // drop-in when it isn't, trading ~10ms of TTFB for a hit that
	6719	+ // shows up in the header and the ratio. (Field report: hit ratio
	6720	+ // pinned at 0% on a working Apache cache.)
	6721	+ if ( Server::APACHE === Server::type() && ! Server::apache_has_mod_headers() ) {
	6722	+ return false;
	6723	+ }
	6724	+ return empty( $opts['mobile_separate'] );
	6725	+ }
	6726	+
	6727	+ /**
	6728	+ * Why the device-blind static rewrite is NOT installed, when it isn't.
	6729	+ * Returns 'mobile_separate' when Separate Mobile Cache is the blocker
	6730	+ * (the static file is one-per-URL, so it can't coexist with per-device
	6731	+ * buckets), 'no_mod_headers' when Apache can't stamp the HIT header,
	6732	+ * '' otherwise. Lets the dashboard explain the slow path instead of
	6733	+ * silently falling back to PHP serving. (FBS-83145)
	6734	+ *
	6735	+ * Every refusal in static_rewrite_allowed() that is NOT self-explanatory
	6736	+ * must have a branch here. Otherwise the Health card falls through to
	6737	+ * "Block missing — toggle Enable Cache off and on to reinstall it",
	6738	+ * advice that cannot work: the same condition that suppressed the write
	6739	+ * suppresses the reinstall, and auto_heal() strips the block again on
	6740	+ * the next admin page load. (Field report: Apache host with mod_headers
	6741	+ * unloaded sat on the slow path with no way to find out why.)
	6742	+ */
	6743	+ /**
	6744	+ * Qualify a raw probe result with what we already KNOW about config.
	6745	+ *
	6746	+ * probe_static_rewrite() writes its own file under the static-cache tree
	6747	+ * and fetches that, which succeeds whenever the web server can serve a
	6748	+ * static file at all — including when static_rewrite_allowed() is false
	6749	+ * and no real page is on the static path. So `active: true` on its own is
	6750	+ * not evidence that pages are being served statically.
	6751	+ *
	6752	+ * The reachable case is nginx with Separate Mobile Cache on: the snippet
	6753	+ * lives in the server block and we cannot remove it, pages are
	6754	+ * deliberately routed to the PHP drop-in, but the probe file is still
	6755	+ * served directly.
	6756	+ *
	6757	+ * The Health panel learned this in 88b4b50; the CLI, REST and MCP paths
	6758	+ * did not, so they kept reporting "active" in exactly that configuration.
	6759	+ * Rather than repeat the reasoning at each call site, they now all come
	6760	+ * through here.
	6761	+ *
	6762	+ * Deliberately does NOT consult rewrite_installed(): on nginx the fast
	6763	+ * path is the pasted snippet and there is no .htaccess marker to find, so
	6764	+ * requiring one would report every correctly-configured nginx site as
	6765	+ * broken.
	6766	+ *
	6767	+ * @param array $probe Raw result from probe_static_rewrite().
	6768	+ * @return array{active:bool,inconclusive:bool,reason:string,block_reason:string}
	6769	+ */
	6770	+ public static function qualify_rewrite_probe( array $probe ): array {
	6771	+ $active = (bool) ( $probe['active'] ?? false );
	6772	+ $inconclusive = (bool) ( $probe['inconclusive'] ?? false );
	6773	+ $reason = (string) ( $probe['reason'] ?? '' );
	6774	+ $block_reason = self::static_rewrite_block_reason();
	6775	+
	6776	+ // Same observed-refusal check Health makes. This is the shared path for
	6777	+ // `wp xspeed cache recheck-rewrite` and POST /cache/recheck-rewrite —
	6778	+ // and, because a CLI command is automatically an MCP tool, for the
	6779	+ // AI-facing surface too. Leaving it out would have fixed the dashboard
	6780	+ // while the CLI kept answering that the fast path was active. (#372)
	6781	+ if ( '' === $block_reason ) {
	6782	+ $skip = self::last_static_skip();
	6783	+ if ( ! empty( $skip['reason'] ) ) {
	6784	+ $block_reason = 'skipped_' . (string) $skip['reason'];
	6785	+ }
	6786	+ }
	6787	+
	6788	+ // With page caching off there is nothing to serve, so `active` can
	6789	+ // never be true here whatever the raw probe says. probe_static_rewrite()
	6790	+ // writes its OWN file under the static tree and fetches that, which
	6791	+ // succeeds whenever the server can serve a static file at all — and on
	6792	+ // nginx the snippet is server-level, so it keeps succeeding after the
	6793	+ // cache is switched off.
	6794	+ //
	6795	+ // block_reason() used to carry this meaning by accident: it returned
	6796	+ // 'mobile_separate' with caching off, and the refusal branch below
	6797	+ // forced active=false. Now that it correctly reports '' (nothing can
	6798	+ // block a fast path that isn't in use), this consumer has to state the
	6799	+ // condition itself — otherwise `wp xspeed cache recheck-rewrite` and
	6800	+ // POST /cache/recheck-rewrite claim "the web server is serving cache
	6801	+ // hits directly" on a site with no cache. That is a positive false
	6802	+ // claim rather than a nag, i.e. worse than the bug being fixed.
	6803	+ $cache_opts = Settings::get();
	6804	+ if ( empty( $cache_opts['cache_enabled'] ) ) {
	6805	+ return array(
	6806	+ 'active' => false,
	6807	+ 'inconclusive' => false,
	6808	+ 'reason' => 'Page caching is off, so there is no cache for the web server to serve.',
	6809	+ 'block_reason' => '',
	6810	+ );
	6811	+ }
	6812	+
	6813	+ // A known refusal outranks the probe, and also outranks
	6814	+ // "inconclusive" — a blocked rewrite whose probe merely failed to
	6815	+ // complete is still definitely blocked.
	6816	+ if ( '' !== $block_reason ) {
	6817	+ $active = false;
	6818	+ $inconclusive = false;
	6819	+ $reason = self::block_reason_text( $block_reason );
	6820	+ }
	6821	+
	6822	+ return array(
	6823	+ 'active' => $active,
	6824	+ 'inconclusive' => $inconclusive,
	6825	+ 'reason' => $reason,
	6826	+ 'block_reason' => $block_reason,
	6827	+ );
	6828	+ }
	6829	+
	6830	+ /**
	6831	+ * Human-readable explanation for a static_rewrite_block_reason() code.
	6832	+ *
	6833	+ * Each one has to say what to DO about it: "mobile_separate" alone tells
	6834	+ * a user nothing, and the whole point of surfacing a refusal instead of
	6835	+ * the probe verdict is that it is actionable.
	6836	+ */
	6837	+ public static function block_reason_text( string $code ): string {
	6838	+ switch ( $code ) {
	6839	+ case 'mobile_separate':
	6840	+ 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.';
	6841	+ case 'no_mod_headers':
	6842	+ 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.";
	6843	+ case 'litespeed_dropin':
	6844	+ 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.';
	6845	+ case 'skipped_nonce':
	6846	+ 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.';
	6847	+ default:
	6848	+ return sprintf( 'The static rewrite is disabled (%s).', $code );
	6849	+ }
	6850	+ }
	6851	+
	6852	+ public static function static_rewrite_block_reason(): string {
	6853	+ // Nothing can be blocking the fast path when there is no cache to
	6854	+ // serve from it. Without this the dashboard told users with page
	6855	+ // caching switched OFF that Separate Mobile Cache "is disabling
	6856	+ // faster static serving" — a fast path they were not using, about a
	6857	+ // cache that did not exist. Every caller of this is a user-facing
	6858	+ // explanation of why the rewrite is off, so "the cache is off" is
	6859	+ // the honest answer, and it is silence. (#108)
	6860	+ $opts = Settings::get();
	6861	+ if ( empty( $opts['cache_enabled'] ) ) {
	6862	+ return '';
	6863	+ }
	6864	+ if ( Server::LITESPEED === Server::type() ) {
	6865	+ // The opt-in is read RAW (stored_cache_opts), not through
	6866	+ // Settings_Manager::get(): the schema's bool coercion is a PHP
	6867	+ // cast, and (bool) "false" is true — so a junk string stored on
	6868	+ // another server (where the key bypasses the schema) would come
	6869	+ // back from the coercion layer as an ENABLE. Raw + the strict
	6870	+ // parse below is the same read static_rewrite_allowed() makes,
	6871	+ // so the two can't disagree either. (QA on #513)
	6872	+ $stored = self::stored_cache_opts();
	6873	+ // The intended default — but no longer silent: with the opt-in
	6874	+ // off, Health must be able to explain the PHP path and point at
	6875	+ // the toggle instead of falling through to "reinstall the block"
	6876	+ // advice that cannot work here. (#509)
	6877	+ if ( ! self::litespeed_optin_enabled( $stored['litespeed_static_rewrite'] ?? false ) ) {
	6878	+ return 'litespeed_dropin';
	6879	+ }
	6880	+ $cache_opts = Settings_Manager::get( 'cache' );
	6881	+ return ! empty( $cache_opts['mobile_separate'] ) ? 'mobile_separate' : '';
	6882	+ }
	6883	+ if ( Server::APACHE === Server::type() && ! Server::apache_has_mod_headers() ) {
	6884	+ return 'no_mod_headers';
	6885	+ }
	6886	+ $cache_opts = Settings_Manager::get( 'cache' );
	6887	+ return ! empty( $cache_opts['mobile_separate'] ) ? 'mobile_separate' : '';
	6888	+ }
	6889	+
	6890	+ /**
	6891	+ * Whether migration flagged Separate Mobile Cache for user review. Set by
	6892	+ * Migration::map_mobile_separate() when a source plugin (WP Rocket / WP
	6893	+ * Super Cache / LiteSpeed) had its "separate mobile cache" option on: we
	6894	+ * import it as OFF (to keep the device-blind static fast path) but record
	6895	+ * this flag so the dashboard can invite the user to turn it back on only
	6896	+ * if their site genuinely serves different HTML per device. (FBS-83145)
	6897	+ */
	6898	+ public static function mobile_separate_needs_review(): bool {
	6899	+ // Same reasoning as static_rewrite_block_reason(): the invitation is
	6900	+ // "turn this back on if your site needs it, to regain the fast path",
	6901	+ // which is meaningless with page caching off — there is no fast path
	6902	+ // to regain, and the equality probe behind the prompt would fetch
	6903	+ // pages that aren't being cached. Gated here rather than at the two
	6904	+ // payload call sites (Admin + Rest_Api) so `enabled`, `blocking` and
	6905	+ // `needs_review` are consistently gated on the same condition. (#108)
	6906	+ $opts = Settings::get();
	6907	+ if ( empty( $opts['cache_enabled'] ) ) {
	6908	+ return false;
	6909	+ }
	6910	+ $cache_opts = Settings_Manager::get( 'cache' );
	6911	+ return ! empty( $cache_opts['mobile_separate_review'] );
	6912	+ }
	6913	+
	6914	+ /**
	6915	+ * Clear the review flag — called when the user has acted on the prompt
	6916	+ * (dismissed it, or turned Separate Mobile Cache on/off deliberately) so
	6917	+ * the dashboard callout doesn't nag forever. Writes the option directly
	6918	+ * (bypassing Settings_Manager) so it never touches schema fields.
	6919	+ */
	6920	+ public static function clear_mobile_separate_review(): void {
	6921	+ $stored = get_option( 'xspeed_module_cache', array() );
	6922	+ if ( ! is_array( $stored ) || empty( $stored['mobile_separate_review'] ) ) {
	6923	+ return;
	6924	+ }
	6925	+ unset( $stored['mobile_separate_review'] );
	6926	+ update_option( 'xspeed_module_cache', $stored );
	6927	+ }
	6928	+
	6929	+ /**
	6930	+ * On-demand probe: does the homepage serve materially the same HTML to a
	6931	+ * desktop and a mobile browser? Fetches home_url() twice over loopback —
	6932	+ * once with a desktop User-Agent, once with a mobile one — strips
	6933	+ * per-request noise (nonces, CSRF tokens, session ids, inline timestamps),
	6934	+ * and compares. When identical, Separate Mobile Cache is almost certainly
	6935	+ * unnecessary and the user can turn it off to regain the static fast path.
	6936	+ *
	6937	+ * NEVER run automatically (no page-load cost) — only from the dashboard
	6938	+ * "Check now" button. Result is cached for 10 minutes so a double-click or
	6939	+ * a re-render doesn't fire two more self-requests. (FBS-83145)
	6940	+ *
	6941	+ * @return array{ identical:bool, checked:bool, reason?:string, desktop_bytes?:int, mobile_bytes?:int }
	6942	+ */
	6943	+ public static function probe_mobile_equality(): array {
	6944	+ $cached = get_transient( 'xspeed_mobile_equality_probe' );
	6945	+ if ( is_array( $cached ) ) {
	6946	+ return $cached;
	6947	+ }
	6948	+
	6949	+ $home = home_url( '/' );
	6950	+ $host = (string) wp_parse_url( $home, PHP_URL_HOST );
	6951	+ if ( '' === $host ) {
	6952	+ $result = array( 'identical' => false, 'checked' => false, 'reason' => 'home_url has no host' );
	6953	+ set_transient( 'xspeed_mobile_equality_probe', $result, MINUTE_IN_SECONDS );
	6954	+ return $result;
	6955	+ }
	6956	+
	6957	+ // Match WP core's own mobile detection (wp_is_mobile) so the probe
	6958	+ // reflects what the site would actually branch on. iPhone Safari for
	6959	+ // mobile; a current desktop Chrome UA for desktop.
	6960	+ $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';
	6961	+ $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';
	6962	+
	6963	+ $is_local = function_exists( 'wp_get_environment_type' )
	6964	+ && in_array( wp_get_environment_type(), array( 'local', 'development' ), true );
	6965	+
	6966	+ $fetch = static function ( string $ua ) use ( $home, $is_local ) {
	6967	+ $resp = wp_remote_get(
	6968	+ $home,
	6969	+ array(
	6970	+ 'timeout' => 5,
	6971	+ 'sslverify' => ! $is_local,
	6972	+ 'redirection' => 2,
	6973	+ // Bust any per-device cache so we compare freshly-rendered
	6974	+ // HTML, and pass the device UA the site would branch on.
	6975	+ 'user-agent' => $ua,
	6976	+ 'headers' => array( 'Cache-Control' => 'no-cache' ),
	6977	+ )
	6978	+ );
	6979	+ if ( is_wp_error( $resp ) || 200 !== (int) wp_remote_retrieve_response_code( $resp ) ) {
	6980	+ return null;
	6981	+ }
	6982	+ return (string) wp_remote_retrieve_body( $resp );
	6983	+ };
	6984	+
	6985	+ $desktop = $fetch( $desktop_ua );
	6986	+ $mobile = $fetch( $mobile_ua );
	6987	+
	6988	+ if ( null === $desktop || null === $mobile ) {
	6989	+ $result = array( 'identical' => false, 'checked' => false, 'reason' => 'could not fetch homepage twice' );
	6990	+ set_transient( 'xspeed_mobile_equality_probe', $result, MINUTE_IN_SECONDS );
	6991	+ return $result;
	6992	+ }
	6993	+
	6994	+ $identical = self::normalize_html_for_diff( $desktop ) === self::normalize_html_for_diff( $mobile );
	6995	+
	6996	+ $result = array(
	6997	+ 'identical' => $identical,
	6998	+ 'checked' => true,
	6999	+ 'desktop_bytes' => strlen( $desktop ),
	7000	+ 'mobile_bytes' => strlen( $mobile ),
	7001	+ );
	7002	+ set_transient( 'xspeed_mobile_equality_probe', $result, 10 * MINUTE_IN_SECONDS );
	7003	+ return $result;
	7004	+ }
	7005	+
	7006	+ /**
	7007	+ * Strip per-request noise from HTML so a desktop-vs-mobile diff reflects
	7008	+ * real structural differences, not nonces / session ids / timestamps that
	7009	+ * change on every render. Deliberately conservative: it normalizes the
	7010	+ * handful of well-known noise sources and collapses whitespace, so a site
	7011	+ * that truly serves different markup per device still compares as different.
