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         /** @var LoadBalancer[] */
  31         private $extLBs = [];
  32
  33         /** @var string */
  34         private $loadMonitorClass;
  35
  36         public function __construct( array $conf ) {
  37                 parent::__construct( $conf );
  38
  39                 $this->loadMonitorClass = isset( $conf['loadMonitorClass'] )
  40                         ? $conf['loadMonitorClass']
  41                         : null;
  42         }
  43
  44         /