For backport to 1.14.

[lhc/web/wiklou.git] / includes / JobQueue.php

diff --git a/includes/JobQueue.php b/includes/JobQueue.php
index 5cec310..afa757d 100644 (file)
--- a/includes/JobQueue.php
+++ b/includes/JobQueue.php
@@ -1,4 +1,7 @@
 <?php
+/**
+ * @defgroup JobQueue JobQueue
+ */
 
 if ( !defined( 'MEDIAWIKI' ) ) {
        die( "This file is part of MediaWiki, it is not a valid entry point\n" );
@@ -6,6 +9,8 @@ if ( !defined( 'MEDIAWIKI' ) ) {
 
 /**
  * Class to both describe a background job and handle jobs.
+ *
+ * @ingroup JobQueue
  */
 abstract class Job {
        var $command,
@@ -37,8 +42,8 @@ abstract class Job {
         */
 
        /**
-        * Pop a job of a certain type.  This tries less hard than pop() to 
-        * actually find a job; it may be adversely affected by concurrent job 
+        * Pop a job of a certain type.  This tries less hard than pop() to
+        * actually find a job; it may be adversely affected by concurrent job
         * runners.
         */
        static function pop_type($type) {
@@ -78,7 +83,7 @@ abstract class Job {
 
        /**
         * Pop a job off the front of the queue
-        * @static
+        *
         * @param $offset Number of jobs to skip
         * @return Job or false if there's no jobs
         */
@@ -87,11 +92,11 @@ abstract class Job {
 
                $dbr = wfGetDB( DB_SLAVE );
 
-               /* Get a job from the slave, start with an offset, 
+               /* Get a job from the slave, start with an offset,
                        scan full set afterwards, avoid hitting purged rows
 
-                       NB: If random fetch previously was used, offset 
-                               will always be ahead of few entries 
+                       NB: If random fetch previously was used, offset
+                               will always be ahead of few entries
                */
 
                $row = $dbr->selectRow( 'job', '*', "job_id >= ${offset}", __METHOD__,
@@ -122,7 +127,7 @@ abstract class Job {
                        // Failed, someone else beat us to it
                        // Try getting a random row
                        $row = $dbw->selectRow( 'job', array( 'MIN(job_id) as minjob',
-                               'MAX(job_id) as maxjob' ), "job_id >= $offset", __METHOD__ );
+                               'MAX(job_id) as maxjob' ), '1=1', __METHOD__ );
                        if ( $row === false || is_null( $row->minjob ) || is_null( $row->maxjob ) ) {
                                // No jobs to get
                                wfProfileOut( __METHOD__ );
@@ -158,7 +163,10 @@ abstract class Job {
                $job = Job::factory( $row->job_cmd, $title, Job::extractBlob( $row->job_params ), $row->job_id );
 
                // Remove any duplicates it may have later in the queue
+               // Deadlock prone section
+               $dbw->begin();
                $dbw->delete( 'job', $job->insertFields(), __METHOD__ );
+               $dbw->commit();
 
                wfProfileOut( __METHOD__ );
                return $job;
@@ -167,10 +175,10 @@ abstract class Job {
        /**
         * Create the appropriate object to handle a specific job
         *
-        * @param string $command Job command
-        * @param Title $title Associated title
-        * @param array $params Job parameters
-        * @param int $id Job identifier
+        * @param $command String: Job command
+        * @param $title Title: Associated title
+        * @param $params Array: Job parameters
+        * @param $id Int: Job identifier
         * @return Job
         */
        static function factory( $command, $title, $params = false, $id = 0 ) {
@@ -181,7 +189,7 @@ abstract class Job {
                }
                throw new MWException( "Invalid job command `{$command}`" );
        }
-               
+
        static function makeBlob( $params ) {
                if ( $params !== false ) {
                        return serialize( $params );
@@ -208,12 +216,23 @@ abstract class Job {
         * @param $jobs array of Job objects
         */
        static function batchInsert( $jobs ) {
-               if( count( $jobs ) ) {
-                       $dbw = wfGetDB( DB_MASTER );
-                       $dbw->begin();
-                       foreach( $jobs as $job ) {
-                               $rows[] = $job->insertFields();
+               if( !count( $jobs ) ) {
+                       return;
+               }
+               $dbw = wfGetDB( DB_MASTER );
+               $rows = array();
+               foreach( $jobs as $job ) {
+                       $rows[] = $job->insertFields();
+                       if ( count( $rows ) >= 50 ) {
+                               # Do a small transaction to avoid slave lag
+                               $dbw->begin();
+                               $dbw->insert( 'job', $rows, __METHOD__, 'IGNORE' );
+                               $dbw->commit();
+                               $rows = array();
                        }
+               }
+               if ( $rows ) {
+                       $dbw->begin();
                        $dbw->insert( 'job', $rows, __METHOD__, 'IGNORE' );
                        $dbw->commit();
                }
@@ -283,9 +302,11 @@ abstract class Job {
                }
        }
 
+       protected function setLastError( $error ) {
+               $this->error = $error;
+       }
+
        function getLastError() {
                return $this->error;
        }
 }
-
-