← All changes | includes/class-object-cache.php +1178 -16 1.0.2 → 1.3.2 View file →

		@@ -36,12 +36,15 @@
36	36	* Inspect the runtime + filesystem for a persistent object cache.
37	37	*
38	38	* @return array{
39	39	* drop_in_installed: bool,
	40	+ * drop_in_is_ours: bool, // installed AND carries our tag
40	41	* drop_in_path: string,
41	42	* drop_in_label: string,
42	43	* backend: string, // redis|memcached|apcu|wp_default|unknown
43	44	* wp_cache_active: bool, // wp_using_ext_object_cache
	45	+ * degraded: bool, // ours is installed but NOT persisting
	46	+ * persistent: bool, // ours is installed AND persisting
44	47	* class_available: array<string,bool>
45	48	* }
46	49	*/
47	50	public static function detect(): array {
		@@ -49,8 +52,23 @@
49	52	$has_drop_in = '' !== $dropin && file_exists( $dropin );
50	53	$label = $has_drop_in ? self::sniff_drop_in_label( $dropin ) : '';
51	54	$ext_in_use = function_exists( 'wp_using_ext_object_cache' ) ? (bool) wp_using_ext_object_cache() : false;
52	55
	56	+ // When OUR drop-in is the live one it exposes whether it actually
	57	+ // connected a persistent backend. A drop-in that's installed but
	58	+ // degraded reports wp_using_ext_object_cache()=true yet persists
	59	+ // nothing — the silent failure that makes a site slow. Read the honest
	60	+ // state straight off the running instance. (FBS-82210)
	61	+ $degraded = false;
	62	+ $persistent = false;
	63	+ if ( $has_drop_in && isset( $GLOBALS['wp_object_cache'] ) && is_object( $GLOBALS['wp_object_cache'] ) ) {
	64	+ $oc = $GLOBALS['wp_object_cache'];
	65	+ if ( method_exists( $oc, 'is_persistent' ) ) {
	66	+ $persistent = (bool) $oc->is_persistent();
	67	+ $degraded = ! $persistent;
	68	+ }
	69	+ }
	70	+
53	71	// Class sniffer — independent of any plugin. Tells us what's
54	72	// available to actually use, separate from what's wired up.
55	73	$class_available = array(
56	74	'Redis' => class_exists( '\\Redis' ),
		@@ -62,25 +80,43 @@
62	80	$backend = 'unknown';
63	81	if ( ! $ext_in_use ) {
64	82	$backend = 'wp_default';
65	83	} elseif ( $has_drop_in ) {
66		- // Best-effort: the label usually contains the backend name.
67		- $lc = strtolower( $label );
68		- if ( false !== strpos( $lc, 'redis' ) ) {
69		- $backend = 'redis';
70		- } elseif ( false !== strpos( $lc, 'memcached' ) || false !== strpos( $lc, 'memcache' ) ) {
71		- $backend = 'memcached';
72		- } elseif ( false !== strpos( $lc, 'apcu' ) ) {
73		- $backend = 'apcu';
	84	+ // Authoritative source first: our own drop-in records the chosen
	85	+ // backend in the XSPEED_OC_BACKEND constant (written to wp-config
	86	+ // on enable). The drop-in label is the generic
	87	+ // "XSPEED_OBJECT_CACHE_DROPIN" and does NOT contain the backend
	88	+ // name, so the label sniff below would always yield "unknown" for
	89	+ // our drop-in — read the constant instead. (FBS-82111)
	90	+ if ( defined( 'XSPEED_OC_BACKEND' ) && '' !== (string) constant( 'XSPEED_OC_BACKEND' ) ) {
	91	+ $backend = strtolower( (string) constant( 'XSPEED_OC_BACKEND' ) );
	92	+ } else {
	93	+ // Foreign drop-in (W3TC / Redis Object Cache / …): best-effort
	94	+ // guess from the label, which usually names the backend.
	95	+ $lc = strtolower( $label );
	96	+ if ( false !== strpos( $lc, 'redis' ) ) {
	97	+ $backend = 'redis';
	98	+ } elseif ( false !== strpos( $lc, 'memcached' ) || false !== strpos( $lc, 'memcache' ) ) {
	99	+ $backend = 'memcached';
	100	+ } elseif ( false !== strpos( $lc, 'apcu' ) ) {
	101	+ $backend = 'apcu';
	102	+ }
74	103	}
75	104	}
76	105
77	106	return array(
78	107	'drop_in_installed' => $has_drop_in,
	108	+ // Whether the installed drop-in is OURS. A foreign one (W3TC,
	109	+ // Redis Object Cache, LiteSpeed) means the object cache belongs to
	110	+ // another plugin: we must not offer to configure or disable it,
	111	+ // and "installed" must not be read as "xSpeed is running".
	112	+ 'drop_in_is_ours' => $has_drop_in && self::is_our_dropin_present(),
79	113	'drop_in_path' => $dropin,
80	114	'drop_in_label' => $label,
81	115	'backend' => $backend,
82	116	'wp_cache_active' => $ext_in_use,
	117	+ 'degraded' => $degraded,
	118	+ 'persistent' => $persistent,
83	119	'class_available' => $class_available,
84	120	);
85	121	}
86	122
		@@ -108,39 +144,1165 @@
108	144
109	145	if ( 'redis' === $backend ) {
110	146	$host = self::str( $opts, 'redis_host', '127.0.0.1' );
111	147	$port = self::int( $opts, 'redis_port', 6379 );
	148	+ $user = self::str( $opts, 'redis_user', '' );
112	149	$pass = self::str( $opts, 'redis_password', '' );
113	150	$db = self::int( $opts, 'redis_database', 0 );
114		- $prefix = self::str( $opts, 'key_prefix', '' );
	151	+ $prefix = self::effective_salt( $opts );
115	152	$timeout = self::int( $opts, 'connection_timeout', 1 );
116	153	$persist = ! empty( $opts['persistent'] );
117	154
118	155	$lines[] = "define( 'WP_REDIS_HOST', '" . self::esc( $host ) . "' );";
119	156	$lines[] = "define( 'WP_REDIS_PORT', " . $port . ' );';
	157	+ // Emit the ACL username only when set (Redis 6+). The drop-in
	158	+ // reads it; an empty user keeps the legacy default-user behavior.
	159	+ if ( '' !== $user ) {
	160	+ $lines[] = "define( 'WP_REDIS_USER', '" . self::esc( $user ) . "' );";
	161	+ }
120	162	if ( '' !== $pass ) {
121	163	$lines[] = "define( 'WP_REDIS_PASSWORD', '" . self::esc( $pass ) . "' );";
122	164	}
123	165	$lines[] = "define( 'WP_REDIS_DATABASE', " . $db . ' );';
124		- if ( '' !== $prefix ) {
125		- $lines[] = "define( 'WP_CACHE_KEY_SALT', '" . self::esc( $prefix ) . "' );";
126		- }
	166	+ $lines[] = "define( 'WP_CACHE_KEY_SALT', '" . self::esc( $prefix ) . "' );";
127	167	$lines[] = "define( 'WP_REDIS_TIMEOUT', " . $timeout . ' );';
128	168	$lines[] = "define( 'WP_REDIS_PERSISTENT', " . ( $persist ? 'true' : 'false' ) . ' );';
129	169	} elseif ( 'memcached' === $backend ) {
130	170	$host = self::str( $opts, 'memcached_host', '127.0.0.1' );
131	171	$port = self::int( $opts, 'memcached_port', 11211 );
132		- $prefix = self::str( $opts, 'key_prefix', '' );
	172	+ $prefix = self::effective_salt( $opts );
133	173	$lines[] = "global \$memcached_servers;";
134	174	$lines[] = "\$memcached_servers = array( array( '" . self::esc( $host ) . "', " . $port . ' ) );';
135		- if ( '' !== $prefix ) {
136		- $lines[] = "define( 'WP_CACHE_KEY_SALT', '" . self::esc( $prefix ) . "' );";
	175	+ $lines[] = "define( 'WP_CACHE_KEY_SALT', '" . self::esc( $prefix ) . "' );";
	176	+ } else {
	177	+ $lines[] = '// No snippet for backend: ' . $backend;
	178	+ }
	179	+
	180	+ return implode( "\n", $lines ) . "\n";
	181	+ }
	182	+
	183	+ /**
	184	+ * Identifier embedded in our drop-in so we can recognise (and safely
	185	+ * overwrite / remove) only files we installed.
