wp-optimize / cache / file-based-page-cache-functions.php

file-based-page-cache-functions.php in WP-Optimize – Cache, Compress images, Minify & Clean database to boost page speed & performance 3.3.0, at cache/file-based-page-cache-functions.php

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1	<?php
2
3	if (!defined('ABSPATH')) die('No direct access allowed');
4
5	/**
6	* Extensions directory.
7	*/
8	if (!defined('WPO_CACHE_EXT_DIR')) define('WPO_CACHE_EXT_DIR', dirname(__FILE__).'/extensions');
9
10	/**
11	* Holds utility functions used by file based cache
12	*/
13
14	/**
15	* Cache output before it goes to the browser. If moving/renaming this function, then also change the check above.
16	*
17	* @param String $buffer Page HTML.
18	* @param Int $flags OB flags to be passed through.
19	*
20	* @return String
21	*/
22	if (!function_exists('wpo_cache')) :
23	function wpo_cache($buffer, $flags) {
24
25	// This case appears to happen for unclear reasons without WP being fully loaded, e.g. https://wordpress.org/support/topic/fatal-error-since-wp-5-8-update/ . It is simplest just to short-circuit it.
26	if ('' === $buffer) return '';
27
28	// This array records reasons why no caching took place. Be careful not to allow actions to proceed that should not - i.e. take note of its state appropriately.
29	$no_cache_because = array();
30
31	if (strlen($buffer) < 255) {
32	$no_cache_because[] = sprintf(__('Output is too small (less than %d bytes) to be worth caching', 'wp-optimize'), 255);
33	}
34
35	// Don't cache pages for logged in users.
36	if (!wpo_cache_loggedin_users() && (!function_exists('is_user_logged_in') \|\| (function_exists('wp_get_current_user') && is_user_logged_in()))) {
37	$no_cache_because[] = __('User is logged in', 'wp-optimize');
38	}
39
40	$restricted_page_type_cache = apply_filters('wpo_restricted_cache_page_type', false);
41	if ($restricted_page_type_cache) {
42	$no_cache_because[] = $restricted_page_type_cache;
43	}
44
45	$conditional_tag_exceptions = apply_filters('wpo_url_in_conditional_tags_exceptions', false);
46	if ($conditional_tag_exceptions) {
47	$no_cache_because[] = $conditional_tag_exceptions;
48	}
49
50	// No root cache folder, so short-circuit here
51	if (!file_exists(WPO_CACHE_DIR)) {
52	$no_cache_because[] = __('WP-O cache parent directory was not found', 'wp-optimize').' ('.WPO_CACHE_DIR.')';
53	} elseif (!file_exists(WPO_CACHE_FILES_DIR)) {
54	// Try creating a folder for cached files, if it was flushed recently
55	if (!mkdir(WPO_CACHE_FILES_DIR)) {
56	$no_cache_because[] = __('WP-O cache directory was not found', 'wp-optimize').' ('.WPO_CACHE_FILES_DIR.')';
57	} else {
58	wpo_disable_cache_directories_viewing();
59	}
60	}
61
62	// If comments are opened and the user has saved his information.
63	if (function_exists('comments_open') && function_exists('get_post') && get_post() && comments_open()) {
64	$commenter = wp_get_current_commenter();
65	// if any of the fields contain something, do not save to cache
66	if ('' != $commenter['comment_author'] \|\| '' != $commenter['comment_author_email'] \|\| '' != $commenter['comment_author_url']) {
67	$no_cache_because[] = __('Comments are opened and the visitor saved his information.', 'wp-optimize');
68	}
69	}
70
71	$can_cache_page = true;
72
73	if (defined('DONOTCACHEPAGE') && DONOTCACHEPAGE) {
74	$can_cache_page = false;
75	}
76
77	/**
78	* Defines if the page can be cached or not
79	*
80	* @param boolean $can_cache_page
81	*/
82	$can_cache_page_filter = apply_filters('wpo_can_cache_page', $can_cache_page);
83
84	if (!$can_cache_page_filter) {
85	if ($can_cache_page) {
86	$can_cache_page = false;
87	$no_cache_because[] = __('wpo_can_cache_page filter forbade it', 'wp-optimize');
88	} else {
89	$no_cache_because[] = __('DONOTCACHEPAGE constant forbade it and wpo_can_cache_page filter did not over-ride it', 'wp-optimize');
90	}
91	}
92
93	if (defined('REST_REQUEST') && REST_REQUEST) {
94	$no_cache_because[] = __('This is a REST API request (identified by REST_REQUEST constant)', 'wp-optimize');
95	}
96
97	// Don't cache with fatal error pages.
98	$last_error = error_get_last();
99	if (is_array($last_error) && E_ERROR == $last_error['type']) {
100	$no_cache_because[] = __('This page has a fatal error', 'wp-optimize');
101	}
102
103	if (http_response_code() >= 500) {
104	$no_cache_because[] = sprintf(__('This page has a critical error (HTTP code %s)', 'wp-optimize'), http_response_code());
105	} elseif (http_response_code() >= 400) {
106	$no_cache_because[] = sprintf(__('This page returned an HTTP unauthorised response code (%s)', 'wp-optimize'), http_response_code());
107	}
108
109	if (empty($no_cache_because)) {
110
111	$buffer = apply_filters('wpo_pre_cache_buffer', $buffer, $flags);
112
113	$url_path = wpo_get_url_path();
114
115	$dirs = explode('/', $url_path);
116
117	$path = WPO_CACHE_FILES_DIR;
118
119	foreach ($dirs as $dir) {
120	if (!empty($dir)) {
121	$path .= '/' . $dir;
122
123	if (!file_exists($path)) {
124	if (!mkdir($path)) {
125	$no_cache_because[] = __('Attempt to create subfolder within cache directory failed', 'wp-optimize')." ($path)";
126	break;
127	}
128	}
129	}
130	}
131	}
132
133	if (!empty($no_cache_because)) {
134
135	$message = implode(', ', $no_cache_because);
136
137	// Add http headers
138	wpo_cache_add_nocache_http_header($message);
139
140	if ((!defined('DOING_CRON') \|\| !DOING_CRON) && (!defined('REST_REQUEST') \|\| !REST_REQUEST)) {
141	$not_cached_details = "";
142
143	// Output the reason only when the user has turned on debugging
144	if (((defined('WP_DEBUG') && WP_DEBUG) \|\| isset($_GET['wpo_cache_debug']))) {
145	$not_cached_details = "because: ".htmlspecialchars($message) . " ";
146	}
147
148	$buffer .= sprintf("\n<!-- WP Optimize page cache - https://getwpo.com - page NOT cached %s-->\n", $not_cached_details);
149	}
150
151	return $buffer;
152
153	} else {
154
155	// Prevent mixed content when there's an http request but the site URL uses https.
