Update to MediaWiki 1.24.1

1 files changed, 350 insertions, 0 deletions

diff --git a/includes/jobqueue/JobRunner.php b/includes/jobqueue/JobRunner.php
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+++ b/includes/jobqueue/JobRunner.php
@@ -0,0 +1,350 @@
+<?php
+/**
+ * Job queue runner utility methods
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup JobQueue
+ */
+
+/**
+ * Job queue runner utility methods
+ *
+ * @ingroup JobQueue
+ * @since 1.24
+ */
+class JobRunner {
+	/** @var callable|null Debug output handler */
+	protected $debug;
+
+	/**
+	 * @param callable $debug Optional debug output handler
+	 */
+	public function setDebugHandler( $debug ) {
+		$this->debug = $debug;
+	}
+
+	/**
+	 * Run jobs of the specified number/type for the specified time
+	 *
+	 * The response map has a 'job' field that lists status of each job, including:
+	 *   - type   : the job type
+	 *   - status : ok/failed
+	 *   - error  : any error message string
+	 *   - time   : the job run time in ms
+	 * The response map also has:
+	 *   - backoffs : the (job type => seconds) map of backoff times
+	 *   - elapsed  : the total time spent running tasks in ms
+	 *   - reached  : the reason the script finished, one of (none-ready, job-limit, time-limit)
+	 *
+	 * This method outputs status information only if a debug handler was set.
+	 * Any exceptions are caught and logged, but are not reported as output.
+	 *
+	 * @param array $options Map of parameters:
+	 *    - type     : the job type (or false for the default types)
+	 *    - maxJobs  : maximum number of jobs to run
+	 *    - maxTime  : maximum time in seconds before stopping
+	 *    - throttle : whether to respect job backoff configuration
+	 * @return array Summary response that can easily be JSON serialized
+	 */
+	public function run( array $options ) {
+		$response = array( 'jobs' => array(), 'reached' => 'none-ready' );
+
+		$type = isset( $options['type'] ) ? $options['type'] : false;
+		$maxJobs = isset( $options['maxJobs'] ) ? $options['maxJobs'] : false;
+		$maxTime = isset( $options['maxTime'] ) ? $options['maxTime'] : false;
+		$noThrottle = isset( $options['throttle'] ) && !$options['throttle'];
+
+		$group = JobQueueGroup::singleton();
+		// Handle any required periodic queue maintenance
+		$count = $group->executeReadyPeriodicTasks();
+		if ( $count > 0 ) {
+			$this->runJobsLog( "Executed $count periodic queue task(s)." );
+		}
+
+		// Flush any pending DB writes for sanity
+		wfGetLBFactory()->commitMasterChanges();
+
+		// Some jobs types should not run until a certain timestamp
+		$backoffs = array(); // map of (type => UNIX expiry)
+		$backoffDeltas = array(); // map of (type => seconds)
+		$wait = 'wait'; // block to read backoffs the first time
+
+		$jobsRun = 0;
+		$timeMsTotal = 0;
+		$flags = JobQueueGroup::USE_CACHE;
+		$startTime = microtime( true ); // time since jobs started running
+		$lastTime = microtime( true ); // time since last slave check
+		do {
+			// Sync the persistent backoffs with concurrent runners
+			$backoffs = $this->syncBackoffDeltas( $backoffs, $backoffDeltas, $wait );
+			$blacklist = $noThrottle ? array() : array_keys( $backoffs );
+			$wait = 'nowait'; // less important now
+
+			if ( $type === false ) {
+				$job = $group->pop( JobQueueGroup::TYPE_DEFAULT, $flags, $blacklist );
+			} elseif ( in_array( $type, $blacklist ) ) {
+				$job = false; // requested queue in backoff state
+			} else {
+				$job = $group->pop( $type ); // job from a single queue
+			}
+
+			if ( $job ) { // found a job
+				$jType = $job->getType();
+
+				// Back off of certain jobs for a while (for throttling and for errors)
+				$ttw = $this->getBackoffTimeToWait( $job );
+				if ( $ttw > 0 ) {
+					// Always add the delta for other runners in case the time running the
+					// job negated the backoff for each individually but not collectively.
+					$backoffDeltas[$jType] = isset( $backoffDeltas[$jType] )
+						? $backoffDeltas[$jType] + $ttw
+						: $ttw;
+					$backoffs = $this->syncBackoffDeltas( $backoffs, $backoffDeltas, $wait );
+				}
+
+				$this->runJobsLog( $job->toString() . " STARTING" );
+
+				// Run the job...
