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