wp-optimize / webp / class-wp-optimize-webp.php

class-wp-optimize-webp.php in WP-Optimize – Cache, Compress images, Minify & Clean database to boost page speed & performance 3.4.2, at webp/class-wp-optimize-webp.php

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1	<?php
2
3	if (!defined('WPO_VERSION')) die('No direct access allowed');
4
5	if (!class_exists('WP_Optimize_WebP')) :
6
7	class WP_Optimize_WebP {
8
9	private $_htaccess = null;
10
11	/**
12	* Set to true when webp is enabled and vice-versa
13	*
14	* @var boolean
15	*/
16	private $_should_use_webp = false;
17
18	/**
19	* Constructor
20	*/
21	private function __construct() {
22	$this->_should_use_webp = (bool) WP_Optimize()->get_options()->get_option('webp_conversion');
23
24	if ($this->_should_use_webp && $this->get_webp_conversion_test_result()) {
25	if (!is_admin()) {
26
27	// Allow filters added in theme files to run
28	add_action('after_setup_theme', array($this, 'maybe_decide_webp_serve_method'));
29	}
30	}
31
32	add_action('wpo_reset_webp_conversion_test_result', array($this, 'reset_webp_serving_method'));
33	}
34
35	/**
36	* Returns singleton instance
37	*
38	* @return WP_Optimize_WebP
39	*/
40	public static function get_instance() {
41	static $instance = null;
42	if (null === $instance) {
43	$instance = new WP_Optimize_WebP();
44	}
45	return $instance;
46	}
47
48	/**
49	* Test Run and find converter status
50	*/
51	private function set_converter_status() {
52	$converter_status = WPO_WebP_Test_Run::get_converter_status();
53	if ($this->is_webp_conversion_successful()) {
54	WP_Optimize()->get_options()->update_option('webp_conversion_test', true);
55	WP_Optimize()->get_options()->update_option('webp_converters', $converter_status['working_converters']);
56	}
57	}
58
59	/**
60	* If .htaccess redirection is not possible, attempts to use the alter_html method
61	*/
62	public function maybe_decide_webp_serve_method() {
63	if (!$this->is_webp_redirection_possible()) {
64	$this->maybe_use_alter_html();
65	}
66	}
67
68	/**
69	* If alter html method is possible, then use it
70	*/
71	private function maybe_use_alter_html() {
72	if ($this->is_alter_html_possible()) {
73	$this->empty_htaccess_file();
74	$this->use_alter_html();
75	}
76	}
77
78	/**
79	* Even if server support .htaccess rewrite, sometimes it is not possible
80	* to serve webp images. So, find it webp redirection is possible or not
81	* Also applies `wpo_force_webp_serve_using_altered_html` filter for users to be able to
82	* force Altered HTML method
83	*
84	* @return bool
85	*/
86	public function is_webp_redirection_possible() {
87	if (apply_filters('wpo_force_webp_serve_using_altered_html', false)) {
88	return false;
89	}
90	$redirection_possible = WP_Optimize()->get_options()->get_option('redirection_possible');
91	if (!empty($redirection_possible)) return 'true' === $redirection_possible;
92	return $this->run_webp_serving_self_test();
93	}
94
95	/**
96	* Decide whether the browser requesting the URL can accept webp images or not
97	*
98	* @return bool
99	*/
100	private function is_browser_accepting_webp() {
101	return (isset($_SERVER['HTTP_ACCEPT']) && false !== strpos($_SERVER['HTTP_ACCEPT'], 'image/webp'));
102	}
103
104	/**
105	* Detect whether using alter HTML method is possible or not
106	*
107	* @return bool
108	*/
109	private function is_alter_html_possible() {
110	if ($this->is_browser_accepting_webp()) {
111	return true;
112	}
113	return false;
114	}
115
116	/**
117	* Setup alter html method
118	*/
119	private function use_alter_html() {
120	WPO_WebP_Alter_HTML::get_instance();
121	}
122
123	/**
124	* Initialize .htaccess
125	*/
126	private function setup_htaccess_file() {
127	if (null !== $this->_htaccess) return;
