xspeed / includes / class-cache-inventory.php

class-cache-inventory.php in xSpeed Cache: AI-Powered Performance Hub with MCP, Caching & CDN 1.3.0, at includes/class-cache-inventory.php

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1	<?php
2	/**
3	* Cache_Inventory — what is actually in the cache, and what it costs.
4	*
5	* The four stat cards on the dashboard answer "how much"; this answers
6	* "which". A number like "412 cached pages" is only trustworthy if you
7	* can open it and see the 412, and a size of "8.4 MB" is only actionable
8	* if you can see what is taking the space.
9	*
10	* Two storage shapes have to be reconciled here:
11	*
12	* flat XSPEED_CACHE_DIR/<md5>.html written by the PHP path
13	* static XSPEED_CACHE_STATIC_DIR/<host><uri>/index.html
14	* served by the web server
15	*
16	* The static tree encodes the URL in its path, so those entries are exact.
17	* The flat tree is keyed by md5( host . uri . device . … ), which cannot be
18	* reversed — so for those we read the first HEAD_BYTES of the body and pull
19	* the canonical/og:url out of the markup. That resolves the overwhelming
20	* majority of real pages, and an entry we cannot name is reported with a
21	* null URL rather than a guess.
22	*
23	* Cost control: scanning is capped (SCAN_CAP) and the result memoized for
24	* CACHE_TTL, because this runs on an admin click, not on a page render.
25	*
26	* @package XSpeed
27	*/
28
29	declare(strict_types=1);
30
31	namespace XSpeed;
32
33	defined( 'ABSPATH' ) \|\| exit;
34
35	final class Cache_Inventory {
36
37	/**
38	* Hard ceiling on entries examined in one pass. A site with 50k cached
39	* pages must not turn one dashboard click into a 50k-file stat storm;
40	* the response says `capped: true` so the UI can say so out loud
41	* instead of quietly showing a partial list as if it were the whole.
42	*/
43	public const SCAN_CAP = 750;
44
45	/** Bytes of each flat entry read to look for a canonical URL. */
46	public const HEAD_BYTES = 16384;
47
48	/** Memoization window for a full scan, in seconds. */
49	public const CACHE_TTL = 60;
50
51	public const TRANSIENT_KEY = 'xspeed_cache_inventory';
52
53	/** Activity-log event types that represent a purge. */
54	private const PURGE_TYPES = array( 'cache_purged', 'cache_purge_url', 'cache_purged_url' );
55
56	/**
57	* Resolve a static-tree file back to the URL that produced it.
58	*
59	* `<root>/example.com/blog/post/index.html` → `https://example.com/blog/post/`.
60	* Returns null for anything that isn't shaped like a static entry, so a
61	* stray file in the tree can't become a bogus row.
62	*
63	* Pure — no filesystem access, so the path logic is testable on its own.
64	*/
65	public static function url_from_static_path( string $file, string $root, bool $https = true ): ?string {
66	$root = rtrim( str_replace( '\\', '/', $root ), '/' );
67	$file = str_replace( '\\', '/', $file );
68
69	if ( '' === $root \|\| 0 !== strpos( $file, $root . '/' ) ) {
70	return null;
71	}
72	if ( substr( $file, -11 ) !== '/index.html' ) {
73	return null;
74	}
75
76	$rel = substr( $file, strlen( $root ) + 1, -11 );
77	if ( '' === $rel ) {
78	return null;
79	}
80
81	$segments = explode( '/', $rel );
82	$host = array_shift( $segments );
83	// Same allowlist store_static() writes with — anything else is not
84	// ours and must not be presented as a cached page.
85	if ( null === $host \|\| '' === $host \|\| preg_match( '/[^a-zA-Z0-9.\-]/', $host ) ) {
86	return null;
87	}
88
89	$path = '' === implode( '/', $segments ) ? '/' : '/' . implode( '/', $segments ) . '/';
90
91	return ( $https ? 'https://' : 'http://' ) . $host . $path;
92	}
93
94	/**
95	* Pull a page URL out of the top of a cached document.
