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

file-based-page-cache-functions.php in WP-Optimize – Cache, Compress images, Minify & Clean database to boost page speed & performance 3.3.2, 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 (!function_exists('is_user_logged_in') \|\| (function_exists('wp_get_current_user') && is_user_logged_in())) {
37	if (!wpo_cache_loggedin_users()) {
38	$no_cache_because[] = __('User is logged in', 'wp-optimize');
39	} elseif (!empty($GLOBALS['wpo_cache_config']['enable_user_caching'])) {
40	// Will only run when "Serve cached pages to logged in users" is checked
41	$no_cache_because[] = __('User is logged in, this works only when the cache is preloaded', 'wp-optimize');
42	}
43	}
44
45	$restricted_page_type_cache = apply_filters('wpo_restricted_cache_page_type', false);
46	if ($restricted_page_type_cache) {
47	$no_cache_because[] = $restricted_page_type_cache;
48	}
49
50	$conditional_tag_exceptions = apply_filters('wpo_url_in_conditional_tags_exceptions', false);
51	if ($conditional_tag_exceptions) {
52	$no_cache_because[] = $conditional_tag_exceptions;
53	}
54
55	// No root cache folder, so short-circuit here
56	if (!file_exists(WPO_CACHE_DIR)) {
57	$no_cache_because[] = __('WP-O cache parent directory was not found', 'wp-optimize').' ('.WPO_CACHE_DIR.')';
58	} elseif (!file_exists(WPO_CACHE_FILES_DIR)) {
59	// Try creating a folder for cached files, if it was flushed recently
60	if (!mkdir(WPO_CACHE_FILES_DIR)) {
61	$no_cache_because[] = __('WP-O cache directory was not found', 'wp-optimize').' ('.WPO_CACHE_FILES_DIR.')';
62	} else {
63	wpo_disable_cache_directories_viewing();
64	}
65	}
66
67	// If comments are opened and the user has saved his information.
68	if (function_exists('comments_open') && function_exists('get_post') && get_post() && comments_open()) {
69	$commenter = wp_get_current_commenter();
70	// if any of the fields contain something, do not save to cache
71	if ('' != $commenter['comment_author'] \|\| '' != $commenter['comment_author_email'] \|\| '' != $commenter['comment_author_url']) {
72	$no_cache_because[] = __('Comments are opened and the visitor saved his information.', 'wp-optimize');
73	}
74	}
75
76	$can_cache_page = true;
77
78	if (defined('DONOTCACHEPAGE') && DONOTCACHEPAGE) {
79	$can_cache_page = false;
80	}
81
82	/**
83	* Defines if the page can be cached or not
84	*
85	* @param boolean $can_cache_page
86	*/
87	$can_cache_page_filter = apply_filters('wpo_can_cache_page', $can_cache_page);
88
89	if (!$can_cache_page_filter) {
90	if ($can_cache_page) {
91	$can_cache_page = false;
92	$no_cache_because[] = __('wpo_can_cache_page filter forbade it', 'wp-optimize');
93	} else {
94	$no_cache_because[] = __('DONOTCACHEPAGE constant forbade it and wpo_can_cache_page filter did not over-ride it', 'wp-optimize');
95	}
96	}
97
98	if (defined('REST_REQUEST') && REST_REQUEST) {
99	$no_cache_because[] = __('This is a REST API request (identified by REST_REQUEST constant)', 'wp-optimize');
100	}
101
102	// Don't cache with fatal error pages.
103	$last_error = error_get_last();
104	if (is_array($last_error) && E_ERROR == $last_error['type']) {
105	$no_cache_because[] = __('This page has a fatal error', 'wp-optimize');
106	}
107
108	if (http_response_code() >= 500) {
109	$no_cache_because[] = sprintf(__('This page has a critical error (HTTP code %s)', 'wp-optimize'), http_response_code());
110	} elseif (http_response_code() >= 400) {
111	$no_cache_because[] = sprintf(__('This page returned an HTTP unauthorised response code (%s)', 'wp-optimize'), http_response_code());
112	}
113
114	if (empty($no_cache_because)) {
115
116	$buffer = apply_filters('wpo_pre_cache_buffer', $buffer, $flags);
117
118	$url_path = wpo_get_url_path();
119
120	$dirs = explode('/', $url_path);
121
122	$path = WPO_CACHE_FILES_DIR;
123
124	foreach ($dirs as $dir) {
125	if (!empty($dir)) {
126	$path .= '/' . $dir;
127
128	if (!file_exists($path)) {
129	if (!mkdir($path)) {
130	$no_cache_because[] = __('Attempt to create subfolder within cache directory failed', 'wp-optimize')." ($path)";
131	break;
132	}
133	}
134	}
135	}
136	}
137
138	if (!empty($no_cache_because)) {
139
140	$message = implode(', ', $no_cache_because);
141
142	// Add http headers
143	wpo_cache_add_nocache_http_header($message);
144
145	if ((!defined('DOING_CRON') \|\| !DOING_CRON) && (!defined('REST_REQUEST') \|\| !REST_REQUEST)) {
146	$not_cached_details = "";
147
148	// Output the reason only when the user has turned on debugging
149	if (((defined('WP_DEBUG') && WP_DEBUG) \|\| isset($_GET['wpo_cache_debug']))) {
150	$not_cached_details = "because: ".htmlspecialchars($message) . " ";
151	}
152
153	$buffer .= sprintf("\n<!-- WP Optimize page cache - https://getwpo.com - page NOT cached %s-->\n", $not_cached_details);
154	}
155
156	return $buffer;
157
158	} else {
159
160	// Prevent mixed content when there's an http request but the site URL uses https.
161	$home_url = get_home_url();
162
163	if (!is_ssl() && 'https' === strtolower(parse_url($home_url, PHP_URL_SCHEME))) {
164	$https_home_url = $home_url;
165	$http_home_url = str_ireplace('https://', 'http://', $https_home_url);
166	$buffer = str_replace(esc_url($http_home_url), esc_url($https_home_url), $buffer);
167	}
168
169	$modified_time = time(); // Take this as soon before writing as possible
170	$timezone_string = '';
171	$utc = isset($GLOBALS['wpo_cache_config']['gmt_offset']) ? (float) $GLOBALS['wpo_cache_config']['gmt_offset'] : 0;
172	$modified_time += $utc * 3600;
173
174	if (!empty($GLOBALS['wpo_cache_config']['timezone_string'])) {
175	$timezone_string = 'UTC' !== $GLOBALS['wpo_cache_config']['timezone_string'] ? $GLOBALS['wpo_cache_config']['timezone_string'] : '';
176	}
177
178	if (!empty($timezone_string)) {
179	$timezone_postfix = "(".$timezone_string." UTC:". $utc .")";
180	} else {
181	$timezone_postfix = "(UTC:" . $utc . ")";
182	}
183
184	$add_to_footer = '';
185
186	/**
187	* Filter whether to display the html comment <!-- Cached by WP-Optimize ... -->
188	*
189	* @param boolean $show - Whether to display the html comment
190	* @return boolean
191	*/
192	if (preg_match('#</html>#i', $buffer) && (apply_filters('wpo_cache_show_cached_by_comment', true) \|\| (defined('WP_DEBUG') && WP_DEBUG))) {
193	$date_time_format = 'F j, Y g:i a';
194	if (!empty($GLOBALS['wpo_cache_config']['date_format']) && !empty($GLOBALS['wpo_cache_config']['time_format'])) {
195	$date_time_format = $GLOBALS['wpo_cache_config']['date_format'] . ' ' . $GLOBALS['wpo_cache_config']['time_format'];
196	}
197
198	if (!empty($GLOBALS['wpo_cache_config']['enable_mobile_caching']) && wpo_is_mobile()) {
199	$add_to_footer .= "\n<!-- Cached by WP-Optimize - for mobile devices - https://getwpo.com - Last modified: " . gmdate($date_time_format, $modified_time) . " " . $timezone_postfix . " -->\n";
200	} else {
201	$add_to_footer .= "\n<!-- Cached by WP-Optimize - https://getwpo.com - Last modified: " . gmdate($date_time_format, $modified_time) . " " . $timezone_postfix . " -->\n";
202	}
203	}
204
205	// Create an empty index.php file in the cache directory for disable directory viewing.
