includes/libs/rdbms/connectionmanager/ConnectionManager.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20 namespace Wikimedia\Rdbms;
  21
  22 use InvalidArgumentException;
  23
  24 /**
  25  * Database connection manager.
  26  *
  27  * This manages access to primary and replica databases.
  28  *
  29  * @since 1.29
  30  * @ingroup Database
  31  * @author Addshore
  32  */
  33 class ConnectionManager {
  34
  35         /**
  36          * @var ILoadBalancer
  37          */
  38         private $loadBalancer;
  39
  40         /**
  41          * The symbolic name of the target database, or false for the local wiki's database.
  42          *
  43          * @var string|false
  44          */
  45         private $domain;
  46
  47         /**
  48          * @var string[]
  49          */
  50         private $groups = [];
  51
  52         /**
  53          * @param ILoadBalancer $loadBalancer
  54          * @param string|false $domain Optional logical DB name, defaults to current wiki.
  55          *        This follows the convention for database names used by $loadBalancer.
  56          * @param string[] $groups see LoadBalancer::getConnection
  57          *
  58          * @throws InvalidArgumentException
  59          */
  60         public function __construct( ILoadBalancer $loadBalancer, $domain = false, array $groups = [] ) {
  61                 if ( !is_string( $domain ) && $domain !== false ) {
  62                         throw new InvalidArgumentException( '$dbName must be a string, or false.' );
  63                 }
  64
  65                 $this->loadBalancer = $loadBalancer;
  66                 $this->domain = $domain;
  67                 $this->groups = $groups;
  68         }
  69
  70         /**
  71          * @param int $i
  72          * @param string[]|null $groups
  73          * @param int $flags
  74          * @return IDatabase
  75          */
  76         private function getConnection( $i, ?array $groups = null, int $flags = 0 ) {
  77                 $groups ??= $this->groups;
  78                 return $this->loadBalancer->getConnection( $i, $groups, $this->domain, $flags );
  79         }
  80
  81         /**
  82          * Returns a connection to the primary DB, for updating.
  83          *
  84          * @since 1.29
  85          * @since 1.37 Added optional $flags parameter
  86          * @param int $flags
  87          * @return IDatabase
  88          */
  89         public function getWriteConnection( int $flags = 0 ) {
  90                 return $this->getConnection( DB_PRIMARY, null, $flags );
  91         }
  92
  93         /**
  94          * Returns a database connection for reading.
  95          *
  96          * @since 1.29
  97          * @since 1.37 Added optional $flags parameter
  98          * @param string[]|null $groups
  99          * @param int $flags
 100          * @return IReadableDatabase
 101          */
 102         public function getReadConnection( ?array $groups = null, int $flags = 0 ) {
 103                 $groups ??= $this->groups;
 104                 return $this->getConnection( DB_REPLICA, $groups, $flags );
 105         }
 106 }