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