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