includes/deferred/DeferredUpdatesScopeMediaWikiStack.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 use MediaWiki\MediaWikiServices;
  22 use Wikimedia\Rdbms\DBTransactionError;
  23
  24 /**
  25  * This class decouples DeferredUpdates's awareness of MediaWikiServices to ease unit testing.
  26  *
  27  * NOTE: As a process-level utility, it is important that MediaWikiServices::getInstance() is
  28  * referenced explicitly each time, so as to not cache potentially stale references.
  29  * For example after the Installer, or MediaWikiIntegrationTestCase, replace the service container.
  30  *
  31  * @internal For use by DeferredUpdates only
  32  * @since 1.41
  33  */
  34 class DeferredUpdatesScopeMediaWikiStack extends DeferredUpdatesScopeStack {
  35
  36         private function areDatabaseTransactionsActive(): bool {
  37                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
  38                 if ( $lbFactory->hasTransactionRound()
  39                         || !$lbFactory->isReadyForRoundOperations()
  40                 ) {
  41                         return true;
  42                 }
  43
  44                 foreach ( $lbFactory->getAllLBs() as $lb ) {
  45                         if ( $lb->hasPrimaryChanges() || $lb->explicitTrxActive() ) {
  46                                 return true;
  47                         }
  48                 }
  49
  50                 return false;
  51         }
  52
  53         public function allowOpportunisticUpdates(): bool {
  54                 global $wgCommandLineMode;
  55
  56                 if ( !$wgCommandLineMode ) {
  57                         // In web req
  58                         return false;
  59                 }
  60
  61                 // Run the updates only if they will have outer transaction scope
  62                 if ( $this->areDatabaseTransactionsActive() ) {
  63                         // transaction round is active or connection is not ready for commit()
  64                         return false;
  65                 }
  66
  67                 return true;
  68         }
  69
  70         public function queueDataUpdate( EnqueueableDataUpdate $update ): void {
  71                 $spec = $update->getAsJobSpecification();
  72                 $jobQueueGroupFactory = MediaWikiServices::getInstance()->getJobQueueGroupFactory();
  73                 $jobQueueGroupFactory->makeJobQueueGroup( $spec['domain'] )->push( $spec['job'] );
  74         }
  75
  76         public function onRunUpdateStart( DeferrableUpdate $update ): void {
  77                 global $wgCommandLineMode;
  78
  79                 // Increment a counter metric
  80                 $type = get_class( $update )
  81                         . ( $update instanceof DeferrableCallback ? '_' . $update->getOrigin() : '' );
  82                 $httpMethod = $wgCommandLineMode ? 'cli' : strtolower( $_SERVER['REQUEST_METHOD'] ?? 'GET' );
  83                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
  84                 $stats->increment( "deferred_updates.$httpMethod.$type" );
  85
  86                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
  87                 $ticket = $lbFactory->getEmptyTransactionTicket( __METHOD__ );
  88                 if ( !$ticket || $lbFactory->hasTransactionRound() ) {
  89                         throw new DBTransactionError( null, "A database transaction round is pending." );
  90                 }
  91
  92                 if ( $update instanceof DataUpdate ) {
  93                         $update->setTransactionTicket( $ticket );
  94                 }
  95
  96                 // Designate $update::doUpdate() as the write round owner
  97                 $fnameTrxOwner = ( $update instanceof DeferrableCallback )
  98                         ? $update->getOrigin()
  99                         : get_class( $update ) . '::doUpdate';
 100
 101                 // Determine whether the write round will be explicit or implicit
 102                 $useExplicitTrxRound = !(
 103                         $update instanceof TransactionRoundAwareUpdate &&
 104                         $update->getTransactionRoundRequirement() == $update::TRX_ROUND_ABSENT
 105                 );
 106
 107                 // Ensure any stale repeatable-read snapshot on the primary DB have been flushed
 108                 // before running the update. E.g. left-over from an implicit transaction round
 109                 if ( $useExplicitTrxRound ) {
 110                         // new explicit round
 111                         $lbFactory->beginPrimaryChanges( $fnameTrxOwner );
 112                 } else {
 113                         // new implicit round
 114                         $lbFactory->commitPrimaryChanges( $fnameTrxOwner );
 115                 }
 116         }
 117
 118         public function onRunUpdateEnd( DeferrableUpdate $update ): void {
 119                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
 120
 121                 $fnameTrxOwner = ( $update instanceof DeferrableCallback )
 122                         ? $update->getOrigin()
 123                         : get_class( $update ) . '::doUpdate';
 124
 125                 // Commit any pending changes from the explicit or implicit transaction round
 126                 $lbFactory->commitPrimaryChanges( $fnameTrxOwner );
 127         }
 128
 129         public function onRunUpdateFailed( DeferrableUpdate $update ): void {
 130                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
 131                 $lbFactory->rollbackPrimaryChanges( __METHOD__ );
 132         }
 133 }