wp-optimize / cache / class-wp-optimize-page-cache-preloader.php

class-wp-optimize-page-cache-preloader.php in WP-Optimize – Cache, Compress images, Minify & Clean database to boost page speed & performance 3.4.2, at cache/class-wp-optimize-page-cache-preloader.php

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1	<?php
2
3	if (!defined('ABSPATH')) die('No direct access allowed');
4
5	if (!class_exists('WP_Optimize_Load_Url_Task')) {
6	require_once(WPO_PLUGIN_MAIN_PATH . 'cache/class-wpo-load-url-task.php');
7	}
8
9	class WP_Optimize_Page_Cache_Preloader extends WP_Optimize_Preloader {
10
11	protected $preload_type = 'page_cache';
12
13	protected $task_type = 'load-url-task';
14
15	static protected $_instance = null;
16
17	/**
18	* WP_Optimize_Page_Cache_Preloader constructor.
19	*/
20	public function __construct() {
21	parent::__construct();
22
23	add_action('wpo_page_cache_schedule_preload', array($this, 'run_scheduled_cache_preload'));
24	add_filter('wpo_preload_headers', array($this, 'preload_headers'));
25	}
26
27	/**
28	* Check if cache is active.
29	*
30	* @return bool
31	*/
32	public function is_option_active() {
33	return WP_Optimize()->get_page_cache()->is_enabled();
34	}
35
36	/**
37	* Schedule or delete automatic preload action on cache settings update.
38	*
39	* @param array $new_settings The new settings
40	* @param array $previous_settings Settings before saving
41	*/
42	public function cache_settings_updated($new_settings, $previous_settings) {
43	if (!$new_settings['enable_page_caching']) {
44	wp_clear_scheduled_hook('wpo_page_cache_schedule_preload');
45	$this->delete_preload_continue_action();
46	return;
47	}
48
49	if (!empty($new_settings['enable_schedule_preload'])) {
50
51	$last_schedule_type = $previous_settings['preload_schedule_type'];
52
53	$last_use_nighttime = $this->options->get_option('page_cache_schedule_preload_nighttime');
54	// By default, we schedule preload events to the nighttime.
55	$use_nighttime = apply_filters('wpo_page_cache_schedule_preload_use_nighttime', 1);
56
57	$this->options->update_option('page_cache_schedule_preload_nighttime', $use_nighttime);
58
59	if (wp_next_scheduled('wpo_page_cache_schedule_preload')) {
60	// if already scheduled this schedule type
61	if ($new_settings['preload_schedule_type'] == $last_schedule_type && ($last_use_nighttime === $use_nighttime)) {
62	// If the schedule type is cache lifespan, check if the cache lifespan changed.
63	if ('wpo_use_cache_lifespan' == $new_settings['preload_schedule_type']) {
64	// Else, if the settings cache lifespan settings haven't changed, returns
65	if ($new_settings['page_cache_length_value'] == $previous_settings['page_cache_length_value'] && $new_settings['page_cache_length_unit'] == $previous_settings['page_cache_length_unit']) {
66	return;
67	}
68	} else {
69	return;
70	}
71	}
72	// clear currently scheduled preload action.
73	wp_clear_scheduled_hook('wpo_page_cache_schedule_preload');
74	}
75
76	// schedule preload action.
77	$timestamp = time() + $this->get_schedule_interval($new_settings['preload_schedule_type']);
78
79	if ($use_nighttime) {
80	$timestamp = $this->make_nighttime($timestamp);
81	}
82
83	wp_schedule_event($timestamp, $new_settings['preload_schedule_type'], 'wpo_page_cache_schedule_preload');
84	} else {
85	wp_clear_scheduled_hook('wpo_page_cache_schedule_preload');
86	}
87
88	}
89
90	/**
91	* Clear active preload tasks, reschedule preload action.
92	*/
93	public function reschedule_preload() {
94	// clear scheduled action.
95	if (wp_next_scheduled('wpo_page_cache_schedule_preload')) {
96	wp_clear_scheduled_hook('wpo_page_cache_schedule_preload');
97	}
98
99	// schedule preload action if need.
100	if ($this->is_scheduled_preload_enabled()) {
101	$preload_schedule_type = $this->get_cache_config('preload_schedule_type');
102	// By default, we schedule preload events to the nighttime.