128	$wp_uploads = wp_get_upload_dir();
129	$htaccess_file = $wp_uploads['basedir'] . '/.htaccess';
130	if (!file_exists($htaccess_file)) {
131	file_put_contents($htaccess_file, '');
132	}
133	$this->_htaccess = new WP_Optimize_Htaccess($htaccess_file);
134	}
135
136	/**
137	* Save .htaccess rules
138	*
139	* @return void
140	*/
141	public function save_htaccess_rules() {
142	$this->setup_htaccess_file();
143	$this->add_webp_mime_type();
144	$htaccess_comment_section = 'WP-Optimize WebP Rules';
145	if ($this->_htaccess->is_commented_section_exists($htaccess_comment_section)) return;
146	$this->_htaccess->update_commented_section($this->prepare_webp_htaccess_rules(), $htaccess_comment_section);
147	$this->_htaccess->write_file();
148	WP_Optimize()->get_options()->update_option('htaccess_has_webp_rules', true);
149	}
150
151	/**
152	* Empty .htaccess file
153	*/
154	public function empty_htaccess_file() {
155	// Setting default to true, so on initial run (when option is not yet present in the DB) we don't break the function here
156	if (!WP_Optimize()->get_options()->get_option('htaccess_has_webp_rules', true)) return;
157	$this->setup_htaccess_file();
158	$htaccess_comment_sections = array(
159	'WP-Optimize WebP Rules',
160	'Register webp mime type',
161	);
162	foreach ($htaccess_comment_sections as $htaccess_comment_section) {
163	if (!$this->_htaccess->is_commented_section_exists($htaccess_comment_section)) continue;
164	$this->_htaccess->remove_commented_section($htaccess_comment_section);
165	$this->_htaccess->write_file();
166	}
167	WP_Optimize()->get_options()->update_option('htaccess_has_webp_rules', false);
168	}
169
170	/**
171	* Prepare array of htaccess rules to use webp images.
172	*
173	* @return array
174	*/
175	private function prepare_webp_htaccess_rules() {
176	return array(
177	array(
178	'<IfModule mod_rewrite.c>',
179	'RewriteEngine On',
180	'',
181	'# Redirect to existing converted image in same dir (if browser supports webp)',
182	'RewriteCond %{HTTP_ACCEPT} image/webp',
183	'RewriteCond %{REQUEST_FILENAME} (?i)(.*)(\.jpe?g\|\.png)$',
184	'RewriteCond %1%2\.webp -f',
185	'RewriteRule (?i)(.*)(\.jpe?g\|\.png)$ %1%2\.webp [T=image/webp,E=EXISTING:1,E=ADDVARY:1,L]',
186	'',
187	'# Make sure that browsers which does not support webp also gets the Vary:Accept header',
188	'# when requesting images that would be redirected to webp on browsers that does.',
189	array(
190	'<IfModule mod_headers.c>',
191	array(
192	'<FilesMatch "(?i)\.(jpe?g\|png)$">',
193	'Header append "Vary" "Accept"',
194	'</FilesMatch>',
195	),
196	'</IfModule>',
197	),
198	'',
199	'</IfModule>',
200	'',
201	),
202	array(
203	'# Rules for handling requests for webp images',
204	'# ---------------------------------------------',
205	'',
206	'# Set Vary:Accept header if we came here by way of our redirect, which set the ADDVARY environment variable',
207	'# The purpose is to make proxies and CDNs aware that the response varies with the Accept header',
208	'<IfModule mod_headers.c>',
209	array(
210	'<IfModule mod_setenvif.c>',
211	'# Apache appends "REDIRECT_" in front of the environment variables defined in mod_rewrite, but LiteSpeed does not',
212	'# So, the next lines are for Apache, in order to set environment variables without "REDIRECT_"',
213	'SetEnvIf REDIRECT_EXISTING 1 EXISTING=1',
214	'SetEnvIf REDIRECT_ADDVARY 1 ADDVARY=1',
215	'',
216	'Header append "Vary" "Accept" env=ADDVARY',
217	'',
218	'# Set X-WPO-WebP header for diagnose purposes',
219	'Header set "X-WPO-WebP" "Redirected directly to existing webp" env=EXISTING',
220	'</IfModule>',
221	),
222	'</IfModule>',
223	),
224	);
225	}
226
227	/**
228	* Add webp mime type to htaccess rules.