96	*
97	* Prefers `<link rel="canonical">` — WordPress emits it for singular
98	* views and it is what the site itself considers the page's address.
99	* Falls back to `og:url`. Returns null rather than guessing from, say,
100	* the first anchor in the body.
101	*
102	* Pure.
103	*/
104	public static function extract_url_from_html( string $head ): ?string {
105	if ( preg_match( '#<link[^>]+rel=["\']canonical["\'][^>]*>#i', $head, $tag ) ) {
106	if ( preg_match( '#href=["\']([^"\']+)["\']#i', $tag[0], $href ) ) {
107	$url = html_entity_decode( trim( $href[1] ), ENT_QUOTES );
108	if ( 0 === stripos( $url, 'http' ) ) {
109	return $url;
110	}
111	}
112	}
113	if ( preg_match( '#<meta[^>]+property=["\']og:url["\'][^>]*>#i', $head, $tag ) ) {
114	if ( preg_match( '#content=["\']([^"\']+)["\']#i', $tag[0], $content ) ) {
115	$url = html_entity_decode( trim( $content[1] ), ENT_QUOTES );
116	if ( 0 === stripos( $url, 'http' ) ) {
117	return $url;
118	}
119	}
120	}
121	return null;
122	}
123
124	/**
125	* Merge the two storage shapes into one row per page.
126	*
127	* A page served by the web-server rewrite usually exists in BOTH trees.
128	* Listing it twice would make the drill-down disagree with the stat card
129	* it was opened from, so rows are keyed by URL when we know it: the
130	* newest mtime wins for "age", disk bytes add up, and `stored_in` records
131	* which copies exist.
132	*
133	* Entries whose URL is unknown can't be merged with anything — they stay
134	* distinct, keyed by their own path.
135	*
136	* Pure: takes already-collected rows, returns merged rows.
137	*
138	* @param array<int,array<string,mixed>> $rows Raw rows from either tree.
139	* @return array<int,array<string,mixed>> Merged, newest-first.
140	*/
141	public static function merge_rows( array $rows ): array {
142	$merged = array();
143
144	foreach ( $rows as $row ) {
145	$url = isset( $row['url'] ) && is_string( $row['url'] ) ? $row['url'] : null;
146	$key = null !== $url ? 'u:' . $url : 'p:' . (string) ( $row['path'] ?? '' );
147
148	if ( ! isset( $merged[ $key ] ) ) {
149	$merged[ $key ] = $row;
150	continue;
151	}
152
153	$existing = $merged[ $key ];
154	$existing['bytes'] = (int) $existing['bytes'] + (int) $row['bytes'];
155	$existing['mtime'] = max( (int) $existing['mtime'], (int) $row['mtime'] );
156	$existing['stored_in'] = array_values( array_unique( array_merge( (array) $existing['stored_in'], (array) $row['stored_in'] ) ) );
157	$existing['compressed'] += (int) $row['compressed'];
158	sort( $existing['stored_in'] );
159	$merged[ $key ] = $existing;
160	}
161
162	$out = array_values( $merged );
163	usort(
164	$out,
165	static function ( array $a, array $b ): int {
166	return (int) $b['mtime'] <=> (int) $a['mtime'];
167	}
168	);
169
170	return $out;
171	}
172
173	/**
174	* The cached-pages drill-down.
175	*
176	* @param int $limit Rows returned.
177	* @param int $offset Rows skipped.
178	* @param bool $fresh Bypass the memoized scan.