206	if (!is_file($path . '/index.php')) file_put_contents($path . '/index.php', '');
207
208	/**
209	* Save $buffer into cache file.
210	*/
211	$file_ext = '.html';
212
213	if (wpo_feeds_caching_enabled()) {
214	if (is_feed()) {
215	$file_ext = '.rss-xml';
216	}
217	}
218
219	$cache_filename = wpo_cache_filename($file_ext);
220	$cache_file = $path . '/' .$cache_filename;
221
222	if (defined('WPO_CACHE_FILENAME_DEBUG') && WPO_CACHE_FILENAME_DEBUG) {
223	$add_to_footer .= "\n<!-- WP Optimize page cache debug information -->\n";
224	if (!empty($GLOBALS['wpo_cache_filename_debug']) && is_array($GLOBALS['wpo_cache_filename_debug'])) {
225	$add_to_footer .= "<!-- \n" . join("\n", array_map('htmlspecialchars', $GLOBALS['wpo_cache_filename_debug'])) . "\n --->";
226	}
227	}
228
229	// if we can then cache gzipped content in .gz file.
230	if (function_exists('gzencode') && apply_filters('wpo_allow_cache_gzip_files', true)) {
231	// Only replace inside the addition, not inside the main buffer (e.g. post content)
232	file_put_contents($cache_file . '.gz', gzencode($buffer.str_replace('by WP-Optimize', 'by WP-Optimize (gzip)', $add_to_footer), apply_filters('wpo_cache_gzip_level', 6)));
233	}
234
235	file_put_contents($cache_file, $buffer.$add_to_footer);
236
237	if (is_callable('WP_Optimize')) {
238	// delete cached information about cache size.
239	WP_Optimize()->get_page_cache()->delete_cache_size_information();
240	} else {
241	// If the shutdown occurs before plugins are loaded,
242	// then this will trigger a fatal error, so, we check first
243	if (!doing_action('shutdown')) {
244	error_log('[WPO_CACHE] WP_Optimize() is not callable.');
245	$message = 'Please report this to WP-O support: ';
246	if (function_exists('wp_debug_backtrace_summary')) {
247	$message .= wp_debug_backtrace_summary();
248	} else {
249	$message .= wpo_debug_backtrace_summary();
250	}
251	error_log($message);
252	}
253	}
254
255	header('Cache-Control: no-cache'); // Check back every time to see if re-download is necessary.
256	header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $modified_time) . ' GMT');
257	header('WPO-Cache-Status: saving to cache');
258
259	if (wpo_cache_can_output_gzip_content()) {
260
261	if (!wpo_cache_is_in_response_headers_list('Content-Encoding', 'gzip')) {
262	header('Content-Encoding: gzip');
263	}
264
265	// Disable php gzip to avoid double compression.
266	ini_set('zlib.output_compression', 'Off');
267
268	return ob_gzhandler($buffer, $flags);
269	} else {
270	return $buffer;
271	}
272	}
273	}
274	endif;
275
276	/**
277	* Load files for support plugins.
278	*/
279	if (!function_exists('wpo_cache_load_extensions')) :
280	function wpo_cache_load_extensions() {
281	$extensions = glob(WPO_CACHE_EXT_DIR . '/*.php');
282
283	// Add external extensions
284	if (defined('WPO_CACHE_CUSTOM_EXT_DIR') && is_dir(WPO_CACHE_CUSTOM_EXT_DIR)) {
285	$extensions = array_merge($extensions, glob(WPO_CACHE_CUSTOM_EXT_DIR . '/*.php'));
286	}
287
288	if (empty($extensions)) return;
289
290	foreach ($extensions as $extension) {
291	if (is_file($extension)) require_once $extension;
292	}
293	}
294	endif;
295
296	if (!function_exists('wpo_restricted_cache_page_type')) {
297	function wpo_restricted_cache_page_type($restricted) {
298	global $post;
299
300	// Don't cache search or password protected.
301	if ((function_exists('is_search') && is_search()) \|\| (function_exists('is_404') && is_404()) \|\| !empty($post->post_password)) {
302	$restricted = __('Page type is not cacheable (search, 404 or password-protected)', 'wp-optimize');
303	}
304
305	// Don't cache the front page if option is set.
306	if (in_array('/', wpo_get_url_exceptions()) && function_exists('is_front_page') && is_front_page()) {
307
308	$restricted = __('In the settings, caching is disabled for the front page', 'wp-optimize');
309	}
310
311	// Don't cache htacesss. Remember to properly escape any output to prevent injection.
312	if (strpos($_SERVER['REQUEST_URI'], '.htaccess') !== false) {
313	$restricted = 'The file path is unsuitable for caching ('.$_SERVER['REQUEST_URI'].')';
314	}
315
316	// Don't cache feeds.
317	if (function_exists('is_feed') && is_feed() && !wpo_feeds_caching_enabled()) {
318	$restricted = __('We don\'t cache RSS feeds', 'wp-optimize');
319	}
320
321	return $restricted;
322	}
323	}
324
325	/**
326	* Returns true if we need cache content for loggedin users.
327	*
328	* @return bool
329	*/
330	if (!function_exists('wpo_cache_loggedin_users')) :
331	function wpo_cache_loggedin_users() {
332	return !empty($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());
333	}
334	endif;
335
336	/**
337	* Get filename for store cache, depending on gzip, mobile and cookie settings.
