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