sem-cache.php

<?php
/*
Plugin Name: Semiologic Cache
Plugin URI: http://www.semiologic.com/software/sem-cache/
Description: An advanced caching module for WordPress.
Version: 3.0.1
Author: Mike Koepke and previously, Denis de Bernardy
Author URI: https://www.semiologic.com
Text Domain: sem-cache
Domain Path: /lang
License: Dual licensed under the MIT and GPLv2 licenses
*/


/*
Terms of use
------------

This software is copyright Denis de Bernardy & Mike Koepke, and is distributed under the terms of the MIT and GPLv2 licenses.
**/


/**
 * sem_cache
 *
 * @package Semiologic Cache
 **/

foreach ( array(
	'sem_cache_debug',
	'SCRIPT_DEBUG',
	'sem_css_debug',
	'sem_sql_debug',
	) as $const ) {
	if ( !defined($const) )
		define($const, false);
}

foreach ( array(
	'static_cache',
	'memory_cache',
	) as $const ) {
	if ( !defined($const) )
		define($const, get_site_option($const) && defined('WP_CACHE') && WP_CACHE);
}

if ( !defined('cache_timeout') )
	define('cache_timeout', 86400);


if ( !defined('auto_enable') )
	define('auto_enable', false);


class sem_cache {
	/**
	 * Plugin instance.
	 *
	 * @see get_instance()
	 * @type object
	 */
	protected static $instance = NULL;

	/**
	 * URL to this plugin's directory.
	 *
	 * @type string
	 */
	public $plugin_url = '';

	/**
	 * Path to this plugin's directory.
	 *
	 * @type string
	 */
	public $plugin_path = '';

	/**
	 * Access this plugin’s working instance
	 *
	 * @wp-hook plugins_loaded
	 * @return  object of this class
	 */
	public static function get_instance()
	{
		NULL === self::$instance and self::$instance = new self;

		return self::$instance;
	}

	/**
	 * Loads translation file.
	 *
	 * Accessible to other classes to load different language files (admin and
	 * front-end for example).
	 *
	 * @wp-hook init
	 * @param   string $domain
	 * @return  void
	 */
	public function load_language( $domain )
	{
		load_plugin_textdomain(
			$domain,
			FALSE,
			dirname(plugin_basename(__FILE__)) . '/lang'
		);
	}

	/**
	 * Constructor.
	 *
	 *
	 */

	public function __construct() {
		$this->plugin_url    = plugins_url( '/', __FILE__ );
		$this->plugin_path   = plugin_dir_path( __FILE__ );
		$this->load_language( 'sem-cache' );

		add_action( 'plugins_loaded', array ( $this, 'init' ) );
    }

	/**
	 * init()
	 *
	 * @return void
	 **/

	function init() {
		// more stuff: register actions and filters
		if (auto_enable)
			register_activation_hook(__FILE__, array($this, 'enable'));
		else
			register_activation_hook(__FILE__, array($this, 'disable'));
		register_deactivation_hook(__FILE__, array($this, 'disable'));

		if ( !class_exists('cache_fs') )
			include $this->plugin_path . '/cache-fs.php';

		if ( !class_exists('sem_cache_manager') )
			include $this->plugin_path . '/sem-cache-manager.php';

		if ( !is_admin() ) {
			if ( get_site_option('query_cache') )
				include $this->plugin_path . '/query-cache.php';

			if ( get_site_option('asset_cache') )
				include $this->plugin_path . '/asset-cache.php';
		}

		if ( class_exists('static_cache') ) {
			add_action('cache_timeout', array($this, 'cache_timeout'));

			if ( !wp_next_scheduled('cache_timeout') )
				wp_schedule_event(time(), 'hourly', 'cache_timeout');

			if ( sem_cache_debug && ( wp_next_scheduled('cache_timeout') - time() > cache_timeout ) )
				wp_schedule_single_event(time() + cache_timeout, 'cache_timeout');

			add_filter('status_header', array('static_cache', 'status_header'), 100, 2);
			add_filter('nocache_headers', array('static_cache', 'disable'));
			add_filter('wp_redirect_status', array('static_cache', 'wp_redirect_status'), 50);
		}

