sqlite-object-cache / includes / class-sqlite-object-cache.php

class-sqlite-object-cache.php in SQLite Object Cache 1.6.3, at includes/class-sqlite-object-cache.php

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1	<?php
2	/**
3	* Main plugin class file.
4	*
5	* @package WordPress Plugin Template/Includes
6	*/
7
8	if ( ! defined( 'ABSPATH' ) ) {
9	exit;
10	}
11
12	/**
13	* Main plugin class.
14	*
15	* Only make one instance of this, please.
16	*/
17	class SQLite_Object_Cache {
18	const CLEAN_EVENT_HOOK = 'sqlite_object_cache_clean';
19
20	/**
21	* Settings class object
22	*
23	* @var object
24	* @access public
25	* @since 1.0.0
26	*/
27	public $settings;
28
29	/**
30	* The version number.
31	*
32	* @var string
33	* @access public
34	* @since 1.0.0
35	*/
36	public $_version;
37
38	/**
39	* The token.
40	*
41	* @var string
42	* @access public
43	* @since 1.0.0
44	*/
45	public $_token;
46
47	/**
48	* The main plugin file.
49	*
50	* @var string
51	* @access public
52	* @since 1.0.0
53	*/
54	public $file;
55
56	/**
57	* The main plugin directory.
58	*
59	* @var string
60	* @access public
61	* @since 1.0.0
62	*/
63	public $dir;
64
65	/**
66	* The plugin assets directory.
67	*
68	* @var string
69	* @access public
70	* @since 1.0.0
71	*/
72	public $assets_dir;
73
74	/**
75	* The plugin assets URL.
76	*
77	* @var string
78	* @access public
79	* @since 1.0.0
80	*/
81	public $assets_url;
82
83	/**
84	* Suffix for JavaScripts.
85	*
86	* @var string
87	* @access public
88	* @since 1.0.0
89	*/
90	public $script_suffix;
91
92	/**
93	* Path for the drop-in when it is working.
94	* @var string
95	*/
96	public $dropinfiledest;
97
98	/**
99	* Path for the drop-in in the plugin tree.
100	* @var string
101	*/
102	public $dropinfilesource;
103
104	/**
105	* Minimum required sqlite version.
106	*
107	* @var string
108	*/
109	public $minimum_sqlite_version = '3.7.0';
110
111	/**
112	* Constructor function.
113	*
114	* @param string $file File constructor.
115	* @param string $version Plugin version.
116	*/
117	public function __construct( $file = '', $version = '1.6.3' ) {
118	$this->_version = $version;
119	$this->_token = 'sqlite_object_cache';
120
121	// Load plugin environment variables.
122	$this->file = $file;
123	$this->dir =
124	trailingslashit( dirname( trailingslashit( WP_PLUGIN_DIR ) . plugin_basename( $this->file ) ) );
125	$this->assets_dir = trailingslashit( $this->dir . 'assets' );
126	$this->dropinfilesource = $this->assets_dir . 'drop-in/object-cache.php';
127	$this->dropinfiledest = trailingslashit( WP_CONTENT_DIR ) . 'object-cache.php';
128
129	$this->assets_url = esc_url( trailingslashit( plugins_url( '/assets/', $this->file ) ) );
130
131	register_activation_hook( $this->file, array( $this, 'on_activation' ) );
132	register_deactivation_hook( $this->file, array( $this, 'on_deactivation' ) );
133
134	if ( is_admin() ) {
135	/* Suppress backups of .sqlite files if possible. */
136	new SQLite_Backup_Exclusion();
137
138	/* Health check */
139	new SQLite_Object_Cache_Opcache();
140
141	add_action( 'admin_notices', function () {
142	$flushed = get_site_transient( 'sqlite-object-cache-flush-on-update' );
143	if ( $flushed ) {
144	delete_site_transient( 'sqlite-object-cache-flush-on-update' );
145	$message = __( 'Flushed the SQLite Object Cache successfully after a software installation or upgrade.', 'sqlite-object-cache' );
146	?>
147	<div class="notice notice-success sqlite-object-cache is-dismissible">
148	<p><?php echo esc_html( $message ); ?></p>
149	</div>
150	<?php
151	}
152	} );
153	}
154