+				wfProfileIn( __METHOD__ . '-' . get_class( $job ) );
+				$jobStartTime = microtime( true );
+				try {
+					++$jobsRun;
+					$status = $job->run();
+					$error = $job->getLastError();
+					wfGetLBFactory()->commitMasterChanges();
+				} catch ( MWException $e ) {
+					MWExceptionHandler::rollbackMasterChangesAndLog( $e );
+					$status = false;
+					$error = get_class( $e ) . ': ' . $e->getMessage();
+					MWExceptionHandler::logException( $e );
+				}
+				$timeMs = intval( ( microtime( true ) - $jobStartTime ) * 1000 );
+				wfProfileOut( __METHOD__ . '-' . get_class( $job ) );
+				$timeMsTotal += $timeMs;
+
+				// Mark the job as done on success or when the job cannot be retried
+				if ( $status !== false || !$job->allowRetries() ) {
+					$group->ack( $job ); // done
+				}
+
+				// Back off of certain jobs for a while (for throttling and for errors)
+				if ( $status === false && mt_rand( 0, 49 ) == 0 ) {
+					$ttw = max( $ttw, 30 ); // too many errors
+					$backoffDeltas[$jType] = isset( $backoffDeltas[$jType] )
+						? $backoffDeltas[$jType] + $ttw
+						: $ttw;
+				}
+
+				if ( $status === false ) {
+					$this->runJobsLog( $job->toString() . " t=$timeMs error={$error}" );
+				} else {
+					$this->runJobsLog( $job->toString() . " t=$timeMs good" );
+				}
+
+				$response['jobs'][] = array(
+					'type'   => $jType,
+					'status' => ( $status === false ) ? 'failed' : 'ok',
+					'error'  => $error,
+					'time'   => $timeMs
+				);
+
+				// Break out if we hit the job count or wall time limits...
+				if ( $maxJobs && $jobsRun >= $maxJobs ) {
+					$response['reached'] = 'job-limit';
+					break;
+				} elseif ( $maxTime && ( microtime( true ) - $startTime ) > $maxTime ) {
+					$response['reached'] = 'time-limit';
+					break;
+				}
+
+				// Don't let any of the main DB slaves get backed up
+				$timePassed = microtime( true ) - $lastTime;
+				if ( $timePassed >= 5 || $timePassed < 0 ) {
+					wfWaitForSlaves( $lastTime );
+					$lastTime = microtime( true );
+				}
+				// Don't let any queue slaves/backups fall behind
+				if ( $jobsRun > 0 && ( $jobsRun % 100 ) == 0 ) {
+					$group->waitForBackups();
+				}
+
+				// Bail if near-OOM instead of in a job
+				$this->assertMemoryOK();
+			}
+		} while ( $job ); // stop when there are no jobs
+
+		// Sync the persistent backoffs for the next runJobs.php pass
+		if ( $backoffDeltas ) {
+			$this->syncBackoffDeltas( $backoffs, $backoffDeltas, 'wait' );
+		}
+
+		$response['backoffs'] = $backoffs;
+		$response['elapsed'] = $timeMsTotal;
+
+		return $response;
+	}
+
+	/**
+	 * @param Job $job
+	 * @return int Seconds for this runner to avoid doing more jobs of this type
+	 * @see $wgJobBackoffThrottling
+	 */
+	private function getBackoffTimeToWait( Job $job ) {
+		global $wgJobBackoffThrottling;
+
+		if ( !isset( $wgJobBackoffThrottling[$job->getType()] ) ||
+			$job instanceof DuplicateJob // no work was done
+		) {
+			return 0; // not throttled
+		}
+
+		$itemsPerSecond = $wgJobBackoffThrottling[$job->getType()];
+		if ( $itemsPerSecond <= 0 ) {
+			return 0; // not throttled
+		}
+
+		$seconds = 0;
+		if ( $job->workItemCount() > 0 ) {
+			$exactSeconds = $job->workItemCount() / $itemsPerSecond;
+			// use randomized rounding
+			$seconds = floor( $exactSeconds );
+			$remainder = $exactSeconds - $seconds;
+			$seconds += ( mt_rand() / mt_getrandmax() < $remainder ) ? 1 : 0;
+		}
+
+		return (int)$seconds;
+	}
+
+	/**
+	 * Get the previous backoff expiries from persistent storage
+	 * On I/O or lock acquisition failure this returns the original $backoffs.
