X-Git-Url: https://git.heureux-cyclage.org/?a=blobdiff_plain;f=includes%2Fjob%2FJobQueue.php;h=9c152cdf693960d6d52fc34d06827a4770f2e911;hb=0f22a50c909662e7a88af2e8603cd7a16d7b7183;hp=7ce654b3bead128ba84ea2d2b323d671319a745f;hpb=4feea6a4ec1fe0a1f7a2518d89c293fdb2df5f22;p=lhc%2Fweb%2Fwiklou.git

diff --git a/includes/job/JobQueue.php b/includes/job/JobQueue.php
index 7ce654b3be..9c152cdf69 100644
--- a/includes/job/JobQueue.php
+++ b/includes/job/JobQueue.php
@@ -33,39 +33,59 @@ abstract class JobQueue {
 	protected $type; // string; job type
 	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
 
-	const MAX_ATTEMPTS = 3; // integer; number of times to try a job
+	const ROOTJOB_TTL = 2419200; // integer; seconds to remember root jobs (28 days)
 
 	/**
 	 * @param $params array
 	 */
 	protected function __construct( array $params ) {
-		$this->wiki     = $params['wiki'];
-		$this->type     = $params['type'];
-		$this->order    = isset( $params['order'] ) ? $params['order'] : 'random';
+		$this->wiki = $params['wiki'];
+		$this->type = $params['type'];
 		$this->claimTTL = isset( $params['claimTTL'] ) ? $params['claimTTL'] : 0;
+		$this->maxTries = isset( $params['maxTries'] ) ? $params['maxTries'] : 3;
+		if ( isset( $params['order'] ) && $params['order'] !== 'any' ) {
+			$this->order = $params['order'];
+		} else {
+			$this->order = $this->optimalOrder();
+		}
+		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." );
+		}
 	}
 
 	/**
 	 * 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. This might be
-	 *                useful for improving concurrency depending on the queue storage medium.
-	 *   - 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.
 	 *
@@ -100,9 +120,38 @@ abstract class JobQueue {
 	}
 
 	/**
-	 * Quickly check if the queue is empty (has no available jobs).
+	 * @return string One of (random, timestamp, fifo)
+	 */
+	final public function getOrder() {
+		return $this->order;
+	}
+
+	/**
+	 * @return Array Subset of (random, timestamp, fifo)
+	 */
+	abstract protected function supportedOrders();
+
+	/**
+	 * @return string One of (random, timestamp, fifo)
+	 */
+	abstract protected function optimalOrder();
+
+	/**
+	 * @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.
+	 * If pop() is called and returns false then it should correct the cache. Also,
+	 * calling flushCaches() first prevents this. However, this affect is typically
+	 * not distinguishable from the race condition between isEmpty() and pop().
+	 *
 	 * @return bool
 	 * @throws MWException
 	 */
@@ -120,9 +169,11 @@ abstract class JobQueue {
 	abstract protected function doIsEmpty();
 
 	/**
-	 * Get the number of available 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
 	 */
@@ -143,6 +194,8 @@ abstract class JobQueue {
 	 * Get the number of acquired 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 MWException
 	 */
@@ -159,9 +212,35 @@ 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 MWException
+	 * @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
+	}
+
 	/**
 	 * 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)
@@ -169,26 +248,34 @@ abstract class JobQueue {
 	 * @throws MWException
 	 */
 	final public function push( $jobs, $flags = 0 ) {
-		$jobs = is_array( $jobs ) ? $jobs : array( $jobs );
-
-		return $this->batchPush( $jobs, $flags );
+		return $this->batchPush( is_array( $jobs ) ? $jobs : array( $jobs ), $flags );
 	}
 