155	add_action( 'admin_init', array( $this, 'maybe_update_dropin' ) );
156
157	/* Ensure nothing is cached after software upgrades. */
158	add_action( 'upgrader_process_complete', function () {
159	add_action( 'shutdown', function () {
160	wp_cache_flush();
161	set_site_transient( 'sqlite-object-cache-flush-on-update', true, HOUR_IN_SECONDS );
162	}, 999 );
163	wp_cache_flush();
164	}, 0 );
165
166
167	/* Handle cron cache cleanup */
168	add_action( self::CLEAN_EVENT_HOOK, array( $this, 'clean_job' ), 10, 0 );
169	if ( ! wp_next_scheduled( self::CLEAN_EVENT_HOOK ) ) {
170	wp_schedule_event( time() + HOUR_IN_SECONDS, 'hourly', self::CLEAN_EVENT_HOOK );
171	}
172	/* Handle probabilistic non-cron cleanup, one request in 2500. */
173	/* We don't need cryptographic-grade random numbering here. */
174	// phpcs:ignore WordPress.WP.AlternativeFunctions.rand_rand
175	if ( 1 === rand( 1, 2500 ) ) {
176	add_action( 'shutdown', function () {
177	$this->clean_job( 1.25 );
178	}, 999, 0 );
179	}
180
181	/* Admin bar flush button - works on both frontend and backend. */
182	$option = get_option( $this->_token . '_settings', array() );
183	if ( array_key_exists ('adminbarflush', $option ) && 'on' === $option['adminbarflush'] ) {
184	add_action( 'init', array( $this, 'handle_admin_bar_flush' ) );
185	add_action ( 'init', function() {
186	if ( ! ( is_multisite() && ! is_main_site() ) && current_user_can( 'manage_options') ) {
187	add_action( 'admin_bar_menu', array( $this, 'admin_bar_flush_button' ), 100 );
188	add_action( 'admin_notices', array( $this, 'maybe_show_flush_notice' ) );
189	}
190	});
191	}
192	}
193
194	/**
195	* WP_Cron task to clean cache entries.
196	*
197	* @param float $grace_factor Default 1.0
198	*
199	* @return void
200	*/
201	public function clean_job( $grace_factor = 1.0 ) {
202	$option = get_option( $this->_token . '_settings', array() );
203	$target_size = empty ( $option['target_size'] ) ? 16 : $option['target_size'];
204	$target_size = ( 1024 1024 );
205	$threshold_size = (int) ( $target_size * $grace_factor );
206
207	global $wp_object_cache;
208	if ( ! method_exists( $wp_object_cache, 'sqlite_get_size' ) ) {
209	return;
210	}
211	/* Clean up old statistics. Do this even when the cache is not over size. */
212	$retention = empty ( $option['retainmeasurements'] ) ? 24 : $option['retainmeasurements'];
213	$wp_object_cache->sqlite_reset_statistics( $retention * HOUR_IN_SECONDS );
214
215	$current_size = $wp_object_cache->sqlite_get_size();
216	/* Skip this if the current size is small enough. */
217	if ( $current_size <= $threshold_size ) {
218	return;
219	}
220
221	/* Remove expired items (transients mostly). */
222	if ( $wp_object_cache->sqlite_remove_expired() ) {
223	/* If anything was removed, get the size again. */
224	$current_size = $wp_object_cache->sqlite_get_size();
225	}
226
227	/* Skip this if the size is small enough, after removing expired items. */
228	if ( $current_size <= $threshold_size ) {
229	return;
230	}
231
232	/* Delete the least-recently-updated items to get to the target size. */
233	$wp_object_cache->sqlite_delete_old( $target_size, $current_size );
234	}
235
236	/**
237	* Plugin activation hook
238	*
239	* @return void
240	*/
241	public function on_activation() {
242
243	$this->sync_apcu_global_to_option( true );
244	if ( true === $this->has_sqlite() ) {
245	add_action( 'shutdown', array( $this, 'update_dropin' ) );
246	add_action( 'shutdown', array( $this, 'delete_all_transients_from_db' ) );
247	}
248	}
249
250	/**
251	* Determine whether we can use SQLite3.
