includes/dao/DBAccessBase.php

   1 <?php
   2
   3 use Wikimedia\Rdbms\IDatabase;
   4 use Wikimedia\Rdbms\LoadBalancer;
   5
   6 /**
   7  * Base class for objects that allow access to other wiki's databases using
   8  * the foreign database access mechanism implemented by LBFactoryMulti.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  23  * http://www.gnu.org/copyleft/gpl.html
  24  *
  25  * @since 1.21
  26  *
  27  * @file
  28  * @ingroup Database
  29  *
  30  * @license GNU GPL v2+
  31  * @author Daniel Kinzler
  32  */
  33 abstract class DBAccessBase implements IDBAccessObject {
  34         /**
  35          * @var string|bool $wiki The target wiki's name. This must be an ID
  36          * that LBFactory can understand.
  37          */
  38         protected $wiki = false;
  39
  40         /**
  41          * @param string|bool $wiki The target wiki's name. This must be an ID
  42          * that LBFactory can understand.
  43          */
  44         public function __construct( $wiki = false ) {
  45                 $this->wiki = $wiki;
  46         }
  47
  48         /**
  49          * Returns a database connection.
  50          *
  51          * @see wfGetDB()
  52          * @see LoadBalancer::getConnection()
  53          *
  54          * @since 1.21
  55          *
  56          * @param int $id Which connection to use
  57          * @param array $groups Query groups
  58          *
  59          * @return IDatabase
  60          */
  61         protected function getConnection( $id, $groups = [] ) {
  62                 $loadBalancer = wfGetLB( $this->wiki );
  63
  64                 return $loadBalancer->getConnection( $id, $groups, $this->wiki );
  65         }
  66
  67         /**
  68          * Releases a database connection and makes it available for recycling.
  69          *
  70          * @see LoadBalancer::reuseConnection()
  71          *
  72          * @since 1.21
  73          *
  74          * @param IDatabase $db The database connection to release.
  75          */
  76         protected function releaseConnection( IDatabase $db ) {
  77                 if ( $this->wiki !== false ) {
  78                         $loadBalancer = $this->getLoadBalancer();
  79                         $loadBalancer->reuseConnection( $db );
  80                 }
  81         }
  82
  83         /**
  84          * Get the database type used for read operations.
  85          *
  86          * @see wfGetLB
  87          *
  88          * @since 1.21
  89          *
  90          * @return LoadBalancer The database load balancer object
  91          */
  92         public function getLoadBalancer() {
  93                 return wfGetLB( $this->wiki );
  94         }
  95 }