 	/**
 	 * Push a batch of 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 array List of Jobs
+	 * @param array $jobs List of Jobs
 	 * @param $flags integer Bitfield (supports JobQueue::QoS_Atomic)
 	 * @return bool Returns false on failure
 	 * @throws MWException
 	 */
 	final public function batchPush( array $jobs, $flags = 0 ) {
+		if ( !count( $jobs ) ) {
+			return true; // nothing to do
+		}
+
 		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." );
 			}
 		}
+
 		wfProfileIn( __METHOD__ );
 		$ok = $this->doBatchPush( $jobs, $flags );
 		wfProfileOut( __METHOD__ );
@@ -204,8 +291,9 @@ abstract class JobQueue {
 	/**
 	 * Pop a job off of the queue.
 	 * This requires $wgJobClasses to be set for the given job type.
+	 * Outside callers should use JobQueueGroup::pop() instead of this function.
 	 *
-	 * @return Job|bool Returns false on failure
+	 * @return Job|bool Returns false if there are no jobs
 	 * @throws MWException
 	 */
 	final public function pop() {
@@ -221,6 +309,15 @@ 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 ) ) {
+				wfIncrStats( 'job-pop-duplicate' );
+				$job = DuplicateJob::newFromJob( $job ); // convert to a no-op
+			}
+		} catch ( MWException $e ) {} // don't lose jobs over this
+
 		return $job;
 	}
 
@@ -234,6 +331,7 @@ abstract class JobQueue {
 	 * Acknowledge that a job was completed.
 	 *
 	 * This does nothing for certain queue classes or if "claimTTL" is not set.
+	 * Outside callers should use JobQueueGroup::ack() instead of this function.
 	 *
 	 * @param $job Job
 	 * @return bool
@@ -302,7 +400,76 @@ abstract class JobQueue {
 	 * @return bool
 	 */
 	protected function doDeduplicateRootJob( Job $job ) {
-		return true;
+		global $wgMemc;
+
+		$params = $job->getParams();
+		if ( !isset( $params['rootJobSignature'] ) ) {
+			throw new MWException( "Cannot register root job; missing 'rootJobSignature'." );
+		} elseif ( !isset( $params['rootJobTimestamp'] ) ) {
+			throw new MWException( "Cannot register root job; missing 'rootJobTimestamp'." );
+		}
+		$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 = $wgMemc->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 $wgMemc->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 MWException
+	 */
+	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 ) {
+		global $wgMemc;
+
+		$params = $job->getParams();
+		if ( !isset( $params['rootJobSignature'] ) ) {
+			return false; // job has no de-deplication info
+		} elseif ( !isset( $params['rootJobTimestamp'] ) ) {
+			trigger_error( "Cannot check root job; missing 'rootJobTimestamp'." );
+			return false;
+		}
+
+		// Get the last time this root job was enqueued
+		$timestamp = $wgMemc->get( $this->getRootJobCacheKey( $params['rootJobSignature'] ) );
+
+		// 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 );
 	}
 
 	/**
@@ -369,4 +536,37 @@ abstract class JobQueue {
 	 * @return void
 	 */
 	protected function doFlushCaches() {}
+
+	/**
+	 * Get an iterator to traverse over all available jobs in this queue.
+	 * This does not include jobs that are currently acquired or delayed.
+	 * This should only be called on a queue that is no longer being popped.
+	 *
+	 * @return Iterator|Traversable|Array
+	 * @throws MWException
+	 */
+	abstract public function getAllQueuedJobs();
+
+	/**
+	 * Get an iterator to traverse over all delayed jobs in this queue.
+	 * This should only be called on a queue that is no longer being popped.
+	 *
+	 * @return Iterator|Traversable|Array
+	 * @throws MWException
+	 * @since 1.22
+	 */
+	public function getAllDelayedJobs() {
+		return array(); // not implemented
+	}
+
+	/**
+	 * Namespace the queue with a key to isolate it for testing
+	 *
+	 * @param $key string
+	 * @return void
+	 * @throws MWException
+	 */
+	public function setTestingPrefix( $key ) {
+		throw new MWException( "Queue namespacing not supported for this queue type." );
+	}
 }