		add_action('wp_footer', array($this, 'stats'), 1000000);
		add_action('admin_footer', array($this, 'stats'), 1000000);

		if ( !class_exists('sem_cache_rules') )
			include $this->plugin_path . '/sem-cache-rules.php';

		add_action('admin_menu', array($this, 'admin_menu'));
		add_action('sem_admin_menu_settings', array($this, 'front_menu'));

		foreach ( array('load-settings_page_sem-cache') as $hook )
			add_action($hook, array($this, 'sem_cache_admin'));

		if ( static_cache || memory_cache || get_site_option('query_cache') ) :

			add_action('pre_post_update', array($this, 'pre_flush_post'));

			foreach ( array(
				'save_post',
				'delete_post',
				) as $hook ) {
				add_action($hook, array($this, 'flush_post'), 1); // before _save_post_hook()
			}

			add_action('wp_update_comment_count', array($this, 'flush_post'), 1, 3); // before _save_post_hook()

			foreach ( array(
				'switch_theme',
				'update_option_active_plugins',
				'update_option_show_on_front',
				'update_option_page_on_front',
				'update_option_page_for_posts',
				'update_option_sidebars_widgets',
				'update_option_sem5_options',
				'update_option_sem6_options',
				'generate_rewrite_rules',
		        'edit_user_profile_update',
				'flush_cache',
				'after_db_upgrade',
				'update_option_sem_seo',
				'update_option_script_manager',
				'wp_upgrade'
				) as $hook ) {
				add_action($hook, array($this, 'flush_cache'));
			}

			foreach ( array(
				'switch_theme',
				'activated_plugin',
				'deactivated_plugin',
				'update_option_script_manager',
				'save_entry_script_manager',
				'wp_upgrade'
			    ) as $hook ) {
			    add_action($hook, array($this, 'flush_assets'));
			}

			if ( $_POST )
			  add_action('load-widgets.php', array($this, 'flush_cache'));

			endif;
	}


	/**
	* sem_cache_admin()
	*
	* @return void
	**/
	function sem_cache_admin() {
		include_once $this->plugin_path . '/sem-cache-admin.php';
	} # sem_cache_admin()

    /**
	 * admin_menu()
	 *
	 * @return void
	 **/

	static function admin_menu() {
		if ( function_exists('is_super_admin') && !is_super_admin() )
			return;
		
		add_options_page(
			__('Cache', 'sem-cache'),
			__('Cache', 'sem-cache'),
			'manage_options',
			'sem-cache',
			array('sem_cache_admin', 'edit_options')
			);
	} # admin_menu()
	
	
	/**
	 * front_menu()
	 *
	 * @return void
	 **/

	static function front_menu() {
		if ( function_exists('is_super_admin') && !is_super_admin() )
			return;
		
		if ( !current_user_can('manage_options') )
			return;
		
		echo '<span class="am_options">'
			. '<a href="' . trailingslashit(admin_url()) . 'options-general.php?page=sem-cache">'
				. __('Cache', 'sem-cache')
				. '</a>'
			. '</span>'
			. ' ';
	} # front_menu()
	
	
	/**
	 * disable()
	 *
	 * @return void
	 **/

	static function disable() {
		if ( !class_exists('sem_cache_manager') )
			include dirname(__FILE__) . '/sem-cache-manager.php';
		
		sem_cache_manager::disable_static();
		sem_cache_manager::disable_memcached();
		sem_cache_manager::disable_assets();
		sem_cache_manager::disable_gzip();
		
		cache_fs::flush('/');
		
		sem_cache_manager::flush_objects();
	} # disable()
	

	/**
	 * enable()
	 *
	 * @return void
	 **/

	static function enable() {
		if ( !class_exists('sem_cache_manager') )
			include dirname(__FILE__) . '/sem-cache-manager.php';

		sem_cache_manager::enable_caching();

		cache_fs::flush('/');

		sem_cache_manager::flush_objects();
	} # enable()


	/**
	 * flush_cache()
	 *
	 * @return void
	 **/

	static function flush_cache() {
		if ( !class_exists('sem_cache_manager') )
			include dirname(__FILE__) . '/sem-cache-manager.php';

		sem_cache_manager::flush_cache();
	} # flush_cache()

