Update to MediaWiki 1.22.0

1 files changed, 313 insertions, 42 deletions

diff --git a/includes/job/JobQueue.php b/includes/job/JobQueue.php
index b0dd9258..6556ee85 100644
--- a/includes/job/JobQueue.php
+++ b/includes/job/JobQueue.php
@@ -34,8 +34,14 @@ abstract class JobQueue {
 	protected $order; // string; job priority for pop()
 	protected $claimTTL; // integer; seconds
 	protected $maxTries; // integer; maximum number of times to try a job
+	protected $checkDelay; // boolean; allow delayed jobs
 
-	const QoS_Atomic = 1; // integer; "all-or-nothing" job insertions
+	/** @var BagOStuff */
+	protected $dupCache;
+
+	const QOS_ATOMIC = 1; // integer; "all-or-nothing" job insertions
+
+	const ROOTJOB_TTL = 2419200; // integer; seconds to remember root jobs (28 days)
 
 	/**
 	 * @param $params array
@@ -53,28 +59,37 @@ abstract class JobQueue {
 		if ( !in_array( $this->order, $this->supportedOrders() ) ) {
 			throw new MWException( __CLASS__ . " does not support '{$this->order}' order." );
 		}
+		$this->checkDelay = !empty( $params['checkDelay'] );
+		if ( $this->checkDelay && !$this->supportsDelayedJobs() ) {
+			throw new MWException( __CLASS__ . " does not support delayed jobs." );
+		}
+		$this->dupCache = wfGetCache( CACHE_ANYTHING );
 	}
 
 	/**
 	 * Get a job queue object of the specified type.
 	 * $params includes:
-	 *   - class    : What job class to use (determines job type)
-	 *   - wiki     : wiki ID of the wiki the jobs are for (defaults to current wiki)
-	 *   - type     : The name of the job types this queue handles
-	 *   - order    : Order that pop() selects jobs, one of "fifo", "timestamp" or "random".
-	 *                If "fifo" is used, the queue will effectively be FIFO. Note that
-	 *                job completion will not appear to be exactly FIFO if there are multiple
-	 *                job runners since jobs can take different times to finish once popped.
-	 *                If "timestamp" is used, the queue will at least be loosely ordered
-	 *                by timestamp, allowing for some jobs to be popped off out of order.
-	 *                If "random" is used, pop() will pick jobs in random order.
-	 *                Note that it may only be weakly random (e.g. a lottery of the oldest X).
-	 *                If "any" is choosen, the queue will use whatever order is the fastest.
-	 *                This might be useful for improving concurrency for job acquisition.
-	 *   - claimTTL : If supported, the queue will recycle jobs that have been popped
-	 *                but not acknowledged as completed after this many seconds. Recycling
-	 *                of jobs simple means re-inserting them into the queue. Jobs can be
-	 *                attempted up to three times before being discarded.
+	 *   - class      : What job class to use (determines job type)
+	 *   - wiki       : wiki ID of the wiki the jobs are for (defaults to current wiki)
+	 *   - type       : The name of the job types this queue handles
+	 *   - order      : Order that pop() selects jobs, one of "fifo", "timestamp" or "random".
+	 *                  If "fifo" is used, the queue will effectively be FIFO. Note that job
+	 *                  completion will not appear to be exactly FIFO if there are multiple
+	 *                  job runners since jobs can take different times to finish once popped.
+	 *                  If "timestamp" is used, the queue will at least be loosely ordered
+	 *                  by timestamp, allowing for some jobs to be popped off out of order.
+	 *                  If "random" is used, pop() will pick jobs in random order.
+	 *                  Note that it may only be weakly random (e.g. a lottery of the oldest X).
+	 *                  If "any" is choosen, the queue will use whatever order is the fastest.
+	 *                  This might be useful for improving concurrency for job acquisition.
+	 *   - claimTTL   : If supported, the queue will recycle jobs that have been popped
+	 *                  but not acknowledged as completed after this many seconds. Recycling
+	 *                  of jobs simple means re-inserting them into the queue. Jobs can be
+	 *                  attempted up to three times before being discarded.
+	 *   - checkDelay : If supported, respect Job::getReleaseTimestamp() in the push functions.
+	 *                  This lets delayed jobs wait in a staging area until a given timestamp is
+	 *                  reached, at which point they will enter the queue. If this is not enabled
+	 *                  or not supported, an exception will be thrown on delayed job insertion.
 	 *
 	 * Queue classes should throw an exception if they do not support the options given.
 	 *
@@ -84,7 +99,7 @@ abstract class JobQueue {
 	 */
 	final public static function factory( array $params ) {
 		$class = $params['class'];
-		if ( !MWInit::classExists( $class ) ) {
+		if ( !class_exists( $class ) ) {
 			throw new MWException( "Invalid job queue class '$class'." );
 		}
 		$obj = new $class( $params );
@@ -109,24 +124,45 @@ abstract class JobQueue {
 	}
 
