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 3.3.1, at cache/file-based-page-cache-functions.php

1,469 lines 45.8 KB

Raw Download Zip

1	<?php
2
3	if (!defined('ABSPATH')) die('No direct access allowed');
4
5	/**
6	* Extensions directory.
7	*/
8	if (!defined('WPO_CACHE_EXT_DIR')) define('WPO_CACHE_EXT_DIR', dirname(__FILE__).'/extensions');
9
10	/**
11	* Holds utility functions used by file based cache
12	*/
13
14	/**
15	* Cache output before it goes to the browser. If moving/renaming this function, then also change the check above.
16	*
17	* @param String $buffer Page HTML.
18	* @param Int $flags OB flags to be passed through.
19	*
20	* @return String
21	*/
22	if (!function_exists('wpo_cache')) :
23	function wpo_cache($buffer, $flags) {
24
25	// This case appears to happen for unclear reasons without WP being fully loaded, e.g. https://wordpress.org/support/topic/fatal-error-since-wp-5-8-update/ . It is simplest just to short-circuit it.
26	if ('' === $buffer) return '';
27
28	// This array records reasons why no caching took place. Be careful not to allow actions to proceed that should not - i.e. take note of its state appropriately.
29	$no_cache_because = array();
30
31	if (strlen($buffer) < 255) {
32	$no_cache_because[] = sprintf(__('Output is too small (less than %d bytes) to be worth caching', 'wp-optimize'), 255);
33	}
34
35	// Don't cache pages for logged in users.
36	if (!wpo_cache_loggedin_users() && (!function_exists('is_user_logged_in') \|\| (function_exists('wp_get_current_user') && is_user_logged_in()))) {
37	$no_cache_because[] = __('User is logged in', 'wp-optimize');
38	}
39
40	$restricted_page_type_cache = apply_filters('wpo_restricted_cache_page_type', false);
41	if ($restricted_page_type_cache) {
42	$no_cache_because[] = $restricted_page_type_cache;
43	}
44
45	$conditional_tag_exceptions = apply_filters('wpo_url_in_conditional_tags_exceptions', false);
46	if ($conditional_tag_exceptions) {
47	$no_cache_because[] = $conditional_tag_exceptions;
48	}
49
50	// No root cache folder, so short-circuit here
51	if (!file_exists(WPO_CACHE_DIR)) {
52	$no_cache_because[] = __('WP-O cache parent directory was not found', 'wp-optimize').' ('.WPO_CACHE_DIR.')';
53	} elseif (!file_exists(WPO_CACHE_FILES_DIR)) {
54	// Try creating a folder for cached files, if it was flushed recently
55	if (!mkdir(WPO_CACHE_FILES_DIR)) {
56	$no_cache_because[] = __('WP-O cache directory was not found', 'wp-optimize').' ('.WPO_CACHE_FILES_DIR.')';
57	} else {
58	wpo_disable_cache_directories_viewing();
59	}
60	}
61
62	// If comments are opened and the user has saved his information.
63	if (function_exists('comments_open') && function_exists('get_post') && get_post() && comments_open()) {
64	$commenter = wp_get_current_commenter();
65	// if any of the fields contain something, do not save to cache
66	if ('' != $commenter['comment_author'] \|\| '' != $commenter['comment_author_email'] \|\| '' != $commenter['comment_author_url']) {
67	$no_cache_because[] = __('Comments are opened and the visitor saved his information.', 'wp-optimize');
68	}
69	}
70
71	$can_cache_page = true;
72
73	if (defined('DONOTCACHEPAGE') && DONOTCACHEPAGE) {
74	$can_cache_page = false;
75	}
76
77	/**
78	* Defines if the page can be cached or not
79	*
80	* @param boolean $can_cache_page
81	*/
82	$can_cache_page_filter = apply_filters('wpo_can_cache_page', $can_cache_page);
83
84	if (!$can_cache_page_filter) {
85	if ($can_cache_page) {
86	$can_cache_page = false;
87	$no_cache_because[] = __('wpo_can_cache_page filter forbade it', 'wp-optimize');
88	} else {
89	$no_cache_because[] = __('DONOTCACHEPAGE constant forbade it and wpo_can_cache_page filter did not over-ride it', 'wp-optimize');
90	}
91	}
92
93	if (defined('REST_REQUEST') && REST_REQUEST) {
94	$no_cache_because[] = __('This is a REST API request (identified by REST_REQUEST constant)', 'wp-optimize');
95	}
96
97	// Don't cache with fatal error pages.
98	$last_error = error_get_last();
99	if (is_array($last_error) && E_ERROR == $last_error['type']) {
100	$no_cache_because[] = __('This page has a fatal error', 'wp-optimize');
101	}
102
103	if (http_response_code() >= 500) {
104	$no_cache_because[] = sprintf(__('This page has a critical error (HTTP code %s)', 'wp-optimize'), http_response_code());
105	} elseif (http_response_code() >= 400) {
106	$no_cache_because[] = sprintf(__('This page returned an HTTP unauthorised response code (%s)', 'wp-optimize'), http_response_code());
107	}
108
109	if (empty($no_cache_because)) {
110
111	$buffer = apply_filters('wpo_pre_cache_buffer', $buffer, $flags);
112
113	$url_path = wpo_get_url_path();
114
115	$dirs = explode('/', $url_path);
116
117	$path = WPO_CACHE_FILES_DIR;
118
119	foreach ($dirs as $dir) {
120	if (!empty($dir)) {
121	$path .= '/' . $dir;
122
123	if (!file_exists($path)) {
124	if (!mkdir($path)) {
125	$no_cache_because[] = __('Attempt to create subfolder within cache directory failed', 'wp-optimize')." ($path)";
126	break;
127	}
128	}
129	}
130	}
131	}
132
133	if (!empty($no_cache_because)) {
134
135	$message = implode(', ', $no_cache_because);
136
137	// Add http headers
138	wpo_cache_add_nocache_http_header($message);
139
140	if ((!defined('DOING_CRON') \|\| !DOING_CRON) && (!defined('REST_REQUEST') \|\| !REST_REQUEST)) {
141	$not_cached_details = "";
142
143	// Output the reason only when the user has turned on debugging
144	if (((defined('WP_DEBUG') && WP_DEBUG) \|\| isset($_GET['wpo_cache_debug']))) {
145	$not_cached_details = "because: ".htmlspecialchars($message) . " ";
146	}
147
148	$buffer .= sprintf("\n<!-- WP Optimize page cache - https://getwpo.com - page NOT cached %s-->\n", $not_cached_details);
149	}
150
151	return $buffer;
152
153	} else {
154
155	// Prevent mixed content when there's an http request but the site URL uses https.
