/**
* Start the output buffer
*
* @since 2.0.0
*
* @param string $output
* @return string
*/
protected function ob($output = '')
{
// Bail if cancelling
if (true === $this->cancel) {
return $output;
}
// PHP5 and objects disappearing before output buffers?
wp_object_cache_init();
// $wp_object_cache was clobbered in wp-settings.php so repeat this
$this->configure_groups();
// Unlock regeneration
wp_cache_delete("{$this->url_key}_genlock", $this->group);
// Do not cache blank pages unless they are HTTP redirects
$output = trim($output);
if (empty($output) && (empty($this->redirect_status) || empty($this->redirect_location))) {
return;
}
// Do not cache 5xx responses
if (isset($this->status_code) && intval($this->status_code / 100) == 5) {
return $output;
}
// Variants and keys
$this->do_variants($this->vary);
$this->generate_keys();
// Construct and save the spider_cache
$this->cache = array('output' => $output, 'time' => time(), 'headers' => array(), 'timer' => $this->timer_stop(false, 3), 'status_header' => $this->status_header, 'redirect_status' => $this->redirect_status, 'redirect_location' => $this->redirect_location, 'version' => $this->url_version);
// PHP5 and higher (
foreach (headers_list() as $header) {
list($k, $v) = array_map('trim', explode(':', $header, 2));
$this->cache['headers'][$k] = $v;
}
// Set uncached headers
if (!empty($this->cache['headers']) && !empty($this->uncached_headers)) {
foreach ($this->uncached_headers as $header) {
unset($this->cache['headers'][$header]);
}
}
// Set cached headers
foreach ($this->cache['headers'] as $header => $values) {
// Bail if cookies were set
if (strtolower($header) === 'set-cookie') {
return $output;
}
foreach ((array) $values as $value) {
if (preg_match('/^Cache-Control:.*max-?age=(\\d+)/i', "{$header}: {$value}", $matches)) {
$this->max_age = intval($matches[1]);
}
}
}
// Set max-age
$this->cache['max_age'] = $this->max_age;
// Set cache
wp_cache_set($this->key, $this->cache, $this->group, $this->max_age + $this->seconds + 30);
// Cache control
if (true === $this->cache_control) {
// Don't clobber Last-Modified header if already set, e.g. by WP::send_headers()
if (!isset($this->cache['headers']['Last-Modified'])) {
header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $this->cache['time']) . ' GMT', true);
}
if (!isset($this->cache['headers']['Cache-Control'])) {
header("Cache-Control: max-age={$this->max_age}, must-revalidate", false);
}
}
$this->do_headers($this->headers);
// Add some debug info just before <head
if (true === $this->debug) {
$this->add_debug_just_cached();
}
// Pass output to next ob handler
return $this->cache['output'];
}
<?php
/**
* Plugin name: Spider-Cache
* Plugin URI: https://wordpress.org/plugins/wp-spider-cache/
* Description: Fully rendered pages stored in & served from Memcached.
* Version: 2.1.0
*/
// Exit if accessed directly
defined('ABSPATH') || exit;
// Required files
require_once WP_CONTENT_DIR . '/plugins/wp-spider-cache/includes/functions.php';
// Initialize the caches
if (!wp_skip_output_cache()) {
wp_object_cache_init();
wp_output_cache_init();
}
/**
* Clear a cached URL
*
* @since 2.3.0
*
* @param string $url
*
* @return boolean
*/
public static function clean_url($url = '')
{
// Bail if no URL
if (empty($url)) {
return false;
}
// Bail if no persistent output cache
if (!function_exists('wp_output_cache')) {
return false;
}
// Normalize the URL
if (0 === strpos($url, 'https://')) {
$url = str_replace('https://', 'http://', $url);
}
if (0 !== strpos($url, 'http://')) {
$url = 'http://' . $url;
}
$url_key = md5($url);
// Get cache objects
$output_cache = wp_output_cache_init();
$object_cache = wp_object_cache_init();
// Bail if either cache is missing
if (empty($output_cache) || empty($object_cache)) {
return;
}
wp_cache_add("{$url_key}_version", 0, $output_cache->group);
$retval = wp_cache_incr("{$url_key}_version", 1, $output_cache->group);
$output_cache_no_remote_group_key = array_search($output_cache->group, (array) $object_cache->no_remote_groups);
// The *_version key needs to be replicated remotely, otherwise invalidation won't work.
// The race condition here should be acceptable.
if (false !== $output_cache_no_remote_group_key) {
unset($object_cache->no_remote_groups[$output_cache_no_remote_group_key]);
$retval = wp_cache_set("{$url_key}_version", $retval, $output_cache->group);
$object_cache->no_remote_groups[$output_cache_no_remote_group_key] = $output_cache->group;
}
return $retval;
}
/**
* Returns the Object Cache Global.
*
* @since 2.0.0
*
* @global WP_Spider_Cache_Object $wp_object_cache WordPress Object Cache
* @return object
*/
function wp_object_cache()
{
if (!isset($GLOBALS['wp_object_cache'])) {
wp_object_cache_init();
}
return $GLOBALS['wp_object_cache'];
}