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

class-sqlite-object-cache.php in SQLite Object Cache 1.5.5, 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	* Local instance of SQLite_Object_Cache_Admin_API
22	*
23	* @var SQLite_Object_Cache_Admin_API\|null
24	*/
25	public $admin;
26
27	/**
28	* Settings class object
29	*
30	* @var object
31	* @access public
32	* @since 1.0.0
33	*/
34	public $settings;
35
36	/**
37	* The version number.
38	*
39	* @var string
40	* @access public
41	* @since 1.0.0
42	*/
43	public $_version;
44
45	/**
46	* The token.
47	*
48	* @var string
49	* @access public
50	* @since 1.0.0
51	*/
52	public $_token;
53
54	/**
55	* The main plugin file.
56	*
57	* @var string
58	* @access public
59	* @since 1.0.0
60	*/
61	public $file;
62
63	/**
64	* The main plugin directory.
65	*
66	* @var string
67	* @access public
68	* @since 1.0.0
69	*/
70	public $dir;
71
72	/**
73	* The plugin assets directory.
74	*
75	* @var string
76	* @access public
77	* @since 1.0.0
78	*/
79	public $assets_dir;
80
81	/**
82	* The plugin assets URL.
83	*
84	* @var string
85	* @access public
86	* @since 1.0.0
87	*/
88	public $assets_url;
89
90	/**
91	* Suffix for JavaScripts.
92	*
93	* @var string
94	* @access public
95	* @since 1.0.0
96	*/
97	public $script_suffix;
98
99	/**
100	* Path for the drop-in when it is working.
101	* @var string
102	*/
103	public $dropinfiledest;
104
105	/**
106	* Path for the drop-in in the plugin tree.
107	* @var string
108	*/
109	public $dropinfilesource;
110
111	/**
112	* Minimum required sqlite version.
113	*
114	* @var string
115	*/
116	public $minimum_sqlite_version = '3.7.0';
117
118	/**
119	* Constructor function.
120	*
121	* @param string $file File constructor.
122	* @param string $version Plugin version.
123	*/
124	public function __construct( $file = '', $version = '1.5.5' ) {
125	$this->_version = $version;
126	$this->_token = 'sqlite_object_cache';
127
128	// Load plugin environment variables.
129	$this->file = $file;
130	$this->dir =
131	trailingslashit( dirname( WP_CONTENT_DIR . '/plugins/' . plugin_basename( $this->file ) ) );
132	$this->assets_dir = trailingslashit( $this->dir . 'assets' );
133	$this->dropinfilesource = $this->assets_dir . 'drop-in/object-cache.php';
134	$this->dropinfiledest = trailingslashit( WP_CONTENT_DIR ) . 'object-cache.php';
135
136	$this->assets_url = esc_url( trailingslashit( plugins_url( '/assets/', $this->file ) ) );
137
138	$this->script_suffix = defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ? '' : '.min';
139
140	register_activation_hook( $this->file, array( $this, 'on_activation' ) );
141	register_deactivation_hook( $this->file, array( $this, 'on_deactivation' ) );
142
143	if ( is_admin() ) {
144	// Load API for generic admin functions.
145	$this->admin = new SQLite_Object_Cache_Admin_API();
146	// Suppress backups
147	new SQLite_Backup_Exclusion();
148	}
149
150	add_action( 'admin_init', array( $this, 'maybe_update_dropin' ) );
151
152	/* handle cron cache cleanup */
153	add_action( self::CLEAN_EVENT_HOOK, array( $this, 'clean_job' ), 10, 0 );
154	if ( ! wp_next_scheduled( self::CLEAN_EVENT_HOOK ) ) {
155	wp_schedule_event( time() + HOUR_IN_SECONDS, 'hourly', self::CLEAN_EVENT_HOOK );
156	}
157	/* Handle probabilistic non-cron cleanup, one request in 2000. */
158	if ( 1 === rand( 1, 2000 ) ) {
159	add_action( 'shutdown', function () {
160	$this->clean_job( 1.25 );
161	}, 999, 0 );
162	}
163	}
164
165	/**
166	* WP_Cron task to clean cache entries.