156	$home_url = get_home_url();
157
158	if (!is_ssl() && 'https' === strtolower(parse_url($home_url, PHP_URL_SCHEME))) {
159	$https_home_url = $home_url;
160	$http_home_url = str_ireplace('https://', 'http://', $https_home_url);
161	$buffer = str_replace(esc_url($http_home_url), esc_url($https_home_url), $buffer);
162	}
163
164	$modified_time = time(); // Take this as soon before writing as possible
165	$timezone_string = '';
166	$utc = isset($GLOBALS['wpo_cache_config']['gmt_offset']) ? (float) $GLOBALS['wpo_cache_config']['gmt_offset'] : 0;
167	$modified_time += $utc * 3600;
168
169	if (!empty($GLOBALS['wpo_cache_config']['timezone_string'])) {
170	$timezone_string = 'UTC' !== $GLOBALS['wpo_cache_config']['timezone_string'] ? $GLOBALS['wpo_cache_config']['timezone_string'] : '';
171	}
172
173	if (!empty($timezone_string)) {
174	$timezone_postfix = "(".$timezone_string." UTC:". $utc .")";
175	} else {
176	$timezone_postfix = "(UTC:" . $utc . ")";
177	}
178
179	$add_to_footer = '';
180
181	/**
182	* Filter whether to display the html comment <!-- Cached by WP-Optimize ... -->
183	*
184	* @param boolean $show - Whether to display the html comment
185	* @return boolean
186	*/
187	if (preg_match('#</html>#i', $buffer) && (apply_filters('wpo_cache_show_cached_by_comment', true) \|\| (defined('WP_DEBUG') && WP_DEBUG))) {
188	$date_time_format = 'F j, Y g:i a';
189	if (!empty($GLOBALS['wpo_cache_config']['date_format']) && !empty($GLOBALS['wpo_cache_config']['time_format'])) {
190	$date_time_format = $GLOBALS['wpo_cache_config']['date_format'] . ' ' . $GLOBALS['wpo_cache_config']['time_format'];
191	}
192
193	if (!empty($GLOBALS['wpo_cache_config']['enable_mobile_caching']) && wpo_is_mobile()) {
194	$add_to_footer .= "\n<!-- Cached by WP-Optimize - for mobile devices - https://getwpo.com - Last modified: " . gmdate($date_time_format, $modified_time) . " " . $timezone_postfix . " -->\n";
195	} else {
196	$add_to_footer .= "\n<!-- Cached by WP-Optimize - https://getwpo.com - Last modified: " . gmdate($date_time_format, $modified_time) . " " . $timezone_postfix . " -->\n";
197	}
198	}
199
200	// Create an empty index.php file in the cache directory for disable directory viewing.
201	if (!is_file($path . '/index.php')) file_put_contents($path . '/index.php', '');
202
203	/**
204	* Save $buffer into cache file.
205	*/
206	$file_ext = '.html';
207
208	if (wpo_feeds_caching_enabled()) {
209	if (is_feed()) {
210	$file_ext = '.rss-xml';
211	}
212	}
213
214	$cache_filename = wpo_cache_filename($file_ext);
215	$cache_file = $path . '/' .$cache_filename;
216
217	if (defined('WPO_CACHE_FILENAME_DEBUG') && WPO_CACHE_FILENAME_DEBUG) {
218	$add_to_footer .= "\n<!-- WP Optimize page cache debug information -->\n";
219	if (!empty($GLOBALS['wpo_cache_filename_debug']) && is_array($GLOBALS['wpo_cache_filename_debug'])) {
220	$add_to_footer .= "<!-- \n" . join("\n", array_map('htmlspecialchars', $GLOBALS['wpo_cache_filename_debug'])) . "\n --->";
221	}
222	}
223
224	// if we can then cache gzipped content in .gz file.
225	if (function_exists('gzencode') && apply_filters('wpo_allow_cache_gzip_files', true)) {
226	// Only replace inside the addition, not inside the main buffer (e.g. post content)
227	file_put_contents($cache_file . '.gz', gzencode($buffer.str_replace('by WP-Optimize', 'by WP-Optimize (gzip)', $add_to_footer), apply_filters('wpo_cache_gzip_level', 6)));
228	}
229
230	file_put_contents($cache_file, $buffer.$add_to_footer);
231
232	if (is_callable('WP_Optimize')) {
233	// delete cached information about cache size.
234	WP_Optimize()->get_page_cache()->delete_cache_size_information();
235	} else {
236	// If the shutdown occurs before plugins are loaded,
237	// then this will trigger a fatal error, so, we check first
238	if (!doing_action('shutdown')) {
239	error_log('[WPO_CACHE] WP_Optimize() is not callable.');
240	$message = 'Please report this to WP-O support: ';
241	if (function_exists('wp_debug_backtrace_summary')) {
242	$message .= wp_debug_backtrace_summary();
243	} else {
244	$message .= wpo_debug_backtrace_summary();
245	}
246	error_log($message);
247	}
248	}
249
250	header('Cache-Control: no-cache'); // Check back every time to see if re-download is necessary.
251	header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $modified_time) . ' GMT');
252	header('WPO-Cache-Status: saving to cache');
253
254	if (wpo_cache_can_output_gzip_content()) {
255
256	if (!wpo_cache_is_in_response_headers_list('Content-Encoding', 'gzip')) {
257	header('Content-Encoding: gzip');
258	}
259
260	// Disable php gzip to avoid double compression.
261	ini_set('zlib.output_compression', 'Off');
262
263	return ob_gzhandler($buffer, $flags);
264	} else {
265	return $buffer;
266	}
267	}
268	}
269	endif;
270
271	/**
272	* Load files for support plugins.
273	*/
274	if (!function_exists('wpo_cache_load_extensions')) :
275	function wpo_cache_load_extensions() {
276	$extensions = glob(WPO_CACHE_EXT_DIR . '/*.php');
277
278	// Add external extensions
279	if (defined('WPO_CACHE_CUSTOM_EXT_DIR') && is_dir(WPO_CACHE_CUSTOM_EXT_DIR)) {
280	$extensions = array_merge($extensions, glob(WPO_CACHE_CUSTOM_EXT_DIR . '/*.php'));
281	}
282
283	if (empty($extensions)) return;
284
285	foreach ($extensions as $extension) {
286	if (is_file($extension)) require_once $extension;
287	}
288	}
289	endif;
290
291	if (!function_exists('wpo_restricted_cache_page_type')) {
292	function wpo_restricted_cache_page_type($restricted) {
293	global $post;
294
295	// Don't cache search or password protected.
296	if ((function_exists('is_search') && is_search()) \|\| (function_exists('is_404') && is_404()) \|\| !empty($post->post_password)) {
297	$restricted = __('Page type is not cacheable (search, 404 or password-protected)', 'wp-optimize');
298	}
299
300	// Don't cache the front page if option is set.
301	if (in_array('/', wpo_get_url_exceptions()) && function_exists('is_front_page') && is_front_page()) {
302
303	$restricted = __('In the settings, caching is disabled for the front page', 'wp-optimize');
304	}
305
306	// Don't cache htacesss. Remember to properly escape any output to prevent injection.
307	if (strpos($_SERVER['REQUEST_URI'], '.htaccess') !== false) {
308	$restricted = 'The file path is unsuitable for caching ('.$_SERVER['REQUEST_URI'].')';
309	}
310
311	// Don't cache feeds.