103	$use_nighttime = apply_filters('wpo_page_cache_schedule_preload_use_nighttime', 1);
104
105	$timestamp = time() + $this->get_schedule_interval($preload_schedule_type);
106	if ($use_nighttime) {
107	$timestamp = $this->make_nighttime($timestamp);
108	}
109
110	wp_schedule_event($timestamp, $preload_schedule_type, 'wpo_page_cache_schedule_preload');
111	}
112	}
113
114	/**
115	* Check if scheduled preload enabled.
116	*
117	* @return bool
118	*/
119	public function is_scheduled_preload_enabled() {
120	$enable_schedule_preload = $this->get_cache_config('enable_schedule_preload');
121	return !empty($enable_schedule_preload);
122	}
123
124	/**
125	* Check if we need run cache preload and run it.
126	*/
127	public function run_scheduled_cache_preload() {
128
129	$schedule_type = WPO_Cache_Config::instance()->get_option('preload_schedule_type');
130	if (!$schedule_type) return;
131
132	// Don't run preload if cache lifespan option enabled and cache not expired yet.
133	if ('wpo_use_cache_lifespan' == $schedule_type) {
134
135	/**
136	* Filters the allowed time difference between the cache exiry and the current time, in seconds.
137	* If the cache expires in less than $allowed_time_difference, preload. Otherwise leave it.
138	*
139	* @param integer $allowed_time_difference The time difference, in seconds (default is same as changed time limit)
140	*/
141	$time_limit = (defined('WP_OPTIMIZE_SET_TIME_LIMIT') && WP_OPTIMIZE_SET_TIME_LIMIT > 15) ? WP_OPTIMIZE_SET_TIME_LIMIT : 1800;
142
143	$allowed_time_difference = apply_filters('wpo_preload_allowed_time_difference', $time_limit);
144	$page_cache_lifespan = WPO_Cache_Config::instance()->get_option('page_cache_length', 0);
145	$last_preload_time = $this->options->get_option('wpo_last_page_cache_preload', 0);
146	$time_since_last_preload = time() - $last_preload_time;
147	$minimum_time_to_next_schedule_preload = $page_cache_lifespan - $allowed_time_difference;
148	// Skip this if the last preload is not as old as the cache lifespan minus $allowed_time_difference
149	if ($page_cache_lifespan > 0 && $time_since_last_preload < $minimum_time_to_next_schedule_preload) return;
150	}
151
152	$this->run();
153	}
154
155
156	/**
157	* Get cache config option value.
158	*
159	* @return mixed
160	*/
161	public function get_cache_config($option) {
162	static $config = null;
163
164	if (null === $config) $config = WPO_Page_Cache::instance()->config->get();
165
166	if (is_array($config) && array_key_exists($option, $config)) {
167	return $config[$option];
168	}
169
170	return false;
171	}
172
173	/**
174	* Create tasks (WP_Optimize_Load_Url_Task) for preload all urls from site.
175	*
176	* @param string $type The preload type (currently: scheduled, manual)
177	* @return void
178	*/
179	public function create_tasks_for_preload_site_urls($type) {
180	$urls = $this->get_site_urls();
181
182	if (!empty($urls)) {
183
184	$this->log(__('Creating tasks for preload site urls.', 'wp-optimize'));
185
186	foreach ($urls as $url) {
187	if (wpo_url_in_exceptions($url)) continue;
188
189	if ($this->url_is_already_cached($url, $type)) {
190	continue;
191	}
192
193	// this description is being used for internal purposes.
194	$description = 'Preload - '.$url;
195	$options = array('url' => $url, 'preload_type' => $type, 'anonymous_user_allowed' => (defined('DOING_CRON') && DOING_CRON) \|\| (defined('WP_CLI') && WP_CLI));
196
197	if (!class_exists('WP_Optimize_Load_Url_Task')) {
198	require_once WPO_PLUGIN_MAIN_PATH . 'cache/class-wpo-load-url-task.php';
199	}
200	WP_Optimize_Load_Url_Task::create_task($this->task_type, $description, $options, 'WP_Optimize_Load_Url_Task');
201	}
202
203	$this->log(__('Tasks for preload site urls created.', 'wp-optimize'));
204	}
205	}
206
207	/**
208	* Preload mobile version from $url.