252	*
253	* @return bool\|string true, or an error message.
254	*/
255	public function has_sqlite() {
256	if ( ! class_exists( 'SQLite3' ) \|\| ! extension_loaded( 'sqlite3' ) ) {
257	return __( 'You cannot use the SQLite Object Cache plugin. Your server does not have php\'s SQLite3 extension installed.', 'sqlite-object-cache' );
258	}
259
260	$sqlite_version = $this->sqlite_get_version();
261	if ( version_compare( $sqlite_version, $this->minimum_sqlite_version ) < 0 ) {
262	return sprintf(
263	/* translators: 1 actual SQLite version. 2 required SQLite version) */
264	__( 'You cannot use the SQLite Object Cache plugin. Your server only offers SQLite3 version %1$s, but at least %2$s is required.', 'sqlite-object-cache' ),
265	$sqlite_version, $this->minimum_sqlite_version );
266	}
267
268	return true;
269	}
270
271	/**
272	* Get the version number for the SQLite extension.
273	*
274	* @return string\|false SQLite's version number.
275	*/
276	public function sqlite_get_version() {
277
278	if ( class_exists( 'SQLite3' ) ) {
279	$version = SQLite3::version();
280
281	return $version['versionString'];
282	}
283
284	return false;
285	}
286
287	/**
288	* Test if we can write in the WP_CONTENT_DIR and modify the `object-cache.php` drop-in
289	*
290	* @return true\|WP_Error
291	* @author Till Krüss
292	*
293	*/
294	public function test_filesystem_writing() {
295	global $wp_filesystem;
296
297	if ( ! $this->initialize_filesystem( '', true ) ) {
298	return new WP_Error( 'fs', __( 'Could not initialize filesystem.', 'sqlite-object-cache' ) );
299	}
300
301	$testfiledest = WP_CONTENT_DIR . '/sqlite-write-test.tmp';
302
303	if ( ! $wp_filesystem->exists( $this->dropinfilesource ) ) {
304	return new WP_Error( 'exists', __( 'Object cache drop-in file doesn’t exist.', 'sqlite-object-cache' ) );
305	}
306
307	if ( $wp_filesystem->exists( $testfiledest ) && ! $wp_filesystem->delete( $testfiledest ) ) {
308	return new WP_Error( 'delete', __( 'Test file exists, but couldn’t be deleted.', 'sqlite-object-cache' ) );
309	}
310
311	if ( ! $wp_filesystem->is_writable( WP_CONTENT_DIR ) ) {
312	return new WP_Error( 'copy', __( 'Content directory is not writable.', 'sqlite-object-cache' ) );
313	}
314
315	if ( ! $wp_filesystem->copy( $this->dropinfilesource, $testfiledest, true, FS_CHMOD_FILE ) ) {
316	return new WP_Error( 'copy', __( 'Failed to copy test file.', 'sqlite-object-cache' ) );
317	}
318
319	if ( ! $wp_filesystem->exists( $testfiledest ) ) {
320	return new WP_Error( 'exists', __( 'Copied test file doesn’t exist.', 'sqlite-object-cache' ) );
321	}
322
323	$meta = get_file_data( $testfiledest, array( 'Version' => 'Version' ) );
324
325	if ( $meta['Version'] !== $this->_version ) {
326	return new WP_Error( 'version', __( 'Couldn’t verify test file contents.', 'sqlite-object-cache' ) );
327	}
328
329	if ( ! $wp_filesystem->delete( $testfiledest ) ) {
330	return new WP_Error( 'delete', __( 'Copied test file couldn’t be deleted.', 'sqlite-object-cache' ) );
331	}
332
333	return true;
334	}
335
336	/**
337	* Initializes the WP filesystem API to be ready for use
338	*
339	* @param string $url The URL to post the form to.
340	* @param bool $silent Whether to ask the user for credentials if necessary or not.