312	if (function_exists('is_feed') && is_feed() && !wpo_feeds_caching_enabled()) {
313	$restricted = __('We don\'t cache RSS feeds', 'wp-optimize');
314	}
315
316	return $restricted;
317	}
318	}
319
320	/**
321	* Returns true if we need cache content for loggedin users.
322	*
323	* @return bool
324	*/
325	if (!function_exists('wpo_cache_loggedin_users')) :
326	function wpo_cache_loggedin_users() {
327	return !empty($GLOBALS['wpo_cache_config']['enable_user_caching']) \|\| !empty($GLOBALS['wpo_cache_config']['enable_user_specific_cache']) \|\| (function_exists('wpo_we_cache_per_role') && wpo_we_cache_per_role());
328	}
329	endif;
330
331	/**
332	* Get filename for store cache, depending on gzip, mobile and cookie settings.
333	*
334	* @param string $ext
335	* @return string
336	*/
337	if (!function_exists('wpo_cache_filename')) :
338	function wpo_cache_filename($ext = '.html') {
339
340	$wpo_cache_filename_debug = array();
341
342	$filename = 'index';
343
344	if (wpo_cache_mobile_caching_enabled() && wpo_is_mobile()) {
345	$filename = 'mobile.' . $filename;
346	}
347
348	if (wpo_webp_images_enabled() && !wpo_is_using_webp_images_redirection() && wpo_is_using_alter_html()) {
349	$filename = $filename . '.webp';
350	}
351
352	$cookies = wpo_cache_cookies();
353
354	$cache_key = '';
355
356	/**
357	* Add cookie values to filename if need.
358	* This section was inspired by things learned from WP-Rocket.
359	*/
360	if (!empty($cookies)) {
361	foreach ($cookies as $key => $cookie_name) {
362	if (is_array($cookie_name) && isset($_COOKIE[$key])) {
363	foreach ($cookie_name as $cookie_key) {
364	if (isset($_COOKIE[$key][$cookie_key]) && '' !== $_COOKIE[$key][$cookie_key]) {
365	$_cache_key = $cookie_key.'='.$_COOKIE[$key][$cookie_key];
366	$_cache_key = preg_replace('/[^a-z0-9_\-\=]/i', '-', $_cache_key);
367	$cache_key .= '-' . $_cache_key;
368	$wpo_cache_filename_debug[] = 'Cookie: name: ' . $key . '[' . $cookie_key . '], value: *** , cache_key:' . $_cache_key;
369	}
370	}
371	continue;
372	}
373
374	if (isset($_COOKIE[$cookie_name]) && '' !== $_COOKIE[$cookie_name]) {
375	$_cache_key = $cookie_name.'='.$_COOKIE[$cookie_name];
376	$_cache_key = preg_replace('/[^a-z0-9_\-\=]/i', '-', $_cache_key);
377	$cache_key .= '-' . $_cache_key;
378	$wpo_cache_filename_debug[] = 'Cookie: name: ' . $cookie_name . ', value: *** , cache_key:' . $_cache_key;
379	}
380	}
381	}
382
383	$query_variables = wpo_cache_query_variables();
384
385	/**
386	* Add GET variables to cache file name if need.
387	*/
388	if (!empty($query_variables)) {
389	foreach ($query_variables as $variable) {
390	if (isset($_GET[$variable]) && !empty($_GET[$variable])) {
391	$_cache_key = $variable.'='.$_GET[$variable];
392	$_cache_key = preg_replace('/[^a-z0-9_\-\=]/i', '-', $_cache_key);
393	$cache_key .= '-' . $_cache_key;
394	$wpo_cache_filename_debug[] = 'GET parameter: name: ' . $variable . ', value:' . htmlentities($_GET[$variable]) . ', cache_key:' . $_cache_key;
395	}
396	}
397	}
398
399	// add hash of queried cookies and variables to cache file name.
400	if ('' !== $cache_key) {
401	$hash = md5($cache_key);
402	$filename .= '-'.$hash;
403	$wpo_cache_filename_debug[] = 'Hash: ' . $hash;
404	}
405
406	$filename = apply_filters('wpo_cache_filename', $filename);
407
408	$wpo_cache_filename_debug[] = 'Extension: ' . $ext;
409	$wpo_cache_filename_debug[] = 'Filename: ' . $filename.$ext;
410
411	$GLOBALS['wpo_cache_filename_debug'] = $wpo_cache_filename_debug;
412
413	return $filename . $ext;
414	}
415	endif;
416
417	/**
418	* Returns site url from site_url() function or if it is not available from cache configuration.
419	*/
420	if (!function_exists('wpo_site_url')) :
421	function wpo_site_url() {
422	if (is_callable('site_url')) return site_url('/');
423
424	$site_url = empty($GLOBALS['wpo_cache_config']['site_url']) ? '' : $GLOBALS['wpo_cache_config']['site_url'];
425	return $site_url;
426	}
427	endif;
428
429	/**
430	* Get cookie names which impact on cache file name.
431	*
432	* @return array
433	*/
434	if (!function_exists('wpo_cache_cookies')) :
435	function wpo_cache_cookies() {
436	$cookies = empty($GLOBALS['wpo_cache_config']['wpo_cache_cookies']) ? array() : $GLOBALS['wpo_cache_config']['wpo_cache_cookies'];
437	return $cookies;
438	}
439	endif;
440
441	/**
442	* Get GET variable names which impact on cache file name.
443	*
444	* @return array
445	*/
446	if (!function_exists('wpo_cache_query_variables')) :
447	function wpo_cache_query_variables() {
448	if (defined('WPO_CACHE_URL_PARAMS') && WPO_CACHE_URL_PARAMS) {
449	$variables = array_keys($_GET);
450	} else {
451	$variables = empty($GLOBALS['wpo_cache_config']['wpo_cache_query_variables']) ? array() : $GLOBALS['wpo_cache_config']['wpo_cache_query_variables'];
452	}
453
454	if (!empty($variables)) {
455	sort($variables);
456	}
457
458	return wpo_cache_maybe_ignore_query_variables($variables);
459	}
460	endif;
461
462	/**
463	* Get list of all received HTTP headers.
464	*
465	* @return array
466	*/
467	if (!function_exists('wpo_get_http_headers')) :
468	function wpo_get_http_headers() {
469
470	static $headers;
471
472	if (!empty($headers)) return $headers;
473
474	$headers = array();
475
476	// if is apache server then use get allheaders() function.
477	if (function_exists('getallheaders')) {
478	$headers = getallheaders();
479	} else {
480	// https://www.php.net/manual/en/function.getallheaders.php
481	foreach ($_SERVER as $key => $value) {
482
483	$key = strtolower($key);
484
485	if ('HTTP_' == substr($key, 0, 5)) {
486	$headers[str_replace(' ', '-', ucwords(str_replace('_', ' ', substr($key, 5))))] = $value;
487	} elseif ('content_type' == $key) {
488	$headers["Content-Type"] = $value;
489	} elseif ('content_length' == $key) {
490	$headers["Content-Length"] = $value;
491	}
492	}
493	}
494
495	return $headers;
496	}
497	endif;
498
499	/**
500	* Check if requested Accept-Encoding headers has gzip value.
