<?php

/**

 * bbPress Cache Helpers

 *

 * Helper functions used to communicate with WordPress's various caches. Many

 * of these functions are used to work around specific WordPress nuances. They

 * are subject to changes, tweaking, and will need iteration as performance

 * improvements are made to WordPress core.

 *

 * @package bbPress

 * @subpackage Cache

 */

// Exit if accessed directly

if ( !defined( 'ABSPATH' ) ) exit;

/** Helpers *******************************************************************/

/**

 * Skip invalidation of child post content when editing a parent.

 *

 * This prevents invalidating caches for topics and replies when editing a forum

 * or a topic. Without this in place, WordPress will attempt to invalidate all

 * child posts whenever a parent post is modified. This can cause thousands of

 * cache invalidations to occur on a single edit, which is no good for anyone.

 *

 * @since bbPress (r4011)

 *

 * @package bbPress

 * @subpackage Cache

 */

class BBP_Skip_Children {

	/**

	 * @var int Post ID being updated

	 */

	private $updating_post = 0;

	/**

	 * @var bool The original value of $_wp_suspend_cache_invalidation global

	 */

	private $original_cache_invalidation = false;

	/** Methods ***************************************************************/

	/**

	 * Hook into the 'pre_post_update' action.

	 *

	 * @since bbPress (r4011)

	 */

	public function __construct() {

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

	}

	/**

	 * Only clean post caches for main bbPress posts.

	 *

	 * Check that the post being updated is a bbPress post type, saves the

	 * post ID to be used later, and adds an action to 'clean_post_cache' that

	 * prevents child post caches from being cleared.

	 *

	 * @since bbPress (r4011)

	 *

	 * @param int $post_id The post ID being updated

	 * @return If invalid post data

	 */

	public function pre_post_update( $post_id = 0 ) {

		// Bail if post ID is not a bbPress post type

		if ( empty( $post_id ) || ! bbp_is_custom_post_type( $post_id ) )

			return;

		// Store the $post_id

		$this->updating_post = $post_id;

		// Skip related post cache invalidation. This prevents invalidating the

		// caches of the child posts when there is no reason to do so.

		add_action( 'clean_post_cache', array( $this, 'skip_related_posts' ) );

	}

	/**

	 * Skip cache invalidation of related posts if the post ID being invalidated

	 * is not the one that was just updated.

	 *

	 * @since bbPress (r4011)

	 *

	 * @param int $post_id The post ID of the cache being invalidated

	 * @return If invalid post data

	 */

	public function skip_related_posts( $post_id = 0 ) {

		// Bail if this post is not the current bbPress post

		if ( empty( $post_id ) || ( $this->updating_post !== $post_id ) )

			return;

		// Stash the current cache invalidation value in a variable, so we can

		// restore back to it nicely in the future.

		global $_wp_suspend_cache_invalidation;

		$this->original_cache_invalidation = $_wp_suspend_cache_invalidation;

		// Turn off cache invalidation

		wp_suspend_cache_invalidation( true );

		// Restore cache invalidation

		add_action( 'wp_insert_post', array( $this, 'restore_cache_invalidation' ) );

	}

	/**

	 * Restore the cache invalidation to its previous value.

	 *

	 * @since bbPress (r4011)

	 * @uses wp_suspend_cache_invalidation()

	 */

	public function restore_cache_invalidation() {

		wp_suspend_cache_invalidation( $this->original_cache_invalidation );

	}

}

new BBP_Skip_Children();

/** General *******************************************************************/

/**

 * Will clean a post in the cache.

 *

 * Will call to clean the term object cache associated with the post ID.

 *

 * @since bbPress (r4040)

 *

 * @uses do_action() Calls 'bbp_clean_post_cache' on $id

 * @param object|int $_post The post object or ID to remove from the cache

 */

function bbp_clean_post_cache( $_post = '' ) {

	// Bail if no post

	$_post = get_post( $_post );

	if ( empty( $_post ) )

		return;

	wp_cache_delete( $_post->ID, 'posts'     );

	wp_cache_delete( $_post->ID, 'post_meta' );

	clean_object_term_cache( $_post->ID, $_post->post_type );

	do_action( 'bbp_clean_post_cache', $_post->ID, $_post );

	// Child query types to clean

	$post_types = array(

		bbp_get_topic_post_type(),

		bbp_get_forum_post_type(),

		bbp_get_reply_post_type()

	);

	// Loop through query types and clean caches

	foreach ( $post_types as $post_type ) {

		wp_cache_delete( 'bbp_get_forum_'     . $_post->ID . '_reply_id',                              'bbpress' );

		wp_cache_delete( 'bbp_parent_'        . $_post->ID . '_type_' . $post_type . '_child_last_id', 'bbpress' );

		wp_cache_delete( 'bbp_parent_'        . $_post->ID . '_type_' . $post_type . '_child_count',   'bbpress' );

		wp_cache_delete( 'bbp_parent_public_' . $_post->ID . '_type_' . $post_type . '_child_ids',     'bbpress' );

		wp_cache_delete( 'bbp_parent_all_'    . $_post->ID . '_type_' . $post_type . '_child_ids',     'bbpress' );

	}

	// Invalidate parent caches

	if ( ! empty( $_post->post_parent ) ) {

		bbp_clean_post_cache( $_post->post_parent );

	}

}