	7012	+ */
	7013	+ private static function normalize_html_for_diff( string $html ): string {
	7014	+ // Every rule here errs toward "they differ" being WRONG rather than
	7015	+ // "they match" being wrong: this check only ever tells a user it is
	7016	+ // SAFE to turn Separate Mobile Cache off, so a false "identical"
	7017	+ // would cost them device-specific output. The risk of being too
	7018	+ // conservative is milder but real — the useful answer never appears,
	7019	+ // and the feature's whole pitch ("we'll prove it's safe to turn
	7020	+ // off") silently never pays out. These close the gaps that made a
	7021	+ // mismatch effectively guaranteed on an ordinary WordPress site. (#108)
	7022	+ $patterns = array(
	7023	+ // WP nonces in attribute or JSON form: data-nonce="…",
	7024	+ // _wpnonce=…, "nonce":"…". The `[:=]` adjacency below misses
	7025	+ // wp_nonce_field()'s own markup — `name="_wpnonce" value="ab…"`
	7026	+ // puts `value=` between the key and the token — which is the
	7027	+ // single most common nonce shape in WordPress, so that form is
	7028	+ // matched explicitly first.
	7029	+ '/name=["\']?(_wpnonce|_ajax_nonce)["\']?\s+value=["\']?[a-z0-9]{8,}/i',
	7030	+ // CSP nonces on script/style tags. Base64, so uppercase and
	7031	+ // +/= appear — the hex-only rules below can never match one,
	7032	+ // and a CSP-enabled site therefore differed on every fetch.
	7033	+ // MUST precede the generic nonce rule: that one stops at the
	7034	+ // first non-alphanumeric, leaving the rest of the token behind
	7035	+ // and the two responses still unequal.
	7036	+ // The quotes are optional so HTML5's legal unquoted attribute
	7037	+ // form (`<script nonce=AbCd+q/r=>`) is covered too — without
	7038	+ // that it fell through to the generic rule, which is the exact
	7039	+ // failure this rule exists to remove.
	7040	+ '/\bnonce=(["\'])?[A-Za-z0-9+\/=_-]{8,}(?(1)\1)/',
	7041	+ '/(_wpnonce|nonce|_ajax_nonce)["\']?\s*[:=]\s*["\']?[a-z0-9]{8,}/i',
	7042	+ // Generic hex tokens: cache busters, session ids, md5/sha
	7043	+ // digests. Was 16+, which left an 11-15 char gap above the
	7044	+ // 10-char nonce rule.
	7045	+ //
	7046	+ // The token MUST contain at least one a-f letter. `[a-f0-9]`
	7047	+ // also matches every decimal digit, so a bare `{10,}` erased
	7048	+ // every 10+ digit INTEGER anywhere in the document — including
	7049	+ // visible body text. A page whose desktop and mobile HTML
	7050	+ // differed only by a per-device numeric id (an AdSense slot, an
	7051	+ // A/B bucket, an analytics property) then compared as identical,
	7052	+ // and the check told the user it was safe to switch off the very
	7053	+ // setting keeping that output correct — the one direction this
	7054	+ // function must never fail in. Decimal-only runs are left to the
	7055	+ // bounded epoch rule below, which is deliberately narrower.
	7056	+ //
	7057	+ // Known, accepted (QA R2): a token whose letters all fall in a-f
	7058	+ // reads as a digest, so a per-device `ABC1234567890` strips even
	7059	+ // though it is an id, not a hash. Deliberately left open — the
	7060	+ // alternatives all cost more than the bug:
	7061	+ //
	7062	+ // Token shape (lowercase-only, case-uniformity, a trailing
	7063	+ // letter) cannot separate it. `ABC1234567890` and
	7064	+ // `ABCDEF012345` — an uppercase digest this rule SHOULD strip —
	7065	+ // are both all-hex, uniformly cased, letters-then-digits.
	7066	+ // Each variant fixed the id only by sparing the digest.
	7067	+ //
	7068	+ // Letter density does separate them (23% letters vs 50%), but
	7069	+ // measured over 2000 md5/sha1/sha256 samples, requiring letters
	7070	+ // spread through the token leaves 21-67% of REAL digests
	7071	+ // unmatched depending on the window. Digest noise is most of
	7072	+ // what this function exists to remove, so that trade guts it.
	7073	+ //
	7074	+ // Context (protecting data-* attribute values from this rule)
	7075	+ // works for ids and still strips digests in URLs, classes and
	7076	+ // query strings — but regresses a CHANGING digest inside a
	7077	+ // non-nonce data-* attribute, and needs a two-pass
	7078	+ // hold/restore. Viable if R2 is ever worth pressing; its
	7079	+ // failure at least errs toward "differ".
	7080	+ //
	7081	+ // An A-F-only prefix on a per-device id is rare, and the earlier
	7082	+ // nonce rules already claim the data-nonce/_wpnonce shapes.
	7083	+ '/\b(?=[a-f0-9]{10,}\b)[0-9]*[a-f][a-f0-9]*\b/i',
	7084	+ // wp-generated unique ids (e.g. wp-block ids, aria ids).
	7085	+ '/(id|for|aria-[a-z]+)="[^"]*-[0-9]{3,}"/i',
	7086	+ // ISO-ish timestamps + epoch-looking numbers in query strings.
	7087	+ '/\?ver=[0-9.]+/',
	7088	+ '/[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9:.+Z-]+/',
	7089	+ // Our own signature's generation stamp. The two fetches are
	7090	+ // sequential and each writes its own entry, so this differs on
	7091	+ // essentially every comparison — and it is space-separated, so
	7092	+ // the ISO rule above (which requires a literal `T`) never
	7093	+ // touches it. Without this the probe reports "differ" for every
	7094	+ // site and the "safe to turn Separate Mobile Cache off" verdict
	7095	+ // can never appear.
	7096	+ '/generated [0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2} UTC/',
	7097	+ // Raw epoch seconds. The two fetches are sequential, so any
	7098	+ // template printing time() guaranteed a mismatch.
	7099	+ //
	7100	+ // This is the ONLY rule that may strip a decimal-only run, so
	7101	+ // its bound is load-bearing rather than decorative — every digit
	7102	+ // it gives away is a class of per-device id it silently erases.
	7103	+ // `1[0-9]{9}` was too loose: it claimed the whole
	7104	+ // 1000000000-1999999999 range (2001-2033) to cover timestamps
	7105	+ // nobody serves, and took every 10-digit AdSense slot, order id
	7106	+ // and SKU beginning with 1 along with it — reproducing the exact
	7107	+ // false-"identical" verdict the hex rule above was tightened to
	7108	+ // stop. `1[6-9]` covers 2020-2033, which is the only span a live
	7109	+ // site can actually print, and collides with roughly a tenth as
	7110	+ // many ids.
	7111	+ //
	7112	+ // Not airtight — an id beginning 16-19 still collides. Closing
	7113	+ // that properly means scoping this to places a timestamp really
	7114	+ // appears (an attribute value, a query parameter, a JSON value)
	7115	+ // rather than bare body text; the bound is the cheap 90% of it.
	7116	+ '/\b1[6-9][0-9]{8}\b/',
	7117	+ );
	7118	+ $html = (string) preg_replace( $patterns, 'X', $html );
	7119	+ // Collapse all whitespace so trivial formatting differences don't count.
	7120	+ return trim( (string) preg_replace( '/\s+/', ' ', $html ) );
	7121	+ }
	7122	+
620	7123	public static function ensure_hits_log_file(): bool {
621		- $dir = XSPEED_CACHE_DIR;
	7124	+ // TWO writers append to this log, and an earlier fix conflated them:
	7125	+ //
	7126	+ // 1. nginx, via the server-level `access_log` directive in
	7127	+ // nginx_snippet() — a DIFFERENT uid, which is why the file needs
	7128	+ // to be world-writable there.
	7129	+ // 2. the PHP drop-in (advanced-cache.php), on EVERY server. A hit it
	7130	+ // serves bypasses WordPress entirely, so it can't call
	7131	+ // Hit_Counter::record_hit() — appending here is the only way that
	7132	+ // hit is ever counted.
	7133	+ //
	7134	+ // The nginx-only early return that used to sit at the top of this
	7135	+ // method was fixing something real: chmod() on a file PHP doesn't own
	7136	+ // raises "Operation not permitted", and off nginx that chmod buys
	7137	+ // nothing. But it took directory creation with it, so on LiteSpeed
	7138	+ // (which always serves via the drop-in), on Apache without mod_headers,
	7139	+ // and anywhere mobile_separate forces the drop-in path, writer 2 was
	7140	+ // appending to a file whose parent directory did not exist. The append
	7141	+ // is @-suppressed and documented as non-fatal, so every one of those
	7142	+ // hits vanished and the dashboard ratio sat at 0% forever.
	7143	+ //
	7144	+ // So: create the dir + file everywhere, and keep only the chmod gated
	7145	+ // to nginx.
	7146	+ $dir = self::hits_log_dir();
622	7147	if ( ! is_dir( $dir ) && ! wp_mkdir_p( $dir ) ) {
623	7148	return false;
624	7149	}
625		- // Ensure the dir is traversable + writable by a different-uid nginx.
626		- // 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.
627		- @chmod( $dir, 0777 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort; the access_log just stays empty if it fails.
628		- $path = $dir . '/hits.log';
	7150	+
	7151	+ $is_nginx = ( Server::NGINX === Server::type() );
	7152	+
	7153	+ if ( $is_nginx ) {
	7154	+ // Ensure the dir is traversable + writable by a different-uid nginx.
	7155	+ // 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.
	7156	+ @chmod( $dir, 0777 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort; the access_log just stays empty if it fails.
	7157	+ }
	7158	+
	7159	+ $path = self::hits_log_path();
629	7160	if ( ! file_exists( $path ) ) {
630	7161	// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_touch -- See docblock: must be a plain touch, not WP_Filesystem.
631	7162	@touch( $path ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- non-fatal helper; failures already covered by the dir check.
632	7163	}
633		- // World-writable so a different-uid nginx can append HIT lines.
634		- // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_chmod -- See docblock.
635		- @chmod( $path, 0666 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort.
	7164	+
	7165	+ if ( $is_nginx ) {
	7166	+ // World-writable so a different-uid nginx can append HIT lines.
	7167	+ // Off nginx the drop-in appends as the same uid that owns the file,
	7168	+ // so this is unnecessary — and would emit the "Operation not
	7169	+ // permitted" warnings the old early return was added to silence.
	7170	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_chmod -- See docblock.
	7171	+ @chmod( $path, 0666 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort.
	7172	+ }
	7173	+
636	7174	return file_exists( $path );
637	7175	}
638	7176
639	7177	public static function nginx_snippet(): ?string {
		@@ -671,22 +7209,82 @@
671	7209	// already had (typically `try_files $uri $uri/ /index.php?$args;`).
672	7210	// Absolute path to the hit-log file from the nginx process's
673	7211	// filesystem view. Nginx's `access_log buffer=N flush=Ns` form
674	7212	// requires a literal path — `$document_root` variables are
675		- // rejected — so we emit `WP_CONTENT_DIR/cache/xspeed/hits.log`
676		- // computed by PHP. Works on every topology where the nginx
	7213	+ // rejected — so PHP computes it. Lives under uploads/ (NOT the
	7214	+ // cache dir): a cache purge or uninstall deletes the cache dir,
	7215	+ // which would orphan this directive's parent directory and make
	7216	+ // `nginx -t` fail [emerg] for EVERY vhost on the host
	7217	+ // (FBS-82478). uploads/ survives both, so the directive can
	7218	+ // never take nginx down. Works on every topology where the nginx
677	7219	// process shares a filesystem with PHP (container or host).
678		- $hits_abs = WP_CONTENT_DIR . '/cache/xspeed/hits.log';
	7220	+ $hits_abs = self::hits_log_path();
679	7221
680	7222	$lines = array();
681		- $lines[] = '# xSpeed static cache — paste at SERVER level (inside `server { }`,';
682		- $lines[] = '# above your existing `location / { … }`; do NOT put it inside any';
683		- $lines[] = '# location block).';
	7223	+ $lines[] = '# xSpeed static cache — paste at server level, above location / { }.';
	7224	+ // Cache host must match the on-disk dir PHP writes: store_static() /
	7225	+ // static_host() take HTTP_HOST and strip every char outside
	7226	+ // [a-zA-Z0-9.\-] — i.e. it removes the colon but KEEPS the port digits
	7227	+ // (localhost:8192 → localhost8192). nginx's own $host can't reproduce
	7228	+ // that: $host has the port already stripped ENTIRELY (→ localhost), so
	7229	+ // the -f check looks for localhost/... while PHP wrote localhost8192/...
	7230	+ // and the rewrite never fires on a non-standard port. Derive
	7231	+ // $xspeed_host from $http_host (which keeps the port) and drop just the
	7232	+ // colon, so it equals the PHP dir on every port. On standard ports
	7233	+ // $http_host has no colon, so $xspeed_host == $host == the bare domain.
	7234	+ $lines[] = 'set $xspeed_host $http_host;'; // default: no port → unchanged (e.g. example.com)
	7235	+ $lines[] = 'if ($http_host ~ "^([^:]+):(\\d+)$") { set $xspeed_host $1$2; }'; // host:port → hostport (matches PHP static_host())
684	7236	$lines[] = 'set $xspeed_no_cache "no-cache";';
685	7237	$lines[] = 'if ($request_method != GET) { set $xspeed_no_cache "$xspeed_no_cache-method"; }';
686	7238	$lines[] = 'if ($args) { set $xspeed_no_cache "$xspeed_no_cache-args"; }';
687		- $lines[] = 'if ($http_cookie ~* "(wordpress_logged_in|comment_author|wp-postpass_)") { set $xspeed_no_cache "$xspeed_no_cache-cookie"; }';
688		- $lines[] = 'if (!-f "$document_root' . $rel . '/$host$uri/index.html") { set $xspeed_no_cache "$xspeed_no_cache-nofile"; }';
	7239	+ // Cookie + user-agent exclusions, generated from the user's actual
	7240	+ // settings rather than a hardcoded list. Before this, the rule
	7241	+ // tested three fixed cookie names and no user agent at all, so
	7242	+ // every excluded_cookies / bypass_user_agents entry applied only
	7243	+ // while a page was cold — on a warm page nginx served the shared
	7244	+ // anonymous copy to carts, members and bypassed bots alike. The
	7245	+ // three historical names survive as a floor inside cookie_rule().
	7246	+ // `~*` is case-insensitive, matching PHP's stripos()/glob checks.
