<?php
if (!defined('WPO_VERSION')) die('No direct access allowed');
if (!class_exists('WP_Optimize_WebP')) :
class WP_Optimize_WebP {
private $_htaccess = null;
private $_should_use_webp = false;
/**
* Constructor
*/
private function __construct() {
$this->_should_use_webp = WP_Optimize()->get_options()->get_option('webp_conversion');
if ($this->should_run_webp_conversion_test()) {
$this->set_converter_status();
}
if ($this->get_webp_conversion_test_result()) {
if (!is_admin()) {
$this->maybe_decide_webp_serve_method();
}
} else {
$this->empty_htaccess_file();
}
$this->init_webp_cron_scheduler();
}
/**
* Returns singleton instance
*
* @return WP_Optimize_WebP
*/
public static function get_instance() {
static $instance = null;
if (null === $instance) {
$instance = new WP_Optimize_WebP();
}
return $instance;
}
/**
* Test Run and find converter status
*/
private function set_converter_status() {
if (!class_exists('WPO_WebP_Test_Run')) {
require_once WPO_PLUGIN_MAIN_PATH . 'webp/class-wpo-webp-test-run.php';
}
$converter_status = WPO_WebP_Test_Run::get_converter_status();
if ($this->is_webp_conversion_successful()) {
WP_Optimize()->get_options()->update_option('webp_conversion_test', true);
WP_Optimize()->get_options()->update_option('webp_converters', $converter_status['working_converters']);
}
}
/**
* If webp images should be used, then decide whether it is possible to server webp
* using rewrite rules or using altered html method
*/
private function maybe_decide_webp_serve_method() {
if (!$this->_should_use_webp) {
$this->empty_htaccess_file();
} else {
$this->save_htaccess_rules();
if (!$this->is_webp_redirection_possible()) {
$this->empty_htaccess_file();
$this->maybe_use_alter_html();
}
}
}
/**
* If alter html method is possible, then use it
*/
private function maybe_use_alter_html() {
if ($this->is_alter_html_possible()) {
$this->use_alter_html();
}
}
/**
* Even if server support .htaccess rewrite, sometimes it is not possible
* to serve webp images. So, find it webp redirection is possible or not
*
* @return bool
*/
private function is_webp_redirection_possible() {
$redirection_possible = WP_Optimize()->get_options()->get_option('redirection_possible');
if (!empty($redirection_possible)) return 'true' === $redirection_possible;
return $this->run_webp_serving_self_test();
}
/**
* Decide whether the browser requesting the URL can accept webp images or not
*
* @return bool
*/
private function is_browser_accepting_webp() {
return (isset($_SERVER['HTTP_ACCEPT']) && false !== strpos($_SERVER['HTTP_ACCEPT'], 'image/webp'));
}
/**
* Detect whether using alter HTML method is possible or not
*
* @return bool
*/
private function is_alter_html_possible() {
if ($this->is_browser_accepting_webp()) {
return true;
}
return false;
}
/**
* Setup alter html method
*/
private function use_alter_html() {
if (!class_exists('WPO_WebP_Alter_HTML')) {
require_once WPO_PLUGIN_MAIN_PATH . 'webp/class-wpo-webp-alter-html.php';
}
WPO_WebP_Alter_HTML::get_instance();
}
/**
* Initialize .htaccess
*/
private function setup_htaccess_file() {
if (null !== $this->_htaccess) return;
$wp_uploads = wp_get_upload_dir();
$htaccess_file = $wp_uploads['basedir'] . '/.htaccess';
if (!file_exists($htaccess_file)) {
file_put_contents($htaccess_file, '');
}
if (!class_exists('WP_Optimize_Htaccess')) {
require_once WPO_PLUGIN_MAIN_PATH . 'includes/class-wp-optimize-htaccess.php';
}
$this->_htaccess = new WP_Optimize_Htaccess($htaccess_file);
}
/**
* Save .htaccess rules
*
* @return void
*/
private function save_htaccess_rules() {
$this->setup_htaccess_file();
$this->add_webp_mime_type();
$htaccess_comment_section = 'WP-Optimize WebP Rules';
if ($this->_htaccess->is_commented_section_exists($htaccess_comment_section)) return;
$this->_htaccess->update_commented_section($this->prepare_webp_htaccess_rules(), $htaccess_comment_section);
$this->_htaccess->write_file();
}
/**
* Empty .htaccess file
*/
public function empty_htaccess_file() {
$this->setup_htaccess_file();
$htaccess_comment_sections = array(
'WP-Optimize WebP Rules',
'Register webp mime type',
);
foreach ($htaccess_comment_sections as $htaccess_comment_section) {
$this->_htaccess->remove_commented_section($htaccess_comment_section);
$this->_htaccess->write_file();
}
}
/**
* Prepare array of htaccess rules to use webp images.