179	* @return array{entries:array<int,array<string,mixed>>,total:int,capped:bool,generated:int}
180	*/
181	public static function entries( int $limit = 50, int $offset = 0, bool $fresh = false ): array {
182	$rows = $fresh ? null : get_transient( self::TRANSIENT_KEY );
183	if ( ! is_array( $rows ) \|\| ! isset( $rows['entries'] ) ) {
184	$rows = self::scan();
185	set_transient( self::TRANSIENT_KEY, $rows, self::CACHE_TTL );
186	}
187
188	$all = is_array( $rows['entries'] ) ? $rows['entries'] : array();
189	$limit = max( 1, min( 200, $limit ) );
190	$offset = max( 0, $offset );
191	$now = time();
192
193	$page = array_slice( $all, $offset, $limit );
194	foreach ( $page as $i => $entry ) {
195	$page[ $i ]['age'] = max( 0, $now - (int) $entry['mtime'] );
196	}
197
198	return array(
199	'entries' => array_values( $page ),
200	'total' => count( $all ),
201	'capped' => (bool) ( $rows['capped'] ?? false ),
202	'generated' => (int) ( $rows['generated'] ?? $now ),
203	);
204	}
205
206	/**
207	* Walk both trees. Separated from entries() so the memoization and the
208	* pagination stay readable, and so a test can drive the walk directly.
209	*
210	* @return array{entries:array<int,array<string,mixed>>,capped:bool,generated:int}
211	*/
212	public static function scan(): array {
213	$rows = array();
214	$scanned = 0;
215	$capped = false;
216
217	// Flat tree — md5-keyed, URL recovered from the markup.
218	// Flat entries live in per-site buckets since #6
219	// (XSPEED_CACHE_DIR/<host>/<md5>.html); the legacy top-level layout
220	// is still globbed so pre-#6 entries remain visible until they age out.
221	$flat = defined( 'XSPEED_CACHE_DIR' )
222	? array_merge(
223	(array) glob( XSPEED_CACHE_DIR . '/*.html' ),
224	(array) glob( XSPEED_CACHE_DIR . '//.html' )
225	)
226	: array();
227	$flat = array_values(
228	array_filter(
229	$flat,
230	static function ( $f ) {
231	// min/ and rest/ are separate buckets, not page entries.
232	return ! in_array( basename( dirname( (string) $f ) ), array( 'min', 'rest', 'combined' ), true );
233	}
234	)
235	);
236	foreach ( $flat as $file ) {
237	if ( $scanned >= self::SCAN_CAP ) {
238	$capped = true;
239	break;
240	}
241	++$scanned;
242
243	$size = (int) @filesize( $file ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- A file purged between glob() and stat() is expected, not exceptional.
244	$rows[] = array(
245	'url' => self::read_url( $file ),
246	'path' => $file,
247	'key' => basename( $file, '.html' ),
248	'bytes' => $size,
249	'compressed' => self::sibling_size( $file . '.br' ),
250	'mtime' => (int) @filemtime( $file ), // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Same race as filesize() above.
251	'stored_in' => array( 'flat' ),
252	);
253	}
254
255	// Static tree — URL is the path, so no read is needed at all.
256	if ( defined( 'XSPEED_CACHE_STATIC_DIR' ) && is_dir( XSPEED_CACHE_STATIC_DIR ) ) {
257	$https = ! function_exists( 'home_url' ) \|\| 0 === stripos( (string) home_url(), 'https://' );
258	self::walk_static( XSPEED_CACHE_STATIC_DIR, XSPEED_CACHE_STATIC_DIR, $https, $rows, $scanned, $capped );
259	}
260
261	return array(
262	'entries' => self::merge_rows( $rows ),
263	'capped' => $capped,
264	'generated' => time(),
265	);
266	}
267
268	/**
269	* Recursive walk of the static tree, mirroring Cache::rmtree_html()'s
270	* traversal so the two can't disagree about what counts as an entry.
271	*
272	* @param array<int,array<string,mixed>> $rows Collected rows, by reference.
273	* @param int $scanned Files examined so far, by reference.
274	* @param bool $capped Set when SCAN_CAP is hit, by reference.