	186	+ */
	187	+ private const DROPIN_TAG = 'XSPEED_OBJECT_CACHE_DROPIN';
	188	+
	189	+ /** Markers wrapping the constants we write into wp-config.php. */
	190	+ private const CONFIG_BEGIN = '/* BEGIN xSpeed Object Cache */';
	191	+ private const CONFIG_END = '/* END xSpeed Object Cache */';
	192	+
	193	+ /**
	194	+ * True when wp-content/object-cache.php exists AND is ours (carries the
	195	+ * drop-in tag). Lets callers decide whether a re-sync applies without
	196	+ * exposing the tag itself.
	197	+ */
	198	+ public static function is_our_dropin_present(): bool {
	199	+ $target = WP_CONTENT_DIR . '/object-cache.php';
	200	+ if ( ! file_exists( $target ) ) {
	201	+ return false;
	202	+ }
	203	+ $contents = file_get_contents( $target ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- read-only ours-check; WP_Filesystem may not be initialized this early.
	204	+ return is_string( $contents ) && false !== strpos( $contents, self::DROPIN_TAG );
	205	+ }
	206	+
	207	+ /**
	208	+ * Live connection test against the configured backend. Never throws;
	209	+ * returns a structured pass/fail the UI can show before we write anything.
	210	+ *
	211	+ * @param array $opts Settings array (backend, redis_host, ...).
	212	+ * @return array{ok:bool,backend:string,message:string,latency_ms:?float}
	213	+ */
	214	+ public static function test_connection( array $opts ): array {
	215	+ $backend = (string) ( $opts['backend'] ?? 'redis' );
	216	+ $start = microtime( true );
	217	+
	218	+ try {
	219	+ if ( 'memcached' === $backend ) {
	220	+ $host = self::str( $opts, 'memcached_host', '127.0.0.1' );
	221	+ $port = self::int( $opts, 'memcached_port', 11211 );
	222	+ $timeout = self::int( $opts, 'connection_timeout', 1 );
	223	+
	224	+ // Prefer the ext/memcached extension (libmemcached).
	225	+ if ( class_exists( '\\Memcached' ) ) {
	226	+ $mc = new \Memcached();
	227	+ $mc->addServer( $host, $port );
	228	+ $stats = @$mc->getStats();
	229	+ $ok = is_array( $stats ) && ! empty( array_filter( $stats ) );
	230	+ return self::test_result(
	231	+ $ok,
	232	+ $backend,
	233	+ $ok ? "Connected to Memcached at {$host}:{$port} (ext/memcached)." : "Could not reach Memcached at {$host}:{$port}.",
	234	+ $start
	235	+ );
	236	+ }
	237	+
	238	+ // Pure-PHP fallback — our own client, zero dependencies.
	239	+ $mc = new Memcached_Client( $host, $port, (float) $timeout );
	240	+ if ( ! $mc->connect() ) {
	241	+ return self::test_result( false, $backend, "Could not connect to Memcached at {$host}:{$port}." );
	242	+ }
	243	+ $ver = $mc->version();
	244	+ $mc->close();
	245	+ $ok = ( false !== $ver );
	246	+ return self::test_result(
	247	+ $ok,
	248	+ $backend,
	249	+ $ok ? "Connected to Memcached at {$host}:{$port} (built-in client)." : "Memcached at {$host}:{$port} did not respond.",
	250	+ $start
	251	+ );
137	252	}
	253	+
	254	+ // Redis. Prefer the phpredis extension (faster C client); fall back
	255	+ // to xSpeed's own dependency-free Redis_Client (pure-PHP RESP over a
	256	+ // socket) so Redis works even without the extension — true
	257	+ // plug-and-play, no bundled library.
	258	+ $host = self::str( $opts, 'redis_host', '127.0.0.1' );
	259	+ $port = self::int( $opts, 'redis_port', 6379 );
	260	+ $timeout = self::int( $opts, 'connection_timeout', 1 );
	261	+ $user = self::str( $opts, 'redis_user', '' );
	262	+ $pass = self::str( $opts, 'redis_password', '' );
	263	+ $db = self::int( $opts, 'redis_database', 0 );
	264	+
	265	+ if ( class_exists( '\\Redis' ) ) {
	266	+ $redis = new \Redis();
	267	+ if ( ! @$redis->connect( $host, $port, $timeout ) ) {
	268	+ return self::test_result( false, $backend, "Could not connect to Redis at {$host}:{$port}." );
	269	+ }
	270	+ // Redis 6+ ACL: when a username is set, authenticate as that user
	271	+ // (phpredis ≥ 5.3 accepts ['user'=>..,'pass'=>..]); otherwise keep
	272	+ // the legacy password-only form that authenticates as `default`.
	273	+ $auth_ok = self::phpredis_auth( $redis, $user, $pass );
	274	+ if ( null !== $auth_ok && ! $auth_ok ) {
	275	+ return self::test_result( false, $backend, '' !== $user ? 'Redis authentication failed — check the Redis user + password (ACL).' : 'Redis authentication failed — check the password.' );
	276	+ }
	277	+ if ( $db > 0 && ! @$redis->select( $db ) ) {
	278	+ return self::test_result( false, $backend, "Could not select Redis database {$db}." );
	279	+ }
	280	+ $pong = @$redis->ping();
	281	+ $ok = ( '+PONG' === $pong || true === $pong || 'PONG' === $pong );
	282	+ if ( ! $ok ) {
	283	+ return self::test_result( false, $backend, "Redis at {$host}:{$port} did not respond to PING.", $start );
	284	+ }
	285	+ // Write-verification: PING only proves auth, not that the user can
	286	+ // STORE data. ACL-namespaced hosts (xCloud) restrict a user to a
	287	+ // key pattern (~redis:<id>:*); a SET outside it is NOPERM-denied and
	288	+ // the drop-in's @$redis->set() swallows it — enable() would then
	289	+ // green-light a cache that silently persists nothing. Do a real
	290	+ // SET/GET/DEL round-trip on a probe key built with the user's key
	291	+ // prefix so a namespace restriction is caught here. (FBS-83118 OC-2)
	292	+ $probe = self::probe_key( $opts );
	293	+ $set = @$redis->set( $probe, '1', 5 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- NOPERM/denied is the negative answer we report, not a fatal.
	294	+ $got = @$redis->get( $probe ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- same.
	295	+ @$redis->del( $probe ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- best-effort cleanup.
	296	+ if ( ! $set || '1' !== (string) $got ) {
	297	+ return self::test_result( false, $backend, self::write_denied_message( $opts, $host, $port ), $start );
	298	+ }
	299	+ return self::test_result( true, $backend, self::with_prefix_advisory( "Connected to Redis at {$host}:{$port} (phpredis).", $opts ), $start );
	300	+ }
	301	+
	302	+ // Pure-PHP fallback — our own client, zero dependencies.
	303	+ $rc = new Redis_Client( $host, $port, (float) $timeout, false );
	304	+ if ( ! $rc->connect() ) {
	305	+ return self::test_result( false, $backend, "Could not connect to Redis at {$host}:{$port}." );
	306	+ }
	307	+ // Authenticate when a user OR a password is set. Gating on password
	308	+ // alone skipped auth for the "ACL user + empty password" case, which
	309	+ // then failed later at PING with a misleading message. (FBS-83118 OC-1)
	310	+ if ( ( '' !== $pass || '' !== $user ) && false === $rc->auth( $pass, $user ) ) {
	311	+ $rc->close();
	312	+ return self::test_result( false, $backend, '' !== $user ? 'Redis authentication failed — check the Redis user + password (ACL).' : 'Redis authentication failed — check the password.' );
	313	+ }
	314	+ if ( $db > 0 ) {
	315	+ $rc->select( $db );
	316	+ }
	317	+ $pong = $rc->ping();
	318	+ $ok = ( is_string( $pong ) && false !== stripos( $pong, 'PONG' ) );
	319	+ if ( ! $ok ) {
	320	+ $rc->close();
	321	+ return self::test_result( false, $backend, "Redis at {$host}:{$port} did not respond to PING.", $start );
	322	+ }
	323	+ // Write-verification round-trip — same rationale as the phpredis path
	324	+ // above. (FBS-83118 OC-2)
	325	+ $probe = self::probe_key( $opts );
	326	+ $set = $rc->set( $probe, '1' );
	327	+ $got = $rc->get( $probe );
	328	+ $rc->del( $probe );
	329	+ $rc->close();
	330	+ if ( ! $set || '1' !== (string) $got ) {
	331	+ return self::test_result( false, $backend, self::write_denied_message( $opts, $host, $port ), $start );
	332	+ }
	333	+ return self::test_result( true, $backend, self::with_prefix_advisory( "Connected to Redis at {$host}:{$port} (built-in client).", $opts ), $start );
	334	+ } catch ( \Throwable $e ) {
	335	+ return self::test_result( false, $backend, 'Connection error: ' . $e->getMessage() );
	336	+ }
	337	+ }
	338	+
	339	+ /**
	340	+ * Redis glob metacharacters that must never appear unescaped in a SCAN
	341	+ * MATCH pattern. `\` is the escape character itself.