	7247	+ // Stored read — reached from boot(); see stored_cache_opts(). The
	7248	+ // fallbacks below mirror the schema's own defaults, which a raw read
	7249	+ // does not apply.
	7250	+ $cache_opts = self::stored_cache_opts();
	7251	+ $cookie_rule = Server_Rules::cookie_rule(
	7252	+ is_array( $cache_opts['excluded_cookies'] ?? null )
	7253	+ ? $cache_opts['excluded_cookies']
	7254	+ : \XSpeed\Modules\Cache\CacheModule::DEFAULT_EXCLUDED_COOKIES
	7255	+ );
	7256	+ $lines[] = 'if ($http_cookie ~* "(' . $cookie_rule['regex'] . ')") { set $xspeed_no_cache "$xspeed_no_cache-cookie"; }';
	7257	+
	7258	+ $ua_rule = Server_Rules::user_agent_rule(
	7259	+ is_array( $cache_opts['bypass_user_agents'] ?? null ) ? $cache_opts['bypass_user_agents'] : array()
	7260	+ );
	7261	+ // Emitted only when the list is non-empty — an empty alternation
	7262	+ // would compile to `(...)` matching every request and disable the
	7263	+ // fast path entirely.
	7264	+ if ( '' !== $ua_rule['regex'] ) {
	7265	+ $lines[] = 'if ($http_user_agent ~* "(' . $ua_rule['regex'] . ')") { set $xspeed_no_cache "$xspeed_no_cache-ua"; }';
	7266	+ }
	7267	+
	7268	+ // URL exclusions. Without this an excluded URL was only excluded
	7269	+ // while its page was cold: PHP won't write a static file for one, so
	7270	+ // there is usually nothing to serve — but a page cached BEFORE the
	7271	+ // rule was added still has its file on disk, and nginx serves it
	7272	+ // without ever asking PHP. The exclusion then does nothing until the
	7273	+ // next purge. (#169)
	7274	+ //
	7275	+ // Matched against $uri, not $request_uri: $uri is the decoded path
	7276	+ // without the query string, which is what Cache::should_cache()
	7277	+ // tests. Using $request_uri would make `/cart` fail to match
	7278	+ // `/cart?x=1` inconsistently with PHP. Same empty-regex guard as the
	7279	+ // UA rule above — an empty alternation matches everything.
	7280	+ $url_rule = Server_Rules::url_rule(
	7281	+ is_array( $cache_opts['excluded_urls'] ?? null ) ? $cache_opts['excluded_urls'] : array()
	7282	+ );
	7283	+ if ( '' !== $url_rule['regex'] ) {
	7284	+ $lines[] = 'if ($uri ~* "(' . $url_rule['regex'] . ')") { set $xspeed_no_cache "$xspeed_no_cache-url"; }';
	7285	+ }
	7286	+ $lines[] = 'if (!-f "$document_root' . $rel . '/$xspeed_host$uri/index.html") { set $xspeed_no_cache "$xspeed_no_cache-nofile"; }';
689	7287	// Neither `add_header` nor `access_log` is allowed inside an `if{}`
690	7288	// at server level (nginx rejects with "directive is not allowed
691	7289	// here"). The logging therefore lives in a `location` block that
692	7290	// matches the rewritten URI after `rewrite … last;` restarts
		@@ -692,28 +7290,47 @@
692	7290	// matches the rewritten URI after `rewrite … last;` restarts
693	7291	// location matching. Every HIT lands there exactly once, every
694	7292	// MISS / PHP-served request never matches it.
695	7293	$lines[] = 'if ($xspeed_no_cache = "no-cache") {';
696		- $lines[] = ' rewrite ^ ' . $rel . '/$host$uri/index.html last;';
	7294	+ $lines[] = ' rewrite ^ ' . $rel . '/$xspeed_host$uri/index.html last;';
697	7295	$lines[] = '}';
698	7296	$lines[] = '';
699		- $lines[] = '# Serve + log the cached HIT. The `^~` modifier is REQUIRED:';
700		- $lines[] = '# the rewrite above lands on a `…/index.html` URI, and nginx';
701		- $lines[] = '# matches regex locations (e.g. a `~* \.html$` block a vhost';
702		- $lines[] = '# commonly has) BEFORE plain prefix locations. Without `^~`,';
703		- $lines[] = '# that regex block wins, this location never matches, the HIT';
704		- $lines[] = '# is never logged, and on some vhosts the request falls through';
705		- $lines[] = '# to PHP — i.e. the static rewrite silently does nothing.';
706		- $lines[] = '# `^~` makes this prefix match beat any regex location, so the';
707		- $lines[] = '# rewritten request always serves here from disk and logs once.';
	7297	+ $lines[] = '# Serve + log the cached HIT — `^~` is required so this beats any regex location.';
708	7298	$lines[] = 'location ^~ ' . $rel . '/ {';
709	7299	$lines[] = ' internal;';
710		- $lines[] = ' access_log ' . $hits_abs . ' combined buffer=16k flush=10s;';
711		- $lines[] = ' # Visible HIT indicator for the fast path: this file was';
712		- $lines[] = ' # served directly by nginx from xSpeed\'s static cache,';
713		- $lines[] = ' # bypassing PHP entirely. The PHP drop-in sends the same';
714		- $lines[] = ' # header with value "HIT (php)" on its slower fallback path.';
	7300	+ // LITERAL log path (not `set $var; access_log $var`). The variable form
	7301	+ // makes nginx open the log lazily per-request and SILENTLY drop the
	7302	+ // line if the open fails — so on a working host hits were served
	7303	+ // (X-XSpeed-Cache fires regardless) but nothing was ever written and
	7304	+ // the hit ratio sat at 0%. A literal path makes nginx open the file at
	7305	+ // config load and actually log every hit.
	7306	+ //
	7307	+ // Deleting the log FILE is still safe with a literal path: nginx
	7308	+ // recreates it on the next write/reload and `nginx -t` stays green
	7309	+ // (verified). The only thing that [emerg]s `nginx -t` is a missing
	7310	+ // parent DIRECTORY — and the log lives under uploads/xspeed/, which
	7311	+ // survives cache purge + uninstall, and which ensure_hits_log_file()
	7312	+ // (run on every admin_init via auto_heal) recreates if it ever goes
	7313	+ // missing. So: hits are logged, and a user deleting the log can't take
	7314	+ // nginx down.
	7315	+ $lines[] = ' access_log ' . $hits_abs . ' combined buffer=16k flush=5s;';
715	7316	$lines[] = ' add_header X-XSpeed-Cache "HIT (nginx)" always;';
	7317	+ // Edge/CDN headers from the same seam the drop-in bakes. nginx serves
	7318	+ // this path without ever starting PHP, so the answer cannot be
	7319	+ // resolved per request — the pairs are resolved HERE, when the
	7320	+ // snippet is generated, and a change of answer needs the snippet
	7321	+ // regenerated and re-pasted to take effect.
	7322	+ //
	7323	+ // Skipped entirely when the static path is switched off. The only
	7324	+ // reason that can fire under `bake` is mobile-split, and mobile-split
	7325	+ // is also what switches the static path off — so the block would be
	7326	+ // baked with a hold it can never serve, and would start serving it
	7327	+ // the moment the setting is turned off and static files reappear,
	7328	+ // until somebody regenerates and re-pastes. A rule that can only be
	7329	+ // served once its premise is false is guaranteed to be stale.
	7330	+ foreach ( self::static_rewrite_allowed() ? self::edge_headers_for( 'HIT', 'bake' ) : array() as $name => $value ) {
	7331	+ $lines[] = ' add_header ' . $name . ' "' . self::quote_directive_value( $value ) . '" always;';
	7332	+ }
716	7333	$lines[] = '}';
717	7334	return implode( "\n", $lines );
718	7335	}
719	7336
		@@ -745,32 +7362,37 @@
745	7362	if ( empty( $blocks ) ) {
746	7363	return null;
747	7364	}
748	7365
749		- $header = "# xSpeed unified nginx config — paste once into your\n"
750		- . "# nginx vhost's `server { }` block (or container nginx\n"
751		- . "# config for containerized hosts), above `location / { }`.\n"
752		- . "# Regenerated on every dashboard load — re-paste after\n"
753		- . "# toggling features so the directives reflect current state.\n";
	7366	+ $header = "# xSpeed unified nginx config — paste into `server { }`, above `location / { }`; re-paste after toggling features.\n";
754	7367
755	7368	return $header . "\n" . implode( "\n\n", $blocks ) . "\n";
756	7369	}
757	7370
758	7371	/**
759		- * Emit LiteSpeed Cache module headers on the cache-miss render
760		- * path so the server caches the response and serves subsequent
761		- * requests at edge speed without booting PHP again.
	7372	+ * Tell LiteSpeed's LSCache module to stand down on the cache-miss
	7373	+ * render path.
762	7374	*
763		- * LSCache reads two response headers:
764		- * - X-LiteSpeed-Cache-Control: public,max-age=N → "cache for N s"
765		- * - X-LiteSpeed-Tag: tag1,tag2 → tag the entry for selective
766		- * purge later via X-LiteSpeed-Purge in any later response.
	7375	+ * History: this method used to emit X-LiteSpeed-Cache-Control:
	7376	+ * public,max-age=N + X-LiteSpeed-Tag, handing caching to the server's
	7377	+ * LSCache store. That delegation backfired — once LSCache cached a
	7378	+ * page it served every subsequent request from its OWN store and
	7379	+ * intercepted the request before our site-root .htaccess static
	7380	+ * rewrite could run. Net effect on LiteSpeed hosts: no X-XSpeed-Cache
	7381	+ * header, our static-cache tree never served, the HIT log never
	7382	+ * written (hit ratio frozen at 0%), and the Health probe reporting a
	7383	+ * false "cache running on PHP fallback" because it never saw an
	7384	+ * xSpeed-served response.
767	7385	*
768		- * Server detection runs through Server::type() so a non-LiteSpeed
769		- * host (Apache / nginx / IIS) sees a no-op — the headers are
770		- * harmless if emitted there, but we skip them to keep response
771		- * headers tidy. The conflict check defers to the LiteSpeed Cache
772		- * plugin when present so we don't double-cache.
	7386	+ * xSpeed now owns the cache on LiteSpeed exactly as it does on Apache:
	7387	+ * our `.htaccess` mod_rewrite block serves hits straight from the
	7388	+ * static-cache tree (with the X-XSpeed-Cache header + access-log HIT
	7389	+ * accounting), and PHP/the drop-in is the fallback. To guarantee
	7390	+ * LSCache doesn't shadow that with its own copy — some LiteSpeed
	7391	+ * configs cache by default — we send an explicit `no-cache` control so
	7392	+ * the server defers to our rewrite. Skipped when the LiteSpeed Cache
	7393	+ * plugin is active (it owns its own header policy; our Conflict
	7394	+ * registry handles that coexistence separately).
773	7395	*/
774	7396	public static function maybe_emit_lscache_headers(): void {
775	7397	if ( headers_sent() ) {
776	7398	return;
		@@ -785,20 +7407,65 @@
785	7407	if ( in_array( 'litespeed-cache/litespeed-cache.php', $active, true ) ) {
786	7408	return;
787	7409	}
788	7410
789		- $opts = Settings_Manager::get( 'cache' );
790		- $expiry = isset( $opts['cache_expiry'] ) ? (int) $opts['cache_expiry'] : DAY_IN_SECONDS;
791		- $expiry = max( 60, min( $expiry, 30 * DAY_IN_SECONDS ) );
	7411	+ // Explicitly opt this response OUT of LSCache so the server can't
	7412	+ // shadow our static-rewrite cache with its own internal copy.
	7413	+ header( 'X-LiteSpeed-Cache-Control: no-cache' );
	7414	+ }
792	7415
793		- // Tags scope the entry so a single post change can purge just
794		- // that page (or its archive) instead of the whole cache. We
795		- // always send the global `xspeed` tag plus a path-derived one.
796		- $request_uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '/';
797		- $path_tag = 'xspeed_' . md5( (string) strtok( $request_uri, '?' ) );
	7416	+ /**
	7417	+ * Restore the drop-in + WP_CACHE constant for a site that had caching
	7418	+ * ON before this activation — and ONLY for such a site.
	7419	+ *
	7420	+ * WordPress runs an upgrade as deactivate → wipe plugin files →
	7421	+ * install → activate. The wipe takes advanced-cache.php with it, so
	7422	+ * without this the site serves 100% uncached from the moment the
	7423	+ * update finishes until the next authenticated wp-admin page load
	7424	+ * (auto_heal() is on admin_init). On a site whose admin logs in
	7425	+ * rarely that window is hours or days of silent cache loss, while
	7426	+ * the dashboard still reports cache_enabled = true. (FBS field
	7427	+ * report against 1.1.2 / Pro 1.0.5.)
	7428	+ *
	7429	+ * The `cache_enabled` guard is the whole contract: a FRESH install
	7430	+ * has the option unset, so activation writes nothing and the user
	7431	+ * still opts in explicitly through Cache::toggle() via the
	7432	+ * /cache/toggle REST endpoint. We only ever put back state the user
	7433	+ * already chose — repair, never a new install path. This is what
	7434	+ * keeps us on the right side of the "don't create drop-ins the user
	7435	+ * didn't ask for" guideline while matching what WP Rocket, W3 Total
	7436	+ * Cache and WP Super Cache all do on activation.
	7437	+ *
	7438	+ * @return bool True when a restore was performed.
	7439	+ */
	7440	+ public static function restore_dropin_if_enabled(): bool {
	7441	+ if ( defined( 'WP_INSTALLING' ) && WP_INSTALLING ) {
	7442	+ return false;
	7443	+ }
798	7444
799		- header( 'X-LiteSpeed-Cache-Control: public,max-age=' . $expiry );
800		- header( 'X-LiteSpeed-Tag: xspeed,' . $path_tag );
	7445	+ // The user's saved choice. Absent/false on a fresh install => no
	7446	+ // drop-in is written and nothing touches wp-config.php.
	7447	+ $opts = get_option( 'xspeed_options', array() );
	7448	+ if ( empty( $opts['cache_enabled'] ) ) {
	7449	+ return false;
	7450	+ }
	7451	+
	7452	+ $state = self::toggle( true, false );
	7453	+ // A refusal reports whether the cache SERVES, which on this path can
	7454	+ // be true for reasons that have nothing to do with this call — so a
	7455	+ // refusal would otherwise log "drop-in restored" for a restore that
	7456	+ // was declined. Restored means the transaction went through.
	7457	+ $restored = empty( $state['blocked'] ) && ! empty( $state['enabled'] );
	7458	+
	7459	+ if ( $restored ) {
	7460	+ Activity_Log::record(
	7461	+ 'cache_dropin_restored',
	7462	+ 'Cache drop-in restored after a plugin update — caching was already enabled.',
	7463	+ Activity_Log::SUCCESS
	7464	+ );
	7465	+ }
	7466	+
	7467	+ return $restored;
801	7468	}
802	7469
803	7470	/**
804	7471	* Reconcile drop-in + WP_CACHE + rewrite block with the user's
		@@ -823,29 +7490,31 @@
823	7490	if ( empty( $opts['cache_enabled'] ) ) {
824	7491	return;
825	7492	}
826	7493
827		- $dropin_target = WP_CONTENT_DIR . '/advanced-cache.php';
828		- $dropin_ours = false;
829		- if ( file_exists( $dropin_target ) ) {
830		- $contents = @file_get_contents( $dropin_target ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
831		- $dropin_ours = is_string( $contents ) && false !== strpos( $contents, 'XSPEED_DROPIN' );
	7494	+ $state = self::toggle( true, false );
	7495	+ // A refusal means something else now owns the page-cache field, or
	7496	+ // the write could not be verified. Either way this is not the moment
	7497	+ // to go on maintaining our rewrite block and log file.