275	*/
276	private static function walk_static( string $dir, string $root, bool $https, array &$rows, int &$scanned, bool &$capped ): void {
277	if ( $capped ) {
278	return;
279	}
280	$entries = @scandir( $dir, SCANDIR_SORT_NONE ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- An unreadable subdir yields no rows; it must not fatal the drill-down.
281	if ( false === $entries ) {
282	return;
283	}
284
285	foreach ( $entries as $entry ) {
286	if ( '.' === $entry \|\| '..' === $entry ) {
287	continue;
288	}
289	$path = $dir . '/' . $entry;
290
291	if ( is_dir( $path ) ) {
292	self::walk_static( $path, $root, $https, $rows, $scanned, $capped );
293	if ( $capped ) {
294	return;
295	}
296	continue;
297	}
298	if ( 'index.html' !== $entry ) {
299	continue;
300	}
301	if ( $scanned >= self::SCAN_CAP ) {
302	$capped = true;
303	return;
304	}
305	++$scanned;
306
307	$rows[] = array(
308	'url' => self::url_from_static_path( $path, $root, $https ),
309	'path' => $path,
310	'key' => '',
311	'bytes' => (int) @filesize( $path ), // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Purge race, see scan().
312	'compressed' => self::sibling_size( $path . '.br' ),
313	'mtime' => (int) @filemtime( $path ), // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Purge race, see scan().
314	'stored_in' => array( 'static' ),
315	);
316	}
317	}
318
319	/** Size of a precompressed sibling, or 0 when there isn't one. */
320	private static function sibling_size( string $path ): int {
321	if ( ! is_readable( $path ) ) {
322	return 0;
323	}
324	return (int) @filesize( $path ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Purge race, see scan().
325	}
326
327	/**
328	* Read just enough of a cached document to find its canonical URL.
329	*
330	* Deliberately a partial read: WP_Filesystem::get_contents() would pull
331	* whole pages into memory, and at SCAN_CAP entries the difference is
332	* megabytes of pointless I/O for data we discard immediately.
333	*/
334	private static function read_url( string $file ): ?string {
335	// phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents, WordPress.PHP.NoSilencedErrors.Discouraged -- Partial read (16KB of head markup); WP_Filesystem has no offset/length API and would read entire pages.
336	$head = @file_get_contents( $file, false, null, 0, self::HEAD_BYTES );
337	if ( ! is_string( $head ) \|\| '' === $head ) {
338	return null;
339	}
340	return self::extract_url_from_html( $head );
341	}
342
343	/**
344	* Where the cache's disk usage actually goes.
345	*
346	* Buckets are what a user can act on — pages, their precompressed
347	* siblings, the REST response cache, minified assets — not what the
348	* code happens to write. `compressed_bytes` is real measured bytes from
349	* `.br` siblings, never an estimate: a made-up compression ratio on a
350	* dashboard is worse than no number.
351	*
352	* @return array<string,mixed>
353	*/
354	public static function size_breakdown(): array {
355	$buckets = array(
356	'pages_flat' => array(
357	'label' => __( 'Cached pages (PHP)', 'xspeed' ),
358	'bytes' => 0,
359	'files' => 0,
360	),
361	'pages_static' => array(
362	'label' => __( 'Cached pages (server-served)', 'xspeed' ),
363	'bytes' => 0,
364	'files' => 0,
365	),
366	'precompressed' => array(
367	'label' => __( 'Precompressed copies', 'xspeed' ),
368	'bytes' => 0,
369	'files' => 0,
370	),
371	'metadata' => array(
372	'label' => __( 'Per-entry metadata', 'xspeed' ),
373	'bytes' => 0,
374	'files' => 0,
375	),
376	'rest' => array(
377	'label' => __( 'REST responses', 'xspeed' ),
378	'bytes' => 0,
379	'files' => 0,
380	),
381	'assets' => array(
382	'label' => __( 'Minified CSS/JS', 'xspeed' ),
383	'bytes' => 0,
384	'files' => 0,
385	),
386	);
387
388	if ( defined( 'XSPEED_CACHE_DIR' ) ) {
389	// Both layouts: per-site buckets (#6) and pre-#6 top level.