 	/**
-	 * @return string One of (random, timestamp, fifo)
+	 * @return string One of (random, timestamp, fifo, undefined)
 	 */
 	final public function getOrder() {
 		return $this->order;
 	}
 
 	/**
-	 * @return Array Subset of (random, timestamp, fifo)
+	 * @return bool Whether delayed jobs are enabled
+	 * @since 1.22
+	 */
+	final public function delayedJobsEnabled() {
+		return $this->checkDelay;
+	}
+
+	/**
+	 * Get the allowed queue orders for configuration validation
+	 *
+	 * @return Array Subset of (random, timestamp, fifo, undefined)
 	 */
 	abstract protected function supportedOrders();
 
 	/**
-	 * @return string One of (random, timestamp, fifo)
+	 * Get the default queue order to use if configuration does not specify one
+	 *
+	 * @return string One of (random, timestamp, fifo, undefined)
 	 */
 	abstract protected function optimalOrder();
 
 	/**
-	 * Quickly check if the queue is empty (has no available jobs).
+	 * Find out if delayed jobs are supported for configuration validation
+	 *
+	 * @return boolean Whether delayed jobs are supported
+	 */
+	protected function supportsDelayedJobs() {
+		return false; // not implemented
+	}
+
+	/**
+	 * Quickly check if the queue has no available (unacquired, non-delayed) jobs.
 	 * Queue classes should use caching if they are any slower without memcached.
 	 *
 	 * If caching is used, this might return false when there are actually no jobs.
@@ -135,7 +171,7 @@ abstract class JobQueue {
 	 * not distinguishable from the race condition between isEmpty() and pop().
 	 *
 	 * @return bool
-	 * @throws MWException
+	 * @throws JobQueueError
 	 */
 	final public function isEmpty() {
 		wfProfileIn( __METHOD__ );
@@ -151,13 +187,13 @@ abstract class JobQueue {
 	abstract protected function doIsEmpty();
 
 	/**
-	 * Get the number of available (unacquired) jobs in the queue.
+	 * Get the number of available (unacquired, non-delayed) jobs in the queue.
 	 * Queue classes should use caching if they are any slower without memcached.
 	 *
 	 * If caching is used, this number might be out of date for a minute.
 	 *
 	 * @return integer
-	 * @throws MWException
+	 * @throws JobQueueError
 	 */
 	final public function getSize() {
 		wfProfileIn( __METHOD__ );
@@ -179,7 +215,7 @@ abstract class JobQueue {
 	 * If caching is used, this number might be out of date for a minute.
 	 *
 	 * @return integer
-	 * @throws MWException
+	 * @throws JobQueueError
 	 */
 	final public function getAcquiredCount() {
 		wfProfileIn( __METHOD__ );
@@ -195,14 +231,63 @@ abstract class JobQueue {
 	abstract protected function doGetAcquiredCount();
 
