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                 $conf['readOnlyReason'] = $this->readOnlyReason;
  39                 $this->lb = new LoadBalancerSingle( $conf );
  40         }
  41
  42         /**
  43          * @param bool|string $wiki
  44          * @return LoadBalancerSingle
  45          */
  46         public function newMainLB( $wiki = false ) {
  47                 return $this->lb;
  48         }
  49
  50         /**
  51          * @param bool|string $wiki
  52          * @return LoadBalancerSingle
  53          */
  54         public function getMainLB( $wiki = false ) {
  55                 return $this->lb;
  56         }
  57
  58         /**
  59          * @param string $cluster External storage cluster, or false for core
  60          * @param bool|string $wiki Wiki ID, or false for the current wiki
  61          * @return LoadBalancerSingle
  62          */
  63         protected function newExternalLB( $cluster, $wiki = false ) {
  64                 return $this->lb;
  65         }
  66
  67         /**
  68          * @param string $cluster External storage cluster, or false for core
  69          * @param bool|string $wiki Wiki ID, or false for the current wiki
  70          * @return LoadBalancerSingle
  71          */
  72         public function &getExternalLB( $cluster, $wiki = false ) {
  73                 return $this->lb;
  74         }
  75
  76         /**
  77          * @param string|callable $callback
  78          * @param array $params
  79          */
  80         public function forEachLB( $callback, array $params = array() ) {
  81                 call_user_func_array( $callback, array_merge( array( $this->lb ), $params ) );
  82         }
  83 }
  84
  85 /**
  86  * Helper class for LBFactorySingle.
  87  */
  88 class LoadBalancerSingle extends LoadBalancer {
  89         /** @var DatabaseBase */
  90         private $db;
  91
  92         /**
  93          * @param array $params
  94          */
  95         public function __construct( array $params ) {
  96                 $this->db = $params['connection'];
  97
  98                 parent::__construct( array(
  99                         'servers' => array(
 100                                 array(
 101                                         'type' => $this->db->getType(),
 102                                         'host' => $this->db->getServer(),
 103                                         'dbname' => $this->db->getDBname(),
 104                                         'load' => 1,
 105                                 )
 106                         )
 107                 ) );
 108
 109                 if ( isset( $params['readOnlyReason'] ) ) {
 110                         $this->db->setLBInfo( 'readOnlyReason', $params['readOnlyReason'] );
 111                 }
 112         }
 113
 114         /**
 115          *
 116          * @param string $server
 117          * @param bool $dbNameOverride
 118          *
 119          * @return DatabaseBase
 120          */
 121         protected function reallyOpenConnection( $server, $dbNameOverride = false ) {
 122                 return $this->db;
 123         }
 124 }