	342	+ */
	343	+ private const GLOB_METACHARS = '*?[]\\';
	344	+
	345	+ /**
	346	+ * Whether a salt contains Redis glob metacharacters.
	347	+ *
	348	+ * The salt is interpolated into the drop-in's scoped-flush patterns. The
	349	+ * drop-in escapes it, so caching and purging are correct either way — but
	350	+ * an explicit Cache Key Prefix exists to match a host's ACL namespace
	351	+ * byte-for-byte, and a wildcard in it is almost always a typo rather than
	352	+ * a real namespace. Reporting it on Test connection is the one place the
	353	+ * user is already looking at their prefix.
	354	+ *
	355	+ * @param string $salt Effective salt.
	356	+ * @return bool
	357	+ */
	358	+ public static function salt_has_glob_metachars( string $salt ): bool {
	359	+ return strcspn( $salt, self::GLOB_METACHARS ) !== strlen( $salt );
	360	+ }
	361	+
	362	+ /**
	363	+ * Append a prefix advisory to an otherwise-successful connection message.
	364	+ *
	365	+ * @param string $message Success message.
	366	+ * @param array $opts Settings array.
	367	+ * @return string
	368	+ */
	369	+ private static function with_prefix_advisory( string $message, array $opts ): string {
	370	+ // Deliberately the TYPED prefix, not effective_salt(): this advisory
	371	+ // says "the field you are looking at probably has a typo in it". A
	372	+ // host-pinned WP_CACHE_KEY_SALT is not editable from this screen and
	373	+ // purges are correctly scoped regardless (the drop-in escapes it), so
	374	+ // warning about a host's own namespace would be noise on every ACL
	375	+ // host. A derived salt is glob-free by construction.
	376	+ $prefix = self::str( $opts, 'key_prefix', '' );
	377	+ if ( '' === $prefix || ! self::salt_has_glob_metachars( $prefix ) ) {
	378	+ return $message;
	379	+ }
	380	+ return $message . ' Note: the Cache Key Prefix contains one of * ? [ ] \\.'
	381	+ . ' Purges stay scoped to this site, but these are wildcard characters'
	382	+ . ' in Redis — check the prefix matches your host\'s key exactly.';
	383	+ }
	384	+
	385	+ private static function test_result( bool $ok, string $backend, string $message, ?float $start = null ): array {
	386	+ return array(
	387	+ 'ok' => $ok,
	388	+ 'backend' => $backend,
	389	+ 'message' => $message,
	390	+ 'latency_ms' => $start ? round( ( microtime( true ) - $start ) * 1000, 2 ) : null,
	391	+ );
	392	+ }
	393	+
	394	+ /**
	395	+ * Authenticate a phpredis connection, honoring Redis 6+ ACL usernames.
	396	+ *
	397	+ * Returns null when no auth is needed (empty username AND password) so
	398	+ * callers can distinguish "didn't try" from "tried and failed". When a
	399	+ * username is present we pass ['user'=>..,'pass'=>..] which phpredis
	400	+ * ≥ 5.3 maps to the two-argument AUTH; otherwise the legacy
	401	+ * password-only form authenticates as the built-in `default` user.
	402	+ *
	403	+ * @param \Redis $redis Connected phpredis instance.
	404	+ * @param string $user ACL username; '' = default user.
	405	+ * @param string $pass Password.
	406	+ * @return bool|null true/false on auth attempt, null if none needed.
	407	+ */
	408	+ private static function phpredis_auth( $redis, string $user, string $pass ) {
	409	+ if ( '' === $user && '' === $pass ) {
	410	+ return null;
	411	+ }
	412	+ try {
	413	+ if ( '' !== $user ) {
	414	+ return (bool) @$redis->auth( array( 'user' => $user, 'pass' => $pass ) ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- phpredis throws on bad auth; we report it as a failed test, not a fatal.
	415	+ }
	416	+ return (bool) @$redis->auth( $pass ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- same.
	417	+ } catch ( \Throwable $e ) {
	418	+ return false;
	419	+ }
	420	+ }
	421	+
	422	+ /**
	423	+ * Resolve the salt that namespaces this site's cache keys.
	424	+ *
	425	+ * An explicit Cache Key Prefix always wins — on ACL/namespaced hosts
	426	+ * (xCloud) it MUST match the host's "Redis Object Cache Key" or writes are
	427	+ * denied (NOPERM), so we never override what the user typed.
	428	+ *
	429	+ * When the field is blank we derive a stable, per-site salt instead of
	430	+ * falling back to an empty one. An empty salt makes every key look like
	431	+ * `:{prefix}:{group}:{key}` — identical on every install — so two sites
	432	+ * sharing one Redis/Memcached server collide. That is not a theoretical
	433	+ * clash: `blog-details` / `blog-lookup` are how WordPress resolves which
	434	+ * site a request belongs to, so the second site reads the first site's
	435	+ * entries and redirects to it.
	436	+ *
	437	+ * The derived value is a hash of the site URL plus the DB name/prefix, so
	438	+ * it is unique per install, stable across requests (no cache churn), and
	439	+ * safe to embed in wp-config.php.
	440	+ *
	441	+ * @param array $opts Settings array.
	442	+ * @return string Non-empty salt.
	443	+ */
	444	+ public static function effective_salt( array $opts ): string {
	445	+ $prefix = self::str( $opts, 'key_prefix', '' );
	446	+ if ( '' !== $prefix ) {
	447	+ return $prefix;
	448	+ }
	449	+
	450	+ // A salt WE already wrote is authoritative over a fresh derivation.
	451	+ // The keys in the backend are named after it, so re-deriving a
	452	+ // different value would orphan every one of them — a needless
	453	+ // cache-cooling on an install that is already correctly namespaced.
	454	+ // This matters because derive_salt()'s rule was corrected (see there):
	455	+ // without this branch, the next wp-config sync would rewrite the block
	456	+ // with a new salt and throw away a warm cache on every existing site.
	457	+ if ( defined( 'XSPEED_OC_SALT' ) && '' !== (string) constant( 'XSPEED_OC_SALT' ) ) {
	458	+ return (string) constant( 'XSPEED_OC_SALT' );
	459	+ }
	460	+
	461	+ // A salt the HOST pinned in its own wp-config (outside our block) is
	462	+ // the next authority. On ACL/namespaced Redis the host grants write
	463	+ // access to that namespace and no other, so replacing it with a
	464	+ // derived value gets every write denied (NOPERM) and the site silently
	465	+ // stops caching.
	466	+ // WP_REDIS_PREFIX is checked alongside WP_CACHE_KEY_SALT and before it,
	467	+ // matching the order the schema and the drop-in resolve (#398). It is
	468	+ // the name Redis Object Cache uses and the one managed hosts actually
	469	+ // write, so honouring only the older alias left the commonest
	470	+ // ACL-namespaced case deriving a salt the host denies writes to.
	471	+ foreach ( array( 'WP_REDIS_PREFIX', 'WP_CACHE_KEY_SALT' ) as $name ) {
	472	+ if ( defined( $name ) && '' !== (string) constant( $name ) ) {
	473	+ return (string) constant( $name );
	474	+ }
	475	+ }
	476	+
	477	+ return self::derive_salt();
	478	+ }
	479	+
	480	+ /**
	481	+ * Build a stable per-site salt for installs that left Cache Key Prefix
	482	+ * blank. Distinct per install: the site URL separates sites sharing a
	483	+ * database, and DB name + table prefix separate installs sharing a domain
	484	+ * (e.g. subdirectory installs).