338	*
339	* @param string $ext
340	* @return string
341	*/
342	if (!function_exists('wpo_cache_filename')) :
343	function wpo_cache_filename($ext = '.html') {
344
345	$wpo_cache_filename_debug = array();
346
347	$filename = 'index';
348
349	if (wpo_cache_mobile_caching_enabled() && wpo_is_mobile()) {
350	$filename = 'mobile.' . $filename;
351	}
352
353	if (wpo_webp_images_enabled() && !wpo_is_using_webp_images_redirection() && wpo_is_using_alter_html()) {
354	$filename = $filename . '.webp';
355	}
356
357	$cookies = wpo_cache_cookies();
358
359	$cache_key = '';
360
361	/**
362	* Add cookie values to filename if need.
363	* This section was inspired by things learned from WP-Rocket.
364	*/
365	if (!empty($cookies)) {
366	foreach ($cookies as $key => $cookie_name) {
367	if (is_array($cookie_name) && isset($_COOKIE[$key])) {
368	foreach ($cookie_name as $cookie_key) {
369	if (isset($_COOKIE[$key][$cookie_key]) && '' !== $_COOKIE[$key][$cookie_key]) {
370	$_cache_key = $cookie_key.'='.$_COOKIE[$key][$cookie_key];
371	$_cache_key = preg_replace('/[^a-z0-9_\-\=]/i', '-', $_cache_key);
372	$cache_key .= '-' . $_cache_key;
373	$wpo_cache_filename_debug[] = 'Cookie: name: ' . $key . '[' . $cookie_key . '], value: *** , cache_key:' . $_cache_key;
374	}
375	}
376	continue;
377	}
378
379	if (isset($_COOKIE[$cookie_name]) && '' !== $_COOKIE[$cookie_name]) {
380	$_cache_key = $cookie_name.'='.$_COOKIE[$cookie_name];
381	$_cache_key = preg_replace('/[^a-z0-9_\-\=]/i', '-', $_cache_key);
382	$cache_key .= '-' . $_cache_key;
383	$wpo_cache_filename_debug[] = 'Cookie: name: ' . $cookie_name . ', value: *** , cache_key:' . $_cache_key;
384	}
385	}
386	}
387
388	$query_variables = wpo_cache_query_variables();
389
390	/**
391	* Add GET variables to cache file name if need.
392	*/
393	if (!empty($query_variables)) {
394	foreach ($query_variables as $variable) {
395	if (isset($_GET[$variable]) && !empty($_GET[$variable])) {
396	$_cache_key = $variable.'='.$_GET[$variable];
397	$_cache_key = preg_replace('/[^a-z0-9_\-\=]/i', '-', $_cache_key);
398	$cache_key .= '-' . $_cache_key;
399	$wpo_cache_filename_debug[] = 'GET parameter: name: ' . $variable . ', value:' . htmlentities($_GET[$variable]) . ', cache_key:' . $_cache_key;
400	}
401	}
402	}
403
404	// add hash of queried cookies and variables to cache file name.
405	if ('' !== $cache_key) {
406	$hash = md5($cache_key);
407	$filename .= '-'.$hash;
408	$wpo_cache_filename_debug[] = 'Hash: ' . $hash;
409	}
410
411	$filename = apply_filters('wpo_cache_filename', $filename);
412
413	$wpo_cache_filename_debug[] = 'Extension: ' . $ext;
414	$wpo_cache_filename_debug[] = 'Filename: ' . $filename.$ext;
415
416	$GLOBALS['wpo_cache_filename_debug'] = $wpo_cache_filename_debug;
417
418	return $filename . $ext;
419	}
420	endif;
421
422	/**
423	* Returns site url from site_url() function or if it is not available from cache configuration.
424	*/
425	if (!function_exists('wpo_site_url')) :
426	function wpo_site_url() {
427	if (is_callable('site_url')) return site_url('/');
428
429	$site_url = empty($GLOBALS['wpo_cache_config']['site_url']) ? '' : $GLOBALS['wpo_cache_config']['site_url'];
430	return $site_url;
431	}
432	endif;
433
434	/**
435	* Get cookie names which impact on cache file name.
436	*
437	* @return array
438	*/
439	if (!function_exists('wpo_cache_cookies')) :
440	function wpo_cache_cookies() {
441	$cookies = empty($GLOBALS['wpo_cache_config']['wpo_cache_cookies']) ? array() : $GLOBALS['wpo_cache_config']['wpo_cache_cookies'];
442	return $cookies;
443	}
444	endif;
445
446	/**
447	* Get GET variable names which impact on cache file name.
448	*
449	* @return array
450	*/
451	if (!function_exists('wpo_cache_query_variables')) :
452	function wpo_cache_query_variables() {
453	if (defined('WPO_CACHE_URL_PARAMS') && WPO_CACHE_URL_PARAMS) {
454	$variables = array_keys($_GET);
455	} else {
456	$variables = empty($GLOBALS['wpo_cache_config']['wpo_cache_query_variables']) ? array() : $GLOBALS['wpo_cache_config']['wpo_cache_query_variables'];
457	}
458
459	if (!empty($variables)) {
460	sort($variables);
461	}
462
463	return wpo_cache_maybe_ignore_query_variables($variables);
464	}
465	endif;
466
467	/**
468	* Get list of all received HTTP headers.
469	*
470	* @return array
471	*/
472	if (!function_exists('wpo_get_http_headers')) :
473	function wpo_get_http_headers() {
474
475	static $headers;
476
477	if (!empty($headers)) return $headers;
478
479	$headers = array();
480
481	// if is apache server then use get allheaders() function.
482	if (function_exists('getallheaders')) {
483	$headers = getallheaders();
484	} else {
485	// https://www.php.net/manual/en/function.getallheaders.php
486	foreach ($_SERVER as $key => $value) {
487
488	$key = strtolower($key);
489
490	if ('HTTP_' == substr($key, 0, 5)) {
491	$headers[str_replace(' ', '-', ucwords(str_replace('_', ' ', substr($key, 5))))] = $value;
492	} elseif ('content_type' == $key) {
493	$headers["Content-Type"] = $value;
494	} elseif ('content_length' == $key) {
495	$headers["Content-Length"] = $value;
496	}
497	}
498	}
499
500	return $headers;
501	}
502	endif;
503
504	/**
505	* Check if requested Accept-Encoding headers has gzip value.
506	*
507	* @return bool
508	*/
509	if (!function_exists('wpo_cache_gzip_accepted')) :
510	function wpo_cache_gzip_accepted() {
511	$headers = wpo_get_http_headers();
512
513	if (isset($headers['Accept-Encoding']) && preg_match('/gzip/i', $headers['Accept-Encoding'])) return true;
514
515	return false;
516	}
517	endif;
518
519	/**
520	* Check if we can output gzip content in current answer, i.e. check Accept-Encoding headers has gzip value
521	* and function ob_gzhandler is available.
522	*
523	* @return bool
524	*/
525	if (!function_exists('wpo_cache_can_output_gzip_content')) :
526	function wpo_cache_can_output_gzip_content() {
527	return wpo_cache_gzip_accepted() && function_exists('ob_gzhandler');
528	}
529	endif;
530
531	/**
532	* Check if header with certain name exists in already prepared headers and has value comparable with $header_value.