341	*
342	* @return bool
343	* @author Till Krüss
344	*
345	*/
346	public function initialize_filesystem( $url, $silent = false ) {
347	require_once ABSPATH . 'wp-admin/includes/file.php';
348	if ( $silent ) {
349	ob_start();
350	}
351
352	$credentials = request_filesystem_credentials( $url );
353
354	if ( false === $credentials ) {
355	if ( $silent ) {
356	ob_end_clean();
357	}
358
359	return false;
360	}
361
362	if ( ! WP_Filesystem( $credentials ) ) {
363	request_filesystem_credentials( $url );
364
365	if ( $silent ) {
366	ob_end_clean();
367	}
368
369	return false;
370	}
371
372	return true;
373	}
374
375	/**
376	* Calls the drop-in update method if necessary
377	*
378	* @return void
379	* @author Till Krüss
380	*/
381	public function maybe_update_dropin() {
382	if ( defined( 'WP_SQLITE_OBJECT_CACHE_DISABLE_DROPIN_AUTOUPDATE' ) && WP_SQLITE_OBJECT_CACHE_DISABLE_DROPIN_AUTOUPDATE ) {
383	return;
384	}
385
386	$has = $this->has_sqlite();
387	if ( ( true === $has ) && $this->object_cache_dropin_needs_updating() ) {
388	add_action( 'shutdown', array( $this, 'update_dropin' ) );
389	}
390	}
391
392	/**
393	* Checks if the `object-cache.php` drop-in is outdated
394	* @return bool
395	* @author Till Krüss
396	*
397	*/
398	public function object_cache_dropin_needs_updating() {
399	global $wp_object_cache;
400	if ( ! method_exists( $wp_object_cache, 'dropin_get_version' ) ) {
401	return true;
402	}
403	return version_compare( $wp_object_cache->dropin_get_version(), $this->_version, '<' );
404	}
405
406	/**
407	* Updates the `object-cache.php` drop-in
408	*
409	* @return void
410	* @author Till Krüss
411	*/
412	public function update_dropin() {
413	global $wp_filesystem;
414	$has = $this->has_sqlite();
415	if ( true === $has && $this->initialize_filesystem( '', true ) ) {
416
417	$this->delete_sqlite_files();
418	$result = $wp_filesystem->copy( $this->dropinfilesource, $this->dropinfiledest, true, FS_CHMOD_FILE );
419	/**
420	* Fires on cache enable event
421	*
422	* @param bool $result Whether the filesystem event (copy of the `object-cache.php` file) was successful.
423	*
424	* @since 0.1.0
425	*/
426	do_action( 'sqlite_object_cache_update_dropin', $result );
427	}
428	}
429
430	/**
431	* Validates the `object-cache.php` drop-in
432	*
433	* @return bool
434	* @author Till Krüss
435	*/
436	public function validate_object_cache_dropin() {
437	global $wp_object_cache;
438
439	if ( ! method_exists( $wp_object_cache, 'dropin_get_version' ) ) {
440	return false;
441	}
442
443	$dropin = get_plugin_data( $this->dropinfiledest );
444	$plugin = get_plugin_data( $this->dropinfilesource );
445
446	/**
447	* Filters the drop-in validation state
448	*
449	* @param bool $state The validation state of the drop-in.
450	* @param string $dropin The `PluginURI` of the drop-in.
451	* @param string $plugin The `PluginURI` of the plugin.
452	*
453	* @since 2.0.16
454	*/
455	return apply_filters(
456	'sqlite_object_cache_validate_dropin',
457	$dropin['PluginURI'] === $plugin['PluginURI'],
458	$dropin['PluginURI'],
459	$plugin['PluginURI']
460	);
461	}
462
463	/**
464	* Plugin deactivation hook
465	*
466	* @param string $plugin Plugin basename.
467	*
468	* @return void
469	* @author Till Krüss
470	*/
471	public function on_deactivation( $plugin ) {
472
473	wp_cache_flush();
474
475	wp_unschedule_hook( self::CLEAN_EVENT_HOOK );
476	$this->delete_sqlite_files();
477	$this->delete_dropin();
478	$this->delete_all_transients_from_db();
479	}
480
481	private function delete_sqlite_files() {
482	global $wp_filesystem;
483	global $wp_object_cache;
484
485	if ( method_exists( $wp_object_cache, 'sqlite_files' ) ) {
486	if ( $this->initialize_filesystem( '', true ) ) {
487	foreach ( $wp_object_cache->sqlite_files() as $file ) {
488	$wp_filesystem->delete( $file );
489	}
490	}
491	}
492	}
493
494	private function delete_dropin() {
495	global $wp_filesystem;
496	ob_start();
497
498	if ( $this->validate_object_cache_dropin() && $this->initialize_filesystem( '', true ) ) {
499	$wp_filesystem->delete( $this->dropinfiledest );
500	}
501
502	ob_end_clean();
503	}
504
505	/**
506	* Deletes all transients from the database.