    /**
     * flush_assets()
     *
     * @return void
     **/

    static function flush_assets() {
        if ( !class_exists('sem_cache_manager') )
            include dirname(__FILE__) . '/sem-cache-manager.php';

        sem_cache_manager::flush_assets();
    } # flush_assets()

	/**
	 * cache_timeout()
	 *
	 * @internal param bool $force
	 * @return bool $success
	 */

	static function cache_timeout() {
		if ( !static_cache )
			return;
		cache_fs::flush('/static', cache_timeout);
		if ( !memory_cache )
			cache_fs::flush('/semi-static', cache_timeout);
	} # cache_timeout()
	

	/**
	 * get_mobile_agents()
	 *
	 * @return array $agents
	 **/

	static function get_mobile_agents() {
		$agents = array(
			'iPhone',
			'iPod',
			'aspen',
			'dream',
            'BB10',
			'BlackBerry',
            'IEMobile',
            'Opera Mobi',
            'Opera Mini',
            'palmos',
            'webos',
            'Googlebot-Mobile'
			);
		return apply_filters('sem_cache_mobile_agents', $agents);
	} # get_mobile_agents()


	/**
	 * get_cookies()
	 *
	 * @return array $cookies
	 **/

	static function get_cookies() {
		$cookies = array(
			LOGGED_IN_COOKIE,
			'comment_author_' . COOKIEHASH,
			'comment_author_email_' . COOKIEHASH,
			'wp-postpass_' . COOKIEHASH,
			);

		return apply_filters('sem_cache_cookies', $cookies);
	} # get_cookies()

	/**
	 * flush_url()
	 *
	 * @param $link
	 * @internal param string $url
	 * @return void
	 */

	static function flush_url($link) {
		$cache_id = md5($link);
		
		wp_cache_delete($cache_id, 'url2posts');
		wp_cache_delete($cache_id, 'url2posts_found');
		
		if ( static_cache ) {
			static $permalink_structure;
			if ( !isset($permalink_structure) )
				$permalink_structure = get_option('permalink_structure');
			# 5 min throttling in case the site is getting hammered by comments
			$timeout = !is_admin() && current_filter() == 'wp_update_comment_count' ? 300 : false;
			if ( $permalink_structure ) {
				$path = trim(preg_replace("|^[^/]+://[^/]+|", '', $link), '/');
				cache_fs::flush('/static/' . $path, $timeout, false);
			}
		}
		if ( memory_cache ) {
			wp_cache_delete($cache_id, 'cached_headers');
			wp_cache_delete($cache_id, 'cached_buffers');
		} elseif ( static_cache ) {
                        $timeout = !is_admin() && current_filter() == 'wp_update_comment_count' ? 300 : false;
			cache_fs::flush('/semi-static/' . $cache_id . '.meta', $timeout, false);
			cache_fs::flush('/semi-static/' . $cache_id . '.html', $timeout, false);
		}
	} # flush_url()


	/**
	 * flush_feed_url()
	 *
	 * @param $link
	 * @internal param string $url
	 * @return void
	 */

	static function flush_feed_url($link) {
		$cache_id = md5($link);
		
		wp_cache_delete($cache_id, 'url2posts');
		wp_cache_delete($cache_id, 'url2posts_found');
		
		if ( memory_cache ) {
			wp_cache_delete($cache_id, 'cached_headers');
			wp_cache_delete($cache_id, 'cached_buffers');
		} elseif ( static_cache ) {
                        $timeout = false;
			cache_fs::flush('/semi-static/' . $cache_id . '.meta', $timeout, false);
			cache_fs::flush('/semi-static/' . $cache_id . '.html', $timeout, false);
		}
	} # flush_feed_url()
	
	
	/**
	 * pre_flush_post()
	 *
	 * @param int $post_id
	 * @return void
	 **/

	static function pre_flush_post($post_id) {
		$post_id = (int) $post_id;
		if ( !$post_id )
			return;
		
		$post = get_post($post_id);
		if ( !$post || wp_is_post_revision($post_id) )
			return;
		
		$old = wp_cache_get($post_id, 'pre_flush_post');
		if ( $old === false )
			$old = array();
		
