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( [
  39                         'readOnlyReason' => $this->readOnlyReason,
  40                         'trxProfiler' => $this->trxProfiler,
  41                         'srvCache' => $this->srvCache,
  42                         'wanCache' => $this->wanCache
  43                 ] + $conf );
  44         }
  45
  46         /**
  47          * @param bool|string $wiki
  48          * @return LoadBalancerSingle
  49          */
  50         public function newMainLB( $wiki = false ) {
  51                 return $this->lb;
  52         }
  53
  54         /**
  55          * @param bool|string $wiki
  56          * @return LoadBalancerSingle
  57          */
  58         public function getMainLB( $wiki = false ) {
  59                 return $this->lb;
  60         }
  61
  62         /**
  63          * @param string $cluster External storage cluster, or false for core
  64          * @param bool|string $wiki Wiki ID, or false for the current wiki
  65          * @return LoadBalancerSingle
  66          */
  67         protected function newExternalLB( $cluster, $wiki = false ) {
  68                 return $this->lb;
  69         }
  70
  71         /**
  72          * @param string $cluster External storage cluster, or false for core
  73          * @param bool|string $wiki Wiki ID, or false for the current wiki
  74          * @return LoadBalancerSingle
  75          */
  76         public function &getExternalLB( $cluster, $wiki = false ) {
  77                 return $this->lb;
  78         }
  79
  80         /**
  81          * @param string|callable $callback
  82          * @param array $params
  83          */
  84         public function forEachLB( $callback, array $params = [] ) {
  85                 call_user_func_array( $callback, array_merge( [ $this->lb ], $params ) );
  86         }
  87 }
  88
  89 /**
  90  * Helper class for LBFactorySingle.
  91  */
  92 class LoadBalancerSingle extends LoadBalancer {
  93         /** @var DatabaseBase */
  94         private $db;
  95
  96         /**
  97          * @param array $params
  98          */
  99         public function __construct( array $params ) {
 100                 $this->db = $params['connection'];
 101
 102                 parent::__construct( [
 103                         'servers' => [
 104                                 [
 105                                         'type' => $this->db->getType(),
 106                                         'host' => $this->db->getServer(),
 107                                         'dbname' => $this->db->getDBname(),
 108                                         'load' => 1,
 109                                 ]
 110                         ],
 111                         'trxProfiler' => isset( $params['trxProfiler'] ) ? $params['trxProfiler'] : null,
 112                         'srvCache' => isset( $params['srvCache'] ) ? $params['srvCache'] : null,
 113                         'wanCache' => isset( $params['wanCache'] ) ? $params['wanCache'] : null
 114                 ] );
 115
 116                 if ( isset( $params['readOnlyReason'] ) ) {
 117                         $this->db->setLBInfo( 'readOnlyReason', $params['readOnlyReason'] );
 118                 }
 119         }
 120
 121         /**
 122          *
 123          * @param string $server
 124          * @param bool $dbNameOverride
 125          *
 126          * @return DatabaseBase
 127          */
 128         protected function reallyOpenConnection( $server, $dbNameOverride = false ) {
 129                 return $this->db;
 130         }
 131 }