 	/**
+	 * Get the number of delayed jobs (these are temporarily out of the queue).
+	 * Queue classes should use caching if they are any slower without memcached.
+	 *
+	 * If caching is used, this number might be out of date for a minute.
+	 *
+	 * @return integer
+	 * @throws JobQueueError
+	 * @since 1.22
+	 */
+	final public function getDelayedCount() {
+		wfProfileIn( __METHOD__ );
+		$res = $this->doGetDelayedCount();
+		wfProfileOut( __METHOD__ );
+		return $res;
+	}
+
+	/**
+	 * @see JobQueue::getDelayedCount()
+	 * @return integer
+	 */
+	protected function doGetDelayedCount() {
+		return 0; // not implemented
+	}
+
+	/**
+	 * Get the number of acquired jobs that can no longer be attempted.
+	 * Queue classes should use caching if they are any slower without memcached.
+	 *
+	 * If caching is used, this number might be out of date for a minute.
+	 *
+	 * @return integer
+	 * @throws JobQueueError
+	 */
+	final public function getAbandonedCount() {
+		wfProfileIn( __METHOD__ );
+		$res = $this->doGetAbandonedCount();
+		wfProfileOut( __METHOD__ );
+		return $res;
+	}
+
+	/**
+	 * @see JobQueue::getAbandonedCount()
+	 * @return integer
+	 */
+	protected function doGetAbandonedCount() {
+		return 0; // not implemented
+	}
+
+	/**
 	 * Push a single jobs into the queue.
 	 * This does not require $wgJobClasses to be set for the given job type.
 	 * Outside callers should use JobQueueGroup::push() instead of this function.
 	 *
 	 * @param $jobs Job|Array
-	 * @param $flags integer Bitfield (supports JobQueue::QoS_Atomic)
+	 * @param $flags integer Bitfield (supports JobQueue::QOS_ATOMIC)
 	 * @return bool Returns false on failure
-	 * @throws MWException
+	 * @throws JobQueueError
 	 */
 	final public function push( $jobs, $flags = 0 ) {
 		return $this->batchPush( is_array( $jobs ) ? $jobs : array( $jobs ), $flags );
@@ -214,9 +299,9 @@ abstract class JobQueue {
 	 * Outside callers should use JobQueueGroup::push() instead of this function.
 	 *
 	 * @param array $jobs List of Jobs
-	 * @param $flags integer Bitfield (supports JobQueue::QoS_Atomic)
+	 * @param $flags integer Bitfield (supports JobQueue::QOS_ATOMIC)
 	 * @return bool Returns false on failure
-	 * @throws MWException
+	 * @throws JobQueueError
 	 */
 	final public function batchPush( array $jobs, $flags = 0 ) {
 		if ( !count( $jobs ) ) {
@@ -225,7 +310,11 @@ abstract class JobQueue {
 
 		foreach ( $jobs as $job ) {
 			if ( $job->getType() !== $this->type ) {
-				throw new MWException( "Got '{$job->getType()}' job; expected '{$this->type}'." );
+				throw new MWException(
+					"Got '{$job->getType()}' job; expected a '{$this->type}' job." );
+			} elseif ( $job->getReleaseTimestamp() && !$this->checkDelay ) {
+				throw new MWException(
+					"Got delayed '{$job->getType()}' job; delays are not supported." );
 			}
 		}
 
@@ -247,7 +336,7 @@ abstract class JobQueue {
 	 * Outside callers should use JobQueueGroup::pop() instead of this function.
 	 *
 	 * @return Job|bool Returns false if there are no jobs
-	 * @throws MWException
+	 * @throws JobQueueError
 	 */
 	final public function pop() {
 		global $wgJobClasses;
@@ -262,6 +351,15 @@ abstract class JobQueue {
 		wfProfileIn( __METHOD__ );
 		$job = $this->doPop();
 		wfProfileOut( __METHOD__ );
+
+		// Flag this job as an old duplicate based on its "root" job...
+		try {
+			if ( $job && $this->isRootJobOldDuplicate( $job ) ) {
+				JobQueue::incrStats( 'job-pop-duplicate', $this->type );
+				$job = DuplicateJob::newFromJob( $job ); // convert to a no-op
+			}
+		} catch ( MWException $e ) {} // don't lose jobs over this
+
 		return $job;
 	}
 
