Comment caching. Reduce queries on edit-comments.php page. Add non-persistent cache groups. Hat tip to hovenko. fixes #4387

git-svn-id: http://svn.automattic.com/wordpress/trunk@5666 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/edit-comments.php

@@ -151,7 +151,8 @@ if ( $extra_comments ) : ?>
   </tr>
 </thead>';
 		foreach ($comments as $comment) {
-		$authordata = get_userdata($wpdb->get_var("SELECT post_author FROM $wpdb->posts WHERE ID = $comment->comment_post_ID"));
+		$post = get_post($comment->comment_post_ID);
+		$authordata = get_userdata($post->post_author);
 		$comment_status = wp_get_comment_status($comment->comment_ID);
 		$class = ('alternate' == $class) ? '' : 'alternate';
 		$class .= ('unapproved' == $comment_status) ? ' unapproved' : '';

wp-admin/includes/template.php

@@ -250,6 +250,8 @@ function _wp_get_comment_list( $s = false, $start, $num ) {
 		$comments = $wpdb->get_results( "SELECT SQL_CALC_FOUND_ROWS * FROM $wpdb->comments WHERE comment_approved = '0' OR comment_approved = '1' ORDER BY comment_date DESC LIMIT $start, $num" );
 	}
 
+	update_comment_cache($comments);
+
 	$total = $wpdb->get_var( "SELECT FOUND_ROWS()" );
 
 	return array($comments, $total);
@@ -260,7 +262,8 @@ function _wp_comment_list_item( $id, $alt = 0 ) {
 	$id = (int) $id;
 	$comment =& get_comment( $id );
 	$class = '';
-	$authordata = get_userdata($wpdb->get_var("SELECT post_author FROM $wpdb->posts WHERE ID = $comment->comment_post_ID"));
+	$post = get_post($comment->comment_post_ID);
+	$authordata = get_userdata($post->post_author);
 	$comment_status = wp_get_comment_status($comment->comment_ID);
 	if ( 'unapproved' == $comment_status )
 		$class .= ' unapproved';

wp-includes/cache.php

@@ -63,6 +63,7 @@ class WP_Object_Cache {
 	var $dirty_objects = array ();
 	var $non_existant_objects = array ();
 	var $global_groups = array ('users', 'userlogins', 'usermeta');
+	var $non_persistent_groups = array('comment');
 	var $blog_id;
 	var $cold_cache_hits = 0;
 	var $warm_cache_hits = 0;
@@ -308,6 +309,9 @@ class WP_Object_Cache {
 		// Loop over dirty objects and save them.
 		$errors = 0;
 		foreach ($this->dirty_objects as $group => $ids) {
+			if ( in_array($group, $this->non_persistent_groups) )
+				continue;
+
 			$group_dir = $this->make_group_dir($group, $dir_perms);
 
 			$ids = array_unique($ids);

wp-includes/comment-template.php

@@ -301,6 +301,7 @@ function comments_template( $file = '/comments.php' ) {
 	// keep $comments for legacy's sake (remember $table*? ;) )
 	$comments = $wp_query->comments = apply_filters( 'comments_array', $comments, $post->ID );
 	$wp_query->comment_count = count($wp_query->comments);
+	update_comment_cache($comments);
 
 	define('COMMENTS_TEMPLATE', true);
 	$include = apply_filters('comments_template', TEMPLATEPATH . $file );

wp-includes/comment.php

@@ -71,7 +71,7 @@ function get_approved_comments($post_id) {
 // Retrieves comment data given a comment ID or comment object.
 // Handles comment caching.
 function &get_comment(&$comment, $output = OBJECT) {
-	global $comment_cache, $wpdb;
+	global $wpdb;
 
 	if ( empty($comment) ) {
 		if ( isset($GLOBALS['comment']) )
@@ -79,21 +79,20 @@ function &get_comment(&$comment, $output = OBJECT) {
 		else
 			$_comment = null;
 	} elseif ( is_object($comment) ) {
-		if ( !isset($comment_cache[$comment->comment_ID]) )
-			$comment_cache[$comment->comment_ID] = &$comment;
-		$_comment = & $comment_cache[$comment->comment_ID];
+		wp_cache_add($comment->comment_ID, $comment, 'comment');
+		$_comment = $comment;
 	} else {
 		$comment = (int) $comment;
 		if ( isset($GLOBALS['comment']) && ($GLOBALS['comment']->comment_ID == $comment) ) {
 			$_comment = & $GLOBALS['comment'];
-		} elseif ( !isset($comment_cache[$comment]) ) {
+		} elseif ( ! $_comment = wp_cache_get($comment, 'comment') ) {
 			$_comment = $wpdb->get_row("SELECT * FROM $wpdb->comments WHERE comment_ID = '$comment' LIMIT 1");
-			$comment_cache[$comment->comment_ID] = & $_comment;
-		} else {
-			$_comment = & $comment_cache[$comment];
+			wp_cache_add($_comment->comment_ID, $_comment, 'comment');
 		}
 	}
 
+	$_comment = apply_filters('get_comment', $_comment);
+
 	if ( $output == OBJECT ) {
 		return $_comment;
 	} elseif ( $output == ARRAY_A ) {
@@ -285,6 +284,8 @@ function wp_delete_comment($comment_id) {
 	if ( $post_id && $comment->comment_approved == 1 )
 		wp_update_comment_count($post_id);
 
+	clean_comment_cache($comment_id);
+
 	do_action('wp_set_comment_status', $comment_id, 'delete');
 	return true;
 }
@@ -293,15 +294,19 @@ function wp_delete_comment($comment_id) {
 function wp_get_comment_status($comment_id) {
 	global $wpdb;
 
-	$result = $wpdb->get_var("SELECT comment_approved FROM $wpdb->comments WHERE comment_ID='$comment_id' LIMIT 1");
+	$comment = get_comment($comment_id);
+	if ( !$comment )
+		return false;
 
-	if ( $result == NULL )
+	$approved = $comment->comment_approved;
+
+	if ( $approved == NULL )
 		return 'deleted';
-	elseif ( $result == '1' )
+	elseif ( $approved == '1' )
 		return 'approved';
-	elseif ( $result == '0' )
+	elseif ( $approved == '0' )
 		return 'unapproved';
-	elseif ( $result == 'spam' )
+	elseif ( $approved == 'spam' )
 		return 'spam';
 	else
 		return false;
@@ -438,9 +443,12 @@ function wp_set_comment_status($comment_id, $comment_status) {
 	if ( !$wpdb->query($query) )
 		return false;
 
+	clean_comment_cache($comment_id);
+
 	do_action('wp_set_comment_status', $comment_id, $comment_status);
 	$comment = get_comment($comment_id);
 	wp_update_comment_count($comment->comment_post_ID);
+
 	return true;
 }
 
@@ -479,6 +487,8 @@ function wp_update_comment($commentarr) {
 		WHERE comment_ID = $comment_ID" );
 
 	$rval = $wpdb->rows_affected;
+
+	clean_comment_cache($comment_ID);
 	wp_update_comment_count($comment_post_ID);
 	do_action('edit_comment', $comment_ID);
 	return $rval;
@@ -793,4 +803,17 @@ function weblog_ping($server = '', $path = '') {
 		$client->query('weblogUpdates.ping', get_option('blogname'), $home);
 }
 
+//
+// Cache
+//
+
+function clean_comment_cache($id) {
+	wp_cache_delete($id, 'comment');
+}
+
+function update_comment_cache($comments) {
+	foreach ( $comments as $comment )
+		wp_cache_add($comment->comment_ID, $comment, 'comment');
+}
+
 ?>