advanced-nav-cache.php

<?php
/**
 * Cache wp_nav_menu output in object cache.
 *
 *
 * @package   Advanced_Nav_Cache
 * @author    Jonathan Harris <jon@spacedmonkey.co.uk>
 * @license   GPL-2.0+
 * @link      http://www.spacedmonkey.com/
 * @copyright 2015 Spacedmonkey
 *
 * @wordpress-plugin
 * Plugin Name:        Advanced Nav Cache
 * Plugin URI:         https://www.github.com/spacedmonkey/advanced-nav-cache
 * Description:        Cache wp_nav_menu output in object cache.
 * Version:            1.1.3
 * Author:             Jonathan Harris
 * Author URI:         http://www.spacedmonkey.com/
 * License:            GPL-2.0+
 * License URI:        http://www.gnu.org/licenses/gpl-2.0.txt
 * GitHub Plugin URI:  https://www.github.com/spacedmonkey/advanced-nav-cache
 */

// If this file is called directly, abort.
if ( ! defined( 'WPINC' ) ) {
	die;
}

// Use definable cache group prefix
defined( 'NAV_CACHE_GROUP_PREFIX' ) or define( 'NAV_CACHE_GROUP_PREFIX', 'advanced_nav_cache' );

// Set the expiry of nav cache objects
defined( 'NAV_CACHE_EXPIRY' ) or define( 'NAV_CACHE_EXPIRY', 0 );

// Set if wish to flush cache on defined hooks
defined( 'NAV_DO_FLUSH_CACHE' ) or define( 'NAV_DO_FLUSH_CACHE', true );

// Enable flushing on nav update
defined( 'NAV_DO_FLUSH_CACHE_NAV' ) or define( 'NAV_DO_FLUSH_CACHE_NAV', true );

// Enable flushing on term update
defined( 'NAV_DO_FLUSH_CACHE_TERM' ) or define( 'NAV_DO_FLUSH_CACHE_TERM', true );

// Enable flushing on any post update
defined( 'NAV_DO_FLUSH_CACHE_POST' ) or define( 'NAV_DO_FLUSH_CACHE_POST', true );

// Enable flushing on any page update
defined( 'NAV_DO_FLUSH_CACHE_PAGE' ) or define( 'NAV_DO_FLUSH_CACHE_PAGE', true );


// Do not re register the class
if ( ! class_exists( 'Advanced_Nav_Cache' ) ) {

	/**
	 * Class Advanced_Nav_Cache
	 */
	class Advanced_Nav_Cache {

		// Flag for temp (within one page load) turning invalidations on and off
		// @see dont_clear_advanced_nav_cache()
		// @see do_clear_advanced_nav_cache()
		// Used to prevent invalidation during new comment
		/**
		 * @var bool
		 */
		var $do_flush_cache = NAV_DO_FLUSH_CACHE;

		// Flag for preventing multiple invalidations in a row: clean_post_cache() calls itself recursively for post children.
		/**
		 * @var bool
		 */
		var $need_to_flush_cache = true; // Currently disabled

		/* Per cache-clear data */
		/**
		 * @var int
		 */
		var $cache_incr = 0; // Increments the cache group (advanced_nav_cache_0, advanced_nav_cache_1, ...)
		/**
		 * @var string
		 */
		var $cache_group = NAV_CACHE_GROUP_PREFIX;

		/**
		 * @var string
		 */
		var $home_url = ''; // Current home URL

		/**
		 * @var string
		 */
		var $home_url_salt = ''; // Current home URL MD5ed

		/**
		 *
		 */
		function __construct() {
			$this->setup_for_blog();

			add_action( 'switch_blog', array( $this, 'setup_for_blog' ), 10, 2 );

			if ( NAV_DO_FLUSH_CACHE_NAV ) {
				add_action( 'wp_update_nav_menu', array( $this, 'clear_advanced_nav_cache' ) );
			}

			if ( NAV_DO_FLUSH_CACHE_TERM ) {
				add_action( 'edited_term', array( $this, 'clear_advanced_nav_cache' ) );
			}

			if ( NAV_DO_FLUSH_CACHE_POST ) {
				add_action( 'clean_post_cache', array( $this, 'clear_advanced_nav_cache' ) );
			}

			if ( NAV_DO_FLUSH_CACHE_PAGE ) {
				add_action( 'clean_page_cache', array( $this, 'clear_advanced_nav_cache' ) );
			}

			// Don't clear Advanced Post Cache for a new comment - temp core hack
			// http://core.trac.wordpress.org/ticket/15565
			add_action( 'wp_updating_comment_count', array( $this, 'dont_clear_advanced_nav_cache' ) );
			add_action( 'wp_update_comment_count', array( $this, 'do_clear_advanced_nav_cache' ) );
			add_action( 'edited_terms', array( $this, 'wp_flush_get_term_cache' ), 10, 2 );
			add_action( 'pre_delete_term', array( $this, 'wp_flush_get_term_cache' ), 10, 2 );

			add_filter( 'wp_nav_menu_args', array( $this, 'wp_nav_menu_args' ) );
			add_filter( 'pre_wp_nav_menu', array( $this, 'pre_wp_nav_menu' ), 9, 2 );
			add_filter( 'wp_nav_menu', array( $this, 'wp_nav_menu' ), 99, 2 );

