elementor / core / base / background-process / wp-background-process.php

wp-background-process.php in Elementor Website Builder – more than just a page builder 3.14.0-beta4, at core/base/background-process/wp-background-process.php

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1	<?php
2	namespace Elementor\Core\Base\BackgroundProcess;
3
4	if ( ! defined( 'ABSPATH' ) ) {
5	exit;
6	}
7
8	/**
9	* https://github.com/A5hleyRich/wp-background-processing GPL v2.0
10	*
11	* WP Background Process
12	*
13	* @package WP-Background-Processing
14	*/
15
16	/**
17	* Abstract WP_Background_Process class.
18	*
19	* @abstract
20	* @extends WP_Async_Request
21	*/
22	abstract class WP_Background_Process extends WP_Async_Request {
23
24	/**
25	* Action
26	*
27	* (default value: 'background_process')
28	*
29	* @var string
30	* @access protected
31	*/
32	protected $action = 'background_process';
33
34	/**
35	* Start time of current process.
36	*
37	* (default value: 0)
38	*
39	* @var int
40	* @access protected
41	*/
42	protected $start_time = 0;
43
44	/**
45	* Cron_hook_identifier
46	*
47	* @var mixed
48	* @access protected
49	*/
50	protected $cron_hook_identifier;
51
52	/**
53	* Cron_interval_identifier
54	*
55	* @var mixed
56	* @access protected
57	*/
58	protected $cron_interval_identifier;
59
60	/**
61	* Initiate new background process
62	*/
63	public function __construct() {
64	parent::__construct();
65
66	$this->cron_hook_identifier = $this->identifier . '_cron';
67	$this->cron_interval_identifier = $this->identifier . '_cron_interval';
68
69	add_action( $this->cron_hook_identifier, array( $this, 'handle_cron_healthcheck' ) );
70	add_filter( 'cron_schedules', array( $this, 'schedule_cron_healthcheck' ) );
71	}
72
73	/**
74	* Dispatch
75	*
76	* @access public
77	* @return array\|\WP_Error
78	*/
79	public function dispatch() {
80	// Schedule the cron healthcheck.
81	$this->schedule_event();
82
83	// Perform remote post.
84	return parent::dispatch();
85	}
86
87	/**
88	* Push to queue
89	*
90	* @param mixed $data Data.
91	*
92	* @return $this
93	*/
94	public function push_to_queue( $data ) {
95	$this->data[] = $data;
96
97	return $this;
98	}
99
100	/**
101	* Save queue
102	*
103	* @return $this
104	*/
105	public function save() {
106	$key = $this->generate_key();
107
108	if ( ! empty( $this->data ) ) {
109	update_site_option( $key, $this->data );
110	}
111
112	return $this;
113	}
114
115	/**
116	* Update queue
117	*
118	* @param string $key Key.
119	* @param array $data Data.
120	*
121	* @return $this
122	*/
123	public function update( $key, $data ) {
124	if ( ! empty( $data ) ) {
125	update_site_option( $key, $data );
126	}
127
128	return $this;
129	}
130
131	/**
132	* Delete queue
133	*
134	* @param string $key Key.
135	*
136	* @return $this
137	*/
138	public function delete( $key ) {
139	delete_site_option( $key );
140
141	return $this;
142	}
143
144	/**
145	* Generate key
146	*
147	* Generates a unique key based on microtime. Queue items are
148	* given a unique key so that they can be merged upon save.
149	*
150	* @param int $length Length.
151	*
152	* @return string
153	*/
154	protected function generate_key( $length = 64 ) {
155	$unique = md5( microtime() . rand() );
156	$prepend = $this->identifier . '_batch_';
157
158	return substr( $prepend . $unique, 0, $length );
159	}
160
161	/**
162	* Maybe process queue
163	*
164	* Checks whether data exists within the queue and that
165	* the process is not already running.
166	*/
167	public function maybe_handle() {
168	// Don't lock up other requests while processing
169	session_write_close();
170
171	if ( $this->is_process_running() ) {
172	// Background process already running.
173	wp_die();
174	}
175
176	if ( $this->is_queue_empty() ) {
177	// No data to process.
178	wp_die();
179	}
180
181	check_ajax_referer( $this->identifier, 'nonce' );
182
183	$this->handle();
184
185	wp_die();
186	}
187
188	/**
189	* Is queue empty
190	*
191	* @return bool
192	*/
193	protected function is_queue_empty() {
194	global $wpdb;
195
196	$table = $wpdb->options;
197	$column = 'option_name';
198
199	if ( is_multisite() ) {
200	$table = $wpdb->sitemeta;
201	$column = 'meta_key';
202	}
203
204	$key = $wpdb->esc_like( $this->identifier . '_batch_' ) . '%';
205
206	// phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
207	// Can't use placeholders for table/column names, it will be wrapped by a single quote (') instead of a backquote (`).
