includes/dao/DBAccessBase.php

   1 <?php
   2
   3 use Wikimedia\Rdbms\LoadBalancer;
   4
   5 /**
   6  * Base class for objects that allow access to other wiki's databases using
   7  * the foreign database access mechanism implemented by LBFactoryMulti.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @since 1.21
  25  *
  26  * @file
  27  * @ingroup Database
  28  *
  29  * @licence GNU GPL v2+
  30  * @author Daniel Kinzler
  31  */
  32 abstract class DBAccessBase implements IDBAccessObject {
  33         /**
  34          * @var string|bool $wiki The target wiki's name. This must be an ID
  35          * that LBFactory can understand.
  36          */
  37         protected $wiki = false;
  38
  39         /**
  40          * @param string|bool $wiki The target wiki's name. This must be an ID
  41          * that LBFactory can understand.
  42          */
  43         public function __construct( $wiki = false ) {
  44                 $this->wiki = $wiki;
  45         }
  46
  47         /**
  48          * Returns a database connection.
  49          *
  50          * @see wfGetDB()
  51          * @see LoadBalancer::getConnection()
  52          *
  53          * @since 1.21
  54          *
  55          * @param int $id Which connection to use
  56          * @param array $groups Query groups
  57          *
  58          * @return Database
  59          */
  60         protected function getConnection( $id, $groups = [] ) {
  61                 $loadBalancer = wfGetLB( $this->wiki );
  62
  63                 return $loadBalancer->getConnection( $id, $groups, $this->wiki );
  64         }
  65
  66         /**
  67          * Releases a database connection and makes it available for recycling.
  68          *
  69          * @see LoadBalancer::reuseConnection()
  70          *
  71          * @since 1.21
  72          *
  73          * @param Database $db The database connection to release.
  74          */
  75         protected function releaseConnection( Database $db ) {
  76                 if ( $this->wiki !== false ) {
  77                         $loadBalancer = $this->getLoadBalancer();
  78                         $loadBalancer->reuseConnection( $db );
  79                 }
  80         }
  81
  82         /**
  83          * Get the database type used for read operations.
  84          *
  85          * @see wfGetLB
  86          *
  87          * @since 1.21
  88          *
  89          * @return LoadBalancer The database load balancer object
  90          */
  91         public function getLoadBalancer() {
  92                 return wfGetLB( $this->wiki );
  93         }
  94 }