156	$home_url = get_home_url();
157
158	if (!is_ssl() && 'https' === strtolower(parse_url($home_url, PHP_URL_SCHEME))) {
159	$https_home_url = $home_url;
160	$http_home_url = str_ireplace('https://', 'http://', $https_home_url);
161	$buffer = str_replace(esc_url($http_home_url), esc_url($https_home_url), $buffer);
162	}
163
164	$modified_time = time(); // Take this as soon before writing as possible
165	$timezone_string = '';
166	$utc = isset($GLOBALS['wpo_cache_config']['gmt_offset']) ? (float) $GLOBALS['wpo_cache_config']['gmt_offset'] : 0;
167	$modified_time += $utc * 3600;
168
169	if (!empty($GLOBALS['wpo_cache_config']['timezone_string'])) {
170	$timezone_string = 'UTC' !== $GLOBALS['wpo_cache_config']['timezone_string'] ? $GLOBALS['wpo_cache_config']['timezone_string'] : '';
171	}
172
173	if (!empty($timezone_string)) {
174	$timezone_postfix = "(".$timezone_string." UTC:". $utc .")";
175	} else {
176	$timezone_postfix = "(UTC:" . $utc . ")";
177	}
178
179	$add_to_footer = '';
180
181	/**
182	* Filter whether to display the html comment <!-- Cached by WP-Optimize ... -->
183	*
184	* @param boolean $show - Whether to display the html comment
185	* @return boolean
186	*/
187	if (preg_match('#</html>#i', $buffer) && (apply_filters('wpo_cache_show_cached_by_comment', true) \|\| (defined('WP_DEBUG') && WP_DEBUG))) {
188	$date_time_format = 'F j, Y g:i a';
189	if (!empty($GLOBALS['wpo_cache_config']['date_format']) && !empty($GLOBALS['wpo_cache_config']['time_format'])) {
190	$date_time_format = $GLOBALS['wpo_cache_config']['date_format'] . ' ' . $GLOBALS['wpo_cache_config']['time_format'];
191	}
192
193	if (!empty($GLOBALS['wpo_cache_config']['enable_mobile_caching']) && wpo_is_mobile()) {
194	$add_to_footer .= "\n<!-- Cached by WP-Optimize - for mobile devices - https://getwpo.com - Last modified: " . gmdate($date_time_format, $modified_time) . " " . $timezone_postfix . " -->\n";
195	} else {
196	$add_to_footer .= "\n<!-- Cached by WP-Optimize - https://getwpo.com - Last modified: " . gmdate($date_time_format, $modified_time) . " " . $timezone_postfix . " -->\n";
197	}
198	}
199
200	// Create an empty index.php file in the cache directory for disable directory viewing.
201	if (!is_file($path . '/index.php')) file_put_contents($path . '/index.php', '');
202
203	/**
204	* Save $buffer into cache file.
205	*/
206	$file_ext = '.html';
207
208	if (wpo_feeds_caching_enabled()) {
209	if (is_feed()) {
210	$file_ext = '.rss-xml';
211	}
212	}
213
214	$cache_filename = wpo_cache_filename($file_ext);
215	$cache_file = $path . '/' .$cache_filename;
216
217	if (defined('WPO_CACHE_FILENAME_DEBUG') && WPO_CACHE_FILENAME_DEBUG) {
218	$add_to_footer .= "\n<!-- WP Optimize page cache debug information -->\n";
219	if (!empty($GLOBALS['wpo_cache_filename_debug']) && is_array($GLOBALS['wpo_cache_filename_debug'])) {
220	$add_to_footer .= "<!-- \n" . join("\n", array_map('htmlspecialchars', $GLOBALS['wpo_cache_filename_debug'])) . "\n --->";
221	}
222	}
223
224	// if we can then cache gzipped content in .gz file.
225	if (function_exists('gzencode') && apply_filters('wpo_allow_cache_gzip_files', true)) {
226	// Only replace inside the addition, not inside the main buffer (e.g. post content)
227	file_put_contents($cache_file . '.gz', gzencode($buffer.str_replace('by WP-Optimize', 'by WP-Optimize (gzip)', $add_to_footer), apply_filters('wpo_cache_gzip_level', 6)));
228	}
229
230	file_put_contents($cache_file, $buffer.$add_to_footer);
231
232	if (is_callable('WP_Optimize')) {
233	// delete cached information about cache size.
234	WP_Optimize()->get_page_cache()->delete_cache_size_information();
235	} else {
236	// If the shutdown occurs before plugins are loaded,
237	// then this will trigger a fatal error, so, we check first
238	if (!doing_action('shutdown')) {
239	error_log('[WPO_CACHE] WP_Optimize() is not callable.');
240	$message = 'Please report this to WP-O support: ';
241	if (function_exists('wp_debug_backtrace_summary')) {
242	$message .= wp_debug_backtrace_summary();
243	} else {
244	$message .= wpo_debug_backtrace_summary();
245	}
246	error_log($message);
247	}
248	}
249
250	header('Cache-Control: no-cache'); // Check back every time to see if re-download is necessary.
251	header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $modified_time) . ' GMT');
252	header('WPO-Cache-Status: saving to cache');
253
254	if (wpo_cache_can_output_gzip_content()) {
255
256	if (!wpo_cache_is_in_response_headers_list('Content-Encoding', 'gzip')) {
257	header('Content-Encoding: gzip');
258	}
259
260	// Disable php gzip to avoid double compression.
261	ini_set('zlib.output_compression', 'Off');
262
263	return ob_gzhandler($buffer, $flags);
264	} else {
265	return $buffer;
266	}
267	}
268	}
269	endif;
270
271	/**
272	* Load files for support plugins.
273	*/
274	if (!function_exists('wpo_cache_load_extensions')) :
275	function wpo_cache_load_extensions() {
276	$extensions = glob(WPO_CACHE_EXT_DIR . '/*.php');
277
278	// Add external extensions
279	if (defined('WPO_CACHE_CUSTOM_EXT_DIR') && is_dir(WPO_CACHE_CUSTOM_EXT_DIR)) {
280	$extensions = array_merge($extensions, glob(WPO_CACHE_CUSTOM_EXT_DIR . '/*.php'));
281	}
282
283	if (empty($extensions)) return;
284
285	foreach ($extensions as $extension) {
286	if (is_file($extension)) require_once $extension;
287	}
288	}
289	endif;
290
291	if (!function_exists('wpo_restricted_cache_page_type')) {
292	function wpo_restricted_cache_page_type($restricted) {
293	global $post;
294
295	// Don't cache search or password protected.
296	if ((function_exists('is_search') && is_search()) \|\| (function_exists('is_404') && is_404()) \|\| !empty($post->post_password)) {
297	$restricted = __('Page type is not cacheable (search, 404 or password-protected)', 'wp-optimize');
298	}
299
300	// Don't cache the front page if option is set.
301	if (in_array('/', wpo_get_url_exceptions()) && function_exists('is_front_page') && is_front_page()) {
302
303	$restricted = __('In the settings, caching is disabled for the front page', 'wp-optimize');
304	}
305
306	// Don't cache htacesss. Remember to properly escape any output to prevent injection.
307	if (strpos($_SERVER['REQUEST_URI'], '.htaccess') !== false) {
308	$restricted = 'The file path is unsuitable for caching ('.$_SERVER['REQUEST_URI'].')';
309	}
310
311	// Don't cache feeds.