	7498	+ if ( ! empty( $state['blocked'] ) || empty( $state['enabled'] ) ) {
	7499	+ return;
832	7500	}
833	7501
834		- if ( ! $dropin_ours ) {
835		- self::install_dropin();
836		- }
837		-
838		- if ( ! defined( 'WP_CACHE' ) || ! WP_CACHE ) {
839		- self::set_wp_cache_constant( true );
840		- }
841		-
842	7502	// Rewrite block goes last. It's what turns the static-cache
843	7503	// tree into a PHP-bypass — every cache hit served by the web
844	7504	// server directly. Without it we still cache, just at drop-in
845	7505	// speed (~85ms TTFB) instead of static-file speed (~25-40ms).
846		- if ( ! self::rewrite_installed() ) {
847		- self::install_rewrite();
	7506	+ //
	7507	+ // Reconcile against mobile_separate: the rewrite is device-blind, so
	7508	+ // it must be ABSENT when mobile_separate is on and PRESENT otherwise.
	7509	+ // auto_heal() runs periodically, so it also repairs a rewrite that
	7510	+ // was left installed before mobile_separate was switched on.
	7511	+ if ( self::static_rewrite_allowed() ) {
	7512	+ if ( ! self::rewrite_installed() ) {
	7513	+ self::install_rewrite();
	7514	+ }
	7515	+ } elseif ( self::rewrite_installed() ) {
	7516	+ self::remove_rewrite();
848	7517	}
849	7518
850	7519	// HITs log file — nginx writes one line per HIT served directly
851	7520	// (see nginx_snippet()), Cache::get_stats() drains the file via
		@@ -855,8 +7524,54 @@
855	7524	self::ensure_hits_log_file();
856	7525	}
857	7526
858	7527	/**
	7528	+ * Keep the generic bypass cookie in sync with PHP's caching verdict.
	7529	+ *
	7530	+ * The server config tests exactly one cookie name (Server_Rules::
	7531	+ * BYPASS_COOKIE) forever, and PHP decides what that name means. Adding
	7532	+ * a new excluded cookie therefore needs no config change and no nginx
	7533	+ * reload — the reason this exists.
	7534	+ *
	7535	+ * Session cookie (expiry 0) so it dies with the browser session, and
	7536	+ * deliberately NOT HttpOnly-sensitive: it carries no identity, only the
	7537	+ * boolean "don't serve this visitor a shared cached page".
	7538	+ *
	7539	+ * Honest limit: this can only ever help a visitor PHP has already seen
	7540	+ * once. A bot's first request to a warm page never reaches PHP, which
	7541	+ * is why user-agent rules are still written into the server config
	7542	+ * rather than relying on this.
	7543	+ *
	7544	+ * @param bool $bypass Whether this visitor must skip the cache.
	7545	+ */
	7546	+ private static function sync_bypass_cookie( bool $bypass ): void {
	7547	+ if ( headers_sent() ) {
	7548	+ return;
	7549	+ }
	7550	+
	7551	+ $name = Server_Rules::BYPASS_COOKIE;
	7552	+ $has = isset( $_COOKIE[ $name ] );
	7553	+
	7554	+ // Only touch the header when the state actually changes — a
	7555	+ // Set-Cookie on every request would make the response uncacheable
	7556	+ // for intermediary caches and add noise to every hit.
	7557	+ if ( $bypass === $has ) {
	7558	+ return;
	7559	+ }
	7560	+
	7561	+ $path = defined( 'COOKIEPATH' ) && COOKIEPATH ? COOKIEPATH : '/';
	7562	+ $domain = defined( 'COOKIE_DOMAIN' ) ? COOKIE_DOMAIN : '';
	7563	+
	7564	+ if ( $bypass ) {
	7565	+ setcookie( $name, '1', 0, $path, (string) $domain, is_ssl(), false );
	7566	+ $_COOKIE[ $name ] = '1';
	7567	+ } else {
	7568	+ setcookie( $name, '', time() - 3600, $path, (string) $domain, is_ssl(), false );
	7569	+ unset( $_COOKIE[ $name ] );
	7570	+ }
	7571	+ }
	7572	+
	7573	+ /**
859	7574	* Build the .htaccess rules that map cacheable requests to the
860	7575	* static-cache tree. Conditions are deliberately strict: GET only,
861	7576	* empty query string, no session/comment-author/post-password
862	7577	* cookie, and the static file must exist on disk. Anything that
		@@ -873,14 +7588,46 @@
873	7588	$rel = str_replace( ABSPATH, '/', XSPEED_CACHE_STATIC_DIR );
874	7589	$rel = '/' . ltrim( $rel, '/' );
875	7590	$rel = rtrim( $rel, '/' );
876	7591
877		- return array(
	7592	+ // Cookie + user-agent exclusions generated from the live settings.
	7593	+ // See the matching block in nginx_snippet() — same generator, same
	7594	+ // floor, so both servers enforce an identical policy. Apache reads
	7595	+ // .htaccess on every request and we already self-heal this file, so
	7596	+ // Apache/LiteSpeed users get the fix on upgrade with no action.
	7597	+ $cache_opts = Settings_Manager::get( 'cache' );
	7598	+ $cookie_rule = Server_Rules::cookie_rule(
	7599	+ is_array( $cache_opts['excluded_cookies'] ?? null ) ? $cache_opts['excluded_cookies'] : array()
	7600	+ );
	7601	+ $ua_rule = Server_Rules::user_agent_rule(
	7602	+ is_array( $cache_opts['bypass_user_agents'] ?? null ) ? $cache_opts['bypass_user_agents'] : array()
	7603	+ );
	7604	+
	7605	+ $lines = array(
878	7606	'<IfModule mod_rewrite.c>',
879	7607	' RewriteEngine On',
880	7608	' RewriteCond %{REQUEST_METHOD} ^GET$',
881	7609	' RewriteCond %{QUERY_STRING} ^$',
882		- ' RewriteCond %{HTTP_COOKIE} !(wordpress_logged_in|comment_author|wp-postpass_) [NC]',
	7610	+ ' RewriteCond %{HTTP_COOKIE} !(' . $cookie_rule['regex'] . ') [NC]',
	7611	+ );
	7612	+
	7613	+ // Only emit the UA condition when there's something to match —
	7614	+ // `!()` would negate an always-true empty match and refuse every
	7615	+ // request, silently disabling the static path.
	7616	+ if ( '' !== $ua_rule['regex'] ) {
	7617	+ // Quoted, because RewriteCond is whitespace-delimited and real
	7618	+ // user-agent fragments contain spaces ("Mozilla/5.0 (compatible").
	7619	+ // Unquoted, a space adds an argument and Apache answers every
	7620	+ // request with a 500 — and because .htaccess is parsed per
	7621	+ // request, `httpd -t` still reports Syntax OK. Server_Rules has
	7622	+ // already excluded quotes and backslashes from the alternation,
	7623	+ // so the closing quote here cannot be escaped away.
	7624	+ $lines[] = ' RewriteCond %{HTTP_USER_AGENT} "!(' . $ua_rule['regex'] . ')" [NC]';
	7625	+ }
	7626	+
	7627	+ $block = array_merge(
	7628	+ $lines,
	7629	+ array(
883	7630	// Capture REQUEST_URI without its trailing slash into %1.
884	7631	// store_static() writes `{host}{uri-without-trailing-slash}/index.html`,
885	7632	// so this normalization lets `/blog/` and `/blog` both hit
886	7633	// the same cache file without producing the double-slash
		@@ -886,11 +7633,66 @@
886	7633	// the same cache file without producing the double-slash
887	7634	// path that would skip the -f check below.
888	7635	' RewriteCond %{REQUEST_URI} ^(.*?)/?$',
889	7636	' RewriteCond %{DOCUMENT_ROOT}' . $rel . '/%{HTTP_HOST}%1/index.html -f',
890		- ' RewriteRule . ' . $rel . '/%{HTTP_HOST}%1/index.html [L]',
	7637	+ // Pattern is `^`, NOT `.`. The per-directory rewrite engine
	7638	+ // strips the leading slash before matching, so the HOMEPAGE
	7639	+ // request `/` arrives here as an EMPTY path. `.` requires at
	7640	+ // least one character and therefore never matches the homepage
	7641	+ // — on LiteSpeed (which honors this strictly) the front page
	7642	+ // fell through to PHP while every inner page rewrote fine.
	7643	+ // `^` matches the empty string AND any non-empty path, so it
	7644	+ // covers `/` and `/blog` alike. (Confirmed on OpenLiteSpeed
	7645	+ // 1.8: `.` → homepage served by PHP drop-in; `^` → served
	7646	+ // directly from the static file.)
	7647	+ ' RewriteRule ^ ' . $rel . '/%{HTTP_HOST}%1/index.html [E=XSPEED_STATIC_HIT:1,L]',
891	7648	'</IfModule>',
	7649	+ // Mark the statically-served response as a cache HIT.
	7650	+ //
	7651	+ // A file served by the rewrite above bypasses PHP entirely, so
	7652	+ // this directive is the ONLY thing that can identify it as
	7653	+ // cached — both for the user reading response headers and for
	7654	+ // Hit_Counter, which reconciles static hits from the access
	7655	+ // log. Without it the cache works perfectly and reports a 0%
	7656	+ // hit ratio, which reads as "the plugin is broken". (Field
	7657	+ // report against 1.1.2: homepage served byte-identical from
	7658	+ // the static tree, no X-XSpeed-Cache header on any response.)
	7659	+ //
	7660	+ // `always` so the header is set on the 200 from the rewritten
	7661	+ // file, not only on the successful-response table. The
	7662	+ // <IfModule> guard keeps a server without mod_headers from
	7663	+ // 500ing on an unknown directive — on such a host the header
	7664	+ // is silently dropped, which is exactly why
	7665	+ // static_rewrite_allowed() refuses the static path there and
	7666	+ // routes hits through the drop-in instead.
	7667	+ '<IfModule mod_headers.c>',
	7668	+ ' <FilesMatch "\\.html$">',
	7669	+ ' Header always set X-XSpeed-Cache "HIT (static)"',
	7670	+ ' </FilesMatch>',
	7671	+ )
892	7672	);
	7673	+
	7674	+ // Edge/CDN headers from the same seam the drop-in bakes. Like the
	7675	+ // nginx snippet, the static rewrite answers without PHP, so the pairs
	7676	+ // are resolved when the block is GENERATED rather than per request.
	7677	+ //
	7678	+ // `env=` rather than the `<FilesMatch>` scoping above, because these
	7679	+ // must ride only on responses the rewrite produced. The marker header
	7680	+ // stays filename-scoped: it is inert, and narrowing it would change a
	7681	+ // header QA reads.
	7682	+ // Same reasoning as the nginx snippet: a bake hold can only come from
	7683	+ // mobile-split, and mobile-split is what turns this path off.
	7684	+ $edge_lines = array();
	7685	+ foreach ( self::static_rewrite_allowed() ? self::edge_headers_for( 'HIT', 'bake' ) : array() as $edge_name => $edge_value ) {
	7686	+ $edge_lines = array_merge(
	7687	+ $edge_lines,
	7688	+ self::static_hit_directives(
	7689	+ ' Header always set ' . $edge_name . ' "' . self::quote_directive_value( $edge_value ) . '"'
	7690	+ )
	7691	+ );
	7692	+ }
	7693	+
	7694	+ return array_merge( $block, $edge_lines, array( '</IfModule>' ) );
893	7695	}
894	7696
895	7697	/**
896	7698	* Active probe that confirms the web-server static-rewrite path is
		@@ -908,18 +7710,49 @@
908	7710	* on every Health card paint.
909	7711	*
910	7712	* @return array{active:bool, reason:string, code?:int, php?:bool, expires?:int}
911	7713	*/
912		- public static function probe_static_rewrite(): array {
	7714	+ /**
	7715	+ * @param bool $allow_probe When false (the default), return ONLY a cached
	7716	+ * result and never make an HTTP request — so admin page loads are never
	7717	+ * blocked by the loopback probe. The actual HTTP probe only runs when a
	7718	+ * caller explicitly opts in (the Health tab / cron). Previously this ran
	7719	+ * synchronously on every dashboard bootstrap, so a slow/timing-out
	7720	+ * loopback request added up to `timeout` seconds to admin page loads on
	7721	+ * hosts that block self-requests. (FBS-82142)
	7722	+ */
	7723	+ /**
	7724	+ * Discard the cached probe result and run a fresh one.
	7725	+ *
	7726	+ * Without this there was no way to re-check: the result sat in a transient
	7727	+ * for five minutes and nothing ever deleted it, so a user who fixed their
	7728	+ * nginx config kept seeing "nginx detected — configure for max cache speed"
	7729	+ * with no means of confirming the fix worked. (FBS-84012)
	7730	+ */
	7731	+ public static function recheck_static_rewrite(): array {
	7732	+ delete_transient( 'xspeed_rewrite_probe' );
	7733	+ return self::probe_static_rewrite( true );
	7734	+ }
	7735	+
	7736	+ public static function probe_static_rewrite( bool $allow_probe = false ): array {
913	7737	$cached = get_transient( 'xspeed_rewrite_probe' );
914	7738	if ( is_array( $cached ) ) {
915	7739	return $cached;
916	7740	}
	7741	+ // No cached result yet and the caller doesn't want to pay for a live
	7742	+ // HTTP probe (e.g. the admin bootstrap): report "pending" without
	7743	+ // blocking. The Health tab will run the real probe on demand.
	7744	+ if ( ! $allow_probe ) {
	7745	+ return array( 'active' => false, 'reason' => 'probe pending', 'pending' => true );
	7746	+ }
917	7747
918	7748	$home = home_url( '/' );
919	7749	$host = (string) wp_parse_url( $home, PHP_URL_HOST );
920	7750	if ( '' === $host ) {
921		- $result = array( 'active' => false, 'reason' => 'home_url has no host' );
	7751	+ // Environmental failure, not evidence the server config is wrong —
	7752	+ // mark it inconclusive so Health surfaces say "could not verify"
	7753	+ // instead of demanding a snippet paste. (#480)
	7754	+ $result = array( 'active' => false, 'inconclusive' => true, 'reason' => 'home_url has no host' );
922	7755	set_transient( 'xspeed_rewrite_probe', $result, MINUTE_IN_SECONDS );
923	7756	return $result;
924	7757	}
925	7758
		@@ -936,9 +7769,12 @@
936	7769	if ( ! file_exists( $probe_dir ) ) {
937	7770	wp_mkdir_p( $probe_dir );
938	7771	}
939	7772	if ( ! is_dir( $probe_dir ) ) {
940		- $result = array( 'active' => false, 'reason' => 'cannot create probe dir' );
	7773	+ // A cache-dir permissions problem — the probe never ran, so this
	7774	+ // says nothing about the nginx config. Inconclusive, not
	7775	+ // "required". (#480)
	7776	+ $result = array( 'active' => false, 'inconclusive' => true, 'reason' => 'cannot create probe dir' );
941	7777	set_transient( 'xspeed_rewrite_probe', $result, MINUTE_IN_SECONDS );
942	7778	return $result;
943	7779	}
944	7780	// 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.
