includes/deferred/AtomicSectionUpdate.php

   1 <?php
   2
   3 use Wikimedia\Rdbms\IDatabase;
   4
   5 /**
   6  * Deferrable Update for closure/callback updates via IDatabase::doAtomicSection()
   7  * @since 1.27
   8  */
   9 class AtomicSectionUpdate implements DeferrableUpdate, DeferrableCallback {
  10         /** @var IDatabase */
  11         private $dbw;
  12         /** @var string */
  13         private $fname;
  14         /** @var callable|null */
  15         private $callback;
  16
  17         /**
  18          * @param IDatabase $dbw DB handle; update aborts if a transaction now this rolls back
  19          * @param string $fname Caller name (usually __METHOD__)
  20          * @param callable $callback
  21          * @param IDatabase[] $conns Abort if a transaction now on one of these rolls back [optional]
  22          * @see IDatabase::doAtomicSection()
  23          */
  24         public function __construct( IDatabase $dbw, $fname, callable $callback, array $conns = [] ) {
  25                 $this->dbw = $dbw;
  26                 $this->fname = $fname;
  27                 $this->callback = $callback;
  28                 // Register DB connections for which uncommitted changes are related to this update
  29                 $conns[] = $dbw;
  30                 foreach ( $conns as $conn ) {
  31                         if ( $conn->trxLevel() ) {
  32                                 $conn->onTransactionResolution( [ $this, 'cancelOnRollback' ], $fname );
  33                         }
  34                 }
  35         }
  36
  37         public function doUpdate() {
  38                 if ( $this->callback ) {
  39                         $this->dbw->doAtomicSection( $this->fname, $this->callback );
  40                 }
  41         }
  42
  43         /**
  44          * @private This method is public so that it works with onTransactionResolution()
  45          * @param int $trigger
  46          */
  47         public function cancelOnRollback( $trigger ) {
  48                 if ( $trigger === IDatabase::TRIGGER_ROLLBACK ) {
  49                         $this->callback = null;
  50                 }
  51         }
  52
  53         public function getOrigin() {
  54                 return $this->fname;
  55         }
  56 }