209	*
210	* @param string $url
211	*
212	* @return void
213	*/
214	public function preload_mobile($url) {
215	static $is_mobile_caching_enabled;
216	if (!isset($is_mobile_caching_enabled)) {
217	$is_mobile_caching_enabled = $this->get_cache_config('enable_mobile_caching');
218	}
219
220	// Only run if option is active
221	if (!$is_mobile_caching_enabled) return;
222
223	$mobile_args = array(
224	'httpversion' => '1.1',
225	'user-agent' => 'Mozilla/5.0 (iPhone; CPU iPhone OS 9_1 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13B143 Safari/601.1',
226	'timeout' => 10,
227	'headers' => apply_filters('wpo_preload_headers', array()),
228	);
229
230	$mobile_args = apply_filters('wpo_page_cache_preloader_mobile_args', $mobile_args, $url);
231
232	$this->log('preload_mobile - ' . $url);
233
234	wp_remote_get($url, $mobile_args);
235	}
236
237	/**
238	* Preload amp version from $url.
239	*
240	* @param string $url
241	*
242	* @return void
243	*/
244	public function preload_amp($url) {
245	if (!apply_filters('wpo_should_preload_amp', false, $url)) return;
246
247	$amp_args = array(
248	'httpversion' => '1.1',
249	'user-agent' => 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.89 Safari/537.36',
250	'timeout' => 10,
251	'headers' => array(
252	'X-WP-Optimize-Cache-Preload' => 'Yes',
253	),
254	);
255
256	$url = untrailingslashit($url) . '/amp/';
257
258	$amp_args = apply_filters('wpo_page_cache_preloader_amp_args', $amp_args, $url);
259
260	$this->log('preload_amp - ' . $url);
261
262	wp_remote_get($url, $amp_args);
263	}
264
265	/**
266	* Check if sitemap exists then returns list of urls from sitemap file otherwise returns all posts urls.
267	*
268	* @return array
269	*/
270	public function get_site_urls() {
271
272	$urls = $this->get_sitemap_urls();
273
274	if (!empty($urls)) {
275	$this->options->update_option('wpo_last_page_cache_preload_type', 'sitemap');
276	} else {
277	$urls = $this->get_post_urls();
278	$this->options->update_option('wpo_last_page_cache_preload_type', 'posts');
279	}
280
281	$this->log(sprintf(_n('%d url found.', '%d urls found.', count($urls), 'wp-optimize'), count($urls)));
282
283	/**
284	* Filter the URLs which will be preloaded
285	*
286	* @param array $urls
287	* @return array
288	*/
289	return apply_filters('wpo_preload_get_site_urls', $urls);
290	}
291
292	/**
293	* Loads sitemap file and returns list of urls.
294	*
295	* @param string $sitemap_url
296	*
297	* @return array\|bool
298	*/
299	public function get_sitemap_urls($sitemap_url = '') {
300
301	$urls = array();
302
303	// if sitemap url is empty then use main sitemap file name.
304	$sitemap_url = ('' === $sitemap_url) ? site_url('/'.$this->get_sitemap_filename()) : $sitemap_url;
305
306	// if simplexml_load_string not available then we don't load sitemap.
307	if (!function_exists('simplexml_load_string')) {
308	return $urls;
309	}
310
311	// load sitemap file.
312	$response = wp_remote_get($sitemap_url, array('timeout' => 30));
313
314	// if we get error then
315	// sometimes returns error due to timeout
316	if (is_wp_error($response)) {
317	$response = file_get_contents($sitemap_url);
318
319	// if response is empty then try load from file.
320	if (empty($response) && '' == $sitemap_url) {
321	$sitemap_file = $this->get_local_sitemap_file();
322
323	if (is_file($sitemap_file)) {
324	$response = file_get_contents($sitemap_file);
325	}
326	}
327
328	if (empty($response)) return $urls;
329
330	$xml = @simplexml_load_string($response); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress warnings when error found in XML data
331	} else {
332	// parse xml answer.
333	$xml = @simplexml_load_string(wp_remote_retrieve_body($response)); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress warnings when error found in XML data
334	}
335
336	// xml file has not valid xml content then return false.
337	if (false === $xml) return false;
338
339	// if exists urls then return them.
