From: jenkins-bot <jenkins-bot@gerrit.wikimedia.org>
Date: Mon, 23 Apr 2018 20:00:14 +0000 (+0000)
Subject: Merge "Avoid locking aggregated SELECT in Category::refresh"
X-Git-Tag: 1.34.0-rc.0~5635
X-Git-Url: https://git.cyclocoop.org/%7B%24admin_url%7Dmembres/modifier.php?a=commitdiff_plain;h=172925ae62e912c1e5484c05473662a45f0055ef;hp=93da7b630b1990879072912ef7b37cd2bc23f100;p=lhc%2Fweb%2Fwiklou.git

Merge "Avoid locking aggregated SELECT in Category::refresh"
---

diff --git a/includes/Category.php b/includes/Category.php
index 6104b8a65a..46b86d8cd8 100644
--- a/includes/Category.php
+++ b/includes/Category.php
@@ -335,18 +335,28 @@ class Category {
 
 		$dbw->startAtomic( __METHOD__ );
 
-		$cond1 = $dbw->conditional( [ 'page_namespace' => NS_CATEGORY ], 1, 'NULL' );
-		$cond2 = $dbw->conditional( [ 'page_namespace' => NS_FILE ], 1, 'NULL' );
-		$result = $dbw->selectRow(
+		// Lock all the `categorylinks` records and gaps for this category;
+		// this is a separate query due to postgres/oracle limitations
+		$dbw->selectRowCount(
 			[ 'categorylinks', 'page' ],
-			[ 'pages' => 'COUNT(*)',
-				'subcats' => "COUNT($cond1)",
-				'files' => "COUNT($cond2)"
-			],
+			'*',
 			[ 'cl_to' => $this->mName, 'page_id = cl_from' ],
 			__METHOD__,
 			[ 'LOCK IN SHARE MODE' ]
 		);
+		// Get the aggregate `categorylinks` row counts for this category
+		$catCond = $dbw->conditional( [ 'page_namespace' => NS_CATEGORY ], 1, 'NULL' );
+		$fileCond = $dbw->conditional( [ 'page_namespace' => NS_FILE ], 1, 'NULL' );
+		$result = $dbw->selectRow(
+			[ 'categorylinks', 'page' ],
+			[
+				'pages' => 'COUNT(*)',
+				'subcats' => "COUNT($catCond)",
+				'files' => "COUNT($fileCond)"
+			],
+			[ 'cl_to' => $this->mName, 'page_id = cl_from' ],
+			__METHOD__
+		);
 
 		$shouldExist = $result->pages > 0 || $this->getTitle()->exists();