507	*
508	* It is necessary to do this when deactivating a persistent object cache
509	* because the transients are kept there, and the ones in the database are
510	* possibly stale.
511	*
512	* This hammers performance. But deactivating a persistent object cache is
513	* not a common operation.
514	*
515	* @global wpdb $wpdb WordPress database abstraction object.
516	*/
517	public function delete_all_transients_from_db() {
518	global $wpdb;
519	if ( ! is_multisite() ) {
520	$this->clear_blog_transients();
521	// Single site stores site transients in the options table.
522	$this->clear_blog_transients( '_site_transient_' );
523	} else {
524	foreach ( get_sites( array( 'number' => 0, 'fields' => 'ids', 'no_found_rows' => true, 'orderby' => false ) ) as $site_id ) {
525	try {
526	switch_to_blog( $site_id );
527	$this->clear_blog_transients();
528	} catch ( Exception $ex ) {
529	/* Empty, intentionally. Don't crash clearing transients. */
530	} finally {
531	restore_current_blog();
532	}
533	}
534	// Multisite stores site transients in the sitemeta table.
535	// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
536	$wpdb->query(
537	$wpdb->prepare(
538	"DELETE FROM {$wpdb->sitemeta} WHERE a.meta_key LIKE %s",
539	$wpdb->esc_like( '_site_transient_' ) . '%'
540	)
541	);
542
543	}
544	}
545
546	/**
547	* DELETE transients from the current blog's options table.
548	*
549	* @param string $tag _site_transient_ or _transient_, the default.
550	*
551	* @return void
552	*/
553	private function clear_blog_transients( $tag = '_transient_') {
554	global $wpdb;
555	// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
556	$wpdb->query(
557	$wpdb->prepare(
558	"DELETE FROM {$wpdb->options} WHERE option_name LIKE %s",
559	$wpdb->esc_like( $tag ) . '%'
560	)
561	);
562	}
563
564	/**
565	* @return bool True if APCu support is activated for this plugin.
566	*/
567	public function apcu_is_activated() {
568	return defined( 'WP_SQLITE_OBJECT_CACHE_APCU' ) && WP_SQLITE_OBJECT_CACHE_APCU
569	&& $this->apcu_extension_is_enabled();
570	}
571
572	/**
573	* @return bool True if the APCu extension is loaded and enabled.
574	*/
575	public function apcu_extension_is_enabled() {
576	return function_exists( 'apcu_enabled' ) && apcu_enabled();
577	}
578
579	/**
580	* Make sure WP_SQLITE_OBJECT_CACHE_APCU and $option['use_apcu'] match.
581	*
582	* @param bool $unconditional true if we should always change the option to match WP_SQLITE_OBJECT_CACHE_APCU.
583	*
584	* @return string 'on' or 'off': the current activation state of epcu.
585	*/
586	public function sync_apcu_global_to_option( $unconditional = true ) {
587	global $wp_object_cache;
588	$option = get_option( $this->_token . '_settings', array() );
589	$option_dirty = false;
590	$updated_flag = array_key_exists( 'use_apcu_updated', $option );
591	$use_apcu = array_key_exists( 'use_apcu', $option ) && 'on' === $option['use_apcu'] ? 'on' : 'off';
592	if ( $updated_flag ) {
593	unset ( $option['use_apcu_updated'] );
594	$option_dirty = true;
595	}
596	$target_use_apcu = $this->apcu_is_activated() ? 'on' : 'off';
597	if ( ! $unconditional && $updated_flag ) {
598	$target_use_apcu = $use_apcu;
599	}
600	if ( $target_use_apcu !== $use_apcu ) {
601	$option['use_apcu'] = $target_use_apcu;
602	$option_dirty = true;
603	}
604	if ( $option_dirty ) {
605	if ( method_exists( $wp_object_cache, 'apcu-clear_cache' ) ) {
606	$wp_object_cache->apcu_clear_cache();
607	}
608	update_option( $this->_token . '_settings', $option, true );
609	}
610
611	return $target_use_apcu;
612	}
613
614	/**
615	* Add a flush button to the admin bar.