167	*
168	* @param float $grace_factor Default 1.0
169	*
170	* @return void
171	*/
172	public function clean_job( $grace_factor = 1.0 ) {
173	$option = get_option( $this->_token . '_settings', array() );
174	$target_size = empty ( $option['target_size'] ) ? 16 : $option['target_size'];
175	$target_size = ( 1024 1024 );
176	$threshold_size = (int) ( $target_size * $grace_factor );
177
178	global $wp_object_cache;
179	if ( ! method_exists( $wp_object_cache, 'sqlite_get_size' ) ) {
180	return;
181	}
182	/* Clean up old statistics. Do this even when the cache is not over size. */
183	$retention = empty ( $option['retainmeasurements'] ) ? 24 : $option['retainmeasurements'];
184	$wp_object_cache->sqlite_reset_statistics( $retention * HOUR_IN_SECONDS );
185
186	$current_size = $wp_object_cache->sqlite_get_size();
187	/* Skip this if the current size is small enough. */
188	if ( $current_size <= $threshold_size ) {
189	return;
190	}
191
192	/* Remove expired items (transients mostly). */
193	if ( $wp_object_cache->sqlite_remove_expired() ) {
194	/* If anything was removed, get the size again. */
195	$current_size = $wp_object_cache->sqlite_get_size();
196	}
197
198	/* Skip this if the size is small enough, after removing expired items. */
199	if ( $current_size <= $threshold_size ) {
200	return;
201	}
202
203	/* Delete the least-recently-updated items to get to the target size. */
204	$wp_object_cache->sqlite_delete_old( $target_size, $current_size );
205	}
206
207	/**
208	* Plugin activation hook
209	*
210	* @return void
211	*/
212	public function on_activation() {
213
214	$this->sync_apcu_global_to_option( true );
215	if ( true === $this->has_sqlite() ) {
216	add_action( 'shutdown', array( $this, 'update_dropin' ) );
217	}
218	}
219
220	/**
221	* Determine whether we can use SQLite3.
222	*
223	* @return bool\|string true, or an error message.
224	*/
225	public function has_sqlite() {
226	if ( ! class_exists( 'SQLite3' ) \|\| ! extension_loaded( 'sqlite3' ) ) {
227	return __( 'You cannot use the SQLite Object Cache plugin. Your server does not have php\'s SQLite3 extension installed.', 'sqlite-object-cache' );
228	}
229
230	$sqlite_version = $this->sqlite_get_version();
231	if ( version_compare( $sqlite_version, $this->minimum_sqlite_version ) < 0 ) {
232	return sprintf(
233	/* translators: 1 actual SQLite version. 2 required SQLite version) */
234	__( 'You cannot use the SQLite Object Cache plugin. Your server only offers SQLite3 version %1$s, but at least %2$s is required.', 'sqlite-object-cache' ),
235	$sqlite_version, $this->minimum_sqlite_version );
236	}
237
238	return true;
239	}
240
241	/**
242	* Get the version number for the SQLite extension.
243	*
244	* @return string\|false SQLite's version number.
245	*/
246	public function sqlite_get_version() {
247
248	if ( class_exists( 'SQLite3' ) ) {
249	$version = SQLite3::version();
250
251	return $version['versionString'];
252	}
253
254	return false;
255	}
256
257	/**
258	* Test if we can write in the WP_CONTENT_DIR and modify the `object-cache.php` drop-in
259	*
260	* @return true\|WP_Error
261	* @author Till Krüss
262	*
263	*/
264	public function test_filesystem_writing() {
265	global $wp_filesystem;
266
267	if ( ! $this->initialize_filesystem( '', true ) ) {
268	return new WP_Error( 'fs', __( 'Could not initialize filesystem.', 'sqlite-object-cache' ) );
269	}
270
271	$testfiledest = WP_CONTENT_DIR . '/sqlite-write-test.tmp';
272
273	if ( ! $wp_filesystem->exists( $this->dropinfilesource ) ) {
274	return new WP_Error( 'exists', __( 'Object cache drop-in file doesn’t exist.', 'sqlite-object-cache' ) );