501	*
502	* @return bool
503	*/
504	if (!function_exists('wpo_cache_gzip_accepted')) :
505	function wpo_cache_gzip_accepted() {
506	$headers = wpo_get_http_headers();
507
508	if (isset($headers['Accept-Encoding']) && preg_match('/gzip/i', $headers['Accept-Encoding'])) return true;
509
510	return false;
511	}
512	endif;
513
514	/**
515	* Check if we can output gzip content in current answer, i.e. check Accept-Encoding headers has gzip value
516	* and function ob_gzhandler is available.
517	*
518	* @return bool
519	*/
520	if (!function_exists('wpo_cache_can_output_gzip_content')) :
521	function wpo_cache_can_output_gzip_content() {
522	return wpo_cache_gzip_accepted() && function_exists('ob_gzhandler');
523	}
524	endif;
525
526	/**
527	* Check if header with certain name exists in already prepared headers and has value comparable with $header_value.
528	*
529	* @param string $header_name header name
530	* @param string $header_value header value as regexp.
531	*
532	* @return bool
533	*/
534	if (!function_exists('wpo_cache_is_in_response_headers_list')) :
535	function wpo_cache_is_in_response_headers_list($header_name, $header_value) {
536	$headers_list = headers_list();
537
538	if (!empty($headers_list)) {
539	$header_name = strtolower($header_name);
540
541	foreach ($headers_list as $value) {
542	$value = explode(':', $value);
543
544	if (strtolower($value[0]) == $header_name) {
545	if (preg_match('/'.$header_value.'/', $value[1])) {
546	return true;
547	} else {
548	return false;
549	}
550	}
551	}
552	}
553
554	return false;
555	}
556	endif;
557
558	/**
559	* Check if mobile cache is enabled and current request is from moblile device.
560	*
561	* @return bool
562	*/
563	if (!function_exists('wpo_cache_mobile_caching_enabled')) :
564	function wpo_cache_mobile_caching_enabled() {
565	if (!empty($GLOBALS['wpo_cache_config']['enable_mobile_caching'])) return true;
566	return false;
567	}
568	endif;
569
570	/**
571	* Check if webp images enabled
572	*
573	* @return bool
574	*/
575	if (!function_exists('wpo_webp_images_enabled')) :
576	function wpo_webp_images_enabled() {
577	if (!empty($GLOBALS['wpo_cache_config']['use_webp_images'])) return true;
578	return false;
579	}
580	endif;
581
582	/**
583	* Check whether webp images using alter html method or not
584	*
585	* @return bool
586	*/
587	if (!function_exists('wpo_is_using_alter_html')) :
588	function wpo_is_using_alter_html() {
589	return (isset($_SERVER['HTTP_ACCEPT']) && false !== strpos($_SERVER['HTTP_ACCEPT'], 'image/webp'));
590	}
591	endif;
592
593	/**
594	* Check whether webp images are served using redirect
595	*
596	* @return bool
597	*/
598	if (!function_exists('wpo_is_using_webp_images_redirection')) :
599	function wpo_is_using_webp_images_redirection() {
600	if (empty($GLOBALS['wpo_cache_config']['uploads'])) return false;
601
602	$uploads_dir = $GLOBALS['wpo_cache_config']['uploads'];
603	$htaccess_file = $uploads_dir . '/.htaccess';
604	if (!file_exists($htaccess_file)) return false;
605	$htaccess_content = file_get_contents($htaccess_file);
606	$comment_sections = array('Register webp mime type', 'WP-Optimize WebP Rules');
607
608	if (function_exists('str_contains')) {
609	return str_contains($htaccess_content, $comment_sections[0]) && str_contains($htaccess_content, $comment_sections[1]);
610	} else {
611	return strpos($htaccess_content, $comment_sections[0]) && strpos($htaccess_content, $comment_sections[1]);
612	}
613	}
614	endif;
615
616	/**
617	* Verify if the current request is related to the Activity Stream
618	*
619	* @return bool
620	*/
621	if (!function_exists('wpo_is_activity_stream_requested')) :
622	function wpo_is_activity_stream_requested() {
623	return (isset($_SERVER['HTTP_ACCEPT']) && false !== strpos($_SERVER['HTTP_ACCEPT'], 'application/activity+json'));
624	}
625	endif;
626
627	/**
628	* Verify if the current request is robots.txt
629	*/
630	if (!function_exists('wpo_is_robots_txt_requested')) :
631	function wpo_is_robots_txt_requested() {
632	return (isset($_SERVER['REQUEST_URI']) && 'robots.txt' === basename($_SERVER['REQUEST_URI']));
633	}
634	endif;
635
636	/**
637	* Serves the cache and exits
638	*/
639	if (!function_exists('wpo_serve_cache')) :
640	function wpo_serve_cache() {
641	$file_name = wpo_cache_filename();
642
643	$file_name_rss_xml = wpo_cache_filename('.rss-xml');
644	$send_as_feed = false;
645
646	$path_dir = WPO_CACHE_FILES_DIR . '/' . wpo_get_url_path() . '/';
647	$path = $path_dir . $file_name;
648
649	if (wpo_feeds_caching_enabled()) {
650	// check for .xml cache file if .html cache file doesn't exist
651	if (!file_exists($path_dir . $file_name) && file_exists($path_dir . $file_name_rss_xml)) {
652	$path = $path_dir . $file_name_rss_xml;
653	$send_as_feed = true;
654	}
655	}
656
657	$use_gzip = false;
658
659	// if we can use gzip and gzipped file exist in cache we use it.
660	// if headers already sent we don't use gzipped file content.
661	if (!headers_sent() && wpo_cache_gzip_accepted() && file_exists($path . '.gz')) {
662	$path .= '.gz';
663	$use_gzip = true;
664	}
665
666	$modified_time = file_exists($path) ? (int) filemtime($path) : time();
667
668	// Cache has expired, purge and exit.
