includes/libs/rdbms/lbfactory/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 namespace Wikimedia\Rdbms;
  25
  26 use InvalidArgumentException;
  27 use BadMethodCallException;
  28
  29 /**
  30  * An LBFactory class that always returns a single database object.
  31  */
  32 class LBFactorySingle extends LBFactory {
  33         /** @var LoadBalancerSingle */
  34         private $lb;
  35
  36         /**
  37          * @param array $conf An associative array with one member:
  38          *  - connection: The IDatabase connection object
  39          */
  40         public function __construct( array $conf ) {
  41                 parent::__construct( $conf );
  42
  43                 if ( !isset( $conf['connection'] ) ) {
  44                         throw new InvalidArgumentException( "Missing 'connection' argument." );
  45                 }
  46
  47                 $lb = new LoadBalancerSingle( array_merge(
  48                         $this->baseLoadBalancerParams( $this->getOwnershipId() ),
  49                         $conf
  50                 ) );
  51                 $this->initLoadBalancer( $lb );
  52
  53                 $this->lb = $lb;
  54         }
  55
  56         /**
  57          * @param IDatabase $db Live connection handle
  58          * @param array $params Parameter map to LBFactorySingle::__constructs()
  59          * @return LBFactorySingle
  60          * @since 1.28
  61          */
  62         public static function newFromConnection( IDatabase $db, array $params = [] ) {
  63                 return new static( array_merge(
  64                         [ 'localDomain' => $db->getDomainID() ],
  65                         $params,
  66                         [ 'connection' => $db ]
  67                 ) );
  68         }
  69
  70         public function newMainLB( $domain = false, $owner = null ) {
  71                 throw new BadMethodCallException( "Method is not supported." );
  72         }
  73
  74         public function getMainLB( $domain = false ) {
  75                 return $this->lb;
  76         }
  77
  78         public function newExternalLB( $cluster, $owner = null ) {
  79                 throw new BadMethodCallException( "Method is not supported." );
  80         }
  81
  82         public function getExternalLB( $cluster ) {
  83                 throw new BadMethodCallException( "Method is not supported." );
  84         }
  85
  86         public function getAllMainLBs() {
  87                 return [ 'DEFAULT' => $this->lb ];
  88         }
  89
  90         public function getAllExternalLBs() {
  91                 return [];
  92         }
  93
  94         public function forEachLB( $callback, array $params = [] ) {
  95                 if ( isset( $this->lb ) ) { // may not be set during _destruct()
  96                         $callback( $this->lb, ...$params );
  97                 }
  98         }
  99 }