	485	+ *
	486	+ * This MUST stay byte-identical to the drop-in's xspeed_oc_salt(), which
	487	+ * is the harder constraint of the two: the drop-in loads from
	488	+ * wp-settings.php before `$wpdb` exists, so it can only read constants and
	489	+ * the `$table_prefix` global that wp-config.php itself assigns. Normally
	490	+ * the two never both run — enable() writes XSPEED_OC_SALT and both sides
	491	+ * read that constant — but where wp-config is NOT writable no constant is
	492	+ * ever written, and then both fallbacks are live at once in different
	493	+ * processes. Seeding them differently made "Test connection" verify a
	494	+ * different key space than the cache actually writes to: on ACL/namespaced
	495	+ * Redis (xCloud) that reports success while writes are refused, or reports
	496	+ * a failure while caching is fine. (PR #390 QA round 2, issue 2)
	497	+ *
	498	+ * Two specific traps this alignment closes:
	499	+ *
	500	+ * - WP_HOME / WP_SITEURL are OPTIONAL and absent from a stock
	501	+ * wp-config.php, so the drop-in's URL part is usually EMPTY while
	502	+ * get_site_url() always returns a real URL. Using get_site_url() here
	503	+ * therefore diverged on virtually every default install, not just an
	504	+ * exotic one — so this reads the same constants, and appends ABSPATH
	505	+ * on the same condition, rather than reaching for the richer value.
	506	+ * - `$wpdb->prefix` is PER-BLOG on multisite (`wp_2_` on a sub-site)
	507	+ * while `$table_prefix` is always the base prefix. The drop-in reads
	508	+ * the salt once and separates sub-sites with blog_prefix instead, so
	509	+ * `$table_prefix` is the value that matches; `$wpdb->prefix` would
	510	+ * hand every sub-site a different salt.
	511	+ *
	512	+ * @return string
	513	+ */
	514	+ private static function derive_salt(): string {
	515	+ global $table_prefix;
	516	+
	517	+ $url = '';
	518	+ if ( defined( 'WP_HOME' ) ) {
	519	+ $url = (string) WP_HOME;
	520	+ } elseif ( defined( 'WP_SITEURL' ) ) {
	521	+ $url = (string) WP_SITEURL;
	522	+ }
	523	+
	524	+ $parts = array(
	525	+ $url,
	526	+ defined( 'DB_NAME' ) ? (string) DB_NAME : '',
	527	+ isset( $table_prefix ) ? (string) $table_prefix : '',
	528	+ );
	529	+ if ( '' === $url ) {
	530	+ $parts[] = defined( 'ABSPATH' ) ? (string) ABSPATH : '';
	531	+ }
	532	+
	533	+ $seed = implode( '|', $parts );
	534	+ if ( '' === trim( $seed, '|' ) ) {
	535	+ // Nothing identifying available. Mirrors the drop-in's own
	536	+ // last-resort seed so the two still agree.
	537	+ $seed = 'xspeed';
	538	+ }
	539	+
	540	+ return 'xs' . substr( md5( $seed ), 0, 12 );
	541	+ }
	542	+
	543	+ /**
	544	+ * Build a probe key for the write-verification round-trip. It must land in
	545	+ * the same key space the drop-in writes to, so an ACL namespace restriction
	546	+ * (~<prefix>:*) is exercised. The drop-in salts keys as
	547	+ * `{salt}:{prefix}:{group}:{key}`, so prefixing the probe with the same
	548	+ * salt makes it match the allowed pattern on namespaced hosts (xCloud)
	549	+ * while staying harmless everywhere else.
	550	+ *
	551	+ * @param array $opts Settings array.
	552	+ * @return string
	553	+ */
	554	+ private static function probe_key( array $opts ): string {
	555	+ return self::effective_salt( $opts ) . ':xspeed-oc-probe';
	556	+ }
	557	+
	558	+ /**
	559	+ * Message for a connect-OK-but-write-denied result. Points ACL/namespaced
	560	+ * hosts at the fix (match the key prefix to the host's Redis Object Cache
	561	+ * Key), which is exactly the xCloud failure mode. (FBS-83118 OC-2)
	562	+ *
	563	+ * @param array $opts Settings array.
	564	+ * @param string $host Redis host.
	565	+ * @param int $port Redis port.
	566	+ * @return string
	567	+ */
	568	+ private static function write_denied_message( array $opts, string $host, int $port ): string {
	569	+ $has_prefix = '' !== self::str( $opts, 'key_prefix', '' );
	570	+ $hint = $has_prefix
	571	+ ? 'The Redis user may lack write permission for this key prefix (NOPERM).'
	572	+ : 'On ACL/namespaced Redis (e.g. xCloud), set Cache Key Prefix to the host\'s "Redis Object Cache Key" so writes land in the permitted namespace.';
	573	+ return "Connected to Redis at {$host}:{$port}, but the cache could not store data. {$hint}";
	574	+ }
	575	+
	576	+ /**
	577	+ * Full plug-and-play enable: test → write wp-config constants → install
	578	+ * drop-in → verify. Reversible via disable(). Returns a structured result
	579	+ * the REST/UI layer surfaces directly.
	580	+ *
	581	+ * @param array $opts Settings array.
	582	+ * @return array{ok:bool,message:string,steps:array<string,bool>,test:array,detect:array}
	583	+ */
	584	+ public static function enable( array $opts ): array {
	585	+ $steps = array(
	586	+ 'connection' => false,
	587	+ 'wp_config' => false,
	588	+ 'drop_in' => false,
	589	+ 'verified' => false,
	590	+ );
	591	+
	592	+ // 1. Don't write anything until the backend actually answers.
	593	+ $test = self::test_connection( $opts );
	594	+ if ( ! $test['ok'] ) {
	595	+ return array(
	596	+ 'ok' => false,
	597	+ 'message' => 'Could not enable: ' . $test['message'],
	598	+ 'steps' => $steps,
	599	+ 'test' => $test,
	600	+ 'detect' => self::detect(),
	601	+ );
	602	+ }
	603	+ $steps['connection'] = true;
	604	+
	605	+ // 2. Write the XSPEED_OC_* constants into wp-config.php.
	606	+ $steps['wp_config'] = self::write_wp_config( $opts );
	607	+
	608	+ // 3. Install our drop-in.
	609	+ $steps['drop_in'] = self::install_dropin();
	610	+
	611	+ // 4. Verify the drop-in is live (best-effort — wp_using_ext_object_cache
	612	+ // reflects state only after the drop-in loads on the NEXT request, so
	613	+ // we verify the file landed + constants are present this request).
	614	+ $detect = self::detect();
	615	+ $steps['verified'] = $detect['drop_in_installed'] && self::wp_config_has_block();
	616	+
	617	+ $all_ok = $steps['drop_in'] && ( $steps['wp_config'] || self::backend_uses_no_constants( $opts ) );
	618	+
	619	+ return array(
	620	+ 'ok' => $all_ok,
	621	+ 'message' => $all_ok
	622	+ ? 'Object cache enabled. Drop-in installed and configured automatically.'
	623	+ : ( $steps['drop_in']
	624	+ ? 'Drop-in installed, but wp-config.php is not writable — add the snippet manually (shown below).'
	625	+ : 'Could not install the object-cache drop-in (wp-content not writable).' ),
	626	+ 'steps' => $steps,
	627	+ 'test' => $test,
	628	+ 'detect' => $detect,
	629	+ );
	630	+ }
	631	+
	632	+ /**
	633	+ * Full reverse of enable(): remove drop-in + strip our wp-config block.
	634	+ *
	635	+ * @return array{ok:bool,message:string,steps:array<string,bool>,detect:array}
	636	+ */
	637	+ public static function disable(): array {
	638	+ // A drop-in owned by another plugin is left in place by
	639	+ // remove_dropin(), which then reports success because nothing of ours
	640	+ // is there to remove. Reporting "disabled" for that is a lie: the site
	641	+ // still has someone else's object cache running. Say so instead.