275	}
276
277	if ( $wp_filesystem->exists( $testfiledest ) && ! $wp_filesystem->delete( $testfiledest ) ) {
278	return new WP_Error( 'delete', __( 'Test file exists, but couldn’t be deleted.', 'sqlite-object-cache' ) );
279	}
280
281	if ( ! $wp_filesystem->is_writable( WP_CONTENT_DIR ) ) {
282	return new WP_Error( 'copy', __( 'Content directory is not writable.', 'sqlite-object-cache' ) );
283	}
284
285	if ( ! $wp_filesystem->copy( $this->dropinfilesource, $testfiledest, true, FS_CHMOD_FILE ) ) {
286	return new WP_Error( 'copy', __( 'Failed to copy test file.', 'sqlite-object-cache' ) );
287	}
288
289	if ( ! $wp_filesystem->exists( $testfiledest ) ) {
290	return new WP_Error( 'exists', __( 'Copied test file doesn’t exist.', 'sqlite-object-cache' ) );
291	}
292
293	$meta = get_file_data( $testfiledest, array( 'Version' => 'Version' ) );
294
295	if ( $meta['Version'] !== $this->_version ) {
296	return new WP_Error( 'version', __( 'Couldn’t verify test file contents.', 'sqlite-object-cache' ) );
297	}
298
299	if ( ! $wp_filesystem->delete( $testfiledest ) ) {
300	return new WP_Error( 'delete', __( 'Copied test file couldn’t be deleted.', 'sqlite-object-cache' ) );
301	}
302
303	return true;
304	}
305
306	/**
307	* Initializes the WP filesystem API to be ready for use
308	*
309	* @param string $url The URL to post the form to.
310	* @param bool $silent Whether to ask the user for credentials if necessary or not.
311	*
312	* @return bool
313	* @author Till Krüss
314	*
315	*/
316	public function initialize_filesystem( $url, $silent = false ) {
317	require_once ABSPATH . 'wp-admin/includes/file.php';
318	if ( $silent ) {
319	ob_start();
320	}
321
322	$credentials = request_filesystem_credentials( $url );
323
324	if ( false === $credentials ) {
325	if ( $silent ) {
326	ob_end_clean();
327	}
328
329	return false;
330	}
331
332	if ( ! WP_Filesystem( $credentials ) ) {
333	request_filesystem_credentials( $url );
334
335	if ( $silent ) {
336	ob_end_clean();
337	}
338
339	return false;
340	}
341
342	return true;
343	}
344
345	/**
346	* Calls the drop-in update method if necessary
347	*
348	* @return void
349	* @author Till Krüss
350	*/
351	public function maybe_update_dropin() {
352	if ( defined( 'WP_SQLITE_OBJECT_CACHE_DISABLE_DROPIN_AUTOUPDATE' ) && WP_SQLITE_OBJECT_CACHE_DISABLE_DROPIN_AUTOUPDATE ) {
353	return;
354	}
355
356	$has = $this->has_sqlite();
357	if ( ( true === $has ) && $this->object_cache_dropin_needs_updating() ) {
358	add_action( 'shutdown', array( $this, 'update_dropin' ) );
359	}
360	}
361
362	/**
363	* Checks if the `object-cache.php` drop-in is outdated
364	* @return bool
365	* @author Till Krüss
366	*
367	*/
368	public function object_cache_dropin_needs_updating() {
369	global $wp_object_cache;
370	if ( ! method_exists( $wp_object_cache, 'dropin_get_version' ) ) {
371	return true;
372	}
373	return version_compare( $wp_object_cache->dropin_get_version(), $this->_version, '<' );
374	}
375
376	/**
377	* Updates the `object-cache.php` drop-in
378	*
379	* @return void
380	* @author Till Krüss
381	*/
382	public function update_dropin() {
383	global $wp_filesystem;
384	$has = $this->has_sqlite();
385	if ( true === $has && $this->initialize_filesystem( '', true ) ) {
386
387	$this->delete_sqlite_files();
388	$result = $wp_filesystem->copy( $this->dropinfilesource, $this->dropinfiledest, true, FS_CHMOD_FILE );
389	/**
390	* Fires on cache enable event
391	*
392	* @param bool $result Whether the filesystem event (copy of the `object-cache.php` file) was successful.