@@ -279,7 +377,7 @@ abstract class JobQueue {
 	 *
 	 * @param $job Job
 	 * @return bool
-	 * @throws MWException
+	 * @throws JobQueueError
 	 */
 	final public function ack( Job $job ) {
 		if ( $job->getType() !== $this->type ) {
@@ -326,7 +424,7 @@ abstract class JobQueue {
 	 *
 	 * @param $job Job
 	 * @return bool
-	 * @throws MWException
+	 * @throws JobQueueError
 	 */
 	final public function deduplicateRootJob( Job $job ) {
 		if ( $job->getType() !== $this->type ) {
@@ -344,7 +442,91 @@ abstract class JobQueue {
 	 * @return bool
 	 */
 	protected function doDeduplicateRootJob( Job $job ) {
-		return true;
+		if ( !$job->hasRootJobParams() ) {
+			throw new MWException( "Cannot register root job; missing parameters." );
+		}
+		$params = $job->getRootJobParams();
+
+		$key = $this->getRootJobCacheKey( $params['rootJobSignature'] );
+		// Callers should call batchInsert() and then this function so that if the insert
+		// fails, the de-duplication registration will be aborted. Since the insert is
+		// deferred till "transaction idle", do the same here, so that the ordering is
+		// maintained. Having only the de-duplication registration succeed would cause
+		// jobs to become no-ops without any actual jobs that made them redundant.
+		$timestamp = $this->dupCache->get( $key ); // current last timestamp of this job
+		if ( $timestamp && $timestamp >= $params['rootJobTimestamp'] ) {
+			return true; // a newer version of this root job was enqueued
+		}
+
+		// Update the timestamp of the last root job started at the location...
+		return $this->dupCache->set( $key, $params['rootJobTimestamp'], JobQueueDB::ROOTJOB_TTL );
+	}
+
+	/**
+	 * Check if the "root" job of a given job has been superseded by a newer one
+	 *
+	 * @param $job Job
+	 * @return bool
+	 * @throws JobQueueError
+	 */
+	final protected function isRootJobOldDuplicate( Job $job ) {
+		if ( $job->getType() !== $this->type ) {
+			throw new MWException( "Got '{$job->getType()}' job; expected '{$this->type}'." );
+		}
+		wfProfileIn( __METHOD__ );
+		$isDuplicate = $this->doIsRootJobOldDuplicate( $job );
+		wfProfileOut( __METHOD__ );
+		return $isDuplicate;
+	}
+
+	/**
+	 * @see JobQueue::isRootJobOldDuplicate()
+	 * @param Job $job
+	 * @return bool
+	 */
+	protected function doIsRootJobOldDuplicate( Job $job ) {
+		if ( !$job->hasRootJobParams() ) {
+			return false; // job has no de-deplication info
+		}
+		$params = $job->getRootJobParams();
+
+		$key = $this->getRootJobCacheKey( $params['rootJobSignature'] );
+		// Get the last time this root job was enqueued
+		$timestamp = $this->dupCache->get( $key );
+
+		// Check if a new root job was started at the location after this one's...
+		return ( $timestamp && $timestamp > $params['rootJobTimestamp'] );
+	}
+
+	/**
+	 * @param string $signature Hash identifier of the root job
+	 * @return string
+	 */
+	protected function getRootJobCacheKey( $signature ) {
+		list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
+		return wfForeignMemcKey( $db, $prefix, 'jobqueue', $this->type, 'rootjob', $signature );
+	}
+
+	/**
+	 * Deleted all unclaimed and delayed jobs from the queue
+	 *
+	 * @return bool Success
+	 * @throws JobQueueError
+	 * @since 1.22
+	 */
+	final public function delete() {
+		wfProfileIn( __METHOD__ );
+		$res = $this->doDelete();
+		wfProfileOut( __METHOD__ );
+		return $res;
+	}
+
+	/**
+	 * @see JobQueue::delete()
+	 * @return bool Success
+	 */
+	protected function doDelete() {
+		throw new MWException( "This method is not implemented." );
 	}
 
