includes/SecondaryDBDataUpdate.php

   1 <?php
   2 /**
   3  * See docs/deferred.txt
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * Abstract base class for update jobs that put some secondary data extracted
  21  * from article content into the database.
  22  */
  23 abstract class SecondaryDBDataUpdate extends SecondaryDataUpdate {
  24
  25         /**@{{
  26          * @private
  27          */
  28         var $mDb,            //!< Database connection reference
  29                 $mOptions;       //!< SELECT options to be used (array)
  30         /**@}}*/
  31
  32         /**
  33          * Constructor
  34      **/
  35     public function __construct( ) {
  36                 global $wgAntiLockFlags;
  37
  38         parent::__construct( );
  39
  40                 if ( $wgAntiLockFlags & ALF_NO_LINK_LOCK ) {
  41                         $this->mOptions = array();
  42                 } else {
  43                         $this->mOptions = array( 'FOR UPDATE' );
  44                 }
  45                 $this->mDb = wfGetDB( DB_MASTER );
  46         }
  47
  48         /**
  49          * Invalidate the cache of a list of pages from a single namespace
  50          *
  51          * @param $namespace Integer
  52          * @param $dbkeys Array
  53          */
  54         public function invalidatePages( $namespace, $dbkeys ) {
  55                 if ( !count( $dbkeys ) ) {
  56                         return;
  57                 }
  58
  59                 /**
  60                  * Determine which pages need to be updated
  61                  * This is necessary to prevent the job queue from smashing the DB with
  62                  * large numbers of concurrent invalidations of the same page
  63                  */
  64                 $now = $this->mDb->timestamp();
  65                 $ids = array();
  66                 $res = $this->mDb->select( 'page', array( 'page_id' ),
  67                         array(
  68                                 'page_namespace' => $namespace,
  69                                 'page_title IN (' . $this->mDb->makeList( $dbkeys ) . ')',
  70                                 'page_touched < ' . $this->mDb->addQuotes( $now )
  71                         ), __METHOD__
  72                 );
  73                 foreach ( $res as $row ) {
  74                         $ids[] = $row->page_id;
  75                 }
  76                 if ( !count( $ids ) ) {
  77                         return;
  78                 }
  79
  80                 /**
  81                  * Do the update
  82                  * We still need the page_touched condition, in case the row has changed since
  83                  * the non-locking select above.
  84                  */
  85                 $this->mDb->update( 'page', array( 'page_touched' => $now ),
  86                         array(
  87                                 'page_id IN (' . $this->mDb->makeList( $ids ) . ')',
  88                                 'page_touched < ' . $this->mDb->addQuotes( $now )
  89                         ), __METHOD__
  90                 );
  91         }
  92
  93 }