		@@ -943,13 +7779,22 @@
943	7779	}
944	7780	// 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.
945	7781	file_put_contents( $probe_file, $nonce, LOCK_EX );
946	7782
	7783	+ // Verify TLS by default — disabling it site-wide is a needless MITM
	7784	+ // exposure (FBS-82142). Only relax verification in local/dev
	7785	+ // environments, where self-signed certs are common and there's no
	7786	+ // real attacker in the loop.
	7787	+ $is_local = function_exists( 'wp_get_environment_type' )
	7788	+ && in_array( wp_get_environment_type(), array( 'local', 'development' ), true );
947	7789	$resp = wp_remote_get(
948	7790	$probe_url,
949	7791	array(
950		- 'timeout' => 4,
951		- 'sslverify' => false,
	7792	+ // 3s cap so a host that hangs on loopback self-requests can't
	7793	+ // stall the caller for long; the result/error is cached so we
	7794	+ // don't repeat the wait every minute.
	7795	+ 'timeout' => 3,
	7796	+ 'sslverify' => ! $is_local,
952	7797	'redirection' => 0,
953	7798	'headers' => array( 'Cache-Control' => 'no-cache' ),
954	7799	)
955	7800	);
		@@ -966,11 +7811,20 @@
966	7811
967	7812	if ( is_wp_error( $resp ) ) {
968	7813	$result = array(
969	7814	'active' => false,
	7815	+ // The request never completed, so we learned NOTHING about the
	7816	+ // rewrite. Flagged inconclusive so the UI doesn't tell the user
	7817	+ // to configure a server that may already be configured — a
	7818	+ // blocked loopback, a self-signed cert, or a timeout is a probe
	7819	+ // failure, not a missing rewrite. (FBS-84012)
	7820	+ 'inconclusive' => true,
970	7821	'reason' => 'http error: ' . $resp->get_error_message(),
971	7822	);
972		- set_transient( 'xspeed_rewrite_probe', $result, MINUTE_IN_SECONDS );
	7823	+ // Cache the failure for the full 5 minutes (not 1) so a host that
	7824	+ // times out on the loopback probe isn't re-probed — and re-stalled
	7825	+ // — on every page load within the window. (FBS-82142)
	7826	+ set_transient( 'xspeed_rewrite_probe', $result, 5 * MINUTE_IN_SECONDS );
973	7827	return $result;
974	7828	}
975	7829
976	7830	$code = (int) wp_remote_retrieve_response_code( $resp );
		@@ -985,25 +7839,41 @@
985	7839	// AND didn't add an X-Powered-By: PHP header. All three are
986	7840	// individually noisy; together they're conclusive.
987	7841	$active = $match && $has_etag && ! $ua_php && 200 === $code;
988	7842
	7843	+ /*
	7844	+ * `inconclusive` separates "we proved the rewrite isn't serving" from
	7845	+ * "the probe couldn't tell". Only the former should drive a
	7846	+ * configure-your-server banner; the latter previously rendered the
	7847	+ * same alarming copy at a user who had already configured nginx
	7848	+ * correctly, and there was no way to clear it. (FBS-84012)
	7849	+ */
	7850	+ $inconclusive = false;
989	7851	if ( $active ) {
990	7852	$reason = 'static-served';
991	7853	} elseif ( 200 === $code && $match && $ua_php ) {
992	7854	$reason = 'php served the file instead of nginx/Apache (rewrite block missing)';
993	7855	} elseif ( 200 === $code && ! $match ) {
994		- $reason = 'unexpected body (CDN cached an older response?)';
	7856	+ // Something answered 200 with content that isn't our nonce — a CDN,
	7857	+ // a proxy, a security plugin. That tells us nothing about the
	7858	+ // origin's rewrite.
	7859	+ $reason = 'unexpected body (CDN cached an older response?)';
	7860	+ $inconclusive = true;
995	7861	} elseif ( 404 === $code ) {
996	7862	$reason = 'probe URL returned 404 (rewrite block missing or wrong path)';
997	7863	} else {
998		- $reason = sprintf( 'unexpected response (HTTP %d, body %d B, php=%s)', $code, strlen( $body ), $ua_php ? 'yes' : 'no' );
	7864	+ // Redirects, 403s from a WAF, 5xx — the probe never reached a
	7865	+ // verdict about the rewrite itself.
	7866	+ $reason = sprintf( 'unexpected response (HTTP %d, body %d B, php=%s)', $code, strlen( $body ), $ua_php ? 'yes' : 'no' );
	7867	+ $inconclusive = true;
999	7868	}
1000	7869
1001	7870	$result = array(
1002		- 'active' => $active,
1003		- 'reason' => $reason,
1004		- 'code' => $code,
1005		- 'php' => $ua_php,
	7871	+ 'active' => $active,
	7872	+ 'inconclusive' => $inconclusive,
	7873	+ 'reason' => $reason,
	7874	+ 'code' => $code,
	7875	+ 'php' => $ua_php,
1006	7876	);
1007	7877	set_transient( 'xspeed_rewrite_probe', $result, 5 * MINUTE_IN_SECONDS );
1008	7878	return $result;
1009	7879	}
		@@ -1035,8 +7905,13 @@
1035	7905	* block manually: strip any prior xSpeed Static Cache markers,
1036	7906	* then write our block followed by the rest of the file.
1037	7907	*/
1038	7908	public static function install_rewrite(): bool {
	7909	+ // The static rewrite is device-blind; never install it when
	7910	+ // mobile_separate is on (see static_rewrite_allowed()).
	7911	+ if ( ! self::static_rewrite_allowed() ) {
	7912	+ return false;
	7913	+ }
1039	7914	$htaccess = ABSPATH . '.htaccess';
1040	7915	$existing = file_exists( $htaccess ) ? @file_get_contents( $htaccess ) : ''; // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
1041	7916	if ( false === $existing ) {
1042	7917	$existing = '';
		@@ -1055,12 +7930,49 @@
1055	7930	$cleaned = self::strip_marker_block( $existing, 'xSpeed Static Cache' );
1056	7931	$block = self::marker_block( 'xSpeed Static Cache', self::rewrite_block_lines() );
1057	7932	$next = $block . ( '' === $cleaned ? '' : "\n" . $cleaned );
1058	7933
	7934	+ /*
	7935	+ * Nothing to change. auto_heal() runs the whole enable transaction on
	7936	+ * every admin_init and this is called unconditionally from it, so
	7937	+ * without this every wp-admin request truncated and rewrote .htaccess
	7938	+ * with byte-identical content. Apache reads that file without a lock,
	7939	+ * so the truncate window is a real 500 on a busy admin, and the churn
	7940	+ * trips host file-integrity monitors.
	7941	+ */
	7942	+ if ( $next === $existing ) {
	7943	+ return true;
	7944	+ }
	7945	+
1059	7946	// 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.
1060	7947	return false !== file_put_contents( $htaccess, $next, LOCK_EX );
1061	7948	}
1062	7949
	7950	+ /**
	7951	+ * Rewrite the .htaccess block in place when — and only when — one is
	7952	+ * already installed.
	7953	+ *
	7954	+ * The block embeds the generated cookie / user-agent exclusion rules,
	7955	+ * so it goes stale the moment those settings change. install_rewrite()
	7956	+ * regenerates it from the live settings, but calling that unconditionally
	7957	+ * on every save would CREATE a block on sites that never enabled the
	7958	+ * static path — silently turning on server-level serving nobody asked
	7959	+ * for. So we refresh only what's already there.
	7960	+ *
	7961	+ * @return bool True when a block was present and rewritten.
	7962	+ */
	7963	+ public static function refresh_rewrite_if_installed(): bool {
	7964	+ $htaccess = ABSPATH . '.htaccess';
	7965	+ if ( ! file_exists( $htaccess ) ) {
	7966	+ return false;
	7967	+ }
	7968	+ $existing = @file_get_contents( $htaccess ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Best-effort read; an unreadable file simply means nothing to refresh.
	7969	+ if ( ! is_string( $existing ) || false === strpos( $existing, '# BEGIN xSpeed Static Cache' ) ) {
	7970	+ return false;
	7971	+ }
	7972	+ return self::install_rewrite();
	7973	+ }
	7974	+
1063	7975	public static function remove_rewrite(): bool {
1064	7976	$htaccess = ABSPATH . '.htaccess';
1065	7977	// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_is_writable -- See install_rewrite() rationale.
1066	7978	if ( ! file_exists( $htaccess ) || ! is_writable( $htaccess ) ) {
		@@ -1081,9 +7993,21 @@
1081	7993	* follows it. Idempotent — returns the input unchanged if the
1082	7994	* marker isn't present.
1083	7995	*/
1084	7996	private static function strip_marker_block( string $contents, string $marker ): string {
1085		- $pattern = '/# BEGIN ' . preg_quote( $marker, '/' ) . '\b.*?# END ' . preg_quote( $marker, '/' ) . "\b[^\n]*\n?\n?/s";
	7997	+ /*
	7998	+ * The body may not contain another BEGIN for this marker.
	7999	+ *
	8000	+ * `.*?` is non-greedy but still spans anything, so an ORPHANED
	8001	+ * `# BEGIN xSpeed Static Cache` — an END line lost to a hand edit or
	8002	+ * a partial write — paired with the END of the NEXT block and deleted
	8003	+ * everything between them. On a site where the orphan sits above
	8004	+ * `# BEGIN WordPress`, that takes WordPress's own rewrite rules with
	8005	+ * it and every permalink 404s. Refusing to cross a second BEGIN makes
	8006	+ * the orphan a no-op instead of a site-wide outage.
	8007	+ */
	8008	+ $begin = '# BEGIN ' . preg_quote( $marker, '/' ) . '\b';
	8009	+ $pattern = '/' . $begin . '(?:(?!' . $begin . ').)*?# END ' . preg_quote( $marker, '/' ) . "\b[^\n]*\n?\n?/s";
1086	8010	$out = preg_replace( $pattern, '', $contents );
1087	8011	return is_string( $out ) ? $out : $contents;
1088	8012	}
1089	8013
		@@ -1095,8 +8019,429 @@
1095	8019	$footer = "# END $marker\n";
1096	8020	return $header . implode( "\n", $lines ) . "\n" . $footer;
1097	8021	}
1098	8022
	8023	+ /**
	8024	+ * Parse the `XSPEED_DROPIN_VERSION: N` stamp out of a drop-in's source.
	8025	+ * Returns 0 when absent (an un-stamped older copy reinstalls). Used to
	8026	+ * detect a stale installed drop-in vs the bundled source.
	8027	+ */
	8028	+ private static function dropin_version( string $contents ): int {
	8029	+ if ( preg_match( '/XSPEED_DROPIN_VERSION:\s*(\d+)/', $contents, $m ) ) {
	8030	+ return (int) $m[1];
	8031	+ }
	8032	+ return 0;
	8033	+ }
	8034	+
	8035	+ /** The advanced-cache.php drop-in is ours. */
	8036	+ public const DROPIN_XSPEED = 'xspeed';
	8037	+ /** Someone else's drop-in is installed. */
	8038	+ public const DROPIN_FOREIGN = 'foreign';
	8039	+ /** No drop-in installed. */
	8040	+ public const DROPIN_NONE = 'none';
	8041	+ /** A drop-in is installed and we could not read it. */
	8042	+ public const DROPIN_UNREADABLE = 'unreadable';
	8043	+ /**
	8044	+ * Present but holding nothing -- empty, or whitespace only. WP Rocket
	8045	+ * truncates advanced-cache.php to 0 bytes on deactivate, and calling that
	8046	+ * FOREIGN made it a permanent blocker with no owner to ask. (#391)
	8047	+ */
	8048	+ public const DROPIN_ABANDONED = 'abandoned';
	8049	+
	8050	+ /**
	8051	+ * Who owns wp-content/advanced-cache.php right now.
	8052	+ *
	8053	+ * WordPress gives every caching plugin the same single file to live in,
	8054	+ * so "is there a drop-in" and "is it ours" are completely different
	8055	+ * questions, and only the second one licenses a write. An unreadable
	8056	+ * drop-in is deliberately its own answer rather than folding into
	8057	+ * "foreign": we cannot even name what we would be destroying.
	8058	+ *
	8059	+ * @return string One of the DROPIN_* constants.
	8060	+ */
	8061	+ public static function dropin_owner(): string {
	8062	+ require_once XSPEED_DIR . 'includes/wp-cache-constant.php';
	8063	+ $target = WP_CONTENT_DIR . '/advanced-cache.php';
	8064	+ if ( ! file_exists( $target ) ) {
	8065	+ return self::DROPIN_NONE;
	8066	+ }
	8067	+
	8068	+ $contents = self::read_file( $target );
	8069	+ if ( null === $contents ) {
	8070	+ return self::DROPIN_UNREADABLE;
	8071	+ }
	8072	+
	8073	+ if ( xspeed_has_canonical_dropin_signature( $contents ) ) {
	8074	+ return self::DROPIN_XSPEED;
	8075	+ }
	8076	+
	8077	+ // Nothing in the file means nothing owns it. Kept distinct from
	8078	+ // FOREIGN so the acquisition gate can tell "someone else's cache" from
	8079	+ // "a husk the last plugin left behind". (#391)
	8080	+ if ( '' === trim( $contents ) ) {
	8081	+ return self::DROPIN_ABANDONED;
	8082	+ }
	8083	+
	8084	+ /*
	8085	+ * The other half of the same question, and it cannot be answered from
	8086	+ * the bytes: a file we cannot attribute is a COMPETITOR only while
	8087	+ * some page cache is actually running. With every candidate switched
	8088	+ * off it is abandoned -- a hosting company's own cache, a hand-rolled
	8089	+ * one, or a plugin that was deleted without cleaning up.
	8090	+ *
	8091	+ * Asking the detector rather than re-deriving it here is the point:
	8092	+ * these two answers disagreeing is a split brain with a bad ending --
	8093	+ * acquisition_blocker() opens the gate, install_dropin() then refuses
	8094	+ * on FOREIGN, and toggle() blames the filesystem for a write it never
	8095	+ * attempted. One question, one answer. (#391, #393)
	8096	+ */
	8097	+ if ( class_exists( __NAMESPACE__ . '\\Page_Cache_Detector' ) ) {
	8098	+ $owner = (string) ( Page_Cache_Detector::inspect()['dropin']['owner'] ?? '' );
	8099	+
	8100	+ // Attributable to a named plugin -> somebody's cache, whatever its
	8101	+ // activation state. Only a file NOBODY can be shown to own, with
	8102	+ // nothing running, is abandoned.
	8103	+ if ( Page_Cache_Detector::OWNER_UNKNOWN === $owner
	8104	+ && ! Page_Cache_Detector::another_page_cache_is_active() ) {
	8105	+ return self::DROPIN_ABANDONED;
	8106	+ }
	8107	+ }
	8108	+
	8109	+ return self::DROPIN_FOREIGN;
	8110	+ }
	8111	+
	8112	+ /**
	8113	+ * Why xSpeed must not install its page-cache artifacts right now, or null
	8114	+ * when it may.
