75 lines
1.6 KiB
PHP
75 lines
1.6 KiB
PHP
<?php
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if (!defined('WPO_VERSION')) die('No direct access allowed');
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if (!class_exists('WPO_WebP_Self_Test')) :
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class WPO_WebP_Self_Test {
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/**
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* Determines whether content type header has webp mime or not
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*
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* @param array $headers An array of headers
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*
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* @return bool
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*/
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private function has_webp_mime($headers) {
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return isset($headers['content-type']) && 0 === strcasecmp('image/webp', $headers['content-type']);
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}
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/**
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* Determines whether headers has `vary` header or not
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*
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* @param array $headers An array of headers
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*
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* @return bool
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*/
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private function has_vary($headers) {
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return isset($headers['vary']) && preg_match('/accept/i', $headers['vary']);
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}
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/**
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* Decided whether webp version is served or not
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*
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* @return bool
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*/
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public function is_webp_served() {
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$args = array(
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'headers' => array(
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'accept' => 'image/webp'
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)
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);
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$upload_dir = wp_upload_dir();
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$url = $upload_dir['baseurl']. '/wpo/images/wpo_logo_small.png';
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$response = wp_remote_head($url, $args);
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if (is_wp_error($response)) return false;
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if (200 != $response['response']['code']) return false;
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$headers = wp_remote_retrieve_headers($response);
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if (method_exists($headers, 'getAll')) {
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$headers = $headers->getAll();
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if ($this->has_webp_mime($headers) && $this->has_vary($headers)) {
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return true;
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}
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}
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return false;
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}
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/**
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* Returns singleton instance
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*
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* @return WPO_WebP_Self_Test
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*/
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public static function get_instance() {
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static $_instance = null;
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if (null === $_instance) {
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$_instance = new self();
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}
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return $_instance;
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}
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}
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endif;
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