669	if (!empty($GLOBALS['wpo_cache_config']['page_cache_length'])) {
670	if (time() > ($GLOBALS['wpo_cache_config']['page_cache_length'] + $modified_time)) {
671	wpo_delete_files($path);
672	return;
673	}
674	}
675
676	if ($use_gzip) {
677	// Disable zlib output compression to avoid double content compression
678	ini_set('zlib.output_compression', 'Off');
679	}
680
681	$gzip_header_already_sent = wpo_cache_is_in_response_headers_list('Content-Encoding', 'gzip');
682
683	header('Cache-Control: no-cache'); // Check back later
684
685	if (!empty($modified_time) && !empty($_SERVER['HTTP_IF_MODIFIED_SINCE']) && strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) === $modified_time) {
686	if ($use_gzip && !$gzip_header_already_sent) {
687	header('Content-Encoding: gzip');
688	}
689
690	if ($send_as_feed) {
691	header('Content-type: application/rss+xml');
692	}
693
694	header('WPO-Cache-Status: cached');
695	header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $modified_time) . ' GMT');
696	header($_SERVER['SERVER_PROTOCOL'] . ' 304 Not Modified', true, 304);
697	exit;
698	}
699
700	if (file_exists($path) && is_readable($path)) {
701
702	if (wpo_is_canonical_redirection_needed()) return;
703
704	if ($use_gzip && !$gzip_header_already_sent) {
705	header('Content-Encoding: gzip');
706	}
707
708	// send correct headers for xml and txt files
709	$filename = basename(dirname($path));
710
711	if (preg_match('/\.xml$/i', $filename)) {
712	header('Content-type: text/xml');
713	}
714
715	if (preg_match('/\.txt$/i', $filename)) {
716	header('Content-type: text/plain');
717	}
718
719	if ($send_as_feed) {
720	header('Content-type: application/rss+xml');
721	}
722
723	header('WPO-Cache-Status: cached');
724	if (!empty($modified_time)) {
725	header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $modified_time) . ' GMT');
726	}
727
728	readfile($path);
729
730	exit;
731	}
732	}
733	endif;
734
735	/**
736	* Checks and does redirection, if needed
737	*
738	* @return bool
739	*/
740	if (!function_exists('wpo_is_canonical_redirection_needed')) :
741	function wpo_is_canonical_redirection_needed() {
742	$permalink_structure = isset($GLOBALS['wpo_cache_config']['permalink_structure']) ? $GLOBALS['wpo_cache_config']['permalink_structure'] : '';
743	$site_url = wpo_site_url();
744
745	// Exit if server variables are not available.
746	if (!isset($_SERVER['HTTP_HOST'])) return false;
747
748	$schema = isset($_SERVER['HTTPS']) && 'on' === $_SERVER['HTTPS'] ? "https" : "http";
749	$url_part = "://" . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
750	$requested_url = $schema . $url_part;
751	$url_parts = parse_url($requested_url);
752	$extension = pathinfo($url_parts['path'], PATHINFO_EXTENSION);
753
754	if (!empty($permalink_structure) && $requested_url != $site_url && ((isset($url_parts['path']) && '/' !== $url_parts['path']) \|\| isset($url_parts['query']))) {
755	$request_uri = rtrim($_SERVER['REQUEST_URI'], '?');
756	if ('/' == substr($permalink_structure, -1) && empty($extension) && empty($url_parts['query']) && empty($url_parts['fragment'])) {
757	$url = preg_replace('/(.+?)([\/]*)(\[\?\#][^\/]+\|$)/', '$1/$3', $request_uri);
758	if (0 !== strcmp($request_uri, $url)) return true;
759	} else {
760	$url = rtrim($request_uri, '/');
761	if (0 !== strcmp($request_uri, $url)) return true;
762	}
763	}
764	return false;
765	}
766	endif;
767
768	/**
769	* Clears the cache
770	*/
771	if (!function_exists('wpo_cache_flush')) :
772	function wpo_cache_flush() {
773
774	if (defined('WPO_CACHE_FILES_DIR') && '' != WPO_CACHE_FILES_DIR) wpo_delete_files(WPO_CACHE_FILES_DIR);
775
776	if (function_exists('wp_cache_flush')) {
777	wp_cache_flush();
778	}
779
780	do_action('wpo_cache_flush');
781	}
782	endif;
783
784	/**
785	* Get URL path for caching
786	*
787	* @since 1.0
788	* @return string
789	*/
790	if (!function_exists('wpo_get_url_path')) :
791	function wpo_get_url_path($url = '') {
792	$url = '' == $url ? wpo_current_url() : $url;
793	$url_parts = parse_url($url);
794
795	if (isset($url_parts['path']) && false !== stripos($url_parts['path'], '/index.php')) {
796	$url_parts['path'] = preg_replace('/(.*?)index\.php(\/.+)/i', '$1index-php$2', $url_parts['path']);
797	}
798
799	/*
800	* Convert the hexadecimal digits within the percent-encoded triplet to uppercase, to ensure that the path remains
801	* consistent. For instance, "example.com/%e0%a6" will be converted to "example.com/%E0%A6".
802	*/
803	if (isset($url_parts['path'])) {
804	$url_parts['path'] = preg_replace_callback('/%[0-9A-F]{2}/i', function($matches) {
805	return strtoupper($matches[0]);
806	}, $url_parts['path']);
807	}
808
809	if (!isset($url_parts['host'])) $url_parts['host'] = '';
810	if (!isset($url_parts['path'])) $url_parts['path'] = '';
811
812	return $url_parts['host'].$url_parts['path'];
813	}
814	endif;
815
816	/**
817	* Get requested url.
818	*
819	* @return string
820	*/
821	if (!function_exists('wpo_current_url')) :
822	function wpo_current_url() {
823	// 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).
824	// Otherwise this function would return a different URL at the beginning and end of the cache process.
825	static $url = '';
826	if ('' != $url) return $url;
827	$http_host = isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : '';
828	$url = rtrim('http' . ((isset($_SERVER['HTTPS']) && ('on' == $_SERVER['HTTPS'] \|\| 1 == $_SERVER['HTTPS']) \|\|
829	isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && 'https' == $_SERVER['HTTP_X_FORWARDED_PROTO']) ? 's' : '' )
830	. '://' . $http_host.$_SERVER['REQUEST_URI'], '/');
831	return $url;
832	}
833	endif;
834
835	/**
836	* Return list of conditional tag exceptions.
837	*
838	* @return array
839	*/
840	if (!function_exists('wpo_get_conditional_tags_exceptions')) :
841	function wpo_get_conditional_tags_exceptions() {
842	static $exceptions = null;
843
844	if (null !== $exceptions) return $exceptions;
845
846	if (!empty($GLOBALS['wpo_cache_config'])) {
847	if (empty($GLOBALS['wpo_cache_config']['cache_exception_conditional_tags'])) {
848	$exceptions = array();
849
850	} else {
851
852	$exceptions = $GLOBALS['wpo_cache_config']['cache_exception_conditional_tags'];
853
854	}
855
856	} elseif (class_exists('WPO_Page_Cache')) {
857
858	$config = WPO_Page_Cache::instance()->config->get();
859
860	if (is_array($config) && array_key_exists('cache_exception_conditional_tags', $config)) {
861	$exceptions = $config['cache_exception_conditional_tags'];
862	} else {
863	$exceptions = array();
864	}
865
866	$exceptions = is_array($exceptions) ? $exceptions : preg_split('#(\n\|\r\|\r\n)#', $exceptions);
867	$exceptions = array_filter($exceptions, 'trim');
868
869	} else {
870	$exceptions = array();
871	}
872
873	return $exceptions;
874	}
875	endif;
876
877	/**
878	* Return list of url exceptions.
879	*
880	* @return array
881	*/
882	if (!function_exists('wpo_get_url_exceptions')) :
883	function wpo_get_url_exceptions() {
884	static $exceptions = null;
885
886	if (null !== $exceptions) return $exceptions;
887
888	// if called from file-based-page-cache.php when WP loading
889	// and cache settings exists then use it otherwise get settings from database.