		$update = false;
		foreach ( array(
			'post_status',
			) as $field ) {
			if ( !isset($old[$field]) ) {
				$old[$field] = $post->$field;
				$update = true;
			}
		}
		
		if ( !isset($old['permalink']) ) {
			$old['permalink'] = apply_filters('the_permalink', get_permalink($post_id));
			$update = true;
		}
		
		if ( $post->post_type == 'post' ) {
			foreach ( array('category', 'post_tag') as $taxonomy ) {
				if ( !isset($old[$taxonomy]) ) {
					$terms = wp_get_object_terms($post_id, $taxonomy);
					$old[$taxonomy] = array();
					if ( !is_wp_error($terms) ) {
						foreach ( $terms as &$term )
							$old[$taxonomy][] = $term->term_id;
					}
					$update = true;
				}
			}
		}
		
		if ( $update )
			wp_cache_set($post_id, $old, 'pre_flush_post');
	} # pre_flush_post()


	/**
	 * flush_post_url()
	 *
	 * @param $link
	 * @internal param string $url
	 * @internal param int $timeout
	 * @return void
	 */

	static function flush_post_url($link) {
		$cache_id = md5($link);
		
		wp_cache_delete($cache_id, 'url2post_id');

        $timeout = !is_admin() && current_filter() == 'wp_update_comment_count' ? 300 : false;

		if ( static_cache ) {
			static $permalink_structure;
			if ( !isset($permalink_structure) )
				$permalink_structure = get_option('permalink_structure');
			# 5 min throttling in case the site is getting hammered by comments

			if ( $permalink_structure ) {
				$path = trim(preg_replace("|^[^/]+://[^/]+|", '', $link), '/');
				cache_fs::flush('/static/' . $path, $timeout, false);
			}
		}
		if ( memory_cache ) {
			wp_cache_delete($cache_id, 'cached_headers');
			wp_cache_delete($cache_id, 'cached_buffers');
		} elseif ( static_cache ) {
			cache_fs::flush('/semi-static/' . $cache_id . '.meta', $timeout, false);
			cache_fs::flush('/semi-static/' . $cache_id . '.html', $timeout, false);
		}
	} # flush_post_url()
	
	
	/**
	 * flush_post()
	 *
	 * @param int $post_id
	 * @param mixed $new
	 * @param mixed $old
	 * @return void
	 **/

	static function flush_post($post_id, $new = null, $old = null) {
		static $done = array();
		
		$post_id = (int) $post_id;
		if ( !$post_id )
			return;
		
		if ( isset($done[$post_id]) )
			return;
		
		$done[$post_id] = true;
		
		# prevent mass-flushing when the permalink structure hasn't changed
		remove_action('generate_rewrite_rules', array('sem_cache_manager', 'flush_cache'));
		
		if ( current_filter() == 'wp_update_comment_count' && $new == $old )
			return;
		
		$post = get_post($post_id);
		if ( !$post || wp_is_post_revision($post_id) )
			return;
		
		$old = wp_cache_get($post_id, 'pre_flush_post');
		
		if ( $post->post_status != 'publish' && ( !$old || $old['post_status'] != 'publish' ) && $post->post_type != 'attachment' )
			return;
		
		# flush the post
		self::do_flush_post($post_id);
		
		# flush the home and blog pages
		self::do_flush_home();
		
		if ( $post->post_type == 'post' && in_array(current_filter(), array('save_post', 'delete_post')) ) {
			# flush categories
			$cats = wp_get_object_terms($post_id, 'category');
			$cat_ids = array();
			if ( !is_wp_error($cats) ) {
				foreach ( $cats as &$cat )
					$cat_ids[] = $cat->term_id;
			}
			if ( $old )
				$cat_ids = array_merge($cat_ids, $old['category']);
			if ( defined('main_cat_id') && main_cat_id )
				$cat_ids = array_diff($cat_ids, array(main_cat_id) );
			foreach ( array_unique($cat_ids) as $cat_id )
				self::do_flush_term($cat_id, 'category');
			
			# flush tags
			$tags = wp_get_object_terms($post_id, 'post_tag');
			$tag_ids = array();
			if ( !is_wp_error($tags) ) {
				foreach ( $tags as &$tag )
					$tag_ids[] = $tag->term_id;
			}
			if ( $old )
				$tag_ids = array_merge($tag_ids, $old['post_tag']);
			foreach ( array_unique($tag_ids) as $tag_id )
				self::do_flush_term($tag_id, 'post_tag');
			