		}

		/**
		 * @param bool $new_blog_id
		 * @param bool $previous_blog_id
		 */
		public function setup_for_blog( $new_blog_id = false, $previous_blog_id = false ) {

			$this->setup_home_url_vars();

			if ( $new_blog_id && $new_blog_id == $previous_blog_id ) {
				return;
			}

			$this->cache_incr = wp_cache_get( 'cache_incrementors', $this->cache_group ); // Get and construct current cache group name
			if ( false === $this->cache_incr ) {
				$this->cache_incr = microtime();
				wp_cache_set( 'cache_incrementors', $this->cache_incr, $this->cache_group );
			}

		}

		/**
		 *
		 */
		protected function setup_home_url_vars() {
			$home_url            = home_url();
			$this->home_url      = $home_url;
			$this->home_url_salt = $this::make_cache_key( $home_url );
		}

		public function wp_nav_menu_args( $args ) {
			if ( $this->is_nav_cached_enabled( $args ) ) {
				$menu = $this->wp_get_nav_menu_object( $args['menu'] );
				// Get the nav menu based on the theme_location
				if ( ! $menu && $args['theme_location'] && ( $locations = get_nav_menu_locations() ) && isset( $locations[ $args['theme_location'] ] ) ) {
					$menu = $this->wp_get_nav_menu_object( $locations[ $args['theme_location'] ] );
				}
				if ( $menu ) {
					$args['menu'] = $menu;
					$args['theme_location'] = false;
				}
			}

			return $args;
		}

		/**
		 * @param $output
		 * @param $args
		 *
		 * @return string
		 */
		public function pre_wp_nav_menu( $output, $args ) {
			if ( $this->is_nav_cached_enabled( $args ) ) {
				// Make sure that the query caching isn't in play
				remove_action( 'parse_query', array( $this, 'parse_query' ) );
				$cached_value = wp_cache_get( $this->get_key( $args ), $this->cache_group );
				if ( false !== $cached_value ) {
					$output = $cached_value;
				} else {
					// If not in cache, enable query caching.
					add_action( 'parse_query', array( $this, 'parse_query' ) );
				}
			}

			return $output;
		}

		/**
		 * @param $output
		 * @param $args
		 *
		 * @return string
		 */
		public function wp_nav_menu( $output, $args ) {
			if ( $this->is_nav_cached_enabled( $args ) ) {
				$cached_value = wp_cache_get( $this->get_key( $args ), $this->cache_group );
				if ( false === $cached_value ) {
					$expire = apply_filters( 'advanced_nav_cache_expire', NAV_CACHE_EXPIRY, $args );
					wp_cache_set( $this->get_key( $args ), $output, $this->cache_group, $expire );
				}
				// Remove query caching after nav is done.
				remove_action( 'parse_query', array( $this, 'parse_query' ) );
			}

			return $output;
		}

		/**
		 * @param $args
		 *
		 * @return string
		 */
		public function get_key( $args ) {

			$args = (array) $args;

			if ( isset( $args['anc_ignore_context'] ) && $args['anc_ignore_context'] ) {
				$context = array( 'no_context' );
			} else {
				$context = $this->get_query_vars();
			}

			$object_id = $this::make_cache_key( $context );
			$flat_args = $this::make_cache_key( $args );
			$cache_key = sprintf( '%s_%s_%s_%s', $object_id, $flat_args, $this->cache_incr, $this->home_url_salt );

			return apply_filters( 'advanced_nav_cache_key', $cache_key, $args, $context, $this->home_url, $this->cache_incr );
		}

		/**
		 * Per page cache salt. If 404 page, just return the same menu as other 404 pages.
		 * Also, on secondary pages, return the same menu. Better for performance.
		 *
		 * @return string
		 */
		public function get_query_vars() {
			global $wp_query;

			if ( $wp_query->is_404() ) {
				$page_variable = array( 'error_404' );
			} else {
				$page_variable = $wp_query->query_vars;

