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

file-based-page-cache-functions.php in WP-Optimize – Cache, Compress images, Minify & Clean database to boost page speed & performance 3.2.3, at cache/file-based-page-cache-functions.php

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