533	*
534	* @param string $header_name header name
535	* @param string $header_value header value as regexp.
536	*
537	* @return bool
538	*/
539	if (!function_exists('wpo_cache_is_in_response_headers_list')) :
540	function wpo_cache_is_in_response_headers_list($header_name, $header_value) {
541	$headers_list = headers_list();
542
543	if (!empty($headers_list)) {
544	$header_name = strtolower($header_name);
545
546	foreach ($headers_list as $value) {
547	$value = explode(':', $value);
548
549	if (strtolower($value[0]) == $header_name) {
550	if (preg_match('/'.$header_value.'/', $value[1])) {
551	return true;
552	} else {
553	return false;
554	}
555	}
556	}
557	}
558
559	return false;
560	}
561	endif;
562
563	/**
564	* Check if mobile cache is enabled and current request is from moblile device.
565	*
566	* @return bool
567	*/
568	if (!function_exists('wpo_cache_mobile_caching_enabled')) :
569	function wpo_cache_mobile_caching_enabled() {
570	if (!empty($GLOBALS['wpo_cache_config']['enable_mobile_caching'])) return true;
571	return false;
572	}
573	endif;
574
575	/**
576	* Check if webp images enabled
577	*
578	* @return bool
579	*/
580	if (!function_exists('wpo_webp_images_enabled')) :
581	function wpo_webp_images_enabled() {
582	if (!empty($GLOBALS['wpo_cache_config']['use_webp_images'])) return true;
583	return false;
584	}
585	endif;
586
587	/**
588	* Check whether webp images using alter html method or not
589	*
590	* @return bool
591	*/
592	if (!function_exists('wpo_is_using_alter_html')) :
593	function wpo_is_using_alter_html() {
594	return (isset($_SERVER['HTTP_ACCEPT']) && false !== strpos($_SERVER['HTTP_ACCEPT'], 'image/webp'));
595	}
596	endif;
597
598	/**
599	* Check whether webp images are served using redirect
600	*
601	* @return bool
602	*/
603	if (!function_exists('wpo_is_using_webp_images_redirection')) :
604	function wpo_is_using_webp_images_redirection() {
605	if (empty($GLOBALS['wpo_cache_config']['uploads'])) return false;
606
607	$uploads_dir = $GLOBALS['wpo_cache_config']['uploads'];
608	$htaccess_file = $uploads_dir . '/.htaccess';
609	if (!file_exists($htaccess_file)) return false;
610	$htaccess_content = file_get_contents($htaccess_file);
611	$comment_sections = array('Register webp mime type', 'WP-Optimize WebP Rules');
612
613	if (function_exists('str_contains')) {
614	return str_contains($htaccess_content, $comment_sections[0]) && str_contains($htaccess_content, $comment_sections[1]);
615	} else {
616	return strpos($htaccess_content, $comment_sections[0]) && strpos($htaccess_content, $comment_sections[1]);
617	}
618	}
619	endif;
620
621	/**
622	* Verify if the current request is related to the Activity Stream
623	*
624	* @return bool
625	*/
626	if (!function_exists('wpo_is_activity_stream_requested')) :
627	function wpo_is_activity_stream_requested() {
628	return (isset($_SERVER['HTTP_ACCEPT']) && false !== strpos($_SERVER['HTTP_ACCEPT'], 'application/activity+json'));
629	}
630	endif;
631
632	/**
633	* Verify if the current request is robots.txt
634	*/
635	if (!function_exists('wpo_is_robots_txt_requested')) :
636	function wpo_is_robots_txt_requested() {
637	return (isset($_SERVER['REQUEST_URI']) && 'robots.txt' === basename($_SERVER['REQUEST_URI']));
638	}
639	endif;
640
641	/**
642	* Serves the cache and exits
643	*/
644	if (!function_exists('wpo_serve_cache')) :
645	function wpo_serve_cache() {
646	$file_name = wpo_cache_filename();
647
648	$file_name_rss_xml = wpo_cache_filename('.rss-xml');
649	$send_as_feed = false;
650
651	$path_dir = WPO_CACHE_FILES_DIR . '/' . wpo_get_url_path() . '/';
652	$path = $path_dir . $file_name;
653
654	if (wpo_feeds_caching_enabled()) {
655	// check for .xml cache file if .html cache file doesn't exist
656	if (!file_exists($path_dir . $file_name) && file_exists($path_dir . $file_name_rss_xml)) {
657	$path = $path_dir . $file_name_rss_xml;
658	$send_as_feed = true;
659	}
660	}
661
662	$use_gzip = false;
663
664	// if we can use gzip and gzipped file exist in cache we use it.
665	// if headers already sent we don't use gzipped file content.
666	if (!headers_sent() && wpo_cache_gzip_accepted() && file_exists($path . '.gz')) {
667	$path .= '.gz';
668	$use_gzip = true;
669	}
670
671	$modified_time = file_exists($path) ? (int) filemtime($path) : time();
672
673	// Cache has expired, purge and exit.
674	if (!empty($GLOBALS['wpo_cache_config']['page_cache_length'])) {
675	if (time() > ($GLOBALS['wpo_cache_config']['page_cache_length'] + $modified_time)) {
676	wpo_delete_files($path);
677	return;
678	}
679	}
680
681	if ($use_gzip) {
682	// Disable zlib output compression to avoid double content compression
683	ini_set('zlib.output_compression', 'Off');
684	}
685
686	$gzip_header_already_sent = wpo_cache_is_in_response_headers_list('Content-Encoding', 'gzip');
687
688	header('Cache-Control: no-cache'); // Check back later
689
690	if (!empty($modified_time) && !empty($_SERVER['HTTP_IF_MODIFIED_SINCE']) && strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) === $modified_time) {
691	if ($use_gzip && !$gzip_header_already_sent) {
692	header('Content-Encoding: gzip');
693	}
694
695	if ($send_as_feed) {
696	header('Content-type: application/rss+xml');
697	}
698
699	header('WPO-Cache-Status: cached');
700	header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $modified_time) . ' GMT');
701	header($_SERVER['SERVER_PROTOCOL'] . ' 304 Not Modified', true, 304);
702	exit;
703	}
704
705	if (file_exists($path) && is_readable($path)) {
706
707	if (wpo_is_canonical_redirection_needed()) return;
708
709	if ($use_gzip && !$gzip_header_already_sent) {
710	header('Content-Encoding: gzip');
711	}
712
713	// send correct headers for xml and txt files
714	$filename = basename(dirname($path));
715
716	if (preg_match('/\.xml$/i', $filename)) {
717	header('Content-type: text/xml');
718	}
719
720	if (preg_match('/\.txt$/i', $filename)) {
721	header('Content-type: text/plain');
722	}
723
724	if ($send_as_feed) {
725	header('Content-type: application/rss+xml');
726	}
727
728	header('WPO-Cache-Status: cached');
729	if (!empty($modified_time)) {
730	header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $modified_time) . ' GMT');
731	}
732
733	readfile($path);
734
735	exit;
736	}
737	}
738	endif;
739
740	/**
741	* Checks and does redirection, if needed
742	*
743	* @return bool
744	*/
745	if (!function_exists('wpo_is_canonical_redirection_needed')) :
746	function wpo_is_canonical_redirection_needed() {
747	$permalink_structure = isset($GLOBALS['wpo_cache_config']['permalink_structure']) ? $GLOBALS['wpo_cache_config']['permalink_structure'] : '';
748	$site_url = wpo_site_url();
749
750	// Exit if server variables are not available.