			}
			$page_variable['paged'] = 0;
			asort( $page_variable );

			return apply_filters( 'advanced_nav_cache_query_vars', $page_variable );
		}

		/**
		 * @param $menu
		 *
		 * @return bool
		 */
		public function wp_get_nav_menu_object( $menu ) {
			$menu_obj = false;
			if ( empty( $menu ) ) {
				return $menu_obj;
			}

			if ( is_object( $menu ) ) {
				$menu_obj = $menu;
			}
			if ( $menu && ! $menu_obj ) {
				if ( is_numeric( $menu ) ) {
					$menu_obj = get_term( $menu, 'nav_menu' );
				}
				if ( ! $menu_obj ) {
					$menu_obj = $this->get_term_by( 'slug', $menu, 'nav_menu' );
				}
				if ( ! $menu_obj ) {
					$menu_obj = $this->get_term_by( 'name', $menu, 'nav_menu' );
				}
			}
			if ( ! $menu_obj || is_wp_error( $menu_obj ) ) {
				$menu_obj = false;
			}

			return $menu_obj;
		}

		/**
		 * @param $field
		 * @param $value
		 * @param string $taxonomy
		 * @param $output
		 * @param string $filter
		 *
		 * @return bool
		 */
		public function get_term_by( $field, $value, $taxonomy = '', $output = OBJECT, $filter = 'raw' ) {
			// ID lookups are cached
			if ( 'id' == $field ) {
				return get_term_by( $field, $value, $taxonomy, $output, $filter );
			}

			$cache_key   = $field . '|' . $taxonomy . '|' . md5( $value );
			$term_id     = wp_cache_get( $cache_key, $this->cache_group );

			if ( false === $term_id ) {
				$term = get_term_by( $field, $value, $taxonomy );
				if ( $term && ! is_wp_error( $term ) ) {
					wp_cache_set( $cache_key, $term->term_id, $this->cache_group );
				} else {
					wp_cache_set( $cache_key, 0, $this->cache_group );
				} // if we get an invalid value, let's cache it anyway
			} else {
				$term = get_term( $term_id, $taxonomy, $output, $filter );
			}

			if ( is_wp_error( $term ) ) {
				$term = false;
			}

			return $term;
		}

		/**
		 * @param $term_id
		 * @param $taxonomy
		 */
		public function wp_flush_get_term_cache( $term_id, $taxonomy ) {
			if ( 'nav_menu' != $taxonomy ) {
				return;
			}
			$term = get_term_by( 'id', $term_id, $taxonomy );
			if ( ! $term ) {
				return;
			}
			foreach ( array( 'name', 'slug' ) as $field ) {
				$cache_key   = $field . '|' . $taxonomy . '|' . md5( $term->$field );
				wp_cache_delete( $cache_key, $this->cache_group );
			}
		}

		/**
		 * @param $key
		 *
		 * @return string
		 */
		static public function make_cache_key( $key ) {
			return md5( serialize( $key ) );
		}

		/**
		 *
		 */
		public function clear_advanced_nav_cache() {
			$this->flush_cache();
		}

		/**
		 *
		 */
		public function do_clear_advanced_nav_cache() {
			$this->do_flush_cache = true;
		}

		/**
		 *
		 */
		public function dont_clear_advanced_nav_cache() {
			$this->do_flush_cache = false;
		}

		/**
		 * @return bool
		 */
		public function get_clear_advanced_nav_cache() {
			return apply_filters( 'advanced_nav_cache_enable_flush', $this->do_flush_cache );
		}

		/* Advanced Nav Cache API */

		/**
		 * Flushes the cache by incrementing the cache group
		 */
		public function flush_cache() {
			// Cache flushes have been disabled
			if ( ! $this->get_clear_advanced_nav_cache() ) {
				return;
			}

			// Bail on post preview
			if ( is_admin() && isset( $_POST['wp-preview'] ) && 'dopreview' == $_POST['wp-preview'] ) {
				return;
			}

			// Bail on autosave
			if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
				return;
			}

			// We already flushed once this page load, and have not put anything into the cache since.
			// OTHER processes may have put something into the cache!  In theory, this could cause stale caches.
			// We do this since clean_post_cache() (which fires the action this method attaches to) is called RECURSIVELY for all descendants.
			// if ( !$this->need_to_flush_cache )
			// return;

			$this->cache_incr = microtime();
			wp_cache_set( 'cache_incrementors', $this->cache_incr, $this->cache_group );

			$this->need_to_flush_cache = false;
		}

		/**
		 *
		 * @return boolean
		 */
		public function is_nav_cached_enabled( $args = array() ) {
			$enabled = true;

			$args = (array) $args;

			if ( isset( $args['anc_no_cache'] ) && $args['anc_no_cache'] ) {
				$enabled = false;
			}

			if ( is_admin() ) {
				$enabled = false;
			}
			if ( is_feed() ) {
				$enabled = false;
			}
			if ( is_preview() ) {
				$enabled = false;
			}
			if ( function_exists( 'is_customize_preview' ) && is_customize_preview() ) {
				$enabled = false;
			}
			if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
				$enabled = false;
			}
			if ( defined( 'DOING_CRON' ) && DOING_CRON ) {
				$enabled = false;
			}
			if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
				$enabled = false;
			}

			return apply_filters( 'advanced_nav_cache_is_enabled', $enabled, $args );
		}

		/**
		 * Improve compatablity with WordPress core caching.
		 *
		 * @param $query
		 */
		function parse_query( &$query ) {
			$query->query_vars['suppress_filters'] = false;
			$query->query_vars['cache_results']    = true;
		}
	}

	global $advanced_nav_cache_object;
	$advanced_nav_cache_object = new Advanced_Nav_Cache();
}