312	if (function_exists('is_feed') && is_feed() && !wpo_feeds_caching_enabled()) {
313	$restricted = __('We don\'t cache RSS feeds', 'wp-optimize');
314	}
315
316	return $restricted;
317	}
318	}
319
320	/**
321	* Returns true if we need cache content for loggedin users.
322	*
323	* @return bool
324	*/
325	if (!function_exists('wpo_cache_loggedin_users')) :
326	function wpo_cache_loggedin_users() {
327	return !empty($GLOBALS['wpo_cache_config']['enable_user_caching']) \|\| !empty($GLOBALS['wpo_cache_config']['enable_user_specific_cache']) \|\| (function_exists('wpo_we_cache_per_role') && wpo_we_cache_per_role());
328	}
329	endif;
330
331	/**
332	* Get filename for store cache, depending on gzip, mobile and cookie settings.
333	*
334	* @param string $ext
335	* @return string
336	*/
337	if (!function_exists('wpo_cache_filename')) :
338	function wpo_cache_filename($ext = '.html') {
339
340	$wpo_cache_filename_debug = array();
341
342	$filename = 'index';
343
344	if (wpo_cache_mobile_caching_enabled() && wpo_is_mobile()) {
345	$filename = 'mobile.' . $filename;
346	}
347
348	if (wpo_webp_images_enabled() && !wpo_is_using_webp_images_redirection() && wpo_is_using_alter_html()) {
349	$filename = $filename . '.webp';
350	}
351
352	$cookies = wpo_cache_cookies();
353
354	$cache_key = '';
355
356	/**
357	* Add cookie values to filename if need.
358	* This section was inspired by things learned from WP-Rocket.
359	*/
360	if (!empty($cookies)) {
361	foreach ($cookies as $key => $cookie_name) {
362	if (is_array($cookie_name) && isset($_COOKIE[$key])) {
363	foreach ($cookie_name as $cookie_key) {
364	if (isset($_COOKIE[$key][$cookie_key]) && '' !== $_COOKIE[$key][$cookie_key]) {
365	$_cache_key = $cookie_key.'='.$_COOKIE[$key][$cookie_key];
366	$_cache_key = preg_replace('/[^a-z0-9_\-\=]/i', '-', $_cache_key);
367	$cache_key .= '-' . $_cache_key;
368	$wpo_cache_filename_debug[] = 'Cookie: name: ' . $key . '[' . $cookie_key . '], value: *** , cache_key:' . $_cache_key;
369	}
370	}
371	continue;
372	}
373
374	if (isset($_COOKIE[$cookie_name]) && '' !== $_COOKIE[$cookie_name]) {
375	$_cache_key = $cookie_name.'='.$_COOKIE[$cookie_name];
376	$_cache_key = preg_replace('/[^a-z0-9_\-\=]/i', '-', $_cache_key);
377	$cache_key .= '-' . $_cache_key;
378	$wpo_cache_filename_debug[] = 'Cookie: name: ' . $cookie_name . ', value: *** , cache_key:' . $_cache_key;
379	}
380	}
381	}
382
383	$query_variables = wpo_cache_query_variables();
384
385	/**
386	* Add GET variables to cache file name if need.
387	*/
388	if (!empty($query_variables)) {
389	foreach ($query_variables as $variable) {
390	if (isset($_GET[$variable]) && !empty($_GET[$variable])) {
391	$_cache_key = $variable.'='.$_GET[$variable];
392	$_cache_key = preg_replace('/[^a-z0-9_\-\=]/i', '-', $_cache_key);
393	$cache_key .= '-' . $_cache_key;
394	$wpo_cache_filename_debug[] = 'GET parameter: name: ' . $variable . ', value:' . htmlentities($_GET[$variable]) . ', cache_key:' . $_cache_key;
395	}
396	}
397	}
398
399	// add hash of queried cookies and variables to cache file name.
400	if ('' !== $cache_key) {
401	$hash = md5($cache_key);
402	$filename .= '-'.$hash;
403	$wpo_cache_filename_debug[] = 'Hash: ' . $hash;
404	}
405
406	$filename = apply_filters('wpo_cache_filename', $filename);
407
408	$wpo_cache_filename_debug[] = 'Extension: ' . $ext;
409	$wpo_cache_filename_debug[] = 'Filename: ' . $filename.$ext;
410
411	$GLOBALS['wpo_cache_filename_debug'] = $wpo_cache_filename_debug;
412
413	return $filename . $ext;
414	}
415	endif;
416
417	/**
418	* Returns site url from site_url() function or if it is not available from cache configuration.
419	*/
420	if (!function_exists('wpo_site_url')) :
421	function wpo_site_url() {
422	if (is_callable('site_url')) return site_url('/');
423
424	$site_url = empty($GLOBALS['wpo_cache_config']['site_url']) ? '' : $GLOBALS['wpo_cache_config']['site_url'];
425	return $site_url;
426	}
427	endif;
428
429	/**
430	* Get cookie names which impact on cache file name.
431	*
432	* @return array
433	*/
434	if (!function_exists('wpo_cache_cookies')) :
435	function wpo_cache_cookies() {
436	$cookies = empty($GLOBALS['wpo_cache_config']['wpo_cache_cookies']) ? array() : $GLOBALS['wpo_cache_config']['wpo_cache_cookies'];
437	return $cookies;
438	}
439	endif;
440
441	/**
442	* Get GET variable names which impact on cache file name.
443	*
444	* @return array
445	*/
446	if (!function_exists('wpo_cache_query_variables')) :
447	function wpo_cache_query_variables() {
448	if (defined('WPO_CACHE_URL_PARAMS') && WPO_CACHE_URL_PARAMS) {
449	$variables = array_keys($_GET);
450	} else {
451	$variables = empty($GLOBALS['wpo_cache_config']['wpo_cache_query_variables']) ? array() : $GLOBALS['wpo_cache_config']['wpo_cache_query_variables'];
452	}
453
454	if (!empty($variables)) {
455	sort($variables);
456	}
457
458	return wpo_cache_maybe_ignore_query_variables($variables);
459	}
460	endif;
461
462	/**
463	* Get list of all received HTTP headers.
464	*
465	* @return array
466	*/
467	if (!function_exists('wpo_get_http_headers')) :
468	function wpo_get_http_headers() {
469
470	static $headers;
471
472	if (!empty($headers)) return $headers;
473
474	$headers = array();
475
476	// if is apache server then use get allheaders() function.
477	if (function_exists('getallheaders')) {
478	$headers = getallheaders();
479	} else {
480	// https://www.php.net/manual/en/function.getallheaders.php
481	foreach ($_SERVER as $key => $value) {
482
483	$key = strtolower($key);
484
485	if ('HTTP_' == substr($key, 0, 5)) {
486	$headers[str_replace(' ', '-', ucwords(str_replace('_', ' ', substr($key, 5))))] = $value;
487	} elseif ('content_type' == $key) {
488	$headers["Content-Type"] = $value;
489	} elseif ('content_length' == $key) {
490	$headers["Content-Length"] = $value;
491	}
492	}
493	}
494
495	return $headers;
496	}
497	endif;
498
499	/**
500	* Check if requested Accept-Encoding headers has gzip value.
