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