616	*
617	* @param WP_Admin_Bar $wp_admin_bar The admin bar instance.
618	*
619	* @return void
620	*/
621	public function admin_bar_flush_button( $wp_admin_bar ) {
622	if ( ! is_admin_bar_showing() ) {
623	return;
624	}
625
626	if ( ! current_user_can( 'manage_options' ) ) {
627	return;
628	}
629
630	// Only show on main site for multisite installations.
631	if ( is_multisite() && ! is_main_site() ) {
632	return;
633	}
634
635	$flush_url = add_query_arg(
636	array( 'sqlite_object_cache_action' => 'flush' ),
637	remove_query_arg( 'sqlite_object_cache_action' )
638	);
639	$nonced_url = wp_nonce_url( $flush_url, 'sqlite_object_cache_flush' );
640
641	$wp_admin_bar->add_node(
642	array(
643	'id' => 'sqlite-object-cache-flush',
644	'title' => __( 'Flush Object Cache', 'sqlite-object-cache' ),
645	'href' => $nonced_url,
646	'meta' => array(
647	'title' => __( 'Delete all object cache entries now, including all transients.', 'sqlite-object-cache' ),
648	),
649	)
650	);
651	}
652
653	/**
654	* Handle the admin bar flush action.
655	*
656	* @return void
657	*/
658	public function handle_admin_bar_flush() {
659	if ( ! isset( $_GET['sqlite_object_cache_action'] ) ) {
660	return;
661	}
662
663	$action = sanitize_key( wp_unslash( $_GET['sqlite_object_cache_action'] ) );
664
665	if ( 'flush' !== $action ) {
666	return;
667	}
668
669	if ( ! current_user_can( 'manage_options' ) ) {
670	wp_die( esc_html__( 'You do not have permission to flush the object cache.', 'sqlite-object-cache' ) );
671	}
672
673	// Only allow flush on main site for multisite installations (matches button visibility).
674	if ( is_multisite() && ! is_main_site() ) {
675	wp_die( esc_html__( 'Cache flush is only available on the main site.', 'sqlite-object-cache' ) );
676	}
677
678	check_admin_referer( 'sqlite_object_cache_flush' );
679
680	wp_cache_flush();
681
682	// Use a user-specific transient so only the initiating user sees the flush notice (applies to both single-site and multisite).
683	$transient_key = 'sqlite_object_cache_flushed_' . get_current_user_id();
684	set_transient( $transient_key, true, 30 );
685
686	$referer = wp_get_referer();
687	if ( $referer ) {
688	$redirect_url = $referer;
689	} else {
690	$redirect_url = is_admin() ? admin_url() : home_url();
691	}
692	// Remove action and nonce query parameters from URL.
693	$redirect_url = remove_query_arg( array( 'sqlite_object_cache_action', '_wpnonce' ), $redirect_url );
694
695	wp_safe_redirect( $redirect_url );
696	exit;
697	}
698
699	/**
700	* Check for flush transient and show notice if set.
701	*
702	* @return void
703	*/
704	public function maybe_show_flush_notice() {
705	$transient_key = 'sqlite_object_cache_flushed_' . get_current_user_id();
706	if ( get_transient( $transient_key ) ) {
707	delete_transient( $transient_key );
708	$this->show_flush_notice();
709	}
710	}
711
712	/**
713	* Display a notice when the object cache was flushed via admin bar.
714	*
715	* @return void
716	*/
717	public function show_flush_notice() {
718	?>
719	<div class="notice notice-success sqlite-object-cache is-dismissible">
720	<p><?php esc_html_e( 'SQLite Object Cache flushed successfully.', 'sqlite-object-cache' ); ?></p>
721	</div>
722	<?php
723	}
724
725	}
726