890	if (!empty($GLOBALS['wpo_cache_config'])) {
891	if (empty($GLOBALS['wpo_cache_config']['cache_exception_urls'])) {
892	$exceptions = array();
893	} else {
894	$exceptions = is_array($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']);
895	}
896	} elseif (class_exists('WPO_Page_Cache')) {
897	$config = WPO_Page_Cache::instance()->config->get();
898
899	if (is_array($config) && array_key_exists('cache_exception_urls', $config)) {
900	$exceptions = $config['cache_exception_urls'];
901	} else {
902	$exceptions = array();
903	}
904
905	$exceptions = is_array($exceptions) ? $exceptions : preg_split('#(\n\|\r)#', $exceptions);
906	$exceptions = array_filter($exceptions, 'trim');
907	} else {
908	$exceptions = array();
909	}
910
911	return apply_filters('wpo_get_url_exceptions', $exceptions);
912	}
913	endif;
914
915	/**
916	* Return true of exception url matches current url
917	*
918	* @param string $exception Exceptions to check URL against.
919	* @param bool $regex Whether to check with regex or not.
920	* @return bool true if matched, false otherwise
921	*/
922	if (!function_exists('wpo_current_url_exception_match')) :
923	function wpo_current_url_exception_match($exception) {
924
925	return wpo_url_exception_match(wpo_current_url(), $exception);
926	}
927	endif;
928
929	/**
930	* Check if url in conditional tags exceptions list.
931	*
932	* @return string
933	*/
934	if (!function_exists('wpo_url_in_conditional_tags_exceptions')) :
935	function wpo_url_in_conditional_tags_exceptions() {
936
937	$exceptions = wpo_get_conditional_tags_exceptions();
938	$restricted = '';
939	$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');
940	//Filter for add more conditional tags to whitelist in the exceptions list.
941	$allowed_functions = apply_filters('wpo_allowed_conditional_tags_exceptions', $allowed_functions);
942	if (!empty($exceptions)) {
943	foreach ($exceptions as $exception) {
944	if (false !== strpos($exception, 'is_')) {
945	$exception_function = $exception;
946	if ('()' == substr($exception, -2)) {
947	$exception_function = substr($exception, 0, -2);
948	}
949
950	if (in_array($exception_function, $allowed_functions) && function_exists($exception_function) && call_user_func($exception_function)) {
951	$restricted = sprintf(__('In the settings, caching is disabled for %s', 'wp-optimize'), $exception_function);
952	}
953	}
954	}
955	}
956	return $restricted;
957	}
958	endif;
959
960
961	/**
962	* Check if url in exceptions list.
963	*
964	* @param string $url
965	*
966	* @return bool
967	*/
968	if (!function_exists('wpo_url_in_exceptions')) :
969	function wpo_url_in_exceptions($url) {
970	$exceptions = wpo_get_url_exceptions();
971
972	if (!empty($exceptions)) {
973	foreach ($exceptions as $exception) {
974
975	// don't check / - front page using regexp, we handle it in wpo_restricted_cache_page_type()
976	if ('/' == $exception) continue;
977
978	if (wpo_url_exception_match($url, $exception)) {
979	// Exception match.
980	return true;
981	}
982	}
983	}
984
985	return false;
986	}
987	endif;
988
989	/**
990	* Checks if an URL matches against listed exceptions.
991	*
992	* @param string $url - complete url string i.e. http(s)://domain/path
993	* @param string $exception - complete url or absolute path, can contain (.*) wildcards; Sometimes can be urlencoded
994	*
995	* @return bool
996	*/
997	if (!function_exists('wpo_url_exception_match')) :
998	function wpo_url_exception_match($url, $exception) {
999	if (preg_match('#^[\s]*$#', $exception)) {
1000	return false;
1001	}
1002
1003	$exception = str_replace('', '.', $exception);
1004
1005	$exception = trim($exception);
1006
1007	// Used to test websites placed in subdirectories.
1008	$sub_dir = '';
1009
1010	// If exception defined from root i.e. /page1 then remove domain part in url.
1011	if (preg_match('/^\//', $exception)) {
1012	// get site sub directory.
1013	$sub_dir = preg_replace('#^(http\|https):\/\/.*\/#Ui', '', wpo_site_url());
1014	// add prefix slash and remove slash.
1015	$sub_dir = ('' == $sub_dir) ? '' : '/' . rtrim($sub_dir, '/');
1016	// get relative path
1017	$url = preg_replace('#^(http\|https):\/\/.*\/#Ui', '/', $url);
1018	}
1019
1020	$url = urldecode(rtrim($url, '/')) . '/';
1021	$exception = rtrim($exception, '/');
1022
1023	// if we have no wildcard in the end of exception then add slash.
1024	if (!preg_match('#$\.\*$$#', $exception)) $exception .= '/';
1025
1026	$exception = preg_quote($exception);
1027
1028	// fix - unescape some possibly escaped mask characters
1029	$search = array(
1030	'\\.\\*',
1031	'\\-',
1032	);
1033	$replace = array(
1034	'.*',
1035	'-',
1036	);
1037	$exception = urldecode(str_replace($search, $replace, $exception));
1038
1039	return (preg_match('#^'.$exception.'$#i', $url) \|\| preg_match('#^'.$sub_dir.$exception.'$#i', $url));
1040	}
1041	endif;
1042
1043	/**
1044	* Checks if its a mobile device
1045	*
1046	* @see https://developer.wordpress.org/reference/functions/wp_is_mobile/
1047	*/
1048	if (!function_exists('wpo_is_mobile')) :
1049	function wpo_is_mobile() {
1050	if (empty($_SERVER['HTTP_USER_AGENT'])) {
1051	$is_mobile = false;
1052	// many mobile devices (all iPhone, iPad, etc.)
1053	} elseif (strpos($_SERVER['HTTP_USER_AGENT'], 'Mobile') !== false
1054	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Android') !== false
1055	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Silk/') !== false
1056	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Kindle') !== false
1057	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'BlackBerry') !== false
1058	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mini') !== false
1059	\|\| strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mobi') !== false
1060	) {
1061	$is_mobile = true;
1062	} else {
1063	$is_mobile = false;
1064	}
1065
1066	return $is_mobile;
1067	}
1068	endif;
1069
1070	/**
1071	* Check if current browser agent is not disabled in options.
1072	*
1073	* @return bool
1074	*/
1075	if (!function_exists('wpo_is_accepted_user_agent')) :
1076	function wpo_is_accepted_user_agent($user_agent) {
1077
1078	$exceptions = is_array($GLOBALS['wpo_cache_config']['cache_exception_browser_agents']) ? $GLOBALS['wpo_cache_config']['cache_exception_browser_agents'] : preg_split('#(\n\|\r)#', $GLOBALS['wpo_cache_config']['cache_exception_browser_agents']);
1079
1080	if (!empty($exceptions)) {
1081	foreach ($exceptions as $exception) {
1082	if ('' == trim($exception)) continue;
1083
1084	if (preg_match('#'.$exception.'#i', $user_agent)) return false;
1085	}
1086	}
1087
1088	return true;
1089	}
1090	endif;
1091
1092	if (!function_exists('wpo_delete_files')) :
1093	/**
1094	* Deletes a specified source file or directory.