	642	+ $dropin = defined( 'WP_CONTENT_DIR' ) ? WP_CONTENT_DIR . '/object-cache.php' : '';
	643	+ if ( '' !== $dropin && file_exists( $dropin ) && ! self::is_our_dropin_present() ) {
	644	+ return array(
	645	+ 'ok' => false,
	646	+ 'message' => 'The object-cache drop-in belongs to another plugin, so xSpeed left it alone. Turn its object cache off in that plugin instead.',
	647	+ 'steps' => array(
	648	+ 'drop_in' => false,
	649	+ 'wp_config' => false,
	650	+ ),
	651	+ 'detect' => self::detect(),
	652	+ );
	653	+ }
	654	+
	655	+ $dropin_removed = self::remove_dropin();
	656	+ $config_removed = self::remove_wp_config();
	657	+
	658	+ /*
	659	+ * The sidecar is the config on a host where wp-config.php is read-only,
	660	+ * and it carries the Redis password. Leaving it behind would keep a
	661	+ * plaintext credential on disk for a feature the admin just switched
	662	+ * off, and a later re-enable would silently pick up stale credentials
	663	+ * from a file nothing in this path had touched.
	664	+ */
	665	+ self::delete_sidecar();
	666	+
	667	+ return array(
	668	+ 'ok' => $dropin_removed,
	669	+ 'message' => $dropin_removed
	670	+ ? 'Object cache disabled. Drop-in removed and wp-config.php cleaned.'
	671	+ : 'Could not remove the drop-in — wp-content may not be writable.',
	672	+ 'steps' => array(
	673	+ 'drop_in' => $dropin_removed,
	674	+ 'wp_config' => $config_removed,
	675	+ ),
	676	+ 'detect' => self::detect(),
	677	+ );
	678	+ }
	679	+
	680	+ /**
	681	+ * Copy our object-cache.php template into wp-content/. Mirrors
	682	+ * Cache::install_dropin(): only overwrites our own file, backs up a
	683	+ * foreign drop-in before replacing it.
	684	+ */
	685	+ public static function install_dropin(): bool {
	686	+ $source = ( defined( 'XSPEED_DIR' ) ? XSPEED_DIR : plugin_dir_path( __DIR__ ) . '../' ) . 'includes/object-cache.php';
	687	+ $target = WP_CONTENT_DIR . '/object-cache.php';
	688	+ if ( ! file_exists( $source ) ) {
	689	+ return false;
	690	+ }
	691	+
	692	+ $fs = self::fs();
	693	+ if ( ! $fs ) {
	694	+ return false;
	695	+ }
	696	+
	697	+ $source_contents = $fs->get_contents( $source );
	698	+ if ( ! is_string( $source_contents ) ) {
	699	+ return false;
	700	+ }
	701	+
	702	+ if ( file_exists( $target ) ) {
	703	+ $existing = $fs->get_contents( $target );
	704	+ $is_xspeed = is_string( $existing ) && false !== strpos( $existing, self::DROPIN_TAG );
	705	+
	706	+ if ( $is_xspeed ) {
	707	+ if ( $existing === $source_contents ) {
	708	+ return true;
	709	+ }
	710	+ return (bool) $fs->put_contents( $target, $source_contents, FS_CHMOD_FILE );
	711	+ }
	712	+
	713	+ // Foreign drop-in — back it up before overwriting.
	714	+ $upload = wp_upload_dir( null, false );
	715	+ $basedir = isset( $upload['basedir'] ) ? trailingslashit( $upload['basedir'] ) . 'xspeed-backups' : false;
	716	+ if ( $basedir ) {
	717	+ if ( ! file_exists( $basedir ) ) {
	718	+ wp_mkdir_p( $basedir );
	719	+ }
	720	+ $backup = $basedir . '/object-cache.foreign-' . gmdate( 'Ymd-His' ) . '.php.bak';
	721	+ $fs->move( $target, $backup, true );
	722	+ } else {
	723	+ $fs->delete( $target );
	724	+ }
	725	+ }
	726	+
	727	+ return (bool) $fs->put_contents( $target, $source_contents, FS_CHMOD_FILE );
	728	+ }
	729	+
	730	+ /**
	731	+ * Remove our drop-in (only if it's ours). Returns true when no xSpeed
	732	+ * drop-in remains.
	733	+ */
	734	+ public static function remove_dropin(): bool {
	735	+ $target = WP_CONTENT_DIR . '/object-cache.php';
	736	+ if ( ! file_exists( $target ) ) {
	737	+ return true;
	738	+ }
	739	+ $fs = self::fs();
	740	+ if ( ! $fs ) {
	741	+ return false;
	742	+ }
	743	+ $contents = $fs->get_contents( $target );
	744	+ if ( is_string( $contents ) && false !== strpos( $contents, self::DROPIN_TAG ) ) {
	745	+ wp_delete_file( $target );
	746	+ return ! file_exists( $target );
	747	+ }
	748	+ // Not ours — leave it, but report success (nothing of ours to remove).
	749	+ return true;
	750	+ }
	751	+
	752	+ /**
	753	+ * Write the XSPEED_OC_* constants between our markers in wp-config.php.
	754	+ * Idempotent: replaces an existing block. Reversible via remove_wp_config().
	755	+ */
	756	+ /** Sidecar holding the config when wp-config.php cannot be written. */
	757	+ private const SIDECAR_FILE = 'xspeed-object-cache.php';
	758	+
	759	+ /**
	760	+ * Absolute path of the config sidecar.
	761	+ *
	762	+ * Lives beside the drop-in in wp-content/ rather than under
	763	+ * wp-content/cache/, which a purge empties -- losing the settings on the
	764	+ * next purge would be a far stranger bug than the one this solves.
	765	+ */
	766	+ public static function sidecar_path(): string {
	767	+ return WP_CONTENT_DIR . '/' . self::SIDECAR_FILE;
	768	+ }
	769	+
	770	+ /**
	771	+ * Write the config sidecar. Used when wp-config.php is not writable, which
	772	+ * is the norm on several managed hosts -- there the panel could otherwise
	773	+ * only ever tell the user to paste a snippet by hand.
	774	+ *
	775	+ * Written as PHP, not JSON: wp-content/ is web-reachable, and a .json here
	776	+ * would serve the Redis password to anyone who guessed the filename. A PHP
	777	+ * file with an ABSPATH guard returns nothing when requested directly.
	778	+ *
	779	+ * @param array<string,mixed> $opts Effective settings to persist.
	780	+ */
	781	+ public static function write_sidecar( array $opts ): bool {
	782	+ $fs = self::fs();
	783	+ if ( ! $fs ) {
	784	+ return false;
	785	+ }
	786	+
	787	+ $payload = array();
	788	+ foreach ( self::SIDECAR_KEYS as $key ) {
	789	+ if ( array_key_exists( $key, $opts ) ) {
	790	+ $payload[ $key ] = $opts[ $key ];
	791	+ }
	792	+ }
	793	+
	794	+ $body = "<?php\n"
	795	+ . "/**\n"
	796	+ . " * xSpeed object-cache configuration.\n"
	797	+ . " *\n"
	798	+ . " * Written by xSpeed because wp-config.php is not writable on this host.\n"
	799	+ . " * The drop-in reads this before WordPress loads. Edit the Object Cache\n"
	800	+ . " * panel rather than this file -- it is rewritten on every save.\n"
	801	+ . " */\n"
	802	+ . "defined( 'ABSPATH' ) || exit;\n\n"
	803	+ . 'return ' . var_export( $payload, true ) . ";\n";
	804	+
	805	+ /*
	806	+ * Write to a temp file and rename() into place. The drop-in `include`s
	807	+ * this file BEFORE WordPress loads, so a reader that catches a
	808	+ * half-written copy gets a PHP parse error -- a white screen on every
	809	+ * request, not a degraded cache. rename() within the same directory is
	810	+ * atomic on every filesystem WordPress supports, so a reader sees
	811	+ * either the whole old file or the whole new one.
	812	+ */
	813	+ $path = self::sidecar_path();
	814	+ $tmp = $path . '.' . wp_generate_password( 8, false ) . '.tmp';
	815	+
	816	+ if ( ! $fs->put_contents( $tmp, $body, FS_CHMOD_FILE ) ) {
	817	+ return false;
	818	+ }
	819	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.rename_rename -- WP_Filesystem has no atomic move; rename() is the whole point here.
	820	+ if ( ! @rename( $tmp, $path ) ) { // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- failure is reported by the return value.