501	*
502	* @return bool
503	*/
504	if (!function_exists('wpo_cache_gzip_accepted')) :
505	function wpo_cache_gzip_accepted() {
506	$headers = wpo_get_http_headers();
507
508	if (isset($headers['Accept-Encoding']) && preg_match('/gzip/i', $headers['Accept-Encoding'])) return true;
509
510	return false;
511	}
512	endif;
513
514	/**
515	* Check if we can output gzip content in current answer, i.e. check Accept-Encoding headers has gzip value
516	* and function ob_gzhandler is available.
517	*
518	* @return bool
519	*/
520	if (!function_exists('wpo_cache_can_output_gzip_content')) :
521	function wpo_cache_can_output_gzip_content() {
522	return wpo_cache_gzip_accepted() && function_exists('ob_gzhandler');
523	}
524	endif;
525
526	/**
527	* Check if header with certain name exists in already prepared headers and has value comparable with $header_value.
528	*
529	* @param string $header_name header name
530	* @param string $header_value header value as regexp.
531	*
532	* @return bool
533	*/
534	if (!function_exists('wpo_cache_is_in_response_headers_list')) :
535	function wpo_cache_is_in_response_headers_list($header_name, $header_value) {
536	$headers_list = headers_list();
537
538	if (!empty($headers_list)) {
539	$header_name = strtolower($header_name);
540
541	foreach ($headers_list as $value) {
542	$value = explode(':', $value);
543
544	if (strtolower($value[0]) == $header_name) {
545	if (preg_match('/'.$header_value.'/', $value[1])) {
546	return true;
547	} else {
548	return false;
549	}
550	}
551	}
552	}
553
554	return false;
555	}
556	endif;
557
558	/**
559	* Check if mobile cache is enabled and current request is from moblile device.
560	*
561	* @return bool
562	*/
563	if (!function_exists('wpo_cache_mobile_caching_enabled')) :
564	function wpo_cache_mobile_caching_enabled() {
565	if (!empty($GLOBALS['wpo_cache_config']['enable_mobile_caching'])) return true;
566	return false;
567	}
568	endif;
569
570	/**
571	* Check if webp images enabled
572	*
573	* @return bool
574	*/
575	if (!function_exists('wpo_webp_images_enabled')) :
576	function wpo_webp_images_enabled() {
577	if (!empty($GLOBALS['wpo_cache_config']['use_webp_images'])) return true;
578	return false;
579	}
580	endif;
581
582	/**
583	* Check whether webp images using alter html method or not
584	*
585	* @return bool
586	*/
587	if (!function_exists('wpo_is_using_alter_html')) :
588	function wpo_is_using_alter_html() {
589	return (isset($_SERVER['HTTP_ACCEPT']) && false !== strpos($_SERVER['HTTP_ACCEPT'], 'image/webp'));
590	}
591	endif;
592
593	/**
594	* Check whether webp images are served using redirect
595	*
596	* @return bool
597	*/
598	if (!function_exists('wpo_is_using_webp_images_redirection')) :
599	function wpo_is_using_webp_images_redirection() {
600	if (empty($GLOBALS['wpo_cache_config']['uploads'])) return false;
601
602	$uploads_dir = $GLOBALS['wpo_cache_config']['uploads'];
603	$htaccess_file = $uploads_dir . '/.htaccess';
604	if (!file_exists($htaccess_file)) return false;
605	$htaccess_content = file_get_contents($htaccess_file);
606	$comment_sections = array('Register webp mime type', 'WP-Optimize WebP Rules');
607
608	if (function_exists('str_contains')) {
609	return str_contains($htaccess_content, $comment_sections[0]) && str_contains($htaccess_content, $comment_sections[1]);
610	} else {
611	return strpos($htaccess_content, $comment_sections[0]) && strpos($htaccess_content, $comment_sections[1]);
612	}
613	}
614	endif;
615
616	/**
617	* Serves the cache and exits
618	*/
619	if (!function_exists('wpo_serve_cache')) :
620	function wpo_serve_cache() {
621	$file_name = wpo_cache_filename();
622
623	$file_name_rss_xml = wpo_cache_filename('.rss-xml');
624	$send_as_feed = false;
625
626	$path_dir = WPO_CACHE_FILES_DIR . '/' . wpo_get_url_path() . '/';
627	$path = $path_dir . $file_name;
628
629	if (wpo_feeds_caching_enabled()) {
630	// check for .xml cache file if .html cache file doesn't exist
631	if (!file_exists($path_dir . $file_name) && file_exists($path_dir . $file_name_rss_xml)) {
632	$path = $path_dir . $file_name_rss_xml;
633	$send_as_feed = true;
634	}
635	}
636
637	$use_gzip = false;
638
639	// if we can use gzip and gzipped file exist in cache we use it.
640	// if headers already sent we don't use gzipped file content.
641	if (!headers_sent() && wpo_cache_gzip_accepted() && file_exists($path . '.gz')) {
642	$path .= '.gz';
643	$use_gzip = true;
644	}
645
646	$modified_time = file_exists($path) ? (int) filemtime($path) : time();
647
648	// Cache has expired, purge and exit.