1095	*
1096	* If $src is a file, only that file will be deleted. If $src is a directory, the behavior depends on the
1097	* $recursive parameter. When $recursive is true, the directory and its contents (including files and subdirectories)
1098	* will be deleted. When $recursive is false, only the files in the top-level directory(eg. $src directory) will be deleted,
1099	* while the $src directory itself and its subdirectories will remain untouched.
1100	*
1101	* @param string $src The path to the source file or directory to delete.
1102	* @param bool $recursive (Optional) When set to true, the directory and its contents (including files and subdirectories)
1103	* will be deleted. If false, only the files in the top-level directory will be deleted while
1104	* its subdirectories will be preserved. Defaults to true.
1105	*
1106	* @return bool Returns true if the specified file or all files within the specified directory (and its subdirectories,
1107	* when $recursive is true) are successfully deleted. Returns false if any file(s) could not be deleted
1108	* due to file permissions or other reasons.
1109	*/
1110	function wpo_delete_files($src, $recursive = true) {
1111	// If the source doesn't exist, consider it deleted and return true
1112	if (!file_exists($src)) {
1113	return true;
1114	}
1115
1116	/*
1117	* If the source is a file, delete it and return the result.
1118	* If `unlink()` fails, we also verify if the file still exists before returning the result, as another
1119	* PHP process may have already deleted the file between the execution of `is_file()` and `unlink()` operations.
1120	*/
1121	if (is_file($src)) {
1122	if (!@unlink($src) && file_exists($src)) { // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1123	return false;
1124	}
1125	return true;
1126	}
1127
1128	$success = true;
1129
1130	// If recursive is false, delete only the top-level files and return the result
1131	if (!$recursive) {
1132	$dir_handle = @opendir($src); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1133
1134	/*
1135	* If opendir() is successful, process directory contents. If not, check if the directory exists.
1136	* If it exists, return false (failure). Otherwise, assume it's already deleted and return true (success).
1137	*/
1138	if (false !== $dir_handle) {
1139
1140	while (false !== ($file = readdir($dir_handle))) {
1141	if ('.' == $file \|\| '..' == $file) {
1142	continue;
1143	}
1144
1145	$full_path = $src . '/' . $file;
1146
1147	// If it's a file, delete it
1148	if (is_file($full_path)) {
1149	if (!wpo_delete_files($full_path)) {
1150	$success = false;
1151	}
1152	}
1153	}
1154
1155	closedir($dir_handle);
1156	} else {
1157	if (file_exists($src)) {
1158	$success = false;
1159	}
1160	}
1161
1162	return $success;
1163	}
1164
1165	// If recursive is true, delete all files and directories recursively
1166	$dir_handle = @opendir($src); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1167
1168	/*
1169	* If opendir() is successful, process directory contents. If not, check if the directory exists.
1170	* If it exists, return false (failure). Otherwise, assume it's already deleted and return true (success).
1171	*/
1172	if (false !== $dir_handle) {
1173
1174	while (false !== ($file = readdir($dir_handle))) {
1175	if ('.' == $file \|\| '..' == $file) {
1176	continue;
1177	}
1178
1179	$full_path = $src . '/' . $file;
1180
1181	if (!wpo_delete_files($full_path)) {
1182	$success = false;
1183	}
1184	}
1185
1186	closedir($dir_handle);
1187	} else {
1188	if (file_exists($src)) {
1189	$success = false;
1190	}
1191	}
1192
1193	/*
1194	* Delete the source directory itself.
1195	* Success of `rmdir` operation is not recorded; we only ultimately care about emptying, not removing
1196	* entirely (empty folders in our context are harmless)
1197	*/
1198	if ($success) {
1199	@rmdir($src); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
1200	}
1201
1202	// Delete cached information about cache size
1203	WP_Optimize()->get_page_cache()->delete_cache_size_information();
1204
1205	return $success;
1206	}
1207	endif;
1208
1209	if (!function_exists('wpo_is_empty_dir')) :
1210	/**
1211	* Check if selected directory is empty or has only index.php which we added for security reasons.
1212	*
1213	* @param string $dir
1214	*
1215	* @return bool
1216	*/
1217	function wpo_is_empty_dir($dir) {
1218	if (!file_exists($dir) \|\| !is_dir($dir)) return false;
1219
1220	$handle = opendir($dir);
1221
1222	if (false === $handle) return false;
1223
1224	$is_empty = true;
1225	$file = readdir($handle);
1226
1227	while (false !== $file) {
1228
1229	if ('.' != $file && '..' != $file && 'index.php' != $file) {
1230	$is_empty = false;
1231	break;
1232	}
1233
1234	$file = readdir($handle);
1235	}
1236
1237	closedir($handle);
1238	return $is_empty;
1239	}
1240	endif;
1241
1242	/**
1243	* Either store for later output, or output now. Only the most-recent call will be effective.
1244	*
1245	* @param String\|Null $output - if not null, then the string to use when called by the shutdown action.
1246	*/
1247	if (!function_exists('wpo_cache_add_footer_output')) :
1248	function wpo_cache_add_footer_output($output = null) {
1249
1250	static $buffered = null;
1251
1252	if (function_exists('current_filter') && 'shutdown' == current_filter()) {
1253	// Only add the line if it was a page, not something else (e.g. REST response)
1254	if (function_exists('did_action') && did_action('wp_footer')) {
1255	echo "\n<!-- WP Optimize page cache - https://getwpo.com - ".$buffered." -->\n";
1256	} elseif (defined('WPO_CACHE_DEBUG') && WPO_CACHE_DEBUG && (!defined('REST_REQUEST') \|\| !REST_REQUEST)) {
1257	error_log('[CACHE DEBUG] '.wpo_current_url() . ' - ' . $buffered);
1258	}
1259	} else {
1260	if (null == $buffered && function_exists('add_action')) add_action('shutdown', 'wpo_cache_add_footer_output', 11);
1261	$buffered = $output;
1262	}
1263
1264	}
1265	endif;
1266
1267	/**
1268	* Remove variable names that shouldn't influence cache.
1269	*
1270	* @param array $variables List of variable names.
1271	*
1272	* @return array
1273	*/
1274	if (!function_exists('wpo_cache_maybe_ignore_query_variables')) :
1275	function wpo_cache_maybe_ignore_query_variables($variables) {
1276
1277	/**
1278	* Filters the current $_GET variables that will be used when caching or excluding from cache.