			# flush author
			$author_ids = array();
			$author_ids[] = $post->post_author;
			if ( $old && isset($old['post_author']))
				$author_ids[] = $old['post_author'];
			foreach ( array_unique($author_ids) as $author_id )
				self::do_flush_author($author_id);
			
			# flush archives
			$dates = array();
			$dates[] = strtotime($post->post_date);
			if ( $old && isset($old['post_date']))
				$dates[] = strtotime($old['post_date']);
			foreach ( array_unique($dates) as $date )
				self::do_flush_date($date);
		}
		
		# in case other plugins want to hook into this...
		do_action('flush_post', $post_id);
	} # flush_post()
	
	
	/**
	 * do_flush_post()
	 *
	 * @param int $post_id
	 * @return void
	 **/

	static function do_flush_post($post_id) {
		static $done = array();
		if ( isset($done[$post_id]) )
			return;
		
		$done[$post_id] = true;
		static $permalink_structure;
		if ( !isset($permalink_structure) )
			$permalink_structure = get_option('permalink_structure');
		
		$post = get_post($post_id);
		$old = wp_cache_get($post_id, 'pre_flush_post');
		
		$links = array();
		$links[] = apply_filters('the_permalink', get_permalink($post_id));
		$pages = isset($post->post_content)
			? preg_match("/<!--nextpage-->/", $post->post_content)
			: 1;
		if ( $old ) {
			$links[] = $old['permalink'];
			$pages = max($pages, preg_match("/<!--nextpage-->/", $old['post_content']));
		}
		
		foreach ( array_unique($links) as $link ) {
			self::flush_post_url($link);
			for ( $i = 1; $i < $pages; $i++ ) {
				if ( !$permalink_structure )
					$extra = $link . '&page=' . $i;
				else
					$extra = trailingslashit($link) . user_trailingslashit($i, 'single_paged');
				self::flush_post_url($extra);
			}
		}
		
		# flush the comments
		wp_cache_delete($post_id, 'cached_comments');
		wp_cache_delete($post_id, 'uncached_comments');
	} # do_flush_post()
	
	
	/**
	 * do_flush_home()
	 *
	 * @return void
	 **/

	static function do_flush_home() {
		static $done = false;
		if ( $done )
			return;
		
		$done = true;
		static $permalink_structure;
		if ( !isset($permalink_structure) )
			$permalink_structure = get_option('permalink_structure');
		
		$links = array();
		$blog_link = trailingslashit(get_option('home'));
		$links[] = $blog_link;
		if ( get_option('show_on_front') != 'posts' && get_option('page_on_front') ) {
			$blog_page_id = get_option('page_for_posts');
			if ( $blog_page_id && get_post($blog_page_id) ) {
				$blog_link = apply_filters('the_permalink', get_permalink($blog_page_id));
				$links[] = $blog_link;
			}
		}
		
		foreach ( array_unique($links) as $link )
			self::flush_url($link);
		
		# flush the next two blog pages
		for ( $i = 2; $i <= 3; $i++ ) {
			if ( !$permalink_structure )
				$link = $blog_link . '&page=' . $i;
			else
				$link = trailingslashit($blog_link) . user_trailingslashit('page/' . $i, 'paged');
			self::flush_url($link);
		}
		
		# flush the blog feeds
		foreach ( array('rss2', 'atom', 'comments_rss2', 'comments_atom') as $feed ) {
			$link = get_feed_link($feed);
			self::flush_feed_url($link);
		}
	} # do_flush_home()
	
	
	/**
	 * do_flush_term()
	 *
	 * @param int $term_id
	 * @param string $taxonomy
	 * @return void
	 **/

	static function do_flush_term($term_id, $taxonomy) {
		static $done = array();
		if ( isset($done[$taxonomy][$term_id]) )
			return;
		