208	$count = $wpdb->get_var( $wpdb->prepare( "
209	SELECT COUNT(*)
210	FROM {$table}
211	WHERE {$column} LIKE %s
212	", $key ) );
213	// phpcs:enable
214
215	return ( $count > 0 ) ? false : true;
216	}
217
218	/**
219	* Is process running
220	*
221	* Check whether the current process is already running
222	* in a background process.
223	*/
224	protected function is_process_running() {
225	if ( get_site_transient( $this->identifier . '_process_lock' ) ) {
226	// Process already running.
227	return true;
228	}
229
230	return false;
231	}
232
233	/**
234	* Lock process
235	*
236	* Lock the process so that multiple instances can't run simultaneously.
237	* Override if applicable, but the duration should be greater than that
238	* defined in the time_exceeded() method.
239	*/
240	protected function lock_process() {
241	$this->start_time = time(); // Set start time of current process.
242
243	$lock_duration = ( property_exists( $this, 'queue_lock_time' ) ) ? $this->queue_lock_time : 60; // 1 minute
244	$lock_duration = apply_filters( $this->identifier . '_queue_lock_time', $lock_duration );
245
246	set_site_transient( $this->identifier . '_process_lock', microtime(), $lock_duration );
247	}
248
249	/**
250	* Unlock process
251	*
252	* Unlock the process so that other instances can spawn.
253	*
254	* @return $this
255	*/
256	protected function unlock_process() {
257	delete_site_transient( $this->identifier . '_process_lock' );
258
259	return $this;
260	}
261
262	/**
263	* Get batch
264	*
265	* @return \stdClass Return the first batch from the queue
266	*/
267	protected function get_batch() {
268	global $wpdb;
269
270	$table = $wpdb->options;
271	$column = 'option_name';
272	$key_column = 'option_id';
273	$value_column = 'option_value';
274
275	if ( is_multisite() ) {
276	$table = $wpdb->sitemeta;
277	$column = 'meta_key';
278	$key_column = 'meta_id';
279	$value_column = 'meta_value';
280	}
281
282	$key = $wpdb->esc_like( $this->identifier . '_batch_' ) . '%';
283
284	// phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
285	// Can't use placeholders for table/column names, it will be wrapped by a single quote (') instead of a backquote (`).
286	$query = $wpdb->get_row( $wpdb->prepare( "
287	SELECT *
288	FROM {$table}
289	WHERE {$column} LIKE %s
290	ORDER BY {$key_column} ASC
291	LIMIT 1
292	", $key ) );
293	// phpcs:enable
294
295	$batch = new \stdClass();
296	$batch->key = $query->$column;
297	$batch->data = maybe_unserialize( $query->$value_column );
298
299	return $batch;
300	}
301
302	/**
303	* Handle
304	*
305	* Pass each queue item to the task handler, while remaining
306	* within server memory and time limit constraints.
307	*/
308	protected function handle() {
309	$this->lock_process();
310
311	do {
312	$batch = $this->get_batch();
313
314	foreach ( $batch->data as $key => $value ) {
315	$task = $this->task( $value );
316
317	if ( false !== $task ) {
318	$batch->data[ $key ] = $task;
319	} else {
320	unset( $batch->data[ $key ] );
321	}
322
323	if ( $this->time_exceeded() \|\| $this->memory_exceeded() ) {
324	// Batch limits reached.
325	break;
326	}
327	}
328
329	// Update or delete current batch.
330	if ( ! empty( $batch->data ) ) {
331	$this->update( $batch->key, $batch->data );
332	} else {
333	$this->delete( $batch->key );
334	}
335	} while ( ! $this->time_exceeded() && ! $this->memory_exceeded() && ! $this->is_queue_empty() );
336
337	$this->unlock_process();
338
339	// Start next batch or complete process.
340	if ( ! $this->is_queue_empty() ) {
341	$this->dispatch();
342	} else {
343	$this->complete();
344	}
345
346	wp_die();
347	}
348
349	/**
350	* Memory exceeded
351	*
352	* Ensures the batch process never exceeds 90%
353	* of the maximum WordPress memory.