649	if (!empty($GLOBALS['wpo_cache_config']['page_cache_length'])) {
650	if (time() > ($GLOBALS['wpo_cache_config']['page_cache_length'] + $modified_time)) {
651	wpo_delete_files($path);
652	return;
653	}
654	}
655
656	if ($use_gzip) {
657	// Disable zlib output compression to avoid double content compression
658	ini_set('zlib.output_compression', 'Off');
659	}
660
661	$gzip_header_already_sent = wpo_cache_is_in_response_headers_list('Content-Encoding', 'gzip');
662
663	header('Cache-Control: no-cache'); // Check back later
664
665	if (!empty($modified_time) && !empty($_SERVER['HTTP_IF_MODIFIED_SINCE']) && strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) === $modified_time) {
666	if ($use_gzip && !$gzip_header_already_sent) {
667	header('Content-Encoding: gzip');
668	}
669
670	if ($send_as_feed) {
671	header('Content-type: application/rss+xml');
672	}
673
674	header('WPO-Cache-Status: cached');
675	header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $modified_time) . ' GMT');
676	header($_SERVER['SERVER_PROTOCOL'] . ' 304 Not Modified', true, 304);
677	exit;
678	}
679
680	if (file_exists($path) && is_readable($path)) {
681
682	if (wpo_is_canonical_redirection_needed()) return;
683
684	if ($use_gzip && !$gzip_header_already_sent) {
685	header('Content-Encoding: gzip');
686	}
687
688	// send correct headers for xml and txt files
689	$filename = basename(dirname($path));
690
691	if (preg_match('/\.xml$/i', $filename)) {
692	header('Content-type: text/xml');
693	}
694
695	if (preg_match('/\.txt$/i', $filename)) {
696	header('Content-type: text/plain');
697	}
698
699	if ($send_as_feed) {
700	header('Content-type: application/rss+xml');
701	}
702
703	header('WPO-Cache-Status: cached');
704	if (!empty($modified_time)) {
705	header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $modified_time) . ' GMT');
706	}
707
708	readfile($path);
709
710	exit;
711	}
712	}
713	endif;
714
715	/**
716	* Checks and does redirection, if needed
717	*
718	* @return bool
719	*/
720	if (!function_exists('wpo_is_canonical_redirection_needed')) :
721	function wpo_is_canonical_redirection_needed() {
722	$permalink_structure = isset($GLOBALS['wpo_cache_config']['permalink_structure']) ? $GLOBALS['wpo_cache_config']['permalink_structure'] : '';
723	$site_url = wpo_site_url();
724
725	$schema = isset($_SERVER['HTTPS']) && 'on' === $_SERVER['HTTPS'] ? "https" : "http";
726	$url_part = "://" . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
727	$requested_url = $schema . $url_part;
728	$url_parts = parse_url($requested_url);
729	$extension = pathinfo($url_parts['path'], PATHINFO_EXTENSION);
730
731	if (!empty($permalink_structure) && $requested_url != $site_url && ((isset($url_parts['path']) && '/' !== $url_parts['path']) \|\| isset($url_parts['query']))) {
732	$request_uri = rtrim($_SERVER['REQUEST_URI'], '?');
733	if ('/' == substr($permalink_structure, -1) && empty($extension) && empty($url_parts['query']) && empty($url_parts['fragment'])) {
734	$url = preg_replace('/(.+?)([\/]*)(\[\?\#][^\/]+\|$)/', '$1/$3', $request_uri);
735	if (0 !== strcmp($request_uri, $url)) return true;
736	} else {
737	$url = rtrim($request_uri, '/');
738	if (0 !== strcmp($request_uri, $url)) return true;
739	}
740	}
741	return false;
742	}
743	endif;
744
745	/**
746	* Clears the cache
747	*/
748	if (!function_exists('wpo_cache_flush')) :
749	function wpo_cache_flush() {
750
751	if (defined('WPO_CACHE_FILES_DIR') && '' != WPO_CACHE_FILES_DIR) wpo_delete_files(WPO_CACHE_FILES_DIR);
752
753	if (function_exists('wp_cache_flush')) {
754	wp_cache_flush();
755	}
756
757	do_action('wpo_cache_flush');
758	}
759	endif;
760
761	/**
762	* Get URL path for caching
763	*
764	* @since 1.0
765	* @return string
766	*/
767	if (!function_exists('wpo_get_url_path')) :
768	function wpo_get_url_path($url = '') {
769	$url = '' == $url ? wpo_current_url() : $url;
770	$url_parts = parse_url($url);
771
772	if (isset($url_parts['path']) && false !== stripos($url_parts['path'], '/index.php')) {
773	$url_parts['path'] = preg_replace('/(.*?)index\.php(\/.+)/i', '$1index-php$2', $url_parts['path']);
774	}
775
776	/*
777	* Convert the hexadecimal digits within the percent-encoded triplet to uppercase, to ensure that the path remains
778	* consistent. For instance, "example.com/%e0%a6" will be converted to "example.com/%E0%A6".
779	*/
780	if (isset($url_parts['path'])) {
781	$url_parts['path'] = preg_replace_callback('/%[0-9A-F]{2}/i', function($matches) {
782	return strtoupper($matches[0]);
783	}, $url_parts['path']);
784	}
785
786	if (!isset($url_parts['host'])) $url_parts['host'] = '';
787	if (!isset($url_parts['path'])) $url_parts['path'] = '';
788
789	return $url_parts['host'].$url_parts['path'];
790	}
791	endif;
792
793	/**
794	* Get requested url.
795	*
796	* @return string
797	*/
798	if (!function_exists('wpo_current_url')) :
799	function wpo_current_url() {
800	// Note: We use `static $url` to save the first value we retrieve, as some plugins change $_SERVER later on in the process (e.g. Weglot).
801	// Otherwise this function would return a different URL at the beginning and end of the cache process.
802	static $url = '';
803	if ('' != $url) return $url;
804	$http_host = isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : '';
805	$url = rtrim('http' . ((isset($_SERVER['HTTPS']) && ('on' == $_SERVER['HTTPS'] \|\| 1 == $_SERVER['HTTPS']) \|\|
806	isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && 'https' == $_SERVER['HTTP_X_FORWARDED_PROTO']) ? 's' : '' )
807	. '://' . $http_host.$_SERVER['REQUEST_URI'], '/');
808	return $url;
809	}
810	endif;
811
812	/**
813	* Return list of conditional tag exceptions.
814	*
815	* @return array
816	*/
817	if (!function_exists('wpo_get_conditional_tags_exceptions')) :
818	function wpo_get_conditional_tags_exceptions() {
819	static $exceptions = null;
820
821	if (null !== $exceptions) return $exceptions;
822
823	if (!empty($GLOBALS['wpo_cache_config'])) {
824	if (empty($GLOBALS['wpo_cache_config']['cache_exception_conditional_tags'])) {
825	$exceptions = array();
826
827	} else {
828
829	$exceptions = $GLOBALS['wpo_cache_config']['cache_exception_conditional_tags'];
830
831	}
832
833	} elseif (class_exists('WPO_Page_Cache')) {
834
835	$config = WPO_Page_Cache::instance()->config->get();
836
837	if (is_array($config) && array_key_exists('cache_exception_conditional_tags', $config)) {
838	$exceptions = $config['cache_exception_conditional_tags'];
839	} else {
840	$exceptions = array();
841	}
842
843	$exceptions = is_array($exceptions) ? $exceptions : preg_split('#(\n\|\r\|\r\n)#', $exceptions);
844	$exceptions = array_filter($exceptions, 'trim');
845
846	} else {
847	$exceptions = array();
848	}
849
850	return $exceptions;
851	}
852	endif;
853
854	/**
855	* Return list of url exceptions.
856	*
857	* @return array
858	*/
859	if (!function_exists('wpo_get_url_exceptions')) :
860	function wpo_get_url_exceptions() {
861	static $exceptions = null;
862
863	if (null !== $exceptions) return $exceptions;
864
865	// if called from file-based-page-cache.php when WP loading
866	// and cache settings exists then use it otherwise get settings from database.
867	if (!empty($GLOBALS['wpo_cache_config'])) {
868	if (empty($GLOBALS['wpo_cache_config']['cache_exception_urls'])) {
869	$exceptions = array();
870	} else {
871	$exceptions = is_array($GLOBALS['wpo_cache_config']['cache_exception_urls']) ? $GLOBALS['wpo_cache_config']['cache_exception_urls'] : preg_split('#(\n\|\r)#', $GLOBALS['wpo_cache_config']['cache_exception_urls']);
872	}
873	} elseif (class_exists('WPO_Page_Cache')) {
874	$config = WPO_Page_Cache::instance()->config->get();
875
876	if (is_array($config) && array_key_exists('cache_exception_urls', $config)) {
877	$exceptions = $config['cache_exception_urls'];
878	} else {
879	$exceptions = array();
880	}
881
882	$exceptions = is_array($exceptions) ? $exceptions : preg_split('#(\n\|\r)#', $exceptions);
883	$exceptions = array_filter($exceptions, 'trim');
884	} else {
885	$exceptions = array();
886	}
887
888	return apply_filters('wpo_get_url_exceptions', $exceptions);
889	}
890	endif;
891
892	/**
893	* Return true of exception url matches current url
894	*
895	* @param string $exception Exceptions to check URL against.