 	/**
@@ -353,7 +535,7 @@ abstract class JobQueue {
 	 * This does nothing for certain queue classes.
 	 *
 	 * @return void
-	 * @throws MWException
+	 * @throws JobQueueError
 	 */
 	final public function waitForBackups() {
 		wfProfileIn( __METHOD__ );
@@ -413,16 +595,98 @@ abstract class JobQueue {
 	protected function doFlushCaches() {}
 
 	/**
-	 * Get an iterator to traverse over all of the jobs in this queue.
-	 * This does not include jobs that are current acquired. In general,
-	 * this should only be called on a queue that is no longer being popped.
+	 * Get an iterator to traverse over all available jobs in this queue.
+	 * This does not include jobs that are currently acquired or delayed.
+	 * Note: results may be stale if the queue is concurrently modified.
 	 *
-	 * @return Iterator|Traversable|Array
-	 * @throws MWException
+	 * @return Iterator
+	 * @throws JobQueueError
 	 */
 	abstract public function getAllQueuedJobs();
 
 	/**
+	 * Get an iterator to traverse over all delayed jobs in this queue.
+	 * Note: results may be stale if the queue is concurrently modified.
+	 *
+	 * @return Iterator
+	 * @throws JobQueueError
+	 * @since 1.22
+	 */
+	public function getAllDelayedJobs() {
+		return new ArrayIterator( array() ); // not implemented
+	}
+
+	/**
+	 * Do not use this function outside of JobQueue/JobQueueGroup
+	 *
+	 * @return string
+	 * @since 1.22
+	 */
+	public function getCoalesceLocationInternal() {
+		return null;
+	}
+
+	/**
+	 * Check whether each of the given queues are empty.
+	 * This is used for batching checks for queues stored at the same place.
+	 *
+	 * @param array $types List of queues types
+	 * @return array|null (list of non-empty queue types) or null if unsupported
+	 * @throws MWException
+	 * @since 1.22
+	 */
+	final public function getSiblingQueuesWithJobs( array $types ) {
+		$section = new ProfileSection( __METHOD__ );
+		return $this->doGetSiblingQueuesWithJobs( $types );
+	}
+
+	/**
+	 * @see JobQueue::getSiblingQueuesWithJobs()
+	 * @param array $types List of queues types
+	 * @return array|null (list of queue types) or null if unsupported
+	 */
+	protected function doGetSiblingQueuesWithJobs( array $types ) {
+		return null; // not supported
+	}
+
+	/**
+	 * Check the size of each of the given queues.
+	 * For queues not served by the same store as this one, 0 is returned.
+	 * This is used for batching checks for queues stored at the same place.
+	 *
+	 * @param array $types List of queues types
+	 * @return array|null (job type => whether queue is empty) or null if unsupported
+	 * @throws MWException
+	 * @since 1.22
+	 */
+	final public function getSiblingQueueSizes( array $types ) {
+		$section = new ProfileSection( __METHOD__ );
+		return $this->doGetSiblingQueueSizes( $types );
+	}
+
+	/**
+	 * @see JobQueue::getSiblingQueuesSize()
+	 * @param array $types List of queues types
+	 * @return array|null (list of queue types) or null if unsupported
+	 */
+	protected function doGetSiblingQueueSizes( array $types ) {
+		return null; // not supported
+	}
+
+	/**
+	 * Call wfIncrStats() for the queue overall and for the queue type
+	 *
+	 * @param string $key Event type
+	 * @param string $type Job type
+	 * @param integer $delta
+	 * @since 1.22
+	 */
+	public static function incrStats( $key, $type, $delta = 1 ) {
+		wfIncrStats( $key, $delta );
+		wfIncrStats( "{$key}-{$type}", $delta );
+	}
+
+	/**
 	 * Namespace the queue with a key to isolate it for testing
 	 *
 	 * @param $key string
@@ -433,3 +697,10 @@ abstract class JobQueue {
 		throw new MWException( "Queue namespacing not supported for this queue type." );
 	}
 }
+
+/**
+ * @ingroup JobQueue
+ * @since 1.22
+ */
+class JobQueueError extends MWException {}
+class JobQueueConnectionError extends JobQueueError {}