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