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 IDatabase;
  27 use InvalidArgumentException;
  28 use BadMethodCallException;
  29
  30 /**
  31  * An LBFactory class that always returns a single database object.
  32  */
  33 class LBFactorySingle extends LBFactory {
  34         /** @var LoadBalancerSingle */
  35         private $lb;
  36
  37         /**
  38          * @param array $conf An associative array with one member:
  39          *  - connection: The IDatabase connection object
  40          */
  41         public function __construct( array $conf ) {
  42                 parent::__construct( $conf );
  43
  44                 if ( !isset( $conf['connection'] ) ) {
  45                         throw new InvalidArgumentException( "Missing 'connection' argument." );
  46                 }
  47
  48                 $lb = new LoadBalancerSingle( array_merge( $this->baseLoadBalancerParams(), $conf ) );
  49                 $this->initLoadBalancer( $lb );
  50                 $this->lb = $lb;
  51         }
  52
  53         /**
  54          * @param IDatabase $db Live connection handle
  55          * @param array $params Parameter map to LBFactorySingle::__constructs()
  56          * @return LBFactorySingle
  57          * @since 1.28
  58          */
  59         public static function newFromConnection( IDatabase $db, array $params = [] ) {
  60                 return new static( [ 'connection' => $db ] + $params );
  61         }
  62
  63         /**
  64          * @param bool|string $domain (unused)
  65          * @return LoadBalancerSingle
  66          */
  67         public function newMainLB( $domain = false ) {
  68                 return $this->lb;
  69         }
  70
  71         /**
  72          * @param bool|string $domain (unused)
  73          * @return LoadBalancerSingle
  74          */
  75         public function getMainLB( $domain = false ) {
  76                 return $this->lb;
  77         }
  78
  79         public function newExternalLB( $cluster ) {
  80                 throw new BadMethodCallException( "Method is not supported." );
  81         }
  82
  83         public function getExternalLB( $cluster ) {
  84                 throw new BadMethodCallException( "Method is not supported." );
  85         }
  86
  87         /**
  88          * @return LoadBalancerSingle[] Map of (cluster name => LoadBalancer)
  89          */
  90         public function getAllMainLBs() {
  91                 return [ 'DEFAULT' => $this->lb ];
  92         }
  93
  94         /**
  95          * @return LoadBalancerSingle[] Map of (cluster name => LoadBalancer)
  96          */
  97         public function getAllExternalLBs() {
  98                 return [];
  99         }
 100
 101         /**
 102          * @param string|callable $callback
 103          * @param array $params
 104          */
 105         public function forEachLB( $callback, array $params = [] ) {
 106                 call_user_func_array( $callback, array_merge( [ $this->lb ], $params ) );
 107         }
 108 }