	8115	+ *
	8116	+ * This is the single gate in front of every write that touches shared
	8117	+ * state — the drop-in and the WP_CACHE define. Both are single-occupancy:
	8118	+ * whatever is there belongs to exactly one plugin, and taking it silently
	8119	+ * breaks that plugin's caching with no way back.
	8120	+ *
	8121	+ * Returns a user-facing string, so a REST caller can hand it straight to
	8122	+ * the dashboard instead of reporting a bare failure.
	8123	+ */
	8124	+ public static function acquisition_blocker(): ?string {
	8125	+ Page_Cache_Detector::invalidate();
	8126	+ $verdict = Page_Cache_Detector::classify();
	8127	+ $owner = self::dropin_owner();
	8128	+ // The reason we refuse, whether that reason already names a plugin,
	8129	+ // and every other page cache the detector counted anywhere in the
	8130	+ // verdict. See the tail of this method for why all three are needed.
	8131	+ $primary = null;
	8132	+ $primary_names = false;
	8133	+ $named = array();
	8134	+ foreach ( $verdict['blockers'] as $blocker ) {
	8135	+ $code = (string) ( $blocker['code'] ?? '' );
	8136	+ // The shared detector quite correctly reports xSpeed itself as a
	8137	+ // page-cache owner. That is not a competitor to this transaction.
	8138	+ //
	8139	+ // Except when the two disagree about the DROP-IN. The detector
	8140	+ // accepts our marker anywhere in a file's header; this plugin's
	8141	+ // own check requires it to open the header, because only this
	8142	+ // side authorizes overwriting and deleting. A foreign drop-in
	8143	+ // that merely carries our marker further down its header is
	8144	+ // attributed to us by the detector, and skipping it here dropped
	8145	+ // the refusal entirely — the write then failed on the stricter
	8146	+ // check and the user was told to go and fix file permissions.
	8147	+ // Where they disagree, believe the stricter one.
	8148	+ if ( self::PLUGIN_FILE === ( $blocker['plugin'] ?? null ) ) {
	8149	+ $about_dropin = in_array(
	8150	+ $code,
	8151	+ array(
	8152	+ Page_Cache_Detector::BLOCKER_FOREIGN_DROPIN,
	8153	+ Page_Cache_Detector::BLOCKER_UNKNOWN_DROPIN,
	8154	+ ),
	8155	+ true
	8156	+ );
	8157	+ if ( ! $about_dropin || self::DROPIN_XSPEED === $owner ) {
	8158	+ continue;
	8159	+ }
	8160	+ }
	8161	+ if ( Page_Cache_Detector::BLOCKER_WP_CACHE_ORPHANED === $code && self::DROPIN_XSPEED === $owner ) {
	8162	+ continue;
	8163	+ }
	8164	+ /*
	8165	+ * Another plugin's drop-in is no longer a refusal.
	8166	+ *
	8167	+ * It used to be: whoever held advanced-cache.php kept it, and
	8168	+ * enabling was blocked with "deactivate its page cache first".
	8169	+ * That left a user who had asked for our cache with no way to get
	8170	+ * it — on a live site the only exit was deleting a file over SSH,
	8171	+ * and the message could not even say which of its two causes
	8172	+ * applied ("is active OR owns advanced-cache.php").
	8173	+ *
	8174	+ * Turning the page cache on is the instruction to serve pages
	8175	+ * from cache, and that is not possible without this file. So we
	8176	+ * take it, and the dashboard says whose file it is first —
	8177	+ * dropin_disclosure() names the owner, the user confirms, and
	8178	+ * install_dropin() writes ours over the top.
	8179	+ *
	8180	+ * A still-active competitor is deliberately NOT re-added as a
	8181	+ * blocker below: it is caught by `active_page_cache`, which the
	8182	+ * capability rule already downgrades to a note. Two page caches
	8183	+ * installed at once is the user's call to make, not ours to
	8184	+ * refuse — they just told us which one they want serving.
	8185	+ *
	8186	+ * UNREADABLE is the exception and stays a refusal: we cannot name
	8187	+ * what we would destroy, and install_dropin() refuses it too, so
	8188	+ * opening the gate here would only produce a failed write.
	8189	+ */
	8190	+ $about_dropin_owner = in_array(
	8191	+ $code,
	8192	+ array(
	8193	+ Page_Cache_Detector::BLOCKER_FOREIGN_DROPIN,
	8194	+ Page_Cache_Detector::BLOCKER_UNKNOWN_DROPIN,
	8195	+ ),
	8196	+ true
	8197	+ );
	8198	+ if ( $about_dropin_owner && self::DROPIN_UNREADABLE !== $owner ) {
	8199	+ continue;
	8200	+ }
	8201	+ /*
	8202	+ * Capability is not possession. `active_page_cache` and
	8203	+ * `multiple_page_caches` both fire on a plugin that merely CAN
	8204	+ * cache pages — the detector cannot prove a competitor's page
	8205	+ * cache is off, so it counts it. As a warning that is right. As
	8206	+ * a gate it refuses a write that takes nothing from anyone.
	8207	+ *
	8208	+ * This gate guards exactly two files: advanced-cache.php and the
	8209	+ * WP_CACHE define that loads it. A plugin that does not hold the
	8210	+ * drop-in has nothing here for us to overwrite, and one that does
	8211	+ * is already refused by `foreign_dropin` / `unknown_dropin` a few
	8212	+ * lines up. So when the field is ours or empty, an active
	8213	+ * competitor is a note, not a refusal.
	8214	+ *
	8215	+ * QA found this on a live OpenLiteSpeed site keeping LiteSpeed
	8216	+ * Cache for images and CDN with its page cache off, while xSpeed
	8217	+ * served the pages. One click of the off switch and it could not
	8218	+ * be turned back on: the only way out was deactivating LiteSpeed
	8219	+ * entirely, and the message told them to "deactivate its page
	8220	+ * cache" — which they already had.
	8221	+ */
	8222	+ $about_capability = in_array(
	8223	+ $code,
	8224	+ array(
	8225	+ Page_Cache_Detector::BLOCKER_ACTIVE_PAGE_CACHE,
	8226	+ Page_Cache_Detector::BLOCKER_MULTIPLE_PAGE_CACHES,
	8227	+ ),
	8228	+ true
	8229	+ );
	8230	+ /*
	8231	+ * FOREIGN belongs in this list now, and it is the whole point.
	8232	+ *
	8233	+ * The rule is still "capability is not possession": these two
	8234	+ * blockers fire on any plugin that CAN cache pages, which the
	8235	+ * detector cannot prove is switched off. What changed is that a
	8236	+ * competitor holding the drop-in no longer stops us either — we
	8237	+ * take the file, having said whose it is. So there is nothing
	8238	+ * left for a merely-installed competitor to protect, and keeping
	8239	+ * the refusal here would put back the dead end by another route:
	8240	+ * "another page cache is active" on a site where the user has
	8241	+ * just told us, by name, which cache they want serving.
	8242	+ *
	8243	+ * UNREADABLE is deliberately still absent — that one refuses.
	8244	+ */
	8245	+ if ( $about_capability
	8246	+ && in_array( $owner, array( self::DROPIN_XSPEED, self::DROPIN_NONE, self::DROPIN_FOREIGN, self::DROPIN_ABANDONED ), true ) ) {
	8247	+ continue;
	8248	+ }
	8249	+ if ( Page_Cache_Detector::BLOCKER_MULTIPLE_PAGE_CACHES === $code ) {
	8250	+ $others = self::other_page_cache_names( $blocker );
	8251	+ if ( array() === $others ) {
	8252	+ // We were the only owner counted — nothing to refuse —
	8253	+ // unless the list is missing entirely, which is an older
	8254	+ // detector copy we still must not talk past.
	8255	+ if ( null === $primary && array() === (array) ( $blocker['plugins'] ?? array() ) ) {
	8256	+ $primary = self::ownership_blocker_message( '', '' );
	8257	+ }
	8258	+ continue;
	8259	+ }
	8260	+ $named = array_values( array_unique( array_merge( $named, $others ) ) );
	8261	+ if ( null === $primary ) {
	8262	+ $primary = self::multiple_page_caches_message( $others );
	8263	+ $primary_names = true;
	8264	+ }
	8265	+ continue;
	8266	+ }
	8267	+ if ( null === $primary ) {
	8268	+ $label = (string) ( $blocker['label'] ?? '' );
	8269	+ $primary = self::ownership_blocker_message( $code, $label );
	8270	+ $primary_names = '' !== $label;
	8271	+ }
	8272	+ }
	8273	+
	8274	+ if ( null === $primary ) {
	8275	+ return null;
	8276	+ }
	8277	+ /*
	8278	+ * The first blocker decides WHY we refuse; it does not always know
	8279	+ * WHO. The detector can only attribute a drop-in it recognises, and
	8280	+ * an unrecognised one produces "its owner cannot be proved" — the
	8281	+ * sentence a W3 Total Cache site used to get while a later blocker in
	8282	+ * the same verdict was holding the name "W3 Total Cache".
	8283	+ *
	8284	+ * So keep the reason and add the names, rather than swapping one for
	8285	+ * the other: the plugin the user must deal with is not necessarily
	8286	+ * the owner of the file we could not identify, and promoting the
	8287	+ * named blocker would have told them to deactivate a plugin that is
	8288	+ * not what is in their way.
	8289	+ */
	8290	+ if ( $primary_names || array() === $named ) {
	8291	+ return $primary;
	8292	+ }
	8293	+ if ( 1 === count( $named ) ) {
	8294	+ return sprintf(
	8295	+ /* translators: 1: the refusal reason, 2: a page-caching plugin's name. */
	8296	+ __( '%1$s %2$s is also active on this site — deactivate its page cache before enabling xSpeed.', 'xspeed' ),
	8297	+ $primary,
	8298	+ $named[0]
	8299	+ );
	8300	+ }
	8301	+ return sprintf(
	8302	+ /* translators: 1: the refusal reason, 2: comma-separated page-caching plugin names. */
	8303	+ __( '%1$s These page caches are also active on this site: %2$s. Deactivate them before enabling xSpeed.', 'xspeed' ),
	8304	+ $primary,
	8305	+ implode( ', ', $named )
	8306	+ );
	8307	+ }
	8308	+
	8309	+ /** How xSpeed's own plugin file appears in the detector's catalog. */
	8310	+ private const PLUGIN_FILE = 'xspeed/xspeed.php';
	8311	+
	8312	+ /**
	8313	+ * Name the OTHER page caches behind a `multiple_page_caches` refusal.
	8314	+ *
	8315	+ * This blocker has no single owner, so the detector leaves `plugin` and
	8316	+ * `label` null and hands over the full list instead. Left unhandled it
	8317	+ * fell through to the anonymous fallback sentence — and it is the blocker
	8318	+ * an ordinary site hits most: xSpeed counts toward "multiple", so the
	8319	+ * count reaches two the moment one other page-cache plugin is activated,
	8320	+ * even one that has not written a drop-in. A site running our cache that
	8321	+ * activated LiteSpeed could not re-enable it and was told only that "the
	8322	+ * page-cache field is occupied".
	8323	+ *
	8324	+ * Returns an empty list when xSpeed was the only owner counted, or when
	8325	+ * an older detector copy sent no list at all — the caller distinguishes
	8326	+ * the two by looking at `plugins`.
	8327	+ *
	8328	+ * @param array<string,mixed> $blocker One entry from Detector::classify().
	8329	+ * @return string[]
	8330	+ */
	8331	+ private static function other_page_cache_names( array $blocker ): array {
	8332	+ $plugins = array_values( (array) ( $blocker['plugins'] ?? array() ) );
	8333	+ $labels = array_values( (array) ( $blocker['labels'] ?? array() ) );
	8334	+
	8335	+ $others = array();
	8336	+ foreach ( $plugins as $i => $plugin ) {
	8337	+ if ( self::PLUGIN_FILE === $plugin ) {
	8338	+ continue;
	8339	+ }
	8340	+ $others[] = isset( $labels[ $i ] ) && '' !== (string) $labels[ $i ]
	8341	+ ? (string) $labels[ $i ]
	8342	+ : (string) $plugin;
	8343	+ }
	8344	+ return array_values( array_unique( $others ) );
	8345	+ }
	8346	+
	8347	+ /**
	8348	+ * The refusal sentence for a `multiple_page_caches` blocker.
	8349	+ *
	8350	+ * @param string[] $others Page caches other than xSpeed. Never empty.
	8351	+ */
	8352	+ private static function multiple_page_caches_message( array $others ): string {
	8353	+ if ( 1 === count( $others ) ) {
	8354	+ return self::ownership_blocker_message( Page_Cache_Detector::BLOCKER_ACTIVE_PAGE_CACHE, $others[0] );
	8355	+ }
	8356	+ return sprintf(
	8357	+ /* translators: %s: comma-separated list of page-caching plugin names. */
	8358	+ __( 'More than one page cache is active on this site (%s). Turn off the other page caches before enabling xSpeed.', 'xspeed' ),
	8359	+ implode( ', ', $others )
	8360	+ );
	8361	+ }
	8362	+
	8363	+ private static function ownership_blocker_message( string $code, string $label ): string {
	8364	+ if ( '' !== $label ) {
	8365	+ return sprintf( __( '%s is active or owns advanced-cache.php. Deactivate its page cache before enabling xSpeed.', 'xspeed' ), $label );
	8366	+ }
	8367	+ $messages = array(
	8368	+ 'wp_cache_orphaned' => __( 'WP_CACHE is true but no page-cache drop-in owner can be proved. xSpeed will not claim it.', 'xspeed' ),
	8369	+ 'wp_cache_duplicate' => __( 'wp-config.php defines WP_CACHE more than once. Remove the duplicate before enabling the cache.', 'xspeed' ),
	8370	+ 'wp_cache_dynamic' => __( 'WP_CACHE is set from an expression in wp-config.php. xSpeed will not rewrite it.', 'xspeed' ),
	8371	+ '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' ),
	8372	+ 'wp_config_unreadable' => __( 'wp-config.php cannot be read, so xSpeed cannot safely change page-cache ownership.', 'xspeed' ),
	8373	+ 'unknown_dropin' => __( 'advanced-cache.php is occupied but its owner cannot be proved. xSpeed will not replace it.', 'xspeed' ),
	8374	+ 'unreadable_dropin' => __( 'advanced-cache.php cannot be read, so xSpeed cannot prove its owner.', 'xspeed' ),
	8375	+ );
	8376	+ return $messages[ $code ] ?? __( 'The page-cache field is occupied or cannot be verified. xSpeed will not change it.', 'xspeed' );
	8377	+ }
	8378	+
	8379	+ /**
	8380	+ * How WP_CACHE is written in wp-config.php, as opposed to what it
	8381	+ * evaluates to at runtime.
	8382	+ *
	8383	+ * The literal is what matters to a writer: a value behind an expression,
	8384	+ * or two competing defines, cannot be rewritten by a regex without
	8385	+ * guessing — and a wrong guess silently disables page caching (ours or
	8386	+ * someone else's) with no error anywhere.
	8387	+ *
	8388	+ * @return string undefined | true | false | duplicate | dynamic | conditional | unreadable
	8389	+ */
	8390	+ public static function wp_cache_define_state(): string {
	8391	+ $path = self::wp_config_path();
	8392	+ if ( '' === $path ) {
	8393	+ return 'unreadable';
	8394	+ }
	8395	+
	8396	+ $config = self::read_file( $path );
	8397	+ if ( null === $config ) {
	8398	+ return 'unreadable';
	8399	+ }
	8400	+
	8401	+ require_once XSPEED_DIR . 'includes/wp-cache-constant.php';
	8402	+ $parsed = \xspeed_parse_wp_cache_defines( $config );
	8403	+ return $parsed['state'];
	8404	+ }
	8405	+
	8406	+ /**
	8407	+ * Classify the captured right-hand side of a WP_CACHE define.