340	if (isset($xml->url)) {
341	foreach ($xml->url as $element) {
342	if (!isset($element->loc)) continue;
343	$urls[] = (string) $element->loc;
344	}
345	} elseif (isset($xml->sitemap)) {
346	// if has links to other sitemap files then get urls from them.
347	foreach ($xml->sitemap as $element) {
348	if (!isset($element->loc)) continue;
349
350	$sitemap_urls = $this->get_sitemap_urls($element->loc);
351
352	if (is_array($sitemap_urls)) {
353	$urls = array_merge($urls, $sitemap_urls);
354	}
355	}
356	}
357
358	return $urls;
359	}
360
361	/**
362	* Get all posts of any post type and returns urls for them.
363	*
364	* @return array
365	*/
366	public function get_post_urls() {
367	global $post;
368
369	$offset = 0;
370	$posts_per_page = 1000;
371	$urls = array();
372
373	$urls[] = site_url('/');
374
375	do {
376	$query = new WP_Query(array(
377	'post_type' => 'any',
378	'post_status' => 'publish',
379	'posts_per_page' => $posts_per_page,
380	'offset' => $offset,
381	'orderby' => 'ID',
382	'order' => 'ASC',
383	'cache_results' => false, // disable cache to avoid memory error.
384	));
385
386	$posts_loaded = $query->post_count;
387
388	while ($query->have_posts()) {
389	$query->the_post();
390	$permalink = get_permalink();
391	$urls[] = $permalink;
392
393	// check page separators in the post content
394	preg_match_all('/\<\!--nextpage--\>/', $post->post_content, $matches);
395	// if there any separators add urls for each page
396	if (count($matches[0])) {
397	$prefix = strpos($permalink, '?') ? '&page=' : '';
398	for ($page = 0; $page < count($matches[0]); $page++) {
399	if ('' != $prefix) {
400	$urls[] = $permalink . $prefix . ($page+2);
401	} else {
402	$urls[] = trailingslashit($permalink) . ($page+2);
403	}
404	}
405	}
406	}
407
408	$offset += $posts_loaded;
409	} while ($posts_loaded > 0);
410
411	/**
412	* If domain mapping enabled then replace domains in urls.
413	*/
414	if ($this->is_domain_mapping_enabled()) {
415	$blog_id = get_current_blog_id();
416
417	$mapped_domain = $this->get_mapped_domain($blog_id);
418	$blog_details = get_blog_details($blog_id);
419
420	if ($mapped_domain) {
421	foreach ($urls as $i => $url) {
422	$urls[$i] = preg_replace('/'.$blog_details->domain.'/i', $mapped_domain, $url, 1);
423	}
424	}
425	}
426
427	wp_reset_postdata();
428
429	return $urls;
430	}
431
432	/**
433	* Check if domain mapping enabled.
434	*
435	* @return bool
436	*/
437	public function is_domain_mapping_enabled() {
438	// SUNRISE constant is defined with installation WordPress MU Domain Mapping plugin.
439	$enabled = is_multisite() && defined('SUNRISE') && 'on' == strtolower(SUNRISE);
440
441	/**
442	* Filters if Multisite Domain mapping is enabled.
443	* Currently, we can only detect if the WordPress MU Domain Mapping plugin is in use.
444	* Using the WP Core functionality should not require this, unless if the domain name is set somewhere else but in the site url option.
445	*/
446	return apply_filters('wpo_is_domain_mapping_enabled', $enabled);
447	}
448
449	/**
450	* Return mapped domain by $blog_id.
451	*
452	* @param int $blog_id
453	*
454	* @return string
455	*/
456	public function get_mapped_domain($blog_id) {
457	global $wpdb;
458
459	$domain = '';
460	$multisite_plugin_table_name = $wpdb->base_prefix.'domain_mapping';
461	// Check if table exists
462	if ($wpdb->get_var("SHOW TABLES LIKE '$multisite_plugin_table_name'") != $multisite_plugin_table_name) {
463	// This table created in WordPress MU Domain Mapping plugin.
464	$row = $wpdb->get_row("SELECT `domain` FROM {$multisite_plugin_table_name} WHERE `blog_id` = {$blog_id} AND `active` = 1", ARRAY_A);
465	if (!empty($row)) {
466	$domain = $row['domain'];
467	}
468	} else {
469	// When using the WP Core method, the site url option contains the mapped domain.