229	*/
230	private function add_webp_mime_type() {
231	$htaccess_comment_section = 'Register webp mime type';
232	if ($this->_htaccess->is_exists() && !$this->_htaccess->is_commented_section_exists($htaccess_comment_section)) {
233	$webp_mime_type = array(
234	array(
235	'<IfModule mod_mime.c>',
236	'AddType image/webp .webp',
237	'</IfModule>',
238	),
239	);
240	$this->_htaccess->update_commented_section($webp_mime_type, $htaccess_comment_section);
241	$this->_htaccess->write_file();
242	}
243	}
244
245	/**
246	* Checks whether webp conversion test is successful or not
247	*
248	* @return bool
249	*/
250	public function is_webp_conversion_successful() {
251	$upload_dir = wp_upload_dir();
252	$destination = $upload_dir['basedir']. '/wpo/images/wpo_logo_small.png.webp';
253	return file_exists($destination);
254	}
255
256	/**
257	* Checks whether sample webp conversion test should be run or not
258	*
259	* @return bool Returns true if sample test should be run, false otherwise
260	*/
261	public function should_run_webp_conversion_test() {
262	$webp_conversion_test = $this->get_webp_conversion_test_result();
263	return (true !== $webp_conversion_test);
264	}
265
266	/**
267	* Returns webp conversion test result
268	*
269	* @return boolean Returns the value of the webp_conversion_test saved in the options table
270	*/
271	private function get_webp_conversion_test_result() {
272	return (bool) WP_Optimize()->get_options()->get_option('webp_conversion_test');
273	}
274
275	/**
276	* Checks whether the webp redirection is possible or not and sets flag
277	*
278	* @return bool Returns true if webp is served successfully, false otherwise
279	*/
280	private function run_webp_serving_self_test() {
281	$self_test = WPO_WebP_Self_Test::get_instance();
282
283	if ($self_test->is_webp_served()) {
284	WP_Optimize()->get_options()->update_option('redirection_possible', 'true');
285	return true;
286	}
287	WP_Optimize()->get_options()->update_option('redirection_possible', 'false');
288	$this->empty_htaccess_file();
289	return false;
290	}
291
292	/**
293	* Resets webp serving method by running self test, if needed purges cache and empties `uploads/.htaccess` file
294	*/
295	public function reset_webp_serving_method() {
296	if (self::is_shell_functions_available() && $this->_should_use_webp) {
297	$this->reset_webp_options();
298	$this->run_self_test();
299	list($old_redirection_possible, $new_redirection_possible) = $this->get_old_and_new_redirection_possibility();
300	$this->maybe_purge_cache($old_redirection_possible, $new_redirection_possible);
301	$this->maybe_empty_htaccess_file($new_redirection_possible);
302	} else {
303	$this->disable_webp_conversion();
304	}
305	}
306
307	/**
308	* Resets WebP related options
309	*/
310	private function reset_webp_options() {
311	$options = WP_Optimize()->get_options();
312	$options->update_option('old_redirection_possible', $options->get_option('redirection_possible'));
313	$options->update_option('webp_conversion_test', false);
314	$options->update_option('webp_converters', false);
315	$options->update_option('redirection_possible', false);
316	$this->remove_webp_test_image_file();
317	}
318
319	/**
320	* Running self test to find available converters and possibility of serving webp using redirection method
321	*/
322	private function run_self_test() {
323	$this->set_converter_status();
324	if ($this->get_webp_conversion_test_result()) {
325	$this->save_htaccess_rules();
326	$this->run_webp_serving_self_test();
327	} else {
328	$this->disable_webp_conversion();
329	}
330	}
331
332	/**
333	* Gets old and new redirection possibility values
334	*
335	* @return array
336	*/
337	private function get_old_and_new_redirection_possibility() {
338	$options = WP_Optimize()->get_options();
339	return array(
340	$options->get_option('old_redirection_possible'),
341	$options->get_option('redirection_possible'),
342	);
343	}
344
345	/**
346	* Cache is cleared when there is a change in the potential for serving WebP using redirection.