+	 *
+	 * @param array $backoffs Map of (job type => UNIX timestamp)
+	 * @param string $mode Lock wait mode - "wait" or "nowait"
+	 * @return array Map of (job type => backoff expiry timestamp)
+	 */
+	private function loadBackoffs( array $backoffs, $mode = 'wait' ) {
+		$section = new ProfileSection( __METHOD__ );
+
+		$file = wfTempDir() . '/mw-runJobs-backoffs.json';
+		if ( is_file( $file ) ) {
+			$noblock = ( $mode === 'nowait' ) ? LOCK_NB : 0;
+			$handle = fopen( $file, 'rb' );
+			if ( !flock( $handle, LOCK_SH | $noblock ) ) {
+				fclose( $handle );
+				return $backoffs; // don't wait on lock
+			}
+			$content = stream_get_contents( $handle );
+			flock( $handle, LOCK_UN );
+			fclose( $handle );
+			$ctime = microtime( true );
+			$cBackoffs = json_decode( $content, true ) ?: array();
+			foreach ( $cBackoffs as $type => $timestamp ) {
+				if ( $timestamp < $ctime ) {
+					unset( $cBackoffs[$type] );
+				}
+			}
+		} else {
+			$cBackoffs = array();
+		}
+
+		return $cBackoffs;
+	}
+
+	/**
+	 * Merge the current backoff expiries from persistent storage
+	 *
+	 * The $deltas map is set to an empty array on success.
+	 * On I/O or lock acquisition failure this returns the original $backoffs.
+	 *
+	 * @param array $backoffs Map of (job type => UNIX timestamp)
+	 * @param array $deltas Map of (job type => seconds)
+	 * @param string $mode Lock wait mode - "wait" or "nowait"
+	 * @return array The new backoffs account for $backoffs and the latest file data
+	 */
+	private function syncBackoffDeltas( array $backoffs, array &$deltas, $mode = 'wait' ) {
+		$section = new ProfileSection( __METHOD__ );
+
+		if ( !$deltas ) {
+			return $this->loadBackoffs( $backoffs, $mode );
+		}
+
+		$noblock = ( $mode === 'nowait' ) ? LOCK_NB : 0;
+		$file = wfTempDir() . '/mw-runJobs-backoffs.json';
+		$handle = fopen( $file, 'wb+' );
+		if ( !flock( $handle, LOCK_EX | $noblock ) ) {
+			fclose( $handle );
+			return $backoffs; // don't wait on lock
+		}
+		$ctime = microtime( true );
+		$content = stream_get_contents( $handle );
+		$cBackoffs = json_decode( $content, true ) ?: array();
+		foreach ( $deltas as $type => $seconds ) {
+			$cBackoffs[$type] = isset( $cBackoffs[$type] ) && $cBackoffs[$type] >= $ctime
+				? $cBackoffs[$type] + $seconds
+				: $ctime + $seconds;
+		}
+		foreach ( $cBackoffs as $type => $timestamp ) {
+			if ( $timestamp < $ctime ) {
+				unset( $cBackoffs[$type] );
+			}
+		}
+		ftruncate( $handle, 0 );
+		fwrite( $handle, json_encode( $cBackoffs ) );
+		flock( $handle, LOCK_UN );
+		fclose( $handle );
+
+		$deltas = array();
+
+		return $cBackoffs;
+	}
+
+	/**
+	 * Make sure that this script is not too close to the memory usage limit.
+	 * It is better to die in between jobs than OOM right in the middle of one.
+	 * @throws MWException
+	 */
+	private function assertMemoryOK() {
+		static $maxBytes = null;
+		if ( $maxBytes === null ) {
+			$m = array();
+			if ( preg_match( '!^(\d+)(k|m|g|)$!i', ini_get( 'memory_limit' ), $m ) ) {
+				list( , $num, $unit ) = $m;
+				$conv = array( 'g' => 1073741824, 'm' => 1048576, 'k' => 1024, '' => 1 );
+				$maxBytes = $num * $conv[strtolower( $unit )];
+			} else {
+				$maxBytes = 0;
+			}
+		}
+		$usedBytes = memory_get_usage();
+		if ( $maxBytes && $usedBytes >= 0.95 * $maxBytes ) {
+			throw new MWException( "Detected excessive memory usage ($usedBytes/$maxBytes)." );
+		}
+	}
+
+	/**
+	 * Log the job message
+	 * @param string $msg The message to log
+	 */
+	private function runJobsLog( $msg ) {
+		if ( $this->debug ) {
+			call_user_func_array( $this->debug, array( wfTimestamp( TS_DB ) . " $msg\n" ) );
+		}
+		wfDebugLog( 'runJobs', $msg );
+	}
+}