470	$domain = get_site_url($blog_id);
471	}
472
473	/**
474	* Filters the mapped domain name
475	*
476	* @param string $domain The domain name
477	* @param integer $blog_id The blog ID
478	*/
479	return apply_filters('wpo_get_mapped_domain', $domain, $blog_id);
480	}
481
482	/**
483	* Captures and logs any interesting messages
484	*
485	* @param String $message - the error message
486	* @param String $error_type - the error type
487	*/
488	public function log($message, $error_type = 'info') {
489
490	if (isset($this->loggers)) {
491	foreach ($this->loggers as $logger) {
492	$logger->log($message, $error_type);
493	}
494	}
495	}
496
497	/**
498	* Instance of WP_Optimize_Page_Cache_Preloader.
499	*
500	* @return WP_Optimize_Page_Cache_Preloader
501	*/
502	public static function instance() {
503	if (empty(self::$_instance)) {
504	self::$_instance = new WP_Optimize_Page_Cache_Preloader();
505	}
506
507	return self::$_instance;
508	}
509
510	/**
511	* Check if the URL is already cached, or needs to be preloaded
512	*
513	* @param string $url The preloaded url
514	* @param string $preload_type The preload type (manual \| scheduled)
515	* @return boolean
516	*/
517	private function url_is_already_cached($url, $preload_type) {
518	static $files = array();
519	$regenerate_count = 0;
520	$folder = trailingslashit(WPO_CACHE_FILES_DIR) . wpo_get_url_path($url);
521	// If the folder does not exist, consider the URL as cleared
522	if (!is_dir($folder)) return false;
523
524	if (empty($files)) {
525	// Check only the base files
526	$files[] = 'index.html';
527
528	if (WPO_Cache_Config::instance()->get_option('enable_mobile_caching')) {
529	$files[] = 'mobile.index.html';
530	}
531	$files = apply_filters('wpo_maybe_clear_files_list', $files);
532	}
533
534	foreach ($files as $file) {
535	$file_path = trailingslashit($folder).$file;
536	if (!file_exists($file_path)) {
537	// The file does not exist, count it as "deleted"
538	$regenerate_count++;
539	continue;
540	}
541
542	if ($this->should_regenerate_file($file_path, $preload_type)) {
543	// delefe the expired cache file
544	unlink($file_path);
545	$regenerate_count++;
546	}
547	}
548
549	// if 0 == $regenerate_count, nothing all the expected files exist, and none were deleted.
550	return 0 == $regenerate_count;
551	}
552
553	/**
554	* Determine if a file should be regenerated
555	*
556	* @param string $path The file to check
557	* @param string $preload_type The preload type (manual \| scheduled)
558	*
559	* @return boolean
560	*/
561	private function should_regenerate_file($path, $preload_type) {
562	// Store the variables, as they'll be used for each file and each file
563	static $is_preloader_scheduled = null;
564	static $lifespan = null;
565	static $schedule_type = null;
566	static $schedule_interval = null;
567	static $lifespan_expiry_threshold = null;
568	static $always_regenerate_file_if_preload_is_manual = null;
569	static $always_regenerate_file_if_preload_is_scheduled = null;
570	static $regenerate_file_when_no_expiry_date = null;
571
572	// Sets the variables once per request:
573	if (null === $is_preloader_scheduled) {
574	$is_preloader_scheduled = WPO_Cache_Config::instance()->get_option('enable_schedule_preload');
575	$schedule_type = WPO_Cache_Config::instance()->get_option('preload_schedule_type');
576	$lifespan = WPO_Cache_Config::instance()->get_option('page_cache_length');
577	$schedule_interval = $this->get_schedule_interval($schedule_type);
578
579	/**
580	* Expiry threshold: the current file will be considered stale if within the threshold. Default: 600s (10min)
581	*/
582	$lifespan_expiry_threshold = apply_filters('wpo_lifespan_expiry_threshold', 600);
583
584	/**
585	* Filters if a cache should systematically be regenerated when running a manual preload. Default: false
586	*/
587	$always_regenerate_file_if_preload_is_manual = apply_filters('wpo_always_regenerate_file_if_preload_is_manual', false);
588
589	/**
590	* Filters if a cache should systematically be regenerated when running a scheduled preload. Default: false
591	*/
592	$always_regenerate_file_if_preload_is_scheduled = apply_filters('wpo_always_regenerate_file_if_preload_is_scheduled', false);
593
594	/**
595	* Filters if a cache should systematically be regenerated when running a preload and no schedule is set, and cache does not expire. Default: true
596	*/
597	$regenerate_file_when_no_expiry_date = apply_filters('wpo_regenerate_file_when_no_expiry_date', true);
598	}
599
600	if (($always_regenerate_file_if_preload_is_manual && 'manual' == $preload_type) \|\| ($always_regenerate_file_if_preload_is_scheduled && 'scheduled' == $preload_type)) {
601	$result = true;
602	} else {
603
604	$modified_time = (int) filemtime($path);
605
606	// cache lifespan is set.
