From 1d0c189f214183538054e647fddfc63b24500079 Mon Sep 17 00:00:00 2001
From: Jonny Harris <spacedmonkey@git.wordpress.org>
Date: Thu, 31 Mar 2022 09:07:02 +0000
Subject: [PATCH] Comments: Improve performance of the `wp_count_comments`
 function.

Improve performance of the `wp_count_comments` function by replacing a complex query with multiple calls to the `get_comments` function. Passing the `count` parameter to the `get_comments` function results in a simple
count query that returns quickly. Using `get_comments` also means that query is cached and run through filters.


Props FolioVision, markjaquith, nacin, ryan, coffee2code, wonderboymusic, ComputerGuru, jb510, SergeyBiryukov, Znuff, Rahe, uday17035, spacedmonkey, peterwilsoncc.
Fixes #19901.



git-svn-id: https://develop.svn.wordpress.org/trunk@53036 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/comment.php                   | 60 ++++++----------
 .../phpunit/tests/comment/getCommentCount.php | 70 +++++++++++++++++++
 2 files changed, 90 insertions(+), 40 deletions(-)

diff --git a/src/wp-includes/comment.php b/src/wp-includes/comment.php
index 6d83b762b7..50e0082283 100644
--- a/src/wp-includes/comment.php
+++ b/src/wp-includes/comment.php
@@ -383,21 +383,6 @@ function get_comment_count( $post_id = 0 ) {
 
 	$post_id = (int) $post_id;
 
-	$where = '';
-	if ( $post_id > 0 ) {
-		$where = $wpdb->prepare( 'WHERE comment_post_ID = %d', $post_id );
-	}
-
-	$totals = (array) $wpdb->get_results(
-		"
-		SELECT comment_approved, COUNT( * ) AS total
-		FROM {$wpdb->comments}
-		{$where}
-		GROUP BY comment_approved
-	",
-		ARRAY_A
-	);
-
 	$comment_count = array(
 		'approved'            => 0,
 		'awaiting_moderation' => 0,
@@ -408,32 +393,27 @@ function get_comment_count( $post_id = 0 ) {
 		'all'                 => 0,
 	);
 
-	foreach ( $totals as $row ) {
-		switch ( $row['comment_approved'] ) {
-			case 'trash':
-				$comment_count['trash'] = $row['total'];
-				break;
-			case 'post-trashed':
-				$comment_count['post-trashed'] = $row['total'];
-				break;
-			case 'spam':
-				$comment_count['spam']            = $row['total'];
-				$comment_count['total_comments'] += $row['total'];
-				break;
-			case '1':
-				$comment_count['approved']        = $row['total'];
-				$comment_count['total_comments'] += $row['total'];
-				$comment_count['all']            += $row['total'];
-				break;
-			case '0':
-				$comment_count['awaiting_moderation'] = $row['total'];
-				$comment_count['total_comments']     += $row['total'];
-				$comment_count['all']                += $row['total'];
-				break;
-			default:
-				break;
-		}
+	$args = array(
+		'count'                     => true,
+		'update_comment_meta_cache' => false,
+	);
+	if ( $post_id > 0 ) {
+		$args['post_id'] = $post_id;
 	}
+	$mapping       = array(
+		'approved'            => 'approve',
+		'awaiting_moderation' => 'hold',
+		'spam'                => 'spam',
+		'trash'               => 'trash',
+		'post-trashed'        => 'post-trashed',
+	);
+	$comment_count = array();
+	foreach ( $mapping as $key => $value ) {
+		$comment_count[ $key ] = get_comments( array_merge( $args, array( 'status' => $value ) ) );
+	}
+
+	$comment_count['all']            = $comment_count['approved'] + $comment_count['awaiting_moderation'];
+	$comment_count['total_comments'] = $comment_count['all'] + $comment_count['spam'];
 
 	return array_map( 'intval', $comment_count );
 }
diff --git a/tests/phpunit/tests/comment/getCommentCount.php b/tests/phpunit/tests/comment/getCommentCount.php
index 7b3ede5f35..7fe6b2aa31 100644
--- a/tests/phpunit/tests/comment/getCommentCount.php
+++ b/tests/phpunit/tests/comment/getCommentCount.php
@@ -11,6 +11,7 @@ class Tests_Get_Comment_Count extends WP_UnitTestCase {
 		$this->assertSame( 0, $count['trash'] );
 		$this->assertSame( 0, $count['post-trashed'] );
 		$this->assertSame( 0, $count['total_comments'] );
+		$this->assertSame( 0, $count['all'] );
 	}
 
 	public function test_get_comment_count_approved() {
@@ -97,4 +98,73 @@ class Tests_Get_Comment_Count extends WP_UnitTestCase {
 		$this->assertSame( 1, $count['post-trashed'] );
 		$this->assertSame( 0, $count['total_comments'] );
 	}
+
+	/**
+	 * @ticket 19901
+	 *
+	 * @covers ::get_comment_count
+	 */
+	public function test_get_comment_count_validate_cache_comment_deleted() {
+
+		$comment_id = self::factory()->comment->create();
+
+		$count = get_comment_count();
+
+		$this->assertSame( 1, $count['total_comments'] );
+
+		wp_delete_comment( $comment_id, true );
+
+		$count = get_comment_count();
+
+		$this->assertSame( 0, $count['total_comments'] );
+	}
+
+	/**
+	 * @ticket 19901
+	 *
+	 * @covers ::get_comment_count
+	 */
+	public function test_get_comment_count_validate_cache_post_deleted() {
+
+		$post_id = self::factory()->post->create();
+
+		$comment_id = self::factory()->comment->create(
+			array(
+				'comment_post_ID' => $post_id,
+			)
+		);
+
+		$count = get_comment_count( $post_id );
+
+		$this->assertSame( 1, $count['total_comments'] );
+
+		wp_delete_post( $post_id, true );
+
+		$count = get_comment_count( $post_id );
+
+		$this->assertSame( 0, $count['total_comments'] );
+	}
+
+	/**
+	 * @ticket 19901
+	 *
+	 * @covers ::get_comment_count
+	 */
+	public function test_get_comment_count_validate_cache_comment_status() {
+		$comment_id = self::factory()->comment->create();
+
+		$count = get_comment_count();
+
+		$this->assertSame( 1, $count['approved'] );
+		$this->assertSame( 0, $count['trash'] );
+		$this->assertSame( 1, $count['total_comments'] );
+
+		wp_set_comment_status( $comment_id, 'trash' );
+
+		$count = get_comment_count();
+
+		$this->assertSame( 0, $count['approved'] );
+		$this->assertSame( 1, $count['trash'] );
+		$this->assertSame( 0, $count['total_comments'] );
+	}
 }