includes/db/loadbalancer/LBFactorySimple.php

   1 <?php
   2 /**
   3  * Generator of database load balancing objects.
   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  * A simple single-master LBFactory that gets its configuration from the b/c globals
  26  */
  27 class LBFactorySimple extends LBFactory {
  28         /** @var LoadBalancer */
  29         private $mainLB;
  30
  31         /** @var LoadBalancer[] */
  32         private $extLBs = array();
  33
  34         /** @var ChronologyProtector */
  35         private $chronProt;
  36
  37         public function __construct( array $conf ) {
  38                 $this->chronProt = new ChronologyProtector;
  39         }
  40
  41         /**
  42          * @param bool|string $wiki
  43          * @return LoadBalancer
  44          */
  45         public function newMainLB( $wiki = false ) {
  46                 global $wgDBservers;
  47                 if ( $wgDBservers ) {
  48                         $servers = $wgDBservers;
  49                 } else {
  50                         global $wgDBserver, $wgDBuser, $wgDBpassword, $wgDBname, $wgDBtype, $wgDebugDumpSql;
  51                         global $wgDBssl, $wgDBcompress;
  52
  53                         $flags = DBO_DEFAULT;
  54                         if ( $wgDebugDumpSql ) {
  55                                 $flags |= DBO_DEBUG;
  56                         }
  57                         if ( $wgDBssl ) {
  58                                 $flags |= DBO_SSL;
  59                         }
  60                         if ( $wgDBcompress ) {
  61                                 $flags |= DBO_COMPRESS;
  62                         }
  63
  64                         $servers = array( array(
  65                                 'host' => $wgDBserver,
  66                                 'user' => $wgDBuser,
  67                                 'password' => $wgDBpassword,
  68                                 'dbname' => $wgDBname,
  69                                 'type' => $wgDBtype,
  70                                 'load' => 1,
  71                                 'flags' => $flags
  72                         ) );
  73                 }
  74
  75                 return new LoadBalancer( array(
  76                         'servers' => $servers,
  77                 ) );
  78         }
  79
  80         /**
  81          * @param bool|string $wiki
  82          * @return LoadBalancer
  83          */
  84         public function getMainLB( $wiki = false ) {
  85                 if ( !isset( $this->mainLB ) ) {
  86                         $this->mainLB = $this->newMainLB( $wiki );
  87                         $this->mainLB->parentInfo( array( 'id' => 'main' ) );
  88                         $this->chronProt->initLB( $this->mainLB );
  89                 }
  90
  91                 return $this->mainLB;
  92         }
  93
  94         /**
  95          * @throws MWException
  96          * @param string $cluster
  97          * @param bool|string $wiki
  98          * @return LoadBalancer
  99          */
 100         protected function newExternalLB( $cluster, $wiki = false ) {
 101                 global $wgExternalServers;
 102                 if ( !isset( $wgExternalServers[$cluster] ) ) {
 103                         throw new MWException( __METHOD__ . ": Unknown cluster \"$cluster\"" );
 104                 }
 105
 106                 return new LoadBalancer( array(
 107                         'servers' => $wgExternalServers[$cluster]
 108                 ) );
 109         }
 110
 111         /**
 112          * @param string $cluster
 113          * @param bool|string $wiki
 114          * @return array
 115          */
 116         public function &getExternalLB( $cluster, $wiki = false ) {
 117                 if ( !isset( $this->extLBs[$cluster] ) ) {
 118                         $this->extLBs[$cluster] = $this->newExternalLB( $cluster, $wiki );
 119                         $this->extLBs[$cluster]->parentInfo( array( 'id' => "ext-$cluster" ) );
 120                         $this->chronProt->initLB( $this->extLBs[$cluster] );
 121                 }
 122
 123                 return $this->extLBs[$cluster];
 124         }
 125
 126         /**
 127          * Execute a function for each tracked load balancer
 128          * The callback is called with the load balancer as the first parameter,
 129          * and $params passed as the subsequent parameters.
 130          *
 131          * @param callable $callback
 132          * @param array $params
 133          */
 134         public function forEachLB( $callback, array $params = array() ) {
 135                 if ( isset( $this->mainLB ) ) {
 136                         call_user_func_array( $callback, array_merge( array( $this->mainLB ), $params ) );
 137                 }
 138                 foreach ( $this->extLBs as $lb ) {
 139                         call_user_func_array( $callback, array_merge( array( $lb ), $params ) );
 140                 }
 141         }
 142
 143         public function shutdown() {
 144                 if ( $this->mainLB ) {
 145                         $this->chronProt->shutdownLB( $this->mainLB );
 146                 }
 147                 foreach ( $this->extLBs as $extLB ) {
 148                         $this->chronProt->shutdownLB( $extLB );
 149                 }
 150                 $this->chronProt->shutdown();
 151                 $this->commitMasterChanges();
 152         }
 153 }