includes/db/loadbalancer/LBFactorySingle.php

   1 <?php
   2 /**
   3  * Simple generator of database connections that always returns the same object.
   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  * @file
  21  * @ingroup Database
  22  */
  23
  24 /**
  25  * An LBFactory class that always returns a single database object.
  26  */
  27 class LBFactorySingle extends LBFactory {
  28         /** @var LoadBalancerSingle */
  29         private $lb;
  30
  31         /**
  32          * @param array $conf An associative array with one member:
  33          *  - connection: The DatabaseBase connection object
  34          */
  35         public function __construct( array $conf ) {
  36                 parent::__construct( $conf );
  37
  38                 $this->lb = new LoadBalancerSingle( $conf );
  39         }
  40
  41         /**
  42          * @param bool|string $wiki
  43          * @return LoadBalancerSingle
  44          */
  45         public function newMainLB( $wiki = false ) {
  46                 return $this->lb;
  47         }
  48
  49         /**
  50          * @param bool|string $wiki
  51          * @return LoadBalancerSingle
  52          */
  53         public function getMainLB( $wiki = false ) {
  54                 return $this->lb;
  55         }
  56
  57         /**
  58          * @param string $cluster External storage cluster, or false for core
  59          * @param bool|string $wiki Wiki ID, or false for the current wiki
  60          * @return LoadBalancerSingle
  61          */
  62         protected function newExternalLB( $cluster, $wiki = false ) {
  63                 return $this->lb;
  64         }
  65
  66         /**
  67          * @param string $cluster External storage cluster, or false for core
  68          * @param bool|string $wiki Wiki ID, or false for the current wiki
  69          * @return LoadBalancerSingle
  70          */
  71         public function &getExternalLB( $cluster, $wiki = false ) {
  72                 return $this->lb;
  73         }
  74
  75         /**
  76          * @param string|callable $callback
  77          * @param array $params
  78          */
  79         public function forEachLB( $callback, array $params = array() ) {
  80                 call_user_func_array( $callback, array_merge( array( $this->lb ), $params ) );
  81         }
  82 }
  83
  84 /**
  85  * Helper class for LBFactorySingle.
  86  */
  87 class LoadBalancerSingle extends LoadBalancer {
  88         /** @var DatabaseBase */
  89         private $db;
  90
  91         /**
  92          * @param array $params
  93          */
  94         public function __construct( array $params ) {
  95                 $this->db = $params['connection'];
  96                 parent::__construct( array( 'servers' => array( array(
  97                         'type' => $this->db->getType(),
  98                         'host' => $this->db->getServer(),
  99                         'dbname' => $this->db->getDBname(),
 100                         'load' => 1,
 101                 ) ) ) );
 102         }
 103
 104         /**
 105          *
 106          * @param string $server
 107          * @param bool $dbNameOverride
 108          *
 109          * @return DatabaseBase
 110          */
 111         protected function reallyOpenConnection( $server, $dbNameOverride = false ) {
 112                 return $this->db;
 113         }
 114 }