347	*
348	* @param string $old_redirection_possible
349	* @param string $new_redirection_possible
350	*/
351	private function maybe_purge_cache($old_redirection_possible, $new_redirection_possible) {
352	if ($old_redirection_possible !== $new_redirection_possible) {
353	WP_Optimize()->get_page_cache()->purge();
354	}
355	}
356
357	/**
358	* Remove redirection rules from `uploads/.htaccess` file if redirection is not possible
359	*
360	* @param string $new_redirection_possible
361	*/
362	private function maybe_empty_htaccess_file($new_redirection_possible) {
363	if ('false' === $new_redirection_possible) {
364	$this->empty_htaccess_file();
365	}
366	}
367
368	/**
369	* Initialize cron scheduler
370	*/
371	public function init_webp_cron_scheduler() {
372	if (!wp_next_scheduled('wpo_reset_webp_conversion_test_result')) {
373	wp_schedule_event(time(), 'wpo_daily', 'wpo_reset_webp_conversion_test_result');
374	}
375	}
376
377	/**
378	* Remove all cron schedules
379	*/
380	public function remove_webp_cron_schedules() {
381	wp_clear_scheduled_hook('wpo_reset_webp_conversion_test_result');
382	}
383
384	/**
385	* Return the true if webp conversion is enabled and vice-versa
386	*
387	* @return bool
388	*/
389	public function is_webp_conversion_enabled() {
390	return $this->_should_use_webp;
391	}
392
393	/**
394	* Set the webp_conversion option value to false and remove webp cron schedules
395	*/
396	public function disable_webp_conversion() {
397	$this->empty_htaccess_file();
398	WP_Optimize()->get_options()->update_option("webp_conversion", false);
399	$this->remove_webp_cron_schedules();
400	}
401
402	/**
403	* Remove webp converted test image file
404	*/
405	private function remove_webp_test_image_file() {
406	$upload_dir = wp_upload_dir();
407	$destination = $upload_dir['basedir']. '/wpo/images/wpo_logo_small.png.webp';
408	if (@file_exists($destination)) { // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
409	@unlink($destination); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- suppress PHP warning in case of failure
410	}
411	}
412
413	/**
414	* Run during plugin deactivation
415	*/
416	public function plugin_deactivate() {
417	$this->empty_htaccess_file();
418	$this->remove_webp_test_image_file();
419	}
420
421	/**
422	* Determines whether the php shell functions are available or not
423	*
424	* @return bool
425	*/
426	public static function is_shell_functions_available() {
427	$shell_functions = self::get_shell_functions();
428	foreach ($shell_functions as $shell_function) {
429	if (!function_exists($shell_function)) return false;
430	}
431	return true;
432	}
433
434	/**
435	* List of php shell function names
436	*
437	* @return string[]
438	*/
439	private static function get_shell_functions() {
440	return array(
441	'escapeshellarg',
442	'escapeshellcmd',
443	'exec',
444	'passthru',
445	'proc_close',
446	'proc_get_status',
447	'proc_nice',
448	'proc_open',
449	'proc_terminate',
450	'shell_exec',
451	'system',
452	);
453	}
454	}
455
456	endif;
457