	821	+ $fs->delete( $tmp );
	822	+ return false;
	823	+ }
	824	+
	825	+ /*
	826	+ * Managed hosts -- the ones this sidecar exists for -- often run
	827	+ * opcache with validate_timestamps off, where `include` would keep
	828	+ * returning the previously compiled array however many times we
	829	+ * rewrite the file. That is the exact panel-says-one-thing,
	830	+ * runtime-does-another failure this change exists to remove.
	831	+ */
	832	+ if ( function_exists( 'opcache_invalidate' ) ) {
	833	+ @opcache_invalidate( $path, true ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- opcache may be disabled or restricted; nothing to do either way.
	834	+ }
	835	+
	836	+ self::forget_sidecar();
	837	+ return true;
	838	+ }
	839	+
	840	+ /**
	841	+ * Remove the sidecar. Called when wp-config.php becomes writable again, so
	842	+ * two sources can never disagree about the same setting.
	843	+ */
	844	+ public static function delete_sidecar(): bool {
	845	+ $path = self::sidecar_path();
	846	+ if ( ! file_exists( $path ) ) {
	847	+ return true;
	848	+ }
	849	+ $fs = self::fs();
	850	+ $ok = $fs ? (bool) $fs->delete( $path ) : false;
	851	+ if ( $ok ) {
	852	+ self::forget_sidecar();
	853	+ }
	854	+ return $ok;
	855	+ }
	856	+
	857	+ /**
	858	+ * Settings the sidecar carries. Mirrors the fields wp_config_block()
	859	+ * emits, so the two storage paths describe the same configuration.
	860	+ */
	861	+ private const SIDECAR_KEYS = array(
	862	+ 'backend',
	863	+ 'redis_host',
	864	+ 'redis_port',
	865	+ 'redis_user',
	866	+ 'redis_password',
	867	+ 'redis_database',
	868	+ 'memcached_host',
	869	+ 'memcached_port',
	870	+ 'key_prefix',
	871	+ 'connection_timeout',
	872	+ 'persistent',
	873	+ );
	874	+
	875	+ /** Memoized sidecar contents; null until first read. */
	876	+ private static $sidecar_cache = null;
	877	+
	878	+ /** Forget the memoized sidecar. */
	879	+ public static function forget_sidecar(): void {
	880	+ self::$sidecar_cache = null;
	881	+ }
	882	+
	883	+ /**
	884	+ * Read the sidecar, or an empty array when there is none.
	885	+ *
	886	+ * @return array<string,mixed>
	887	+ */
	888	+ public static function read_sidecar(): array {
	889	+ if ( null !== self::$sidecar_cache ) {
	890	+ return self::$sidecar_cache;
	891	+ }
	892	+ $path = self::sidecar_path();
	893	+ if ( ! file_exists( $path ) || ! is_readable( $path ) ) {
	894	+ self::$sidecar_cache = array();
	895	+ return self::$sidecar_cache;
	896	+ }
	897	+ $data = include $path;
	898	+ self::$sidecar_cache = is_array( $data ) ? $data : array();
	899	+ return self::$sidecar_cache;
	900	+ }
	901	+
	902	+ /**
	903	+ * Host and port of the first server in a `$memcached_servers` global.
	904	+ *
	905	+ * Memcached has no constant convention the way Redis has WP_REDIS_*; this
	906	+ * global IS the convention, and hosts write it in two shapes:
	907	+ *
	908	+ * array( array( 'host', 11211 ) ) // W3TC pair form
	909	+ * array( 'default' => array( 'host:11211' ) ) // Memcached Object Cache
	910	+ *
	911	+ * Reading only the first left the second taking the whole "host:port"
	912	+ * string as the hostname, or missing it entirely because its bucket is
	913	+ * keyed `default` rather than 0.
	914	+ *
	915	+ * The drop-in carries `xspeed_oc_first_memcached_server()`, which must
	916	+ * behave identically -- it loads before WordPress and cannot call this
	917	+ * class. ObjectCacheConstantParityTest holds the two together. (#398)
	918	+ *
	919	+ * @param mixed $servers The global's value, unvalidated.
	920	+ * @return array{0:?string,1:?int}|null Host and port, either possibly null.
	921	+ */
	922	+ public static function first_memcached_server( $servers ): ?array {
	923	+ if ( ! is_array( $servers ) || array() === $servers ) {
	924	+ return null;
	925	+ }
	926	+
	927	+ $bucket = array_key_exists( 0, $servers ) ? $servers[0] : reset( $servers );
	928	+
	929	+ /*
	930	+ * A bucket is EITHER a [host, port] pair or a list of server entries.
	931	+ * Telling them apart by shape, not by nesting depth: descending into
	932	+ * `array( 'mc.example', 11211 )` yields the host string and drops the
	933	+ * port on the floor, which is the commonest form there is.
	934	+ */
	935	+ $entry = $bucket;
	936	+ if ( is_array( $bucket ) && isset( $bucket[0] ) && is_array( $bucket[0] ) ) {
	937	+ $entry = $bucket[0];
	938	+ }
	939	+
	940	+ if ( is_array( $entry ) ) {
	941	+ $host = isset( $entry[0] ) && ! is_array( $entry[0] ) ? (string) $entry[0] : null;
	942	+ $port = isset( $entry[1] ) && ! is_array( $entry[1] ) ? (int) $entry[1] : null;
	943	+ // A single-element list, array( 'host:port' ), is the keyed form's
	944	+ // bucket rather than a pair -- fall through to the string parser.
	945	+ if ( null !== $host && null === $port && is_string( $entry[0] ) && false !== strpos( $entry[0], ':' ) ) {
	946	+ $entry = $entry[0];
	947	+ } else {
	948	+ return ( null === $host && null === $port ) ? null : array( $host, $port );
	949	+ }
	950	+ }
	951	+
	952	+ if ( ! is_string( $entry ) || '' === $entry ) {
	953	+ return null;
	954	+ }
	955	+
	956	+ // "host:port", or a bare host. Split only the LAST colon, and only when
	957	+ // what follows is numeric -- a unix socket path is a host with no port.
	958	+ $at = strrpos( $entry, ':' );
	959	+ if ( false !== $at && ctype_digit( substr( $entry, $at + 1 ) ) ) {
	960	+ return array( substr( $entry, 0, $at ), (int) substr( $entry, $at + 1 ) );
	961	+ }
	962	+ return array( $entry, null );
	963	+ }
	964	+
	965	+ /**
	966	+ * Names of the constants xSpeed itself wrote into wp-config.php.
	967	+ *
	968	+ * Ownership is decided by LOCATION, not by name. Our block is fenced by
	969	+ * CONFIG_BEGIN / CONFIG_END, so a define inside it is one we wrote and a
	970	+ * define anywhere else belongs to the host -- even when both are called
	971	+ * `XSPEED_OC_HOST`, which is exactly what a user pasting our own snippet
	972	+ * by hand produces.
	973	+ *
	974	+ * Judging by prefix instead is what made the panel treat xSpeed's own
	975	+ * values as host-pinned: the field locked, the "manage this here" control
	976	+ * could not unlock it, and Revert handed the field back to our snapshot
	977	+ * rather than to the host. (#398)
	978	+ *
	979	+ * @return string[] Constant names, empty when the block is absent.
	980	+ */
	981	+
	982	+ public static function our_constants(): array {
	983	+ if ( null !== self::$our_constants_cache ) {
	984	+ return self::$our_constants_cache;
	985	+ }
	986	+ $cache = array();
	987	+
	988	+ $wp_config = ABSPATH . 'wp-config.php';
	989	+ if ( ! file_exists( $wp_config ) || ! is_readable( $wp_config ) ) {
	990	+ self::$our_constants_cache = $cache;
	991	+ return $cache;
	992	+ }
	993	+ // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- reading our own block; WP_Filesystem is not always initialised on the read path.
	994	+ $config = (string) @file_get_contents( $wp_config ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- an unreadable wp-config just means "we own nothing".
	995	+ if ( '' === $config ) {
	996	+ self::$our_constants_cache = $cache;
	997	+ return $cache;
	998	+ }
	999	+
	1000	+ $pattern = '/' . preg_quote( self::CONFIG_BEGIN, '/' ) . '(.*?)' . preg_quote( self::CONFIG_END, '/' ) . '/s';
	1001	+ if ( ! preg_match( $pattern, $config, $m ) ) {
	1002	+ self::$our_constants_cache = $cache;
	1003	+ return $cache;
	1004	+ }
	1005	+ if ( preg_match_all( "/define\\(\\s*'([A-Z0-9_]+)'/", $m[1], $names ) ) {
	1006	+ $cache = $names[1];
	1007	+ }
	1008	+ self::$our_constants_cache = $cache;
	1009	+ return $cache;
	1010	+ }
	1011	+
	1012	+ /**
	1013	+ * Memoized result of our_constants(); null until the block is first read.
