includes/dao/DBAccessBase.php

   1 <?php
   2
   3 use MediaWiki\MediaWikiServices;
   4 use Wikimedia\Rdbms\IDatabase;
   5 use Wikimedia\Rdbms\ILoadBalancer;
   6
   7 /**
   8  * Base class for objects that allow access to other wiki's databases using
   9  * the foreign database access mechanism implemented by LBFactoryMulti.
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with this program; if not, write to the Free Software Foundation, Inc.,
  23  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  24  * http://www.gnu.org/copyleft/gpl.html
  25  *
  26  * @since 1.21
  27  *
  28  * @file
  29  * @ingroup Database
  30  *
  31  * @license GPL-2.0-or-later
  32  * @author Daniel Kinzler
  33  */
  34 abstract class DBAccessBase implements IDBAccessObject {
  35         /**
  36          * @var string|bool $wiki The target wiki's name. This must be an ID
  37          * that LBFactory can understand.
  38          */
  39         protected $wiki = false;
  40
  41         /**
  42          * @param string|bool $wiki The target wiki's name. This must be an ID
  43          * that LBFactory can understand.
  44          */
  45         public function __construct( $wiki = false ) {
  46                 $this->wiki = $wiki;
  47         }
  48
  49         /**
  50          * Returns a database connection.
  51          *
  52          * @see wfGetDB()
  53          * @see LoadBalancer::getConnection()
  54          *
  55          * @since 1.21
  56          *
  57          * @param int $id Which connection to use
  58          * @param array $groups Query groups
  59          *
  60          * @return IDatabase
  61          */
  62         protected function getConnection( $id, array $groups = [] ) {
  63                 $loadBalancer = $this->getLoadBalancer();
  64
  65                 return $loadBalancer->getConnection( $id, $groups, $this->wiki );
  66         }
  67
  68         /**
  69          * Releases a database connection and makes it available for recycling.
  70          *
  71          * @see LoadBalancer::reuseConnection()
  72          *
  73          * @since 1.21
  74          *
  75          * @param IDatabase $db The database connection to release.
  76          */
  77         protected function releaseConnection( IDatabase $db ) {
  78                 if ( $this->wiki !== false ) {
  79                         $loadBalancer = $this->getLoadBalancer();
  80                         $loadBalancer->reuseConnection( $db );
  81                 }
  82         }
  83
  84         /**
  85          * Get the database type used for read operations.
  86          *
  87          * @see MediaWikiServices::getInstance()->getDBLoadBalancer
  88          *
  89          * @since 1.21
  90          *
  91          * @return ILoadBalancer The database load balancer object
  92          */
  93         public function getLoadBalancer() {
  94                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
  95                 return $lbFactory->getMainLB( $this->wiki );
  96         }
  97 }