751	if (!isset($_SERVER['HTTP_HOST'])) return false;
752
753	$schema = isset($_SERVER['HTTPS']) && 'on' === $_SERVER['HTTPS'] ? "https" : "http";
754	$url_part = "://" . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
755	$requested_url = $schema . $url_part;
756	$url_parts = parse_url($requested_url);
757	$extension = pathinfo($url_parts['path'], PATHINFO_EXTENSION);
758
759	if (!empty($permalink_structure) && $requested_url != $site_url && ((isset($url_parts['path']) && '/' !== $url_parts['path']) \|\| isset($url_parts['query']))) {
760	$request_uri = rtrim($_SERVER['REQUEST_URI'], '?');
761	if ('/' == substr($permalink_structure, -1) && empty($extension) && empty($url_parts['query']) && empty($url_parts['fragment'])) {
762	$url = preg_replace('/(.+?)([\/]*)(\[\?\#][^\/]+\|$)/', '$1/$3', $request_uri);
763	if (0 !== strcmp($request_uri, $url)) return true;
764	} else {
765	$url = rtrim($request_uri, '/');
766	if (0 !== strcmp($request_uri, $url)) return true;
767	}
768	}
769	return false;
770	}
771	endif;
772
773	/**
774	* Clears the cache
775	*/
776	if (!function_exists('wpo_cache_flush')) :
777	function wpo_cache_flush() {
778
779	if (defined('WPO_CACHE_FILES_DIR') && '' != WPO_CACHE_FILES_DIR) wpo_delete_files(WPO_CACHE_FILES_DIR);
780
781	if (function_exists('wp_cache_flush')) {
782	wp_cache_flush();
783	}
784
785	do_action('wpo_cache_flush');
786	}
787	endif;
788
789	/**
790	* Get URL path for caching
791	*
792	* @since 1.0
793	* @return string
794	*/
795	if (!function_exists('wpo_get_url_path')) :
796	function wpo_get_url_path($url = '') {
797	$url = '' == $url ? wpo_current_url() : $url;
798	$url_parts = parse_url($url);
799
800	if (isset($url_parts['path']) && false !== stripos($url_parts['path'], '/index.php')) {
801	$url_parts['path'] = preg_replace('/(.*?)index\.php(\/.+)/i', '$1index-php$2', $url_parts['path']);
802	}
803
804	/*
805	* Convert the hexadecimal digits within the percent-encoded triplet to uppercase, to ensure that the path remains
806	* consistent. For instance, "example.com/%e0%a6" will be converted to "example.com/%E0%A6".
807	*/
808	if (isset($url_parts['path'])) {
809	$url_parts['path'] = preg_replace_callback('/%[0-9A-F]{2}/i', function($matches) {
810	return strtoupper($matches[0]);
811	}, $url_parts['path']);
812	}
813
814	if (!isset($url_parts['host'])) $url_parts['host'] = '';
815	if (!isset($url_parts['path'])) $url_parts['path'] = '';
816
817	return $url_parts['host'].$url_parts['path'];
818	}
819	endif;
820
821	/**
822	* Get requested url.
823	*
824	* @return string
825	*/
826	if (!function_exists('wpo_current_url')) :
827	function wpo_current_url() {
828	// 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).
829	// Otherwise this function would return a different URL at the beginning and end of the cache process.
830	static $url = '';
831	if ('' != $url) return $url;
832	$http_host = isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : '';
833	$url = rtrim('http' . ((isset($_SERVER['HTTPS']) && ('on' == $_SERVER['HTTPS'] \|\| 1 == $_SERVER['HTTPS']) \|\|
834	isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && 'https' == $_SERVER['HTTP_X_FORWARDED_PROTO']) ? 's' : '' )
835	. '://' . $http_host.$_SERVER['REQUEST_URI'], '/');
836	return $url;
837	}
838	endif;
839
840	/**
841	* Return list of conditional tag exceptions.
842	*
843	* @return array
844	*/
845	if (!function_exists('wpo_get_conditional_tags_exceptions')) :
846	function wpo_get_conditional_tags_exceptions() {
847	static $exceptions = null;
848
849	if (null !== $exceptions) return $exceptions;
850
851	if (!empty($GLOBALS['wpo_cache_config'])) {
852	if (empty($GLOBALS['wpo_cache_config']['cache_exception_conditional_tags'])) {
853	$exceptions = array();
854
855	} else {
856
857	$exceptions = $GLOBALS['wpo_cache_config']['cache_exception_conditional_tags'];
858
859	}
860
861	} elseif (class_exists('WPO_Page_Cache')) {
862
863	$config = WPO_Page_Cache::instance()->config->get();
864
865	if (is_array($config) && array_key_exists('cache_exception_conditional_tags', $config)) {
866	$exceptions = $config['cache_exception_conditional_tags'];
867	} else {
868	$exceptions = array();
869	}
870
871	$exceptions = is_array($exceptions) ? $exceptions : preg_split('#(\n\|\r\|\r\n)#', $exceptions);
872	$exceptions = array_filter($exceptions, 'trim');
873
874	} else {
875	$exceptions = array();
876	}
877
878	return $exceptions;
879	}
880	endif;
881
882	/**
883	* Return list of url exceptions.
884	*
885	* @return array
886	*/
887	if (!function_exists('wpo_get_url_exceptions')) :
888	function wpo_get_url_exceptions() {
889	static $exceptions = null;
890
891	if (null !== $exceptions) return $exceptions;
892
893	// if called from file-based-page-cache.php when WP loading
894	// and cache settings exists then use it otherwise get settings from database.
895	if (!empty($GLOBALS['wpo_cache_config'])) {
896	if (empty($GLOBALS['wpo_cache_config']['cache_exception_urls'])) {
897	$exceptions = array();
898	} else {
899	$exceptions = is_array($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']);
900	}
901	} elseif (class_exists('WPO_Page_Cache')) {
902	$config = WPO_Page_Cache::instance()->config->get();
903
904	if (is_array($config) && array_key_exists('cache_exception_urls', $config)) {
905	$exceptions = $config['cache_exception_urls'];
906	} else {
907	$exceptions = array();
908	}
909
910	$exceptions = is_array($exceptions) ? $exceptions : preg_split('#(\n\|\r)#', $exceptions);
911	$exceptions = array_filter($exceptions, 'trim');
912	} else {
913	$exceptions = array();
914	}
915
916	return apply_filters('wpo_get_url_exceptions', $exceptions);
917	}
918	endif;
919
920	/**
921	* Return true of exception url matches current url
922	*
923	* @param string $exception Exceptions to check URL against.