	8408	+ *
	8409	+ * Hosts and older tutorials write the value several ways —
	8410	+ * `1`, `'1'`, `TRUE` — and all of them are literals a rewrite can safely
	8411	+ * replace. Only a value we cannot evaluate by looking at it (a variable, a
	8412	+ * function call, a ternary) counts as dynamic, because that is the case
	8413	+ * where rewriting means guessing.
	8414	+ *
	8415	+ * @return string true | false | dynamic
	8416	+ */
	8417	+ private static function classify_wp_cache_literal( string $raw ): string {
	8418	+ $literal = strtolower( trim( $raw ) );
	8419	+ $literal = trim( $literal, "'\"" );
	8420	+
	8421	+ if ( in_array( $literal, array( 'true', '1' ), true ) ) {
	8422	+ return 'true';
	8423	+ }
	8424	+ if ( in_array( $literal, array( 'false', '0', '', 'null' ), true ) ) {
	8425	+ return 'false';
	8426	+ }
	8427	+ return 'dynamic';
	8428	+ }
	8429	+
	8430	+ /**
	8431	+ * Read a file for an ownership decision. Null on any failure — callers
	8432	+ * treat null as "unknown", never as "empty", because an empty string
	8433	+ * would read as "no marker found" and license an overwrite.
	8434	+ */
	8435	+ private static function read_file( string $path ): ?string {
	8436	+ if ( ! is_readable( $path ) ) {
	8437	+ return null;
	8438	+ }
	8439	+ // 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.
	8440	+ $contents = @file_get_contents( $path ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- A failed read is a valid answer ("unknown"), not an error to surface.
	8441	+ return is_string( $contents ) ? $contents : null;
	8442	+ }
	8443	+
1099	8444	public static function install_dropin() {
1100	8445	$source = XSPEED_DIR . 'includes/advanced-cache.php';
1101	8446	$target = WP_CONTENT_DIR . '/advanced-cache.php';
1102	8447	if ( ! file_exists( $source ) ) {
		@@ -1102,8 +8447,26 @@
1102	8447	if ( ! file_exists( $source ) ) {
1103	8448	return false;
1104	8449	}
1105	8450
	8451	+ /*
	8452	+ * A drop-in we cannot READ is the one thing still refused here. Not
	8453	+ * because of who owns it — we no longer refuse on ownership — but
	8454	+ * because an unreadable file is usually a permissions problem, and
	8455	+ * writing over it would fail anyway or destroy something we were
	8456	+ * never able to look at.
	8457	+ *
	8458	+ * Everything else is ours to take. Enabling the page cache IS the
	8459	+ * user's instruction to serve the cache, and serving it means holding
	8460	+ * advanced-cache.php; the dashboard says whose file it is replacing
	8461	+ * before the click (Page_Cache_Detector::dropin_disclosure()), so the
	8462	+ * takeover is consented rather than silent.
	8463	+ */
	8464	+ $owner = self::dropin_owner();
	8465	+ if ( self::DROPIN_UNREADABLE === $owner ) {
	8466	+ return false;
	8467	+ }
	8468	+
1106	8469	global $wp_filesystem;
1107	8470	if ( ! function_exists( 'WP_Filesystem' ) ) {
1108	8471	require_once ABSPATH . 'wp-admin/includes/file.php';
1109	8472	}
		@@ -1116,35 +8479,96 @@
1116	8479	if ( ! is_string( $source_contents ) ) {
1117	8480	return false;
1118	8481	}
1119	8482
	8483	+ // Bake the absolute hit-log path into the drop-in. It runs before
	8484	+ // WordPress loads, so it can't resolve wp_upload_dir() itself — we
	8485	+ // substitute the @@XSPEED_HITS_LOG@@ token with the real uploads path
	8486	+ // (never the cache dir; see hits_log_dir() / FBS-82478). Use a single
	8487	+ // quoted PHP string literal so the installed file stays valid PHP.
	8488	+ $source_contents = str_replace(
	8489	+ '@@XSPEED_HITS_LOG@@',
	8490	+ str_replace( "'", "\\'", self::hits_log_path() ),
	8491	+ $source_contents
	8492	+ );
	8493	+
	8494	+ // Bake the cookie + user-agent exclusion rules in too. The drop-in
	8495	+ // runs before WordPress loads, so it cannot read the settings — and
	8496	+ // without them it served the shared anonymous page to any visitor
	8497	+ // PHP had not yet seen (a first-time cart visitor, a bypassed bot).
	8498	+ // The generic bypass cookie only covers repeat visitors; these two
	8499	+ // regexes are what make the FIRST request correct.
	8500	+ //
	8501	+ // Both are already fully escaped by Server_Rules, and each is
	8502	+ // embedded as a single-quoted PHP literal, so a settings value can
	8503	+ // neither break the drop-in's syntax nor execute.
	8504	+ $cache_opts = Settings_Manager::get( 'cache' );
	8505	+ $cookie_rule = Server_Rules::cookie_rule(
	8506	+ is_array( $cache_opts['excluded_cookies'] ?? null ) ? $cache_opts['excluded_cookies'] : array()
	8507	+ );
	8508	+ $ua_rule = Server_Rules::user_agent_rule(
	8509	+ is_array( $cache_opts['bypass_user_agents'] ?? null ) ? $cache_opts['bypass_user_agents'] : array()
	8510	+ );
	8511	+
	8512	+ $source_contents = str_replace(
	8513	+ '@@XSPEED_COOKIE_RE@@',
	8514	+ str_replace( "'", "\\'", $cookie_rule['regex'] ),
	8515	+ $source_contents
	8516	+ );
	8517	+ $source_contents = str_replace(
	8518	+ '@@XSPEED_UA_RE@@',
	8519	+ str_replace( "'", "\\'", $ua_rule['regex'] ),
	8520	+ $source_contents
	8521	+ );
	8522	+
	8523	+ /*
	8524	+ * Ours or absent — the ownership gate at the top of this method ruled
	8525	+ * out everything else. The old code path that moved a foreign drop-in
	8526	+ * into uploads/xspeed-backups and wrote ours on top is gone: it
	8527	+ * disabled the other plugin's page cache the moment an xSpeed install
	8528	+ * ran, with nothing in its own UI to explain why.
	8529	+ */
	8530	+
	8531	+ // Bake the configured cache lifetime in. The drop-in runs before
	8532	+ // WordPress loads, so it cannot read the option — it previously fell
	8533	+ // back to a hardcoded 86400 for every ordinary page, because
	8534	+ // write_meta() only emits a `ttl` sidecar when the value DIFFERS from
	8535	+ // the page default. That made the admin's "1 to 720 hours" control a
	8536	+ // no-op at the layer that actually answers the request: 12h served
	8537	+ // stale for up to 2x the configured lifetime, and 168h lost the fast
	8538	+ // path for 6 of every 7 days (issue #240).
	8539	+ //
	8540	+ // This is re-baked on every cache settings save (see CacheModule::boot),
	8541	+ // exactly like the cookie / user-agent rules above.
	8542	+ $expiry_hours = isset( $cache_opts['cache_expiry'] ) ? (int) $cache_opts['cache_expiry'] : 24;
	8543	+ if ( $expiry_hours < 1 || $expiry_hours > 720 ) {
	8544	+ $expiry_hours = 24;
	8545	+ }
	8546	+ $source_contents = str_replace(
	8547	+ '@@XSPEED_DEFAULT_TTL@@',
	8548	+ (string) ( $expiry_hours * HOUR_IN_SECONDS ),
	8549	+ $source_contents
	8550	+ );
	8551	+
	8552	+ // Bake the site-wide edge answer in. Resolved in a `bake` context, so
	8553	+ // nothing per-page and nothing a request header vouched for can reach
	8554	+ // it: a bake runs once, in an admin or CLI request, and answers for
	8555	+ // every page on the site. A page that disagrees gets a sidecar
	8556	+ // instead — see per_entry_edge_headers().
	8557	+ //
	8558	+ // Re-baked on every cache settings save (see CacheModule::boot),
	8559	+ // exactly like the cookie, user-agent and lifetime rules above.
	8560	+ $source_contents = str_replace(
	8561	+ "'@@XSPEED_EDGE_HEADERS@@'",
	8562	+ self::edge_headers_literal( self::edge_headers_for( 'HIT', 'bake' ) ),
	8563	+ $source_contents
	8564	+ );
	8565	+
1120	8566	if ( file_exists( $target ) ) {
1121	8567	$existing = $wp_filesystem->get_contents( $target );
1122		- $is_xspeed = is_string( $existing ) && false !== strpos( $existing, 'XSPEED_DROPIN' );
1123		-
1124		- if ( $is_xspeed ) {
1125		- if ( $existing === $source_contents ) {
1126		- return true;
1127		- }
1128		- return (bool) $wp_filesystem->put_contents( $target, $source_contents, FS_CHMOD_FILE );
	8568	+ if ( is_string( $existing ) && $existing === $source_contents ) {
	8569	+ return true;
1129	8570	}
1130		-
1131		- // Foreign drop-in (e.g. left over from another cache plugin) — back it up
1132		- // before overwriting so the user can recover if needed. Uploads dir
1133		- // (not wp-content root) keeps the backup out of WordPress's reserved
1134		- // drop-in location.
1135		- $upload = wp_upload_dir( null, false );
1136		- $basedir = isset( $upload['basedir'] ) ? trailingslashit( $upload['basedir'] ) . 'xspeed-backups' : false;
1137		- if ( $basedir ) {
1138		- if ( ! file_exists( $basedir ) ) {
1139		- wp_mkdir_p( $basedir );
1140		- self::write_silence( $basedir );
1141		- }
1142		- $backup = $basedir . '/advanced-cache.foreign-' . gmdate( 'Ymd-His' ) . '.php.bak';
1143		- $wp_filesystem->move( $target, $backup, true );
1144		- } else {
1145		- $wp_filesystem->delete( $target );
1146		- }
1147	8571	}
1148	8572
1149	8573	return (bool) $wp_filesystem->put_contents( $target, $source_contents, FS_CHMOD_FILE );
1150	8574	}
		@@ -1164,61 +8588,374 @@
1164	8588	return;
1165	8589	}
1166	8590
1167	8591	$contents = $wp_filesystem->get_contents( $target );
1168		- if ( is_string( $contents ) && false !== strpos( $contents, 'XSPEED_DROPIN' ) ) {
	8592	+ if ( is_string( $contents ) && xspeed_has_canonical_dropin_signature( $contents ) ) {
1169	8593	wp_delete_file( $target );
1170	8594	}
1171	8595	}
1172	8596
	8597	+ /**
	8598	+ * Where wp-config.php actually is.
	8599	+ *
	8600	+ * WordPress core supports the file one directory ABOVE ABSPATH, and
	8601	+ * plenty of installs use that layout. This used to look only in ABSPATH
	8602	+ * and bail, so on those sites the constant could never be written — while
	8603	+ * Health, which did fall back to the parent, reported the file writable
	8604	+ * and told the user to toggle the cache off and on. The advice could
	8605	+ * never work, and its fallback hint ("another plugin left WP_CACHE false
	8606	+ * behind") was wrong too: there was no define at all. (#19, QA on #174)
	8607	+ *
	8608	+ * Returns '' when no wp-config.php can be found in either location.
	8609	+ */
	8610	+ public static function wp_config_path(): string {
	8611	+ $candidates = array( ABSPATH . 'wp-config.php', dirname( ABSPATH ) . '/wp-config.php' );
	8612	+ foreach ( $candidates as $path ) {
	8613	+ if ( file_exists( $path ) ) {
	8614	+ return $path;
	8615	+ }
	8616	+ }
	8617	+ return '';
	8618	+ }
	8619	+
	8620	+ /**
	8621	+ * Can we actually write the constant right now?
	8622	+ *
	8623	+ * This is the single oracle for that question — Health asks THIS rather
	8624	+ * than running its own `wp_is_writable()` test, so the message a user
	8625	+ * reads can never disagree with what the plugin will do. The two differed
	8626	+ * in both directions: on the path (above) and on the test itself, since
	8627	+ * an FTP/SSH WP_Filesystem transport can refuse a file that
	8628	+ * `wp_is_writable()` reports as writable. (#19, QA on #174)
	8629	+ */
	8630	+ public static function can_write_wp_config(): bool {
	8631	+ $wp_config = self::wp_config_path();
	8632	+ if ( '' === $wp_config ) {
	8633	+ return false;
	8634	+ }
	8635	+
	8636	+ global $wp_filesystem;
	8637	+ if ( ! function_exists( 'WP_Filesystem' ) ) {
	8638	+ require_once ABSPATH . 'wp-admin/includes/file.php';
	8639	+ }
	8640	+ WP_Filesystem();
	8641	+ return (bool) ( $wp_filesystem && $wp_filesystem->is_writable( $wp_config ) );
	8642	+ }
	8643	+
1173	8644	public static function set_wp_cache_constant( $enable ) {
1174		- $wp_config = ABSPATH . 'wp-config.php';
1175		- if ( ! file_exists( $wp_config ) ) {
	8645	+ $wp_config = self::wp_config_path();
	8646	+ if ( '' === $wp_config ) {
1176	8647	return false;
1177	8648	}
1178	8649
	8650	+ /*
	8651	+ * WP_CACHE belongs to whoever owns the drop-in — it is the switch that
	8652	+ * makes core load that one file. Editing it while someone else's
	8653	+ * drop-in is installed either turns THEIR cache on or off; either way
	8654	+ * it is a write to another plugin's state. So: no ownership, no edit.
	8655	+ */
	8656	+ $owner = self::dropin_owner();
	8657	+ if ( self::DROPIN_FOREIGN === $owner || self::DROPIN_UNREADABLE === $owner ) {
	8658	+ return false;
	8659	+ }
	8660	+
	8661	+ $state = self::wp_cache_define_state();
	8662	+ if ( 'duplicate' === $state || 'dynamic' === $state ) {
	8663	+ // Two competing defines, or a value behind an expression. A regex
	8664	+ // rewrite here is a guess, and a wrong guess silently kills page
	8665	+ // caching with no error anywhere.
	8666	+ return false;
	8667	+ }
1179	8668	global $wp_filesystem;
1180	8669	if ( ! function_exists( 'WP_Filesystem' ) ) {
1181	8670	require_once ABSPATH . 'wp-admin/includes/file.php';
1182	8671	}
1183	8672	WP_Filesystem();
1184		- if ( ! $wp_filesystem || ! $wp_filesystem->is_writable( $wp_config ) ) {
	8673	+ if ( ! $wp_filesystem ) {
1185	8674	return false;
1186	8675	}
1187	8676
1188	8677	$config = $wp_filesystem->get_contents( $wp_config );
	8678	+ if ( ! is_string( $config ) ) {
	8679	+ return false;
	8680	+ }
	8681	+ require_once XSPEED_DIR . 'includes/wp-cache-constant.php';
	8682	+ $marker = $enable ? self::wp_cache_receipt() : '';
	8683	+ $updated = xspeed_rewrite_wp_cache_define( $config, (bool) $enable, $marker );
	8684	+ if ( ! is_string( $updated ) ) {
	8685	+ return false;
	8686	+ }
1189	8687
1190		- if ( $enable ) {
1191		- if ( strpos( $config, "define( 'WP_CACHE'" ) !== false || strpos( $config, "define('WP_CACHE'" ) !== false ) {
1192		- return true;
	8688	+ /*
	8689	+ * Removing a WP_CACHE line we cannot prove we wrote is somebody else's
	8690	+ * configuration, so a disable needs either our drop-in or our receipt.