		$done[$taxonomy][$term_id] = true;
		
		if ( $taxonomy == 'category' )
			$link = @get_category_link($term_id);
		else
			$link = @get_tag_link($term_id);
		if ( is_wp_error($link) || !$link )
			return;
		self::flush_url($link);
		
		foreach ( array('rss2', 'atom') as $feed ) {
			if ( $taxonomy == 'category' )
				$link = get_category_feed_link($term_id, $feed);
			else
				$link = get_tag_feed_link($term_id, $feed);
			$link = str_replace('&amp;', '&', $link);
			self::flush_feed_url($link);
		}
	} # do_flush_term()
	
	
	/**
	 * do_flush_author()
	 *
	 * @param int $author_id
	 * @return void
	 **/

	static function do_flush_author($author_id) {
		static $done = array();
		if ( isset($done[$author_id]) )
			return;
		
		$done[$author_id] = true;
		
		$link = get_author_posts_url($author_id);
		self::flush_url($link);
		
		foreach ( array('rss2', 'atom') as $feed ) {
			$link = str_replace('&amp;', '&', get_author_feed_link($author_id, $feed));
			self::flush_feed_url($link);
		}
	} # do_flush_author()


	/**
	 * do_flush_date()
	 *
	 * @param $date
	 * @return void
	 */

	static function do_flush_date($date) {
		static $done;
		
		if ( !is_numeric($date) )
			$date = @strtotime($date);
		if ( !$date )
			return;
		
		$year = date('Y', $date);
		$month = date('m', $date);
		$day = date('d', $date);
		
		if ( !isset($done["$year"]) ) {
			$link = get_year_link($year);
			self::flush_url($link);
			$done["$year"] = true;
		}
		
		if ( !isset($done["$year-$month"]) ) {
			$link = get_month_link($year, $month);
			self::flush_url($link);
			$done["$year-$month"] = true;
		}
		
		if ( !isset($done["$year-$month-$day"]) ) {
			$link = get_day_link($year, $month, $day);
			self::flush_url($link);
			$done["$year-$month-$day"] = true;
		}
	} # do_flush_date()
	
	
	/**
	 * get_stats()
	 *
	 * @return string $stats
	 **/

	static function get_stats() {
		$date = date('Y-m-d @ H:i:s');
		
		$time_spent = ( 1000 * timer_stop() ) . 'ms';
		$style = 'text-align: center; font-size: 8px;';
		$stats = "Served in $time_spent on $date.";

		if ( function_exists('memory_get_usage') ) {
			$memory = number_format(memory_get_usage() / ( 1024 * 1024 ), 1);
			$stats .= " Memory: {$memory}MB.";
		}
		
		global $wpdb;
		$queries = get_num_queries();
		if ( get_site_option('query_cache') && !is_admin() ) {
			$queries += $wpdb->cache_hits;
			$stats .= " Query Cache: $wpdb->cache_hits hits / $queries.";
		} else {
			$stats .= " Queries: $queries.";
		}

		global $wp_object_cache;
		$stats .= " Object Cache: $wp_object_cache->cache_hits hits / " . ( $wp_object_cache->cache_hits + $wp_object_cache->cache_misses ) . ".";
		
		if ( !is_feed() &&
			( sem_cache_debug || !is_admin() ) &&
			current_user_can('manage_options') &&
			( !function_exists('is_super_admin') || is_super_admin() ) )
			return "\n<p style='$style'>$stats</p>";
		elseif ( sem_cache_debug )
			return "\n<!-- $stats -->";
		else
			return "\n<!-- $date -->\n";
	} # get_stats()
	
	
	/**
	 * stats()
	 *
	 * @return void
	 **/
	
	static function stats() {
		echo self::get_stats();
	} # stats()


	static function url_to_domain($url)
	{
	    $host = @parse_url($url, PHP_URL_HOST);

	    // If the URL can't be parsed, use the original URL
	    // Change to "return false" if you don't want that
	    if (!$host) {
	        return false;
	    }

	    // The "www." prefix isn't really needed if you're just using
	    // this to display the domain to the user
	    if (substr($host, 0, 4) == "www.") {
	        $host = substr($host, 4);
	    }

	    // You might also want to limit the length if screen space is limited
	    if (strlen($host) > 50) {
	        $host = substr($host, 0, 47) . '...';
	    }

	    return $host;
	}
} # sem_cache

$sem_cache = sem_cache::get_instance();