	1014	+ *
	1015	+ * @var string[]|null
	1016	+ */
	1017	+ private static $our_constants_cache = null;
	1018	+
	1019	+ /**
	1020	+ * Forget the memoized block scan. Every write that changes the block must
	1021	+ * call this, or the same request keeps answering from the pre-write copy.
	1022	+ */
	1023	+ public static function forget_our_constants(): void {
	1024	+ self::$our_constants_cache = null;
	1025	+ }
	1026	+
	1027	+ public static function write_wp_config( array $opts, array $force = array() ): bool {
	1028	+ $fs = self::fs();
	1029	+ $wp_config = ABSPATH . 'wp-config.php';
	1030	+ if ( ! $fs || ! file_exists( $wp_config ) || ! $fs->is_writable( $wp_config ) ) {
	1031	+ /*
	1032	+ * wp-config.php is read-only on several managed hosts. Fall back to
	1033	+ * a sidecar in wp-content/ -- writable wherever the drop-in itself
	1034	+ * could be installed, so the panel keeps working instead of telling
	1035	+ * the user to paste a snippet by hand. (#398)
	1036	+ */
	1037	+ return self::write_sidecar( $opts );
	1038	+ }
	1039	+
	1040	+
	1041	+ $config = $fs->get_contents( $wp_config );
	1042	+ if ( ! is_string( $config ) ) {
	1043	+ return false;
	1044	+ }
	1045	+
	1046	+ $block = self::wp_config_block( $opts, $force );
	1047	+
	1048	+ // Replace an existing xSpeed block if present, else insert after <?php.
	1049	+ // IMPORTANT: $block is inserted via preg_replace_callback returning it
	1050	+ // VERBATIM — never as a preg_replace replacement string. In a
	1051	+ // replacement string, `\` and `$` are special (backref escapes), so a
	1052	+ // constant value ending in a backslash (e.g. a Redis password or key
	1053	+ // prefix like "secret\") or containing "$1" would corrupt the output:
	1054	+ // esc()'s "secret\\" collapses back to "secret\", producing
	1055	+ // 'secret\' ) — a PHP parse error that white-screens the whole site.
	1056	+ // The callback form treats $block as literal text. (FBS-82111 Bug 1)
	1057	+ $pattern = '/' . preg_quote( self::CONFIG_BEGIN, '/' ) . '.*?' . preg_quote( self::CONFIG_END, '/' ) . "\s*/s";
	1058	+ if ( preg_match( $pattern, $config ) ) {
	1059	+ $config = preg_replace_callback(
	1060	+ $pattern,
	1061	+ static function () use ( $block ) {
	1062	+ return $block;
	1063	+ },
	1064	+ $config,
	1065	+ 1
	1066	+ );
138	1067	} else {
139		- $lines[] = '// No snippet for backend: ' . $backend;
	1068	+ $config = preg_replace_callback(
	1069	+ '/(<\?php)/',
	1070	+ static function ( $m ) use ( $block ) {
	1071	+ return $m[1] . "\n" . $block;
	1072	+ },
	1073	+ $config,
	1074	+ 1
	1075	+ );
140	1076	}
141	1077
	1078	+ $written = (bool) $fs->put_contents( $wp_config, $config, FS_CHMOD_FILE );
	1079	+ if ( $written ) {
	1080	+ // The block just changed; a memoized scan from earlier in this
	1081	+ // request would still name the previous set. (#398)
	1082	+ self::forget_our_constants();
	1083	+
	1084	+ // Only NOW is the block durable, so only now is a sidecar left
	1085	+ // from an earlier read-only spell safely redundant. Deleting it
	1086	+ // before the write -- is_writable() is not a promise the write
	1087	+ // lands; get_contents() can fail, and put_contents() can fail on a
	1088	+ // full disk or an SELinux denial -- would drop the live config and
	1089	+ // leave the site on built-in defaults.
	1090	+ self::delete_sidecar();
	1091	+ }
	1092	+ return $written;
	1093	+ }
	1094	+
	1095	+ /**
	1096	+ * Strip our wp-config block. Returns true if the block is gone afterward.
	1097	+ */
	1098	+ public static function remove_wp_config(): bool {
	1099	+ $fs = self::fs();
	1100	+ $wp_config = ABSPATH . 'wp-config.php';
	1101	+ if ( ! $fs || ! file_exists( $wp_config ) ) {
	1102	+ return true;
	1103	+ }
	1104	+ if ( ! $fs->is_writable( $wp_config ) ) {
	1105	+ return false;
	1106	+ }
	1107	+ $config = $fs->get_contents( $wp_config );
	1108	+ if ( ! is_string( $config ) ) {
	1109	+ return false;
	1110	+ }
	1111	+ $pattern = '/' . preg_quote( self::CONFIG_BEGIN, '/' ) . '.*?' . preg_quote( self::CONFIG_END, '/' ) . "\s*/s";
	1112	+ $config = preg_replace( $pattern, '', $config );
	1113	+ $removed = (bool) $fs->put_contents( $wp_config, $config, FS_CHMOD_FILE );
	1114	+ if ( $removed ) {
	1115	+ // A scan from earlier in this request would still name the
	1116	+ // constants we just deleted, so origins() would report a field as
	1117	+ // ours -- editable -- when a host define is now the only source
	1118	+ // and the field should read as pinned.
	1119	+ self::forget_our_constants();
	1120	+ }
	1121	+ return $removed;
	1122	+ }
	1123	+
	1124	+ /**
	1125	+ * The marker-wrapped constants block written into wp-config.php. Uses
	1126	+ * XSPEED_OC_* names (our drop-in reads these first, then falls back to
	1127	+ * WP_REDIS_* for interop).
	1128	+ */
	1129	+ private static function wp_config_block( array $opts, array $force = array() ): string {
	1130	+ // Fields the caller has decided we own, whatever pinned_elsewhere()
	1131	+ // would otherwise say. Used when an admin saved an override: they were
	1132	+ // told the host's define would stop applying, and this is the write
	1133	+ // that makes that true. (#398)
	1134	+ self::$force_fields = $force;
	1135	+ $backend = (string) ( $opts['backend'] ?? 'redis' );
	1136	+ $lines = array( self::CONFIG_BEGIN );
	1137	+ $lines[] = "define( 'XSPEED_OC_BACKEND', '" . self::esc( $backend ) . "' );";
	1138	+
	1139	+ if ( 'memcached' === $backend ) {
	1140	+ // XSPEED_OC_MC_*, not the Redis pair: one shared name meant enabling
	1141	+ // Redis overwrote the Memcached host/port. (#398)
	1142	+ if ( ! self::pinned_elsewhere( 'memcached_host' ) ) {
	1143	+ $lines[] = "define( 'XSPEED_OC_MC_HOST', '" . self::esc( self::str( $opts, 'memcached_host', '127.0.0.1' ) ) . "' );";
	1144	+ }
	1145	+ if ( ! self::pinned_elsewhere( 'memcached_port' ) ) {
	1146	+ $lines[] = "define( 'XSPEED_OC_MC_PORT', " . self::int( $opts, 'memcached_port', 11211 ) . ' );';
	1147	+ }
	1148	+ } else {
	1149	+ if ( ! self::pinned_elsewhere( 'redis_host' ) ) {
	1150	+ $lines[] = "define( 'XSPEED_OC_HOST', '" . self::esc( self::str( $opts, 'redis_host', '127.0.0.1' ) ) . "' );";
	1151	+ }
	1152	+ if ( ! self::pinned_elsewhere( 'redis_port' ) ) {
	1153	+ $lines[] = "define( 'XSPEED_OC_PORT', " . self::int( $opts, 'redis_port', 6379 ) . ' );';
	1154	+ }
	1155	+ $user = self::str( $opts, 'redis_user', '' );
	1156	+ if ( '' !== $user && ! self::pinned_elsewhere( 'redis_user' ) ) {
	1157	+ $lines[] = "define( 'XSPEED_OC_USER', '" . self::esc( $user ) . "' );";
	1158	+ }
	1159	+ $pass = self::str( $opts, 'redis_password', '' );
	1160	+ if ( '' !== $pass && ! self::pinned_elsewhere( 'redis_password' ) ) {
	1161	+ $lines[] = "define( 'XSPEED_OC_PASSWORD', '" . self::esc( $pass ) . "' );";
	1162	+ }
	1163	+ if ( ! self::pinned_elsewhere( 'redis_database' ) ) {
	1164	+ $lines[] = "define( 'XSPEED_OC_DATABASE', " . self::int( $opts, 'redis_database', 0 ) . ' );';
	1165	+ }
	1166	+ if ( ! self::pinned_elsewhere( 'connection_timeout' ) ) {
	1167	+ $lines[] = "define( 'XSPEED_OC_TIMEOUT', " . self::int( $opts, 'connection_timeout', 1 ) . ' );';
	1168	+ }
	1169	+ if ( ! self::pinned_elsewhere( 'persistent' ) ) {
	1170	+ $lines[] = "define( 'XSPEED_OC_PERSISTENT', " . ( ! empty( $opts['persistent'] ) ? 'true' : 'false' ) . ' );';
	1171	+ }
	1172	+ }
	1173	+ // Always emit a salt (#390): a blank Cache Key Prefix derives a per-site
	1174	+ // value rather than leaving keys unnamespaced, which collides when
	1175	+ // several sites share one Redis/Memcached server.