390	self::add_glob( $buckets['pages_flat'], XSPEED_CACHE_DIR . '/*.html' );
391	self::add_glob( $buckets['metadata'], XSPEED_CACHE_DIR . '/*.meta' );
392	self::add_glob( $buckets['precompressed'], XSPEED_CACHE_DIR . '/*.br' );
393	self::add_glob( $buckets['pages_flat'], XSPEED_CACHE_DIR . '//.html' );
394	self::add_glob( $buckets['metadata'], XSPEED_CACHE_DIR . '//.meta' );
395	self::add_glob( $buckets['precompressed'], XSPEED_CACHE_DIR . '//.br' );
396	self::add_glob( $buckets['rest'], XSPEED_CACHE_DIR . '/rest/*.json' );
397	self::add_glob( $buckets['assets'], XSPEED_CACHE_DIR . '/min/*.css' );
398	self::add_glob( $buckets['assets'], XSPEED_CACHE_DIR . '/min/*.js' );
399	self::add_glob( $buckets['assets'], XSPEED_CACHE_DIR . '/min/combined/*.css' );
400	self::add_glob( $buckets['assets'], XSPEED_CACHE_DIR . '/min/combined/*.js' );
401	}
402
403	if ( defined( 'XSPEED_CACHE_STATIC_DIR' ) && is_dir( XSPEED_CACHE_STATIC_DIR ) ) {
404	$static = self::measure_static( XSPEED_CACHE_STATIC_DIR );
405	$buckets['pages_static']['bytes'] = $static['html_bytes'];
406	$buckets['pages_static']['files'] = $static['html_files'];
407	$buckets['precompressed']['bytes'] += $static['br_bytes'];
408	$buckets['precompressed']['files'] += $static['br_files'];
409	}
410
411	$total_bytes = 0;
412	$total_files = 0;
413	$out = array();
414	foreach ( $buckets as $key => $bucket ) {
415	$total_bytes += $bucket['bytes'];
416	$total_files += $bucket['files'];
417	$out[] = array(
418	'key' => $key,
419	'label' => $bucket['label'],
420	'bytes' => $bucket['bytes'],
421	'files' => $bucket['files'],
422	);
423	}
424
425	return array(
426	'buckets' => $out,
427	'total_bytes' => $total_bytes,
428	'total_files' => $total_files,
429	// What a visitor actually downloads for the pages that have a
430	// precompressed copy. Pages without one are served compressed by
431	// the web server at request time, which we cannot measure from
432	// here — so this is a floor, and the UI labels it as one.
433	'compressed_bytes' => $buckets['precompressed']['bytes'],
434	'pages' => $buckets['pages_flat']['files'] + $buckets['pages_static']['files'],
435	);
436	}
437
438	/**
439	* Accumulate a glob into a bucket.
440	*
441	* @param array{label:string,bytes:int,files:int} $bucket By reference.
442	*/
443	private static function add_glob( array &$bucket, string $pattern ): void {
444	foreach ( (array) glob( $pattern ) as $file ) {
445	if ( ! is_string( $file ) ) {
446	continue;
447	}
448	$bucket['bytes'] += (int) @filesize( $file ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Purge race, see scan().
449	++$bucket['files'];
450	}
451	}
452
453	/**
454	* Total the static tree without collecting per-file rows.
455	*
456	* @return array{html_bytes:int,html_files:int,br_bytes:int,br_files:int}
457	*/
458	private static function measure_static( string $dir ): array {
459	$totals = array(
460	'html_bytes' => 0,
461	'html_files' => 0,
462	'br_bytes' => 0,
463	'br_files' => 0,
464	);
465	$entries = @scandir( $dir, SCANDIR_SORT_NONE ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Unreadable subdir contributes nothing rather than fataling.