1279	* Currently:
1280	* - 'wpo_cache_debug' (Shows the reason for not being cached even when WP_DEBUG isn't set)
1281	* - 'doing_wp_cron' (alternative cron)
1282	* - 'aiosp_sitemap_path', 'aiosp_sitemap_page' (All in one SEO sitemap)
1283	* - 'xml_sitemap', 'seopress_sitemap', 'seopress_news', 'seopress_video', 'seopress_cpt', 'seopress_paged' (SEOPress sitemap)
1284	* - 'sitemap', 'sitemap_n' (YOAST SEO sitemap)
1285	*/
1286	$exclude_variables = array(
1287	'wpo_cache_debug', // Shows the reason for not being cached even when WP_DEBUG isn't set
1288	'doing_wp_cron', // alternative cron
1289	'aiosp_sitemap_path', // All in one SEO sitemap
1290	'aiosp_sitemap_page',
1291	'xml_sitemap', // SEOPress sitemap
1292	'seopress_sitemap',
1293	'seopress_news',
1294	'seopress_video',
1295	'seopress_cpt',
1296	'seopress_paged',
1297	'sitemap', // YOAST SEO sitemap
1298	'sitemap_n',
1299	);
1300	$exclude_variables = function_exists('apply_filters') ? apply_filters('wpo_cache_ignore_query_variables', $exclude_variables) : $exclude_variables;
1301
1302	if (empty($exclude_variables)) return $variables;
1303
1304	foreach ($exclude_variables as $variable) {
1305	$exclude = array_search($variable, $variables);
1306	if (false !== $exclude) {
1307	array_splice($variables, $exclude, 1);
1308	}
1309	}
1310
1311	return $variables;
1312	}
1313	endif;
1314
1315	/**
1316	* Get cache config
1317	*
1318	* @param string $key - The config item
1319	* @param mixed $default - The default value
1320	*
1321	* @return mixed
1322	*/
1323	if (!function_exists('wpo_cache_config_get')) :
1324	function wpo_cache_config_get($key, $default = false) {
1325	$config = $GLOBALS['wpo_cache_config'];
1326
1327	if (!$config) return false;
1328
1329	if (isset($config[$key])) {
1330	return $config[$key];
1331	} else {
1332	return $default;
1333	}
1334	}
1335	endif;
1336
1337	if (!function_exists('wpo_disable_cache_directories_viewing')) :
1338	function wpo_disable_cache_directories_viewing() {
1339	global $is_apache, $is_IIS, $is_iis7;
1340
1341	if (!is_dir(WPO_CACHE_FILES_DIR)) return;
1342
1343	// Create .htaccess file for apache server.
1344	if ($is_apache) {
1345	$htaccess_filename = WPO_CACHE_FILES_DIR . '/.htaccess';
1346
1347	// CS does not like heredoc
1348	// phpcs:disable
1349	$htaccess_content = <<<EOF
1350	# Disable directory browsing
1351	Options -Indexes
1352
1353	# Disable access to any files
1354	<FilesMatch ".*">
1355	Order allow,deny
1356	Deny from all
1357	</FilesMatch>
1358	EOF;
1359	// phpcs:enable
1360
1361	if (!is_file($htaccess_filename)) @file_put_contents($htaccess_filename, $htaccess_content); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress the error when there is file permission issues
1362	}
1363
1364	// Create web.config file for IIS servers.
1365	if ($is_IIS \|\| $is_iis7) {
1366	$webconfig_filename = WPO_CACHE_FILES_DIR . '/web.config';
1367	$webconfig_content = "<configuration>\n<system.webServer>\n<authorization>\n<deny users=\"*\" />\n</authorization>\n</system.webServer>\n</configuration>\n";
1368
1369	if (!is_file($webconfig_filename)) @file_put_contents($webconfig_filename, $webconfig_content); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress the error when there is file permission issues
1370	}
1371
1372	// Create empty index.php file for all servers.
1373	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
1374	}
1375	endif;
1376
1377	/**
1378	* Add the headers indicating why the page is not cached or served from cache
1379	*
1380	* @param string $message - The headers
1381	*
1382	* @return void
1383	*/
1384	if (!function_exists('wpo_cache_add_nocache_http_header')) :
1385	function wpo_cache_add_nocache_http_header($message = '') {
1386	static $buffered_message = null;
1387
1388	if (function_exists('current_filter') && 'send_headers' === current_filter() && $buffered_message && !headers_sent()) {
1389	header('WPO-Cache-Status: not cached');
1390	header('WPO-Cache-Message: '. trim(str_replace(array("\r", "\n", ':'), ' ', strip_tags($buffered_message))));
1391	} else {
1392	if (!$buffered_message && function_exists('add_action')) add_action('send_headers', 'wpo_cache_add_nocache_http_header', 11);
1393	$buffered_message = $message;
1394	}
1395	}
1396	endif;
1397
1398	/**
1399	* Check if feeds caching enabled
1400	*
1401	* @return bool
1402	*/
1403	if (!function_exists('wpo_feeds_caching_enabled')) :
1404	function wpo_feeds_caching_enabled() {
1405	return apply_filters('wpo_feeds_caching_enabled', true);
1406	}
1407	endif;
1408
1409	if (!function_exists('wpo_debug_backtrace_summary')) {
1410	function wpo_debug_backtrace_summary($ignore_class = null, $skip_frames = 0, $pretty = true) {
1411	static $truncate_paths;
1412
1413	$trace = debug_backtrace(false);
1414	$caller = array();
1415	$check_class = !is_null($ignore_class);
1416	$skip_frames++; // Skip this function.
1417
1418	if (!isset($truncate_paths)) {
1419	$truncate_paths = array(
1420	wpo_normalize_path(WP_CONTENT_DIR),
1421	wpo_normalize_path(ABSPATH),
1422	);
1423	}
1424
1425	foreach ($trace as $call) {
1426	if ($skip_frames > 0) {
1427	$skip_frames--;
1428	} elseif (isset($call['class'])) {
1429	if ($check_class && $ignore_class == $call['class']) {
1430	continue; // Filter out calls.
1431	}
1432
1433	$caller[] = "{$call['class']}{$call['type']}{$call['function']}";
1434	} else {
1435	if (in_array($call['function'], array('do_action', 'apply_filters', 'do_action_ref_array', 'apply_filters_ref_array'), true)) {
1436	$caller[] = "{$call['function']}('{$call['args'][0]}')";
1437	} elseif (in_array($call['function'], array('include', 'include_once', 'require', 'require_once'), true)) {
1438	$filename = isset($call['args'][0]) ? $call['args'][0] : '';
1439	$caller[] = $call['function'] . "('" . str_replace($truncate_paths, '', wpo_normalize_path($filename)) . "')";
1440	} else {
1441	$caller[] = $call['function'];
1442	}
1443	}
1444	}
1445	if ($pretty) {
1446	return implode(', ', array_reverse($caller));
1447	} else {
1448	return $caller;
1449	}
1450	}
1451	}
1452
1453	if (!function_exists('wpo_normalize_path')) {
1454	function wpo_normalize_path($path) {
1455	// Standardise all paths to use '/'.
1456	$path = str_replace('\\', '/', $path);
1457
1458	// Replace multiple slashes down to a singular, allowing for network shares having two slashes.
1459	$path = preg_replace('\|(?<=.)/+\|', '/', $path);
1460
1461	// Windows paths should uppercase the drive letter.
1462	if (':' === substr($path, 1, 1)) {
1463	$path = ucfirst($path);
1464	}
1465
1466	return $path;
1467	}
1468	}
1469