354	*
355	* @return bool
356	*/
357	protected function memory_exceeded() {
358	$memory_limit = $this->get_memory_limit() * 0.9; // 90% of max memory
359	$current_memory = memory_get_usage( true );
360	$return = false;
361
362	if ( $current_memory >= $memory_limit ) {
363	$return = true;
364	}
365
366	return apply_filters( $this->identifier . '_memory_exceeded', $return );
367	}
368
369	/**
370	* Get memory limit
371	*
372	* @return int
373	*/
374	protected function get_memory_limit() {
375	if ( function_exists( 'ini_get' ) ) {
376	$memory_limit = ini_get( 'memory_limit' );
377	} else {
378	// Sensible default.
379	$memory_limit = '128M';
380	}
381
382	if ( ! $memory_limit \|\| -1 === intval( $memory_limit ) ) {
383	// Unlimited, set to 32GB.
384	$memory_limit = '32000M';
385	}
386
387	return intval( $memory_limit ) * 1024 * 1024;
388	}
389
390	/**
391	* Time exceeded.
392	*
393	* Ensures the batch never exceeds a sensible time limit.
394	* A timeout limit of 30s is common on shared hosting.
395	*
396	* @return bool
397	*/
398	protected function time_exceeded() {
399	$finish = $this->start_time + apply_filters( $this->identifier . '_default_time_limit', 20 ); // 20 seconds
400	$return = false;
401
402	if ( time() >= $finish ) {
403	$return = true;
404	}
405
406	return apply_filters( $this->identifier . '_time_exceeded', $return );
407	}
408
409	/**
410	* Complete.
411	*
412	* Override if applicable, but ensure that the below actions are
413	* performed, or, call parent::complete().
414	*/
415	protected function complete() {
416	// Unschedule the cron healthcheck.
417	$this->clear_scheduled_event();
418	}
419
420	/**
421	* Schedule cron healthcheck
422	*
423	* @access public
424	* @param mixed $schedules Schedules.
425	* @return mixed
426	*/
427	public function schedule_cron_healthcheck( $schedules ) {
428	$interval = apply_filters( $this->identifier . '_cron_interval', 5 );
429
430	if ( property_exists( $this, 'cron_interval' ) ) {
431	$interval = apply_filters( $this->identifier . '_cron_interval', $this->cron_interval );
432	}
433
434	// Adds every 5 minutes to the existing schedules.
435	$schedules[ $this->identifier . '_cron_interval' ] = array(
436	'interval' => MINUTE_IN_SECONDS * $interval,
437	/* translators: %d: Interval in minutes. */
438	'display' => sprintf( esc_html__( 'Every %d minutes', 'elementor' ), $interval ),
439	);
440
441	return $schedules;
442	}
443
444	/**
445	* Handle cron healthcheck
446	*
447	* Restart the background process if not already running
448	* and data exists in the queue.
449	*/
450	public function handle_cron_healthcheck() {
451	if ( $this->is_process_running() ) {
452	// Background process already running.
453	exit;
454	}
455
456	if ( $this->is_queue_empty() ) {
457	// No data to process.
458	$this->clear_scheduled_event();
459	exit;
460	}
461
462	$this->handle();
463
464	exit;
465	}
466
467	/**
468	* Schedule event
469	*/
470	protected function schedule_event() {
471	if ( ! wp_next_scheduled( $this->cron_hook_identifier ) ) {
472	wp_schedule_event( time(), $this->cron_interval_identifier, $this->cron_hook_identifier );
473	}
474	}
475
476	/**
477	* Clear scheduled event
478	*/
479	protected function clear_scheduled_event() {
480	$timestamp = wp_next_scheduled( $this->cron_hook_identifier );
481
482	if ( $timestamp ) {
483	wp_unschedule_event( $timestamp, $this->cron_hook_identifier );
484	}
485	}
486
487	/**
488	* Cancel Process
489	*
490	* Stop processing queue items, clear cronjob and delete batch.
491	*
492	*/
493	public function cancel_process() {
494	if ( ! $this->is_queue_empty() ) {
495	$batch = $this->get_batch();
496
497	$this->delete( $batch->key );
498
499	wp_clear_scheduled_hook( $this->cron_hook_identifier );
500	}
501
502	}
503
504	/**
505	* Task
506	*
507	* Override this method to perform any actions required on each
508	* queue item. Return the modified item for further processing
509	* in the next pass through. Or, return false to remove the
510	* item from the queue.
511	*
512	* @param mixed $item Queue item to iterate over.
513	*
514	* @return mixed
515	*/
516	abstract protected function task( $item );
517
518	}
519