466	if ( false === $entries ) {
467	return $totals;
468	}
469
470	foreach ( $entries as $entry ) {
471	if ( '.' === $entry \|\| '..' === $entry ) {
472	continue;
473	}
474	$path = $dir . '/' . $entry;
475	if ( is_dir( $path ) ) {
476	$sub = self::measure_static( $path );
477	foreach ( $totals as $k => $v ) {
478	$totals[ $k ] = $v + $sub[ $k ];
479	}
480	continue;
481	}
482	if ( 'index.html' === $entry ) {
483	$totals['html_bytes'] += (int) @filesize( $path ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Purge race, see scan().
484	++$totals['html_files'];
485	} elseif ( substr( $entry, -3 ) === '.br' ) {
486	$totals['br_bytes'] += (int) @filesize( $path ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Purge race, see scan().
487	++$totals['br_files'];
488	}
489	}
490
491	return $totals;
492	}
493
494	/**
495	* Filter the activity log down to purge events.
496	*
497	* The log already carries the cause in its message ("post saved",
498	* "settings change", "manual"), which is the whole point of the
499	* drill-down: "Last purge — 4h ago" is trivia until you can see that it
500	* was a post save rather than something clearing the cache every hour.
501	*
502	* Pure with respect to the entries passed in, so the type filter is
503	* testable without a WordPress transient.
504	*
505	* @param array<int,array<string,mixed>> $entries Activity_Log::entries() output.
506	* @return array<int,array<string,mixed>>
507	*/
508	public static function filter_purges( array $entries, int $limit = 25 ): array {
509	$out = array();
510	foreach ( $entries as $entry ) {
511	$type = isset( $entry['type'] ) ? (string) $entry['type'] : '';
512	if ( ! in_array( $type, self::PURGE_TYPES, true ) ) {
513	continue;
514	}
515	$out[] = array(
516	'ts' => (int) ( $entry['ts'] ?? 0 ),
517	'type' => $type,
518	'message' => (string) ( $entry['message'] ?? '' ),
519	'severity' => (string) ( $entry['severity'] ?? 'info' ),
520	);
521	if ( count( $out ) >= $limit ) {
522	break;
523	}
524	}
525	return $out;
526	}
527
528	/**
529	* The last-purge drill-down.
530	*
531	* `last_gc` / `gc_removed` / `gc_removed_total` come from the daily
532	* `xspeed_gc` sweep (Cache_GC) so the collector is verifiable from the
533	* dashboard instead of over SSH.
534	*
535	* @return array{events:array<int,array<string,mixed>>,last_purge:int,last_gc:int,gc_removed:int,gc_removed_total:int,gc_next_run:int}
536	*/
537	public static function purge_log( int $limit = 25 ): array {
538	$limit = max( 1, min( 50, $limit ) );
539	$events = self::filter_purges( Activity_Log::entries(), $limit );
540	$stats = get_option( 'xspeed_stats', array() );
541	$stats = is_array( $stats ) ? $stats : array();
542
543	return array(
544	'events' => $events,
545	'last_purge' => (int) ( $stats['last_purge'] ?? 0 ),
546	'last_gc' => (int) ( $stats['last_gc'] ?? 0 ),
547	'gc_removed' => (int) ( $stats['gc_removed'] ?? 0 ),
548	'gc_removed_total' => (int) ( $stats['gc_removed_total'] ?? 0 ),
549	'gc_next_run' => (int) wp_next_scheduled( Cache_GC::CRON_HOOK ),
550	);
551	}
552
553	/** Drop the memoized scan — called after a purge so the list can't lie. */
554	public static function invalidate(): void {
555	delete_transient( self::TRANSIENT_KEY );
556	}
557	}
558