896	* @param bool $regex Whether to check with regex or not.
897	* @return bool true if matched, false otherwise
898	*/
899	if (!function_exists('wpo_current_url_exception_match')) :
900	function wpo_current_url_exception_match($exception) {
901
902	return wpo_url_exception_match(wpo_current_url(), $exception);
903	}
904	endif;
905
906	/**
907	* Check if url in conditional tags exceptions list.
908	*
909	* @return string
910	*/
911	if (!function_exists('wpo_url_in_conditional_tags_exceptions')) :
912	function wpo_url_in_conditional_tags_exceptions() {
913
914	$exceptions = wpo_get_conditional_tags_exceptions();
915	$restricted = '';
916	$allowed_functions = array('is_single', 'is_page', 'is_front_page', 'is_home', 'is_archive', 'is_tag', 'is_category', 'is_feed', 'is_search', 'is_author', 'is_woocommerce', 'is_shop', 'is_product', 'is_account_page', 'is_product_category', 'is_product_tag', 'is_wc_endpoint_url', 'is_bbpress', 'bbp_is_forum_archive', 'bbp_is_topic_archive', 'bbp_is_topic_tag', 'bbp_is_single_forum', 'bbp_is_single_topic', 'bbp_is_single_view', 'bbp_is_single_user', 'bbp_is_user_home', 'bbp_is_search');
917	//Filter for add more conditional tags to whitelist in the exceptions list.
918	$allowed_functions = apply_filters('wpo_allowed_conditional_tags_exceptions', $allowed_functions);
919	if (!empty($exceptions)) {
920	foreach ($exceptions as $exception) {
921	if (false !== strpos($exception, 'is_')) {
922	$exception_function = $exception;
923	if ('()' == substr($exception, -2)) {
924	$exception_function = substr($exception, 0, -2);
925	}
926
927	if (in_array($exception_function, $allowed_functions) && function_exists($exception_function) && call_user_func($exception_function)) {
928	$restricted = sprintf(__('In the settings, caching is disabled for %s', 'wp-optimize'), $exception_function);
929	}
930	}
931	}
932	}
933	return $restricted;
934	}
935	endif;
936
937
938	/**
939	* Check if url in exceptions list.
940	*
941	* @param string $url
942	*
943	* @return bool
944	*/
945	if (!function_exists('wpo_url_in_exceptions')) :
946	function wpo_url_in_exceptions($url) {
947	$exceptions = wpo_get_url_exceptions();
948
949	if (!empty($exceptions)) {
950	foreach ($exceptions as $exception) {
951
952	// don't check / - front page using regexp, we handle it in wpo_restricted_cache_page_type()
953	if ('/' == $exception) continue;
954
955	if (wpo_url_exception_match($url, $exception)) {
956	// Exception match.
957	return true;
958	}
959	}
960	}
961
962	return false;
963	}
964	endif;
965
966	/**
967	* Checks if an URL matches against listed exceptions.
968	*
969	* @param string $url - complete url string i.e. http(s)://domain/path
970	* @param string $exception - complete url or absolute path, can contain (.*) wildcards; Sometimes can be urlencoded
971	*
972	* @return bool
973	*/
974	if (!function_exists('wpo_url_exception_match')) :
975	function wpo_url_exception_match($url, $exception) {
976	if (preg_match('#^[\s]*$#', $exception)) {
977	return false;
978	}
979
980	$exception = str_replace('', '.', $exception);
981
982	$exception = trim($exception);
983
984	// Used to test websites placed in subdirectories.
985	$sub_dir = '';
986
987	// If exception defined from root i.e. /page1 then remove domain part in url.
988	if (preg_match('/^\//', $exception)) {
989	// get site sub directory.
990	$sub_dir = preg_replace('#^(http\|https):\/\/.*\/#Ui', '', wpo_site_url());
991	// add prefix slash and remove slash.
992	$sub_dir = ('' == $sub_dir) ? '' : '/' . rtrim($sub_dir, '/');
993	// get relative path
994	$url = preg_replace('#^(http\|https):\/\/.*\/#Ui', '/', $url);
995	}
996
997	$url = urldecode(rtrim($url, '/')) . '/';
998	$exception = rtrim($exception, '/');
999
1000	// if we have no wildcard in the end of exception then add slash.
1001	if (!preg_match('#$\.\*$$#', $exception)) $exception .= '/';
1002
1003	$exception = preg_quote($exception);
1004
1005	// fix - unescape some possibly escaped mask characters
1006	$search = array(
1007	'\\.\\*',
1008	'\\-',
1009	);
1010	$replace = array(
1011	'.*',
1012	'-',
1013	);
1014	$exception = urldecode(str_replace($search, $replace, $exception));
1015
1016	return (preg_match('#^'.$exception.'$#i', $url) \|\| preg_match('#^'.$sub_dir.$exception.'$#i', $url));
1017	}
1018	endif;
1019
1020	/**
1021	* Checks if its a mobile device
1022	*
1023	* @see https://developer.wordpress.org/reference/functions/wp_is_mobile/
1024	*/
1025	if (!function_exists('wpo_is_mobile')) :
1026	function wpo_is_mobile() {
1027	if (empty($_SERVER['HTTP_USER_AGENT'])) {
1028	$is_mobile = false;
1029	// many mobile devices (all iPhone, iPad, etc.)
1030	} elseif (strpos($_SERVER['HTTP_USER_AGENT'], 'Mobile') !== false
1031	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Android') !== false
1032	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Silk/') !== false
1033	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Kindle') !== false
1034	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'BlackBerry') !== false
1035	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mini') !== false
1036	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mobi') !== false
1037	) {
1038	$is_mobile = true;
1039	} else {
1040	$is_mobile = false;
1041	}
1042
1043	return $is_mobile;
1044	}
1045	endif;
1046
1047	/**
1048	* Check if current browser agent is not disabled in options.
1049	*
1050	* @return bool
1051	*/
1052	if (!function_exists('wpo_is_accepted_user_agent')) :
1053	function wpo_is_accepted_user_agent($user_agent) {
1054
1055	$exceptions = is_array($GLOBALS['wpo_cache_config']['cache_exception_browser_agents']) ? $GLOBALS['wpo_cache_config']['cache_exception_browser_agents'] : preg_split('#(\n\|\r)#', $GLOBALS['wpo_cache_config']['cache_exception_browser_agents']);
1056
1057	if (!empty($exceptions)) {
1058	foreach ($exceptions as $exception) {
1059	if ('' == trim($exception)) continue;
1060
1061	if (preg_match('#'.$exception.'#i', $user_agent)) return false;
1062	}
1063	}
1064
1065	return true;
1066	}
1067	endif;
1068
1069	if (!function_exists('wpo_delete_files')) :
1070	/**
1071	* Deletes a specified source file or directory.
