includes/DeferredUpdates.php

   1 <?php
   2 /**
   3  * Interface that deferrable updates should implement. Basically required so we
   4  * can validate input on DeferredUpdates::addUpdate()
   5  *
   6  * @since 1.19
   7  */
   8 interface DeferrableUpdate {
   9         /**
  10          * Perform the actual work
  11          */
  12         function doUpdate();
  13 }
  14
  15 /**
  16  * Class for mananging the deferred updates.
  17  *
  18  * @since 1.19
  19  */
  20 class DeferredUpdates {
  21         /**
  22          * Store of updates to be deferred until the end of the request.
  23          */
  24         private static $updates = array();
  25
  26         /**
  27          * Add an update to the deferred list
  28          * @param $update DeferrableUpdate Some object that implements doUpdate()
  29          */
  30         public static function addUpdate( DeferrableUpdate $update ) {
  31                 array_push( self::$updates, $update );
  32         }
  33
  34         /**
  35          * HTMLCacheUpdates are the most common deferred update people use. This
  36          * is a shortcut method for that.
  37          * @see HTMLCacheUpdate::__construct()
  38          * @param $title
  39          * @param $table
  40          */
  41         public static function addHTMLCacheUpdate( $title, $table ) {
  42                 self::addUpdate( new HTMLCacheUpdate( $title, $table ) );
  43         }
  44
  45         /**
  46          * Do any deferred updates and clear the list
  47          *
  48          * @param $commit String: set to 'commit' to commit after every update to
  49          *                prevent lock contention
  50          */
  51         public static function doUpdates( $commit = '' ) {
  52                 global $wgDeferredUpdateList;
  53
  54                 wfProfileIn( __METHOD__ );
  55
  56                 $updates = array_merge( $wgDeferredUpdateList, self::$updates );
  57
  58                 // No need to get master connections in case of empty updates array
  59                 if ( !count( $updates ) ) {
  60                         wfProfileOut( __METHOD__ );
  61                         return;
  62                 }
  63
  64                 $doCommit = $commit == 'commit';
  65                 if ( $doCommit ) {
  66                         $dbw = wfGetDB( DB_MASTER );
  67                 }
  68
  69                 foreach ( $updates as $update ) {
  70                         $update->doUpdate();
  71
  72                         if ( $doCommit && $dbw->trxLevel() ) {
  73                                 $dbw->commit( __METHOD__ );
  74                         }
  75                 }
  76
  77                 self::clearPendingUpdates();
  78                 wfProfileOut( __METHOD__ );
  79         }
  80
  81         /**
  82          * Clear all pending updates without performing them. Generally, you don't
  83          * want or need to call this. Unit tests need it though.
  84          */
  85         public static function clearPendingUpdates() {
  86                 global $wgDeferredUpdateList;
  87                 $wgDeferredUpdateList = self::$updates = array();
  88         }
  89 }