	8691	+ *
	8692	+ * The test is on the REWRITE, not on the request: it used to run
	8693	+ * before the rewrite and refuse a disable that had nothing to remove.
	8694	+ * An ordinary site with no drop-in and no define — every fresh
	8695	+ * install — therefore failed to turn page caching off, so the
	8696	+ * onboarding wizard reported "setup needs attention" to every user who
	8697	+ * declined it and Migration reported the cache import as failed.
	8698	+ */
	8699	+ if ( ! $enable && $updated !== $config
	8700	+ && self::DROPIN_XSPEED !== $owner
	8701	+ && ! self::wp_cache_receipt_matches_source( $config ) ) {
	8702	+ return false;
	8703	+ }
	8704	+
	8705	+ /*
	8706	+ * Nothing to write. auto_heal() runs the whole enable transaction on
	8707	+ * every admin_init, so without this every wp-admin request rewrote
	8708	+ * wp-config.php with byte-identical content: pointless disk churn
	8709	+ * that trips host file-integrity monitors and widens the window for
	8710	+ * a concurrent write on a busy admin.
	8711	+ *
	8712	+ * It is also what makes a correct WP_CACHE on a read-only
	8713	+ * wp-config.php succeed. A managed host that ships the file
	8714	+ * unwritable, on a site where the user already pasted the define,
	8715	+ * is in the state we wanted — the writability test below is about
	8716	+ * whether we can CHANGE the file, and there is nothing to change.
	8717	+ */
	8718	+ if ( $updated === $config ) {
	8719	+ if ( ! $enable ) {
	8720	+ // Our line is not in the file, so the receipt that proved we
	8721	+ // wrote it is stale — drop it on the same terms as a real
	8722	+ // removal, or uninstall keeps a claim on nothing.
	8723	+ delete_option( 'xspeed_page_cache_ownership_receipt' );
1193	8724	}
1194		- $config = preg_replace( '/(<\?php)/', "$1\ndefine( 'WP_CACHE', true );", $config, 1 );
1195		- } else {
1196		- $config = preg_replace( "/define\\(\\s*['\"]WP_CACHE['\"]\\s*,\\s*true\\s*\\);\\s*\\n?/", '', $config );
	8725	+ return true;
1197	8726	}
1198	8727
1199		- return (bool) $wp_filesystem->put_contents( $wp_config, $config, FS_CHMOD_FILE );
	8728	+ if ( ! $wp_filesystem->is_writable( $wp_config ) ) {
	8729	+ return false;
	8730	+ }
	8731	+ $written = (bool) $wp_filesystem->put_contents( $wp_config, $updated, FS_CHMOD_FILE );
	8732	+ if ( $written && ! $enable ) {
	8733	+ delete_option( 'xspeed_page_cache_ownership_receipt' );
	8734	+ }
	8735	+ return $written;
1200	8736	}
1201	8737
	8738	+ private static function wp_cache_receipt(): string {
	8739	+ $receipt = get_option( 'xspeed_page_cache_ownership_receipt', '' );
	8740	+ if ( is_string( $receipt ) && preg_match( '/^[a-f0-9]{32}$/', $receipt ) ) {
	8741	+ return $receipt;
	8742	+ }
	8743	+ $receipt = substr( hash( 'sha256', XSPEED_DIR . microtime( true ) . mt_rand() ), 0, 32 );
	8744	+ update_option( 'xspeed_page_cache_ownership_receipt', $receipt, false );
	8745	+ return $receipt;
	8746	+ }
	8747	+
	8748	+ /**
	8749	+ * Is the WP_CACHE line in wp-config.php ours to REMOVE?
	8750	+ *
	8751	+ * Two different questions live here and only one of them matters. "Did we
	8752	+ * write it" is answered by our drop-in on disk or by our receipt comment
	8753	+ * beside the define. "Is it ours to remove" also asks what the line does
	8754	+ * NOW — and once a competitor owns advanced-cache.php, a line we wrote
	8755	+ * ourselves is the switch that loads THEIR drop-in. They had no reason to
	8756	+ * touch an already-true define, so our receipt is still sitting on it.
	8757	+ * Removing it there would stop their live page cache.
	8758	+ *
	8759	+ * So a foreign or unreadable owner is never ours to remove, whatever the
	8760	+ * receipt says, and the caller treats that as a reason to leave the line
	8761	+ * and get on with disabling our own cache — not as a reason to refuse.
	8762	+ */
	8763	+ private static function wp_cache_define_is_ours_to_remove( string $owner ): bool {
	8764	+ if ( self::DROPIN_FOREIGN === $owner || self::DROPIN_UNREADABLE === $owner ) {
	8765	+ return false;
	8766	+ }
	8767	+ if ( self::DROPIN_XSPEED === $owner ) {
	8768	+ return true;
	8769	+ }
	8770	+ $path = self::wp_config_path();
	8771	+ if ( '' === $path ) {
	8772	+ return false;
	8773	+ }
	8774	+ $config = self::read_file( $path );
	8775	+ return is_string( $config ) && self::wp_cache_receipt_matches_source( $config );
	8776	+ }
	8777	+
	8778	+ private static function wp_cache_receipt_matches_source( string $source ): bool {
	8779	+ $receipt = get_option( 'xspeed_page_cache_ownership_receipt', '' );
	8780	+ require_once XSPEED_DIR . 'includes/wp-cache-constant.php';
	8781	+ return xspeed_wp_cache_receipt_matches( $source, $receipt );
	8782	+ }
	8783	+
	8784	+ /**
	8785	+ * Admin-bar purge menu — a parent node plus one child per visible cache
	8786	+ * type (LiteSpeed-style), instead of a single "Purge All" link. Each
	8787	+ * child posts to the same admin-post handler with its type slug. The
	8788	+ * per-type items only appear for active/licensed modules; "Purge All"
	8789	+ * always shows and always sweeps everything. (FBS-83114)
	8790	+ *
	8791	+ * The parent node links to the settings page rather than a purge URL —
	8792	+ * clicking the top-level item used to wipe the whole cache instantly with
	8793	+ * no confirmation, which is far too destructive for a stray click. Purging
	8794	+ * stays available (and explicit) through the child items. (FBS-84068)
	8795	+ */
1202	8796	public function admin_bar_purge( $wp_admin_bar ) {
1203	8797	if ( ! current_user_can( 'manage_options' ) ) {
1204	8798	return;
1205	8799	}
	8800	+
1206	8801	$wp_admin_bar->add_node(
1207	8802	array(
1208	8803	'id' => 'xspeed-purge',
1209		- 'title' => __( 'Purge xSpeed Cache', 'xspeed' ),
1210		- 'href' => wp_nonce_url( admin_url( 'admin-post.php?action=xspeed_purge' ), 'xspeed_purge' ),
	8804	+ 'title' => __( 'xSpeed Cache', 'xspeed' ),
	8805	+ 'href' => admin_url( 'admin.php?page=' . Admin::PAGE_SLUG ),
1211	8806	)
1212	8807	);
	8808	+
	8809	+ // Settings first, then the two whole-errand actions (Purge All,
	8810	+ // Purge this URL), then the per-type items. The order is the one WP
	8811	+ // Rocket uses, and it front-loads what people open this menu for:
	8812	+ // nobody reaches for "Purge Object Cache" as often as they reach for
	8813	+ // the page they are looking at.
	8814	+ $wp_admin_bar->add_node(
	8815	+ array(
	8816	+ 'id' => 'xspeed-purge-settings',
	8817	+ 'parent' => 'xspeed-purge',
	8818	+ 'title' => esc_html__( 'Settings', 'xspeed' ),
	8819	+ 'href' => admin_url( 'admin.php?page=' . Admin::PAGE_SLUG ),
	8820	+ )
	8821	+ );
	8822	+
	8823	+ $types = self::purge_types();
	8824	+
	8825	+ // 'all' is rendered out of band so the single-URL item can sit
	8826	+ // directly under it. A filter that reorders or drops it is honoured:
	8827	+ // the loop below skips whatever was emitted here.
	8828	+ $emitted = array();
	8829	+ if ( ! empty( $types['all']['visible'] ) ) {
	8830	+ $wp_admin_bar->add_node(
	8831	+ array(
	8832	+ 'id' => 'xspeed-purge-all',
	8833	+ 'parent' => 'xspeed-purge',
	8834	+ 'title' => esc_html( $types['all']['label'] ),
	8835	+ 'href' => self::purge_type_url( 'all' ),
	8836	+ )
	8837	+ );
	8838	+ $emitted['all'] = true;
	8839	+ }
	8840	+
	8841	+ // Only when the current screen is about one thing — a front-end view,
	8842	+ // or a published post's edit screen. On a list table or a settings
	8843	+ // page there is nothing for "this" to mean, so the item stays hidden
	8844	+ // rather than silently targeting the dashboard. Purge_Ui decides both
	8845	+ // the label and the scope, which differ between the two contexts.
	8846	+ $context = Purge_Ui::context_node();
	8847	+ if ( null !== $context ) {
	8848	+ $wp_admin_bar->add_node(
	8849	+ array(
	8850	+ 'id' => 'xspeed-purge-this-url',
	8851	+ 'parent' => 'xspeed-purge',
	8852	+ 'title' => esc_html( $context['title'] ),
	8853	+ 'href' => $context['href'],
	8854	+ )
	8855	+ );
	8856	+ }
	8857	+
	8858	+ foreach ( $types as $slug => $type ) {
	8859	+ if ( empty( $type['visible'] ) || isset( $emitted[ $slug ] ) ) {
	8860	+ continue;
	8861	+ }
	8862	+ $wp_admin_bar->add_node(
	8863	+ array(
	8864	+ 'id' => 'xspeed-purge-' . $slug,
	8865	+ 'parent' => 'xspeed-purge',
	8866	+ 'title' => esc_html( $type['label'] ),
	8867	+ 'href' => self::purge_type_url( $slug ),
	8868	+ )
	8869	+ );
	8870	+ }
1213	8871	}
1214	8872
	8873	+ /**
	8874	+ * Nonce-protected admin-post URL for purging a single type. The nonce
	8875	+ * action is per-type so a leaked URL can't be replayed for a different
	8876	+ * scope.
	8877	+ */
	8878	+ private static function purge_type_url( string $type ): string {
	8879	+ return wp_nonce_url(
	8880	+ admin_url( 'admin-post.php?action=xspeed_purge&type=' . rawurlencode( $type ) ),
	8881	+ 'xspeed_purge_' . $type
	8882	+ );
	8883	+ }
	8884	+
1215	8885	public function handle_admin_bar_purge() {
1216	8886	if ( ! current_user_can( 'manage_options' ) ) {
1217	8887	wp_die( esc_html__( 'Unauthorized.', 'xspeed' ), 403 );
1218	8888	}
1219		- check_admin_referer( 'xspeed_purge' );
1220		- self::purge_all();
1221		- wp_safe_redirect( wp_get_referer() ?: admin_url() );
	8889	+ $type = isset( $_GET['type'] ) ? sanitize_key( wp_unslash( $_GET['type'] ) ) : 'all';
	8890	+ check_admin_referer( 'xspeed_purge_' . $type );
	8891	+
	8892	+ // Only honour known types; anything else falls back to a full purge.
	8893	+ if ( ! array_key_exists( $type, self::purge_types() ) ) {
	8894	+ $type = 'all';
	8895	+ }
	8896	+
	8897	+ // Answer the browser BEFORE purging. "Purge All" fans out to the local
	8898	+ // sweep, the object cache, CSS/edge listeners (outbound HTTP) and
	8899	+ // third-party render caches, all in this one request — on a large site
	8900	+ // that can outlive PHP-FPM's request_terminate_timeout, FPM kills the
	8901	+ // worker mid-purge, and nginx answers the admin's click with a 502.
	8902	+ // fastcgi_finish_request() exists on exactly those FPM setups: send
	8903	+ // the redirect, close the connection, then keep purging in the same
	8904	+ // process. Elsewhere (mod_php, CLI tests) fall back to purge-then-
	8905	+ // redirect as before.
	8906	+ $redirect = self::safe_purge_redirect( wp_get_referer() );
	8907	+ if ( function_exists( 'ignore_user_abort' ) ) {
	8908	+ ignore_user_abort( true );
	8909	+ }
	8910	+ if ( function_exists( 'set_time_limit' ) ) {
	8911	+ @set_time_limit( 300 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort under safe-mode-like restrictions.
	8912	+ }
	8913	+ if ( function_exists( 'fastcgi_finish_request' ) ) {
	8914	+ wp_safe_redirect( $redirect );
	8915	+ fastcgi_finish_request();
	8916	+ self::purge_type( $type );
	8917	+ exit;
	8918	+ }
	8919	+
	8920	+ self::purge_type( $type );
	8921	+ wp_safe_redirect( $redirect );
1222	8922	exit;
	8923	+ }
	8924	+
	8925	+ /**
	8926	+ * Resolve a safe redirect target for an admin-bar purge.
	8927	+ *
	8928	+ * The purge sends the admin back where they came from — but the referer
	8929	+ * can be a ONE-SHOT action URL (e.g. update.php?action=upload-plugin from
	8930	+ * installing a plugin zip, or any *.php?action=… that consumed a POST /
	8931	+ * temp upload). Redirecting there re-runs the action with nothing to act
	8932	+ * on, so WordPress dies — the classic "Please select a file" from
	8933	+ * File_Upload_Upgrader. Strip the transient action args so we return to a
	8934	+ * safe, re-GET-able view of the same page; fall back to the dashboard when
	8935	+ * there is no usable referer.
	8936	+ *
	8937	+ * @param string|false $referer Raw wp_get_referer() value.
	8938	+ * @return string Safe URL to redirect to.
	8939	+ */
	8940	+ public static function safe_purge_redirect( $referer ): string {
	8941	+ $referer = is_string( $referer ) ? $referer : '';
	8942	+ if ( '' === $referer ) {
	8943	+ return admin_url();
	8944	+ }
	8945	+
	8946	+ // A referer that lands on an action-processing endpoint (update.php,
	8947	+ // update-core.php, plugin/theme install/upload flows) can't be safely
	8948	+ // re-requested — send them to the dashboard instead of replaying it.
	8949	+ $path = (string) wp_parse_url( $referer, PHP_URL_PATH );
	8950	+ if ( preg_match( '#/wp-admin/(update|update-core)\.php$#', $path ) ) {
	8951	+ return admin_url();
	8952	+ }
	8953	+
	8954	+ // Otherwise keep them on the same page but drop the query args that
	8955	+ // would re-trigger a form action or upload on load.
	8956	+ return remove_query_arg(
	8957	+ array( 'action', 'action2', 'package', 'overwrite', 'plugin', 'theme', 'file', '_wpnonce', '_ajax_nonce' ),
	8958	+ $referer
	8959	+ );
1223	8960	}
1224	8961	}