1072	*
1073	* If $src is a file, only that file will be deleted. If $src is a directory, the behavior depends on the
1074	* $recursive parameter. When $recursive is true, the directory and its contents (including files and subdirectories)
1075	* will be deleted. When $recursive is false, only the files in the top-level directory(eg. $src directory) will be deleted,
1076	* while the $src directory itself and its subdirectories will remain untouched.
1077	*
1078	* @param string $src The path to the source file or directory to delete.
1079	* @param bool $recursive (Optional) When set to true, the directory and its contents (including files and subdirectories)
1080	* will be deleted. If false, only the files in the top-level directory will be deleted while
1081	* its subdirectories will be preserved. Defaults to true.
1082	*
1083	* @return bool Returns true if the specified file or all files within the specified directory (and its subdirectories,
1084	* when $recursive is true) are successfully deleted. Returns false if any file(s) could not be deleted
1085	* due to file permissions or other reasons.
1086	*/
1087	function wpo_delete_files($src, $recursive = true) {
1088	// If the source doesn't exist, consider it deleted and return true
1089	if (!file_exists($src)) {
1090	return true;
1091	}
1092
1093	/*
1094	* If the source is a file, delete it and return the result.
1095	* If `unlink()` fails, we also verify if the file still exists before returning the result, as another
1096	* PHP process may have already deleted the file between the execution of `is_file()` and `unlink()` operations.
1097	*/
1098	if (is_file($src)) {
1099	if (!@unlink($src) && file_exists($src)) { // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1100	return false;
1101	}
1102	return true;
1103	}
1104
1105	$success = true;
1106
1107	// If recursive is false, delete only the top-level files and return the result
1108	if (!$recursive) {
1109	$dir_handle = @opendir($src); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1110
1111	/*
1112	* If opendir() is successful, process directory contents. If not, check if the directory exists.
1113	* If it exists, return false (failure). Otherwise, assume it's already deleted and return true (success).
1114	*/
1115	if (false !== $dir_handle) {
1116
1117	while (false !== ($file = readdir($dir_handle))) {
1118	if ('.' == $file \|\| '..' == $file) {
1119	continue;
1120	}
1121
1122	$full_path = $src . '/' . $file;
1123
1124	// If it's a file, delete it
1125	if (is_file($full_path)) {
1126	if (!wpo_delete_files($full_path)) {
1127	$success = false;
1128	}
1129	}
1130	}
1131
1132	closedir($dir_handle);
1133	} else {
1134	if (file_exists($src)) {
1135	$success = false;
1136	}
1137	}
1138
1139	return $success;
1140	}
1141
1142	// If recursive is true, delete all files and directories recursively
1143	$dir_handle = @opendir($src); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1144
1145	/*
1146	* If opendir() is successful, process directory contents. If not, check if the directory exists.
1147	* If it exists, return false (failure). Otherwise, assume it's already deleted and return true (success).
1148	*/
1149	if (false !== $dir_handle) {
1150
1151	while (false !== ($file = readdir($dir_handle))) {
1152	if ('.' == $file \|\| '..' == $file) {
1153	continue;
1154	}
1155
1156	$full_path = $src . '/' . $file;
1157
1158	if (!wpo_delete_files($full_path)) {
1159	$success = false;
1160	}
1161	}
1162
1163	closedir($dir_handle);
1164	} else {
1165	if (file_exists($src)) {
1166	$success = false;
1167	}
1168	}
1169
1170	/*
1171	* Delete the source directory itself.
1172	* Success of `rmdir` operation is not recorded; we only ultimately care about emptying, not removing
1173	* entirely (empty folders in our context are harmless)
1174	*/
1175	if ($success) {
1176	@rmdir($src); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1177	}
1178
1179	// Delete cached information about cache size
1180	WP_Optimize()->get_page_cache()->delete_cache_size_information();
1181
1182	return $success;
1183	}
1184	endif;
1185
1186	if (!function_exists('wpo_is_empty_dir')) :
1187	/**
1188	* Check if selected directory is empty or has only index.php which we added for security reasons.
1189	*
1190	* @param string $dir
1191	*
1192	* @return bool
1193	*/
1194	function wpo_is_empty_dir($dir) {
1195	if (!file_exists($dir) \|\| !is_dir($dir)) return false;
1196
1197	$handle = opendir($dir);
1198
1199	if (false === $handle) return false;
1200
1201	$is_empty = true;
1202	$file = readdir($handle);
1203
1204	while (false !== $file) {
1205
1206	if ('.' != $file && '..' != $file && 'index.php' != $file) {
1207	$is_empty = false;
1208	break;
1209	}
1210
1211	$file = readdir($handle);
1212	}
1213
1214	closedir($handle);
1215	return $is_empty;
1216	}
1217	endif;
1218
1219	/**
1220	* Either store for later output, or output now. Only the most-recent call will be effective.
1221	*
1222	* @param String\|Null $output - if not null, then the string to use when called by the shutdown action.
1223	*/
1224	if (!function_exists('wpo_cache_add_footer_output')) :
1225	function wpo_cache_add_footer_output($output = null) {
1226
1227	static $buffered = null;
1228
1229	if (function_exists('current_filter') && 'shutdown' == current_filter()) {
1230	// Only add the line if it was a page, not something else (e.g. REST response)
1231	if (function_exists('did_action') && did_action('wp_footer')) {
1232	echo "\n<!-- WP Optimize page cache - https://getwpo.com - ".$buffered." -->\n";
1233	} elseif (defined('WPO_CACHE_DEBUG') && WPO_CACHE_DEBUG && (!defined('REST_REQUEST') \|\| !REST_REQUEST)) {
1234	error_log('[CACHE DEBUG] '.wpo_current_url() . ' - ' . $buffered);
1235	}
1236	} else {
1237	if (null == $buffered && function_exists('add_action')) add_action('shutdown', 'wpo_cache_add_footer_output', 11);
1238	$buffered = $output;
1239	}
1240
1241	}
1242	endif;
1243
1244	/**
1245	* Remove variable names that shouldn't influence cache.
1246	*
1247	* @param array $variables List of variable names.
1248	*
1249	* @return array
1250	*/
1251	if (!function_exists('wpo_cache_maybe_ignore_query_variables')) :
1252	function wpo_cache_maybe_ignore_query_variables($variables) {
1253
1254	/**
1255	* Filters the current $_GET variables that will be used when caching or excluding from cache.