924	* @param bool $regex Whether to check with regex or not.
925	* @return bool true if matched, false otherwise
926	*/
927	if (!function_exists('wpo_current_url_exception_match')) :
928	function wpo_current_url_exception_match($exception) {
929
930	return wpo_url_exception_match(wpo_current_url(), $exception);
931	}
932	endif;
933
934	/**
935	* Check if url in conditional tags exceptions list.
936	*
937	* @return string
938	*/
939	if (!function_exists('wpo_url_in_conditional_tags_exceptions')) :
940	function wpo_url_in_conditional_tags_exceptions() {
941
942	$exceptions = wpo_get_conditional_tags_exceptions();
943	$restricted = '';
944	$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');
945	//Filter for add more conditional tags to whitelist in the exceptions list.
946	$allowed_functions = apply_filters('wpo_allowed_conditional_tags_exceptions', $allowed_functions);
947	if (!empty($exceptions)) {
948	foreach ($exceptions as $exception) {
949	if (false !== strpos($exception, 'is_')) {
950	$exception_function = $exception;
951	if ('()' == substr($exception, -2)) {
952	$exception_function = substr($exception, 0, -2);
953	}
954
955	if (in_array($exception_function, $allowed_functions) && function_exists($exception_function) && call_user_func($exception_function)) {
956	$restricted = sprintf(__('In the settings, caching is disabled for %s', 'wp-optimize'), $exception_function);
957	}
958	}
959	}
960	}
961	return $restricted;
962	}
963	endif;
964
965
966	/**
967	* Check if url in exceptions list.
968	*
969	* @param string $url
970	*
971	* @return bool
972	*/
973	if (!function_exists('wpo_url_in_exceptions')) :
974	function wpo_url_in_exceptions($url) {
975	$exceptions = wpo_get_url_exceptions();
976
977	if (!empty($exceptions)) {
978	foreach ($exceptions as $exception) {
979
980	// don't check / - front page using regexp, we handle it in wpo_restricted_cache_page_type()
981	if ('/' == $exception) continue;
982
983	if (wpo_url_exception_match($url, $exception)) {
984	// Exception match.
985	return true;
986	}
987	}
988	}
989
990	return false;
991	}
992	endif;
993
994	/**
995	* Checks if an URL matches against listed exceptions.
996	*
997	* @param string $url - complete url string i.e. http(s)://domain/path
998	* @param string $exception - complete url or absolute path, can contain (.*) wildcards; Sometimes can be urlencoded
999	*
1000	* @return bool
1001	*/
1002	if (!function_exists('wpo_url_exception_match')) :
1003	function wpo_url_exception_match($url, $exception) {
1004	if (preg_match('#^[\s]*$#', $exception)) {
1005	return false;
1006	}
1007
1008	$exception = str_replace('', '.', $exception);
1009
1010	$exception = trim($exception);
1011
1012	// Used to test websites placed in subdirectories.
1013	$sub_dir = '';
1014
1015	// If exception defined from root i.e. /page1 then remove domain part in url.
1016	if (preg_match('/^\//', $exception)) {
1017	// get site sub directory.
1018	$sub_dir = preg_replace('#^(http\|https):\/\/.*\/#Ui', '', wpo_site_url());
1019	// add prefix slash and remove slash.
1020	$sub_dir = ('' == $sub_dir) ? '' : '/' . rtrim($sub_dir, '/');
1021	// get relative path
1022	$url = preg_replace('#^(http\|https):\/\/.*\/#Ui', '/', $url);
1023	}
1024
1025	$url = urldecode(rtrim($url, '/')) . '/';
1026	$exception = rtrim($exception, '/');
1027
1028	// if we have no wildcard in the end of exception then add slash.
1029	if (!preg_match('#$\.\*$$#', $exception)) $exception .= '/';
1030
1031	$exception = preg_quote($exception);
1032
1033	// fix - unescape some possibly escaped mask characters
1034	$search = array(
1035	'\\.\\*',
1036	'\\-',
1037	);
1038	$replace = array(
1039	'.*',
1040	'-',
1041	);
1042	$exception = urldecode(str_replace($search, $replace, $exception));
1043
1044	return (preg_match('#^'.$exception.'$#i', $url) \|\| preg_match('#^'.$sub_dir.$exception.'$#i', $url));
1045	}
1046	endif;
1047
1048	/**
1049	* Checks if its a mobile device
1050	*
1051	* @see https://developer.wordpress.org/reference/functions/wp_is_mobile/
1052	*/
1053	if (!function_exists('wpo_is_mobile')) :
1054	function wpo_is_mobile() {
1055	if (empty($_SERVER['HTTP_USER_AGENT'])) {
1056	$is_mobile = false;
1057	// many mobile devices (all iPhone, iPad, etc.)
1058	} elseif (strpos($_SERVER['HTTP_USER_AGENT'], 'Mobile') !== false
1059	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Android') !== false
1060	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Silk/') !== false
1061	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Kindle') !== false
1062	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'BlackBerry') !== false
1063	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mini') !== false
1064	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mobi') !== false
1065	) {
1066	$is_mobile = true;
1067	} else {
1068	$is_mobile = false;
1069	}
1070
1071	return $is_mobile;
1072	}
1073	endif;
1074
1075	/**
1076	* Check if current browser agent is not disabled in options.
1077	*
1078	* @return bool
1079	*/
1080	if (!function_exists('wpo_is_accepted_user_agent')) :
1081	function wpo_is_accepted_user_agent($user_agent) {
1082
1083	$exceptions = is_array($GLOBALS['wpo_cache_config']['cache_exception_browser_agents']) ? $GLOBALS['wpo_cache_config']['cache_exception_browser_agents'] : preg_split('#(\n\|\r)#', $GLOBALS['wpo_cache_config']['cache_exception_browser_agents']);
1084
1085	if (!empty($exceptions)) {
1086	foreach ($exceptions as $exception) {
1087	if ('' == trim($exception)) continue;
1088
1089	if (preg_match('#'.$exception.'#i', $user_agent)) return false;
1090	}
1091	}
1092
1093	return true;
1094	}
1095	endif;
1096
1097	if (!function_exists('wpo_delete_files')) :
1098	/**
1099	* Deletes a specified source file or directory.
1100	*
1101	* If $src is a file, only that file will be deleted. If $src is a directory, the behavior depends on the
1102	* $recursive parameter. When $recursive is true, the directory and its contents (including files and subdirectories)
1103	* will be deleted. When $recursive is false, only the files in the top-level directory(eg. $src directory) will be deleted,
1104	* while the $src directory itself and its subdirectories will remain untouched.
1105	*
1106	* @param string $src The path to the source file or directory to delete.
1107	* @param bool $recursive (Optional) When set to true, the directory and its contents (including files and subdirectories)
1108	* will be deleted. If false, only the files in the top-level directory will be deleted while
1109	* its subdirectories will be preserved. Defaults to true.