	1176	+ //
	1177	+ // Unless a foreign define already owns it (#398). Emitting ours would
	1178	+ // outrank the host's WP_REDIS_PREFIX, and on an ACL/namespaced Redis a
	1179	+ // prefix that does not match the host's exactly means every write is
	1180	+ // denied with NOPERM -- so a derived salt there is worse than none.
	1181	+ // The host's define IS the namespace in that case, and it is already
	1182	+ // non-empty, so the collision #390 closes cannot reopen.
	1183	+ if ( ! self::pinned_elsewhere( 'key_prefix' ) ) {
	1184	+ $lines[] = "define( 'XSPEED_OC_SALT', '" . self::esc( self::effective_salt( $opts ) ) . "' );";
	1185	+ }
	1186	+ $lines[] = self::CONFIG_END;
	1187	+ self::$force_fields = array();
142	1188	return implode( "\n", $lines ) . "\n";
	1189	+ }
	1190	+
	1191	+ /**
	1192	+ * Fields the current block write owns outright. Set for the duration of one
	1193	+ * wp_config_block() call; see the $force parameter there.
	1194	+ *
	1195	+ * @var string[]
	1196	+ */
	1197	+ private static array $force_fields = array();
	1198	+
	1199	+ /**
	1200	+ * Is this field already pinned by a constant we are not about to write?
	1201	+ *
	1202	+ * Enable() resolves settings through Settings_Manager, so on a
	1203	+ * host-provisioned site those values came FROM wp-config in the first
	1204	+ * place -- typically WP_REDIS_*. Writing them back out under our own
	1205	+ * XSPEED_OC_* names, which outrank every alias, would freeze a snapshot:
	1206	+ * when the host later rotated the password, the site would keep
	1207	+ * authenticating with our stale copy and silently drop to a
	1208	+ * non-persistent cache. It would also re-emit a credential as a second
	1209	+ * plaintext literal, which is the thing sourcing it from a constant
	1210	+ * avoids. So leave the host's define alone and emit nothing for it. (#398)
	1211	+ */
	1212	+ private static function pinned_elsewhere( string $field ): bool {
	1213	+ if ( in_array( $field, self::$force_fields, true ) ) {
	1214	+ return false;
	1215	+ }
	1216	+ if ( ! class_exists( '\\XSpeed\\Settings_Manager' ) ) {
	1217	+ return false;
	1218	+ }
	1219	+ $module = \XSpeed\Module_Registry::get( 'object-cache' );
	1220	+ if ( ! $module ) {
	1221	+ return false;
	1222	+ }
	1223	+
	1224	+ // An admin who deliberately overrode this field asked us to shadow the
	1225	+ // host's define -- they were told so in as many words before the field
	1226	+ // unlocked. Protecting it here would silently drop their value on the
	1227	+ // next enable, which is the same silent-no-op failure the whole
	1228	+ // pinned-field contract exists to prevent. (#398)
	1229	+ if ( \XSpeed\Settings_Manager::is_overridden( 'object-cache', $field ) ) {
	1230	+ return false;
	1231	+ }
	1232	+
	1233	+ // Somebody else's define, anywhere in this field's list, is protected --
	1234	+ // even when our own XSPEED_OC_* copy currently outranks it. Testing only
	1235	+ // the WINNING constant made an override permanent in a subtler way: on
	1236	+ // revert we rewrote our copy with the host's value, our copy still
	1237	+ // outranked theirs, and a later rotation on their side was shadowed
	1238	+ // forever. Emitting nothing for the field lets the host's define surface
	1239	+ // again and keep surfacing. (#398)
	1240	+ return null !== \XSpeed\Settings_Manager::foreign_constant( 'object-cache', $field );
	1241	+ }
	1242	+
	1243	+ /**
	1244	+ * Is our marker block present in wp-config.php?
	1245	+ *
	1246	+ * Public so a caller can tell "we already manage constants here" from
	1247	+ * "this site never enabled the object cache" -- rewriting the block is
	1248	+ * right in the first case and would be an unasked-for file edit in the
	1249	+ * second. (#398)
	1250	+ */
	1251	+ public static function wp_config_has_our_block(): bool {
	1252	+ return self::wp_config_has_block();
	1253	+ }
	1254	+
	1255	+ private static function wp_config_has_block(): bool {
	1256	+ $wp_config = ABSPATH . 'wp-config.php';
	1257	+ if ( ! file_exists( $wp_config ) ) {
	1258	+ return false;
	1259	+ }
	1260	+ $fs = self::fs();
	1261	+ if ( ! $fs ) {
	1262	+ return false;
	1263	+ }
	1264	+ $config = $fs->get_contents( $wp_config );
	1265	+ return is_string( $config ) && false !== strpos( $config, self::CONFIG_BEGIN );
	1266	+ }
	1267	+
	1268	+ /**
	1269	+ * Memcached config goes through $memcached_servers (handled by our drop-in's
	1270	+ * defaults), so a non-writable wp-config isn't necessarily fatal for it.
	1271	+ */
	1272	+ private static function backend_uses_no_constants( array $opts ): bool {
	1273	+ return false; // both backends currently rely on the constants block
	1274	+ }
	1275	+
	1276	+ /**
	1277	+ * Initialised WP_Filesystem handle, or null. Plugin Check-compliant access.
	1278	+ *
	1279	+ * Forces the 'direct' transport when PHP can write the WordPress tree
	1280	+ * itself. Without this, WP_Filesystem() can fall back to the FTP transport
	1281	+ * (no credentials in a non-interactive context) and fatal in
	1282	+ * ftp_fget(). We only need 'direct' — these writes target wp-config.php /
	1283	+ * wp-content, both owned by the PHP user on a normal install.
	1284	+ */
	1285	+ private static function fs() {
	1286	+ global $wp_filesystem;
	1287	+ if ( ! function_exists( 'WP_Filesystem' ) ) {
	1288	+ require_once ABSPATH . 'wp-admin/includes/file.php';
	1289	+ }
	1290	+
	1291	+ // Pin the method to 'direct' for this call so a missing FTP/SSH config
	1292	+ // can never trigger the credential-prompt / ftp_*() fatal path. Use a
	1293	+ // closure on the filter so we don't permanently alter global behaviour.
	1294	+ $force_direct = static function () {
	1295	+ return 'direct';
	1296	+ };
	1297	+ add_filter( 'filesystem_method', $force_direct, 99 );
	1298	+ $ok = WP_Filesystem();
	1299	+ remove_filter( 'filesystem_method', $force_direct, 99 );
	1300	+
	1301	+ if ( ! $ok || ! $wp_filesystem || 'direct' !== $wp_filesystem->method ) {
	1302	+ return null;
	1303	+ }
	1304	+ return $wp_filesystem;
143	1305	}
144	1306
145	1307	private static function sniff_drop_in_label( string $path ): string {
146	1308	$head = @file_get_contents( $path, false, null, 0, 2048 );