1256	* Currently:
1257	* - 'wpo_cache_debug' (Shows the reason for not being cached even when WP_DEBUG isn't set)
1258	* - 'doing_wp_cron' (alternative cron)
1259	* - 'aiosp_sitemap_path', 'aiosp_sitemap_page' (All in one SEO sitemap)
1260	* - 'xml_sitemap', 'seopress_sitemap', 'seopress_news', 'seopress_video', 'seopress_cpt', 'seopress_paged' (SEOPress sitemap)
1261	* - 'sitemap', 'sitemap_n' (YOAST SEO sitemap)
1262	*/
1263	$exclude_variables = array(
1264	'wpo_cache_debug', // Shows the reason for not being cached even when WP_DEBUG isn't set
1265	'doing_wp_cron', // alternative cron
1266	'aiosp_sitemap_path', // All in one SEO sitemap
1267	'aiosp_sitemap_page',
1268	'xml_sitemap', // SEOPress sitemap
1269	'seopress_sitemap',
1270	'seopress_news',
1271	'seopress_video',
1272	'seopress_cpt',
1273	'seopress_paged',
1274	'sitemap', // YOAST SEO sitemap
1275	'sitemap_n',
1276	);
1277	$exclude_variables = function_exists('apply_filters') ? apply_filters('wpo_cache_ignore_query_variables', $exclude_variables) : $exclude_variables;
1278
1279	if (empty($exclude_variables)) return $variables;
1280
1281	foreach ($exclude_variables as $variable) {
1282	$exclude = array_search($variable, $variables);
1283	if (false !== $exclude) {
1284	array_splice($variables, $exclude, 1);
1285	}
1286	}
1287
1288	return $variables;
1289	}
1290	endif;
1291
1292	/**
1293	* Get cache config
1294	*
1295	* @param string $key - The config item
1296	* @param mixed $default - The default value
1297	*
1298	* @return mixed
1299	*/
1300	if (!function_exists('wpo_cache_config_get')) :
1301	function wpo_cache_config_get($key, $default = false) {
1302	$config = $GLOBALS['wpo_cache_config'];
1303
1304	if (!$config) return false;
1305
1306	if (isset($config[$key])) {
1307	return $config[$key];
1308	} else {
1309	return $default;
1310	}
1311	}
1312	endif;
1313
1314	if (!function_exists('wpo_disable_cache_directories_viewing')) :
1315	function wpo_disable_cache_directories_viewing() {
1316	global $is_apache, $is_IIS, $is_iis7;
1317
1318	if (!is_dir(WPO_CACHE_FILES_DIR)) return;
1319
1320	// Create .htaccess file for apache server.
1321	if ($is_apache) {
1322	$htaccess_filename = WPO_CACHE_FILES_DIR . '/.htaccess';
1323
1324	// CS does not like heredoc
1325	// phpcs:disable
1326	$htaccess_content = <<<EOF
1327	# Disable directory browsing
1328	Options -Indexes
1329
1330	# Disable access to any files
1331	<FilesMatch ".*">
1332	Order allow,deny
1333	Deny from all
1334	</FilesMatch>
1335	EOF;
1336	// phpcs:enable
1337
1338	if (!is_file($htaccess_filename)) @file_put_contents($htaccess_filename, $htaccess_content); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress the error when there is file permission issues
1339	}
1340
1341	// Create web.config file for IIS servers.
1342	if ($is_IIS \|\| $is_iis7) {
1343	$webconfig_filename = WPO_CACHE_FILES_DIR . '/web.config';
1344	$webconfig_content = "<configuration>\n<system.webServer>\n<authorization>\n<deny users=\"*\" />\n</authorization>\n</system.webServer>\n</configuration>\n";
1345
1346	if (!is_file($webconfig_filename)) @file_put_contents($webconfig_filename, $webconfig_content); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress the error when there is file permission issues
1347	}
1348
1349	// Create empty index.php file for all servers.
1350	if (!is_file(WPO_CACHE_FILES_DIR . '/index.php')) @file_put_contents(WPO_CACHE_FILES_DIR . '/index.php', '');// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress the error when there is file permission issues
1351	}
1352	endif;
1353
1354	/**
1355	* Add the headers indicating why the page is not cached or served from cache
1356	*
1357	* @param string $message - The headers
1358	*
1359	* @return void
1360	*/
1361	if (!function_exists('wpo_cache_add_nocache_http_header')) :
1362	function wpo_cache_add_nocache_http_header($message = '') {
1363	static $buffered_message = null;
1364
1365	if (function_exists('current_filter') && 'send_headers' === current_filter() && $buffered_message && !headers_sent()) {
1366	header('WPO-Cache-Status: not cached');
1367	header('WPO-Cache-Message: '. trim(str_replace(array("\r", "\n", ':'), ' ', strip_tags($buffered_message))));
1368	} else {
1369	if (!$buffered_message && function_exists('add_action')) add_action('send_headers', 'wpo_cache_add_nocache_http_header', 11);
1370	$buffered_message = $message;
1371	}
1372	}
1373	endif;
1374
1375	/**
1376	* Check if feeds caching enabled
1377	*
1378	* @return bool
1379	*/
1380	if (!function_exists('wpo_feeds_caching_enabled')) :
1381	function wpo_feeds_caching_enabled() {
1382	return apply_filters('wpo_feeds_caching_enabled', true);
1383	}
1384	endif;
1385
1386	if (!function_exists('wpo_debug_backtrace_summary')) {
1387	function wpo_debug_backtrace_summary($ignore_class = null, $skip_frames = 0, $pretty = true) {
1388	static $truncate_paths;
1389
1390	$trace = debug_backtrace(false);
1391	$caller = array();
1392	$check_class = !is_null($ignore_class);
1393	$skip_frames++; // Skip this function.
1394
1395	if (!isset($truncate_paths)) {
1396	$truncate_paths = array(
1397	wpo_normalize_path(WP_CONTENT_DIR),
1398	wpo_normalize_path(ABSPATH),
1399	);
1400	}
1401
1402	foreach ($trace as $call) {
1403	if ($skip_frames > 0) {
1404	$skip_frames--;
1405	} elseif (isset($call['class'])) {
1406	if ($check_class && $ignore_class == $call['class']) {
1407	continue; // Filter out calls.
1408	}
1409
1410	$caller[] = "{$call['class']}{$call['type']}{$call['function']}";
1411	} else {
1412	if (in_array($call['function'], array('do_action', 'apply_filters', 'do_action_ref_array', 'apply_filters_ref_array'), true)) {
1413	$caller[] = "{$call['function']}('{$call['args'][0]}')";
1414	} elseif (in_array($call['function'], array('include', 'include_once', 'require', 'require_once'), true)) {
1415	$filename = isset($call['args'][0]) ? $call['args'][0] : '';
1416	$caller[] = $call['function'] . "('" . str_replace($truncate_paths, '', wpo_normalize_path($filename)) . "')";
1417	} else {
1418	$caller[] = $call['function'];
1419	}
1420	}
1421	}
1422	if ($pretty) {
1423	return implode(', ', array_reverse($caller));
1424	} else {
1425	return $caller;
1426	}
1427	}
1428	}
1429
1430	if (!function_exists('wpo_normalize_path')) {
1431	function wpo_normalize_path($path) {
1432	// Standardise all paths to use '/'.
1433	$path = str_replace('\\', '/', $path);
1434
1435	// Replace multiple slashes down to a singular, allowing for network shares having two slashes.
1436	$path = preg_replace('\|(?<=.)/+\|', '/', $path);
1437
1438	// Windows paths should uppercase the drive letter.
1439	if (':' === substr($path, 1, 1)) {
1440	$path = ucfirst($path);
1441	}
1442
1443	return $path;
1444	}
1445	}
1446