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