*
* @return array
*/
private function prepare_webp_htaccess_rules() {
return array(
array(
'<IfModule mod_rewrite.c>',
'RewriteEngine On',
'',
'# Redirect to existing converted image in same dir (if browser supports webp)',
'RewriteCond %{HTTP_ACCEPT} image/webp',
'RewriteCond %{REQUEST_FILENAME} (?i)(.*)(\.jpe?g|\.png)$',
'RewriteCond %1%2\.webp -f',
'RewriteRule (?i)(.*)(\.jpe?g|\.png)$ %1%2\.webp [T=image/webp,E=EXISTING:1,E=ADDVARY:1,L]',
'',
'# Make sure that browsers which does not support webp also gets the Vary:Accept header',
'# when requesting images that would be redirected to webp on browsers that does.',
array(
'<IfModule mod_headers.c>',
array(
'<FilesMatch "(?i)\.(jpe?g|png)$">',
'Header append "Vary" "Accept"',
'</FilesMatch>',
),
'</IfModule>',
),
'',
'</IfModule>',
'',
),
array(
'# Rules for handling requests for webp images',
'# ---------------------------------------------',
'',
'# Set Vary:Accept header if we came here by way of our redirect, which set the ADDVARY environment variable',
'# The purpose is to make proxies and CDNs aware that the response varies with the Accept header',
'<IfModule mod_headers.c>',
array(
'<IfModule mod_setenvif.c>',
'# Apache appends "REDIRECT_" in front of the environment variables defined in mod_rewrite, but LiteSpeed does not',
'# So, the next lines are for Apache, in order to set environment variables without "REDIRECT_"',
'SetEnvIf REDIRECT_EXISTING 1 EXISTING=1',
'SetEnvIf REDIRECT_ADDVARY 1 ADDVARY=1',
'',
'Header append "Vary" "Accept" env=ADDVARY',
'',
'# Set X-WPO-WebP header for diagnose purposes',
'Header set "X-WPO-WebP" "Redirected directly to existing webp" env=EXISTING',
'</IfModule>',
),
'</IfModule>',
),
);
}
/**
* Add webp mime type to htaccess rules.
*/
private function add_webp_mime_type() {
$htaccess_comment_section = 'Register webp mime type';
if ($this->_htaccess->is_exists() && !$this->_htaccess->is_commented_section_exists($htaccess_comment_section)) {
$webp_mime_type = array(
array(
'<IfModule mod_mime.c>',
'AddType image/webp .webp',
'</IfModule>',
),
);
$this->_htaccess->update_commented_section($webp_mime_type, $htaccess_comment_section);
$this->_htaccess->write_file();
}
}
/**
* Checks whether webp conversion test is successful or not
*
* @return bool
*/
private function is_webp_conversion_successful() {
$upload_dir = wp_upload_dir();
$destination = $upload_dir['basedir']. '/wpo/images/wpo_logo_small.png.webp';
return file_exists($destination);
}
/**
* Checks whether sample webp conversion test should be run or not
*
* @return bool Returns true if sample test should be run, false otherwise
*/
private function should_run_webp_conversion_test() {
$webp_conversion_test = $this->get_webp_conversion_test_result();
return (true != $webp_conversion_test);
}
/**
* Returns webp conversion test result
*/
private function get_webp_conversion_test_result() {
return WP_Optimize()->get_options()->get_option('webp_conversion_test');
}
/**
* Checks whether the webp redirection is possible or not and sets flag
*
* @return bool Returns true if webp is served successfully, false otherwise
*/
private function run_webp_serving_self_test() {
$self_test = WPO_WebP_Self_Test::get_instance();
if ($self_test->is_webp_served()) {
WP_Optimize()->get_options()->update_option('redirection_possible', 'true');
return true;
}
WP_Optimize()->get_options()->update_option('redirection_possible', 'false');
$this->empty_htaccess_file();
return false;
}
/**
* Resets webp serving method by running self test, if needed purges cache and empties `uploads/.htaccess` file
*/
public function reset_webp_serving_method() {
$this->reset_webp_options();
$this->run_self_test();
list($old_redirection_possible, $new_redirection_possible) = $this->get_old_and_new_redirection_possibility();
$this->maybe_purge_cache($old_redirection_possible, $new_redirection_possible);
$this->maybe_empty_htaccess_file($new_redirection_possible);
}
/**
* Resets WebP related options
*/
private function reset_webp_options() {
$options = WP_Optimize()->get_options();
$options->update_option('old_redirection_possible', $options->get_option('redirection_possible'));
$options->update_option('webp_conversion_test', false);
$options->update_option('webp_converters', false);
$options->update_option('redirection_possible', false);
}
/**
* Running self test to find available converters and possibility of serving webp using redirection method
*/
private function run_self_test() {
$this->set_converter_status();
if ($this->get_webp_conversion_test_result()) {
$this->save_htaccess_rules();
$this->run_webp_serving_self_test();
}
}
/**
* Gets old and new redirection possibility values
*
* @return array
*/
private function get_old_and_new_redirection_possibility() {
$options = WP_Optimize()->get_options();
return array(
$options->get_option('old_redirection_possible'),
$options->get_option('redirection_possible'),
);
}
/**
* Cache is cleared when there is a change in the potential for serving WebP using redirection.
*
* @param string $old_redirection_possible
* @param string $new_redirection_possible
*/
private function maybe_purge_cache($old_redirection_possible, $new_redirection_possible) {
if ($old_redirection_possible !== $new_redirection_possible) {
WP_Optimize()->get_page_cache()->purge();
}
}
/**
* Remove redirection rules from `uploads/.htaccess` file if redirection is not possible
*
* @param string $new_redirection_possible
*/
private function maybe_empty_htaccess_file($new_redirection_possible) {
if ('false' === $new_redirection_possible) {
$this->empty_htaccess_file();
}
}
/**
* Initialize cron scheduler
*/
private function init_webp_cron_scheduler() {
WPO_WebP_Cron_Scheduler::get_instance();
}
/**
* Determines whether the php shell functions are available or not
*
* @return bool
*/
public static function is_shell_functions_available() {
$shell_functions = self::get_shell_functions();
foreach ($shell_functions as $shell_function) {
if (!function_exists($shell_function)) return false;
}
return true;
}
/**
* List of php shell function names
*
* @return string[]
*/
public static function get_shell_functions() {
return array(
'escapeshellarg',
'escapeshellcmd',
'exec',
'passthru',
'proc_close',
'proc_get_status',
'proc_nice',
'proc_open',
'proc_terminate',
'shell_exec',
'system',
);
}
}
endif;