1110	*
1111	* @return bool Returns true if the specified file or all files within the specified directory (and its subdirectories,
1112	* when $recursive is true) are successfully deleted. Returns false if any file(s) could not be deleted
1113	* due to file permissions or other reasons.
1114	*/
1115	function wpo_delete_files($src, $recursive = true) {
1116	// If the source doesn't exist, consider it deleted and return true
1117	if (!file_exists($src)) {
1118	return true;
1119	}
1120
1121	/*
1122	* If the source is a file, delete it and return the result.
1123	* If `unlink()` fails, we also verify if the file still exists before returning the result, as another
1124	* PHP process may have already deleted the file between the execution of `is_file()` and `unlink()` operations.
1125	*/
1126	if (is_file($src)) {
1127	if (!@unlink($src) && file_exists($src)) { // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1128	return false;
1129	}
1130	return true;
1131	}
1132
1133	$success = true;
1134
1135	// If recursive is false, delete only the top-level files and return the result
1136	if (!$recursive) {
1137	$dir_handle = @opendir($src); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1138
1139	/*
1140	* If opendir() is successful, process directory contents. If not, check if the directory exists.
1141	* If it exists, return false (failure). Otherwise, assume it's already deleted and return true (success).
1142	*/
1143	if (false !== $dir_handle) {
1144
1145	while (false !== ($file = readdir($dir_handle))) {
1146	if ('.' == $file \|\| '..' == $file) {
1147	continue;
1148	}
1149
1150	$full_path = $src . '/' . $file;
1151
1152	// If it's a file, delete it
1153	if (is_file($full_path)) {
1154	if (!wpo_delete_files($full_path)) {
1155	$success = false;
1156	}
1157	}
1158	}
1159
1160	closedir($dir_handle);
1161	} else {
1162	if (file_exists($src)) {
1163	$success = false;
1164	}
1165	}
1166
1167	return $success;
1168	}
1169
1170	// If recursive is true, delete all files and directories recursively
1171	$dir_handle = @opendir($src); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1172
1173	/*
1174	* If opendir() is successful, process directory contents. If not, check if the directory exists.
1175	* If it exists, return false (failure). Otherwise, assume it's already deleted and return true (success).
1176	*/
1177	if (false !== $dir_handle) {
1178
1179	while (false !== ($file = readdir($dir_handle))) {
1180	if ('.' == $file \|\| '..' == $file) {
1181	continue;
1182	}
1183
1184	$full_path = $src . '/' . $file;
1185
1186	if (!wpo_delete_files($full_path)) {
1187	$success = false;
1188	}
1189	}
1190
1191	closedir($dir_handle);
1192	} else {
1193	if (file_exists($src)) {
1194	$success = false;
1195	}
1196	}
1197
1198	/*
1199	* Delete the source directory itself.
1200	* Success of `rmdir` operation is not recorded; we only ultimately care about emptying, not removing
1201	* entirely (empty folders in our context are harmless)
1202	*/
1203	if ($success) {
1204	@rmdir($src); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1205	}
1206
1207	// Delete cached information about cache size
1208	WP_Optimize()->get_page_cache()->delete_cache_size_information();
1209
1210	return $success;
1211	}
1212	endif;
1213
1214	if (!function_exists('wpo_is_empty_dir')) :
1215	/**
1216	* Check if selected directory is empty or has only index.php which we added for security reasons.
1217	*
1218	* @param string $dir
1219	*
1220	* @return bool
1221	*/
1222	function wpo_is_empty_dir($dir) {
1223	if (!file_exists($dir) \|\| !is_dir($dir)) return false;
1224
1225	$handle = opendir($dir);
1226
1227	if (false === $handle) return false;
1228
1229	$is_empty = true;
1230	$file = readdir($handle);
1231
1232	while (false !== $file) {
1233
1234	if ('.' != $file && '..' != $file && 'index.php' != $file) {
1235	$is_empty = false;
1236	break;
1237	}
1238
1239	$file = readdir($handle);
1240	}
1241
1242	closedir($handle);
1243	return $is_empty;
1244	}
1245	endif;
1246
1247	/**
1248	* Either store for later output, or output now. Only the most-recent call will be effective.
1249	*
1250	* @param String\|Null $output - if not null, then the string to use when called by the shutdown action.
1251	*/
1252	if (!function_exists('wpo_cache_add_footer_output')) :
1253	function wpo_cache_add_footer_output($output = null) {
1254
1255	static $buffered = null;
1256
1257	if (function_exists('current_filter') && 'shutdown' == current_filter()) {
1258	// Only add the line if it was a page, not something else (e.g. REST response)
1259	if (function_exists('did_action') && did_action('wp_footer')) {
1260	echo "\n<!-- WP Optimize page cache - https://getwpo.com - ".$buffered." -->\n";
1261	} elseif (defined('WPO_CACHE_DEBUG') && WPO_CACHE_DEBUG && (!defined('REST_REQUEST') \|\| !REST_REQUEST)) {
1262	error_log('[CACHE DEBUG] '.wpo_current_url() . ' - ' . $buffered);
1263	}
1264	} else {
1265	if (null == $buffered && function_exists('add_action')) add_action('shutdown', 'wpo_cache_add_footer_output', 11);
1266	$buffered = $output;
1267	}
1268
1269	}
1270	endif;
1271
1272	/**
1273	* Remove variable names that shouldn't influence cache.
1274	*
1275	* @param array $variables List of variable names.
1276	*
1277	* @return array
1278	*/
1279	if (!function_exists('wpo_cache_maybe_ignore_query_variables')) :
1280	function wpo_cache_maybe_ignore_query_variables($variables) {
1281
1282	/**
1283	* Filters the current $_GET variables that will be used when caching or excluding from cache.
