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