393	*
394	* @since 0.1.0
395	*/
396	do_action( 'sqlite_object_cache_update_dropin', $result );
397	}
398	}
399
400	/**
401	* Validates the `object-cache.php` drop-in
402	*
403	* @return bool
404	* @author Till Krüss
405	*/
406	public function validate_object_cache_dropin() {
407	global $wp_object_cache;
408
409	if ( ! method_exists( $wp_object_cache, 'dropin_get_version' ) ) {
410	return false;
411	}
412
413	$dropin = get_plugin_data( $this->dropinfiledest );
414	$plugin = get_plugin_data( $this->dropinfilesource );
415
416	/**
417	* Filters the drop-in validation state
418	*
419	* @param bool $state The validation state of the drop-in.
420	* @param string $dropin The `PluginURI` of the drop-in.
421	* @param string $plugin The `PluginURI` of the plugin.
422	*
423	* @since 2.0.16
424	*/
425	return apply_filters(
426	'sqlite_object_cache_validate_dropin',
427	$dropin['PluginURI'] === $plugin['PluginURI'],
428	$dropin['PluginURI'],
429	$plugin['PluginURI']
430	);
431	}
432
433	/**
434	* Plugin deactivation hook
435	*
436	* @param string $plugin Plugin basename.
437	*
438	* @return void
439	* @author Till Krüss
440	*/
441	public function on_deactivation( $plugin ) {
442
443	wp_cache_flush();
444
445	wp_unschedule_hook( self::CLEAN_EVENT_HOOK );
446	$this->delete_sqlite_files();
447	$this->delete_dropin();
448	}
449
450	private function delete_sqlite_files() {
451	global $wp_filesystem;
452	global $wp_object_cache;
453
454	if ( method_exists( $wp_object_cache, 'sqlite_files' ) ) {
455	if ( $this->initialize_filesystem( '', true ) ) {
456	foreach ( $wp_object_cache->sqlite_files() as $file ) {
457	$wp_filesystem->delete( $file );
458	}
459	}
460	}
461	}
462
463	private function delete_dropin() {
464	global $wp_filesystem;
465	ob_start();
466
467	if ( $this->validate_object_cache_dropin() && $this->initialize_filesystem( '', true ) ) {
468	$wp_filesystem->delete( $this->dropinfiledest );
469	}
470
471	ob_end_clean();
472	}
473
474	/**
475	* @return bool True if APCu support is activated for this plugin.
476	*/
477	public function apcu_is_activated() {
478	return defined( 'WP_SQLITE_OBJECT_CACHE_APCU' ) && WP_SQLITE_OBJECT_CACHE_APCU
479	&& $this->apcu_extension_is_enabled();
480	}
481
482	/**
483	* @return bool True if the APCu extension is loaded and enabled.
484	*/
485	public function apcu_extension_is_enabled() {
486	return function_exists( 'apcu_enabled' ) && apcu_enabled();
487	}
488
489	/**
490	* Make sure WP_SQLITE_OBJECT_CACHE_APCU and $option['use_apcu'] match.
491	*
492	* @param bool $unconditional true if we should always change the option to match WP_SQLITE_OBJECT_CACHE_APCU.
493	*
494	* @return string 'on' or 'off': the current activation state of epcu.
495	*/
496	public function sync_apcu_global_to_option( $unconditional = true ) {
497	global $wp_object_cache;
498	$option = get_option( $this->_token . '_settings', array() );
499	$option_dirty = false;
500	$updated_flag = array_key_exists( 'use_apcu_updated', $option );
501	$use_apcu = array_key_exists( 'use_apcu', $option ) && 'on' === $option['use_apcu'] ? 'on' : 'off';
502	if ( $updated_flag ) {
503	unset ( $option['use_apcu_updated'] );
504	$option_dirty = true;
505	}
506	$target_use_apcu = $this->apcu_is_activated() ? 'on' : 'off';
507	if ( ! $unconditional && $updated_flag ) {
508	$target_use_apcu = $use_apcu;
509	}
510	if ( $target_use_apcu !== $use_apcu ) {
511	$option['use_apcu'] = $target_use_apcu;
512	$option_dirty = true;
513	}
514	if ( $option_dirty ) {
515	if ( method_exists( $wp_object_cache, 'apcu-clear_cache' ) ) {
516	$wp_object_cache->apcu_clear_cache();
517	}
518	update_option( $this->_token . '_settings', $option, true );
519	}
520
521	return $target_use_apcu;
522	}
523
524
525	}
526