1284	* Currently:
1285	* - 'wpo_cache_debug' (Shows the reason for not being cached even when WP_DEBUG isn't set)
1286	* - 'doing_wp_cron' (alternative cron)
1287	* - 'aiosp_sitemap_path', 'aiosp_sitemap_page' (All in one SEO sitemap)
1288	* - 'xml_sitemap', 'seopress_sitemap', 'seopress_news', 'seopress_video', 'seopress_cpt', 'seopress_paged' (SEOPress sitemap)
1289	* - 'sitemap', 'sitemap_n' (YOAST SEO sitemap)
1290	*/
1291	$exclude_variables = array(
1292	'wpo_cache_debug', // Shows the reason for not being cached even when WP_DEBUG isn't set
1293	'doing_wp_cron', // alternative cron
1294	'aiosp_sitemap_path', // All in one SEO sitemap
1295	'aiosp_sitemap_page',
1296	'xml_sitemap', // SEOPress sitemap
1297	'seopress_sitemap',
1298	'seopress_news',
1299	'seopress_video',
1300	'seopress_cpt',
1301	'seopress_paged',
1302	'sitemap', // YOAST SEO sitemap
1303	'sitemap_n',
1304	);
1305	$exclude_variables = function_exists('apply_filters') ? apply_filters('wpo_cache_ignore_query_variables', $exclude_variables) : $exclude_variables;
1306
1307	if (empty($exclude_variables)) return $variables;
1308
1309	foreach ($exclude_variables as $variable) {
1310	$exclude = array_search($variable, $variables);
1311	if (false !== $exclude) {
1312	array_splice($variables, $exclude, 1);
1313	}
1314	}
1315
1316	return $variables;
1317	}
1318	endif;
1319
1320	/**
1321	* Get cache config
1322	*
1323	* @param string $key - The config item
1324	* @param mixed $default - The default value
1325	*
1326	* @return mixed
1327	*/
1328	if (!function_exists('wpo_cache_config_get')) :
1329	function wpo_cache_config_get($key, $default = false) {
1330	$config = $GLOBALS['wpo_cache_config'];
1331
1332	if (!$config) return false;
1333
1334	if (isset($config[$key])) {
1335	return $config[$key];
1336	} else {
1337	return $default;
1338	}
1339	}
1340	endif;
1341
1342	if (!function_exists('wpo_disable_cache_directories_viewing')) :
1343	function wpo_disable_cache_directories_viewing() {
1344	global $is_apache, $is_IIS, $is_iis7;
1345
1346	if (!is_dir(WPO_CACHE_FILES_DIR)) return;
1347
1348	// Create .htaccess file for apache server.
1349	if ($is_apache) {
1350	$htaccess_filename = WPO_CACHE_FILES_DIR . '/.htaccess';
1351
1352	// CS does not like heredoc
1353	// phpcs:disable
1354	$htaccess_content = <<<EOF
1355	# Disable directory browsing
1356	Options -Indexes
1357
1358	# Disable access to any files
1359	<FilesMatch ".*">
1360	Order allow,deny
1361	Deny from all
1362	</FilesMatch>
1363	EOF;
1364	// phpcs:enable
1365
1366	if (!is_file($htaccess_filename)) @file_put_contents($htaccess_filename, $htaccess_content); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress the error when there is file permission issues
1367	}
1368
1369	// Create web.config file for IIS servers.
1370	if ($is_IIS \|\| $is_iis7) {
1371	$webconfig_filename = WPO_CACHE_FILES_DIR . '/web.config';
1372	$webconfig_content = "<configuration>\n<system.webServer>\n<authorization>\n<deny users=\"*\" />\n</authorization>\n</system.webServer>\n</configuration>\n";
1373
1374	if (!is_file($webconfig_filename)) @file_put_contents($webconfig_filename, $webconfig_content); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress the error when there is file permission issues
1375	}
1376
1377	// Create empty index.php file for all servers.
1378	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
1379	}
1380	endif;
1381
1382	/**
1383	* Add the headers indicating why the page is not cached or served from cache
1384	*
1385	* @param string $message - The headers
1386	*
1387	* @return void
1388	*/
1389	if (!function_exists('wpo_cache_add_nocache_http_header')) :
1390	function wpo_cache_add_nocache_http_header($message = '') {
1391	if (!headers_sent()) {
1392	header('WPO-Cache-Status: not cached');
1393	header('WPO-Cache-Message: '. trim(str_replace(array("\r", "\n", ':'), ' ', strip_tags($message))));
1394	}
1395	}
1396	endif;
1397
1398	/**
1399	* Add the headers indicating why the page is not cached or served from cache by integrating with the send_headers filter
1400	*
1401	* @param string $message - The headers
1402	*
1403	* @return void
1404	*/
1405	if (!function_exists('wpo_cache_add_nocache_http_header_with_send_headers_action')) :
1406	function wpo_cache_add_nocache_http_header_with_send_headers_action($message = '') {
1407	static $buffered_message = null;
1408
1409	if (function_exists('current_filter') && 'send_headers' === current_filter() && $buffered_message && !headers_sent()) {
1410	wpo_cache_add_nocache_http_header($buffered_message);
1411	} else {
1412	if (!$buffered_message && function_exists('add_action')) add_action('send_headers', 'wpo_cache_add_nocache_http_header_with_send_headers_action', 11);
1413	$buffered_message = $message;
1414	}
1415	}
1416	endif;
1417
1418	/**
1419	* Check if feeds caching enabled
1420	*
1421	* @return bool
1422	*/
1423	if (!function_exists('wpo_feeds_caching_enabled')) :
1424	function wpo_feeds_caching_enabled() {
1425	return apply_filters('wpo_feeds_caching_enabled', true);
1426	}
1427	endif;
1428
1429	if (!function_exists('wpo_debug_backtrace_summary')) {
1430	function wpo_debug_backtrace_summary($ignore_class = null, $skip_frames = 0, $pretty = true) {
1431	static $truncate_paths;
1432
1433	$trace = debug_backtrace(false);
1434	$caller = array();
1435	$check_class = !is_null($ignore_class);
1436	$skip_frames++; // Skip this function.
1437
1438	if (!isset($truncate_paths)) {
1439	$truncate_paths = array(
1440	wpo_normalize_path(WP_CONTENT_DIR),
1441	wpo_normalize_path(ABSPATH),
1442	);
1443	}
1444
1445	foreach ($trace as $call) {
1446	if ($skip_frames > 0) {
1447	$skip_frames--;
1448	} elseif (isset($call['class'])) {
1449	if ($check_class && $ignore_class == $call['class']) {
1450	continue; // Filter out calls.
1451	}
1452
1453	$caller[] = "{$call['class']}{$call['type']}{$call['function']}";
1454	} else {
1455	if (in_array($call['function'], array('do_action', 'apply_filters', 'do_action_ref_array', 'apply_filters_ref_array'), true)) {
1456	$caller[] = "{$call['function']}('{$call['args'][0]}')";
1457	} elseif (in_array($call['function'], array('include', 'include_once', 'require', 'require_once'), true)) {
1458	$filename = isset($call['args'][0]) ? $call['args'][0] : '';
1459	$caller[] = $call['function'] . "('" . str_replace($truncate_paths, '', wpo_normalize_path($filename)) . "')";
1460	} else {
1461	$caller[] = $call['function'];
1462	}
1463	}
1464	}
1465	if ($pretty) {
1466	return implode(', ', array_reverse($caller));
1467	} else {
1468	return $caller;
1469	}
1470	}
1471	}
1472
1473	if (!function_exists('wpo_normalize_path')) {
1474	function wpo_normalize_path($path) {
1475	// Standardise all paths to use '/'.
1476	$path = str_replace('\\', '/', $path);
1477
1478	// Replace multiple slashes down to a singular, allowing for network shares having two slashes.
1479	$path = preg_replace('\|(?<=.)/+\|', '/', $path);
1480
1481	// Windows paths should uppercase the drive letter.
1482	if (':' === substr($path, 1, 1)) {
1483	$path = ucfirst($path);
1484	}
1485
1486	return $path;
1487	}
1488	}
1489