From b27cf31bc59a146f86cfdea2ebe89ef7c778e100 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 17 Oct 2013 20:00:24 -0700
Subject: [PATCH] Small JobQueueFederated performance tweaks

* Made "find non-empty queues" and isEmpty() checks start with the most
  weighted partitions first
* Cleaned up a few exception catches to use JobQueueError
* Added short-circuit for doGetSiblingQueuesWithJobs()

Change-Id: I4d96a8c61c6b1c41dbb44000ccda0fa05a418a09
---
 includes/job/JobQueueFederated.php | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/includes/job/JobQueueFederated.php b/includes/job/JobQueueFederated.php
index fb2ef0dc25..d3ce164af9 100644
--- a/includes/job/JobQueueFederated.php
+++ b/includes/job/JobQueueFederated.php
@@ -47,9 +47,9 @@
  * @since 1.22
  */
 class JobQueueFederated extends JobQueue {
-	/** @var Array (partition name => weight) */
+	/** @var Array (partition name => weight) reverse sorted by weight */
 	protected $partitionMap = array();
-	/** @var Array (partition name => JobQueue) */
+	/** @var Array (partition name => JobQueue) reverse sorted by weight */
 	protected $partitionQueues = array();
 	/** @var HashRing */
 	protected $partitionPushRing;
@@ -82,7 +82,10 @@ class JobQueueFederated extends JobQueue {
 		if ( !isset( $params['partitionsBySection'][$section] ) ) {
 			throw new MWException( "No configuration for section '$section'." );
 		}
+		// Get the full partition map
 		$this->partitionMap = $params['partitionsBySection'][$section];
+		arsort( $this->partitionMap, SORT_NUMERIC );
+		// Get the partitions jobs can actually be pushed to
 		$partitionPushMap = $this->partitionMap;
 		if ( isset( $params['partitionsNoPush'] ) ) {
 			foreach ( $params['partitionsNoPush'] as $partition ) {
@@ -104,7 +107,7 @@ class JobQueueFederated extends JobQueue {
 			$this->partitionQueues[$partition] = JobQueue::factory(
 				$baseConfig + $params['configByPartition'][$partition] );
 		}
-		// Get the ring of partitions to push job de-duplication information into
+		// Get the ring of partitions to push jobs into
 		$this->partitionPushRing = new HashRing( $partitionPushMap );
 		// Aggregate cache some per-queue values if there are multiple partition queues
 		$this->cache = count( $this->partitionMap ) > 1 ? wfGetMainCache() : new EmptyBagOStuff();
@@ -327,7 +330,7 @@ class JobQueueFederated extends JobQueue {
 		$partitions = $this->partitionPushRing->getLocations( $params['rootJobSignature'], 2 );
 		try {
 			return $this->partitionQueues[$partitions[0]]->doIsRootJobOldDuplicate( $job );
-		} catch ( MWException $e ) {
+		} catch ( JobQueueError $e ) {
 			if ( isset( $partitions[1] ) ) { // check fallback partition
 				return $this->partitionQueues[$partitions[1]]->doIsRootJobOldDuplicate( $job );
 			}
@@ -340,7 +343,7 @@ class JobQueueFederated extends JobQueue {
 		$partitions = $this->partitionPushRing->getLocations( $params['rootJobSignature'], 2 );
 		try {
 			return $this->partitionQueues[$partitions[0]]->doDeduplicateRootJob( $job );
-		} catch ( MWException $e ) {
+		} catch ( JobQueueError $e ) {
 			if ( isset( $partitions[1] ) ) { // check fallback partition
 				return $this->partitionQueues[$partitions[1]]->doDeduplicateRootJob( $job );
 			}
@@ -421,15 +424,18 @@ class JobQueueFederated extends JobQueue {
 			try {
 				$nonEmpty = $queue->doGetSiblingQueuesWithJobs( $types );
 				if ( is_array( $nonEmpty ) ) {
-					$result = array_merge( $result, $nonEmpty );
+					$result = array_unique( array_merge( $result, $nonEmpty ) );
 				} else {
 					return null; // not supported on all partitions; bail
 				}
+				if ( count( $result ) == count( $types ) ) {
+					break; // short-circuit
+				}
 			} catch ( JobQueueError $e ) {
 				MWExceptionHandler::logException( $e );
 			}
 		}
-		return array_values( array_unique( $result ) );
+		return array_values( $result );
 	}
 
 	protected function doGetSiblingQueueSizes( array $types ) {
-- 
2.20.1