607	if (0 != $lifespan) {
608	$expiry_time = $modified_time + $lifespan - $lifespan_expiry_threshold;
609	$result = time() > $expiry_time;
610	} elseif ($is_preloader_scheduled) {
611	$expiry_time = $modified_time + $schedule_interval - $lifespan_expiry_threshold;
612	$result = time() > $expiry_time;
613	} else {
614	$result = $regenerate_file_when_no_expiry_date;
615	}
616
617	}
618
619	return apply_filters('wpo_preloader_should_regenerate_file', $result, $path, $preload_type);
620	}
621
622	/**
623	* Add preloader headers
624	*/
625	public function preload_headers($headers) {
626	$headers['X-WP-Optimize-Cache-Preload'] = 'Yes';
627	return $headers;
628	}
629
630	/**
631	* Option disabled error message
632	*
633	* @return array
634	*/
635	protected function get_option_disabled_error() {
636	return array(
637	'success' => false,
638	'error' => __('Page cache is disabled.', 'wp-optimize')
639	);
640	}
641
642	/**
643	* Get preload already running error message
644	*
645	* @return array
646	*/
647	protected function get_preload_already_running_error() {
648	return array(
649	'success' => false,
650	'error' => __('Probably page cache preload is running already.', 'wp-optimize')
651	);
652	}
653
654	protected function get_preload_data() {
655	return WP_Optimize()->get_page_cache()->get_cache_size();
656	}
657
658	protected function get_preloading_message($cache_size) {
659	return array(
660	'done' => false,
661	'message' => __('Loading URLs...', 'wp-optimize'),
662	'size' => WP_Optimize()->format_size($cache_size['size']),
663	'file_count' => $cache_size['file_count']
664	);
665	}
666
667	protected function get_last_preload_message($cache_size, $last_preload_time_str) {
668	return array(
669	'done' => true,
670	'message' => sprintf(__('Last preload finished at %s', 'wp-optimize'), $last_preload_time_str),
671	'size' => WP_Optimize()->format_size($cache_size['size']),
672	'file_count' => $cache_size['file_count']
673	);
674	}
675
676	protected function get_preload_success_message($cache_size) {
677	return array(
678	'done' => true,
679	'size' => WP_Optimize()->format_size($cache_size['size']),
680	'file_count' => $cache_size['file_count']
681	);
682	}
683
684	protected function get_preload_progress_message($cache_size, $preloaded_message, $preload_resuming_in) {
685	return array(
686	'done' => false,
687	'message' => $preloaded_message,
688	'size' => WP_Optimize()->format_size($cache_size['size']),
689	'file_count' => $cache_size['file_count'],
690	'resume_in' => $preload_resuming_in
691	);
692	}
693
694	/**
695	* Shifts the given timestamp to nighttime.
696	*
697	* @param int $time
698	*
699	* @return int
700	*/
701	private function make_nighttime($time) {
702
703	$gmt_offset = WP_Optimize_Utils::get_gmt_offset();
704
705	// Set time to random time from 1 a.m. to 4:59 a.m.
706	$random_time = sprintf('%02d:%02d', rand(1, 4), rand(0, 59));
707	$nighttime = strtotime(date("Y-m-d {$random_time}:00", $time)) - $gmt_offset;
708
709	if ($nighttime < time()) $nighttime += 24 * 3600;
710
711	return $nighttime;
712	}
713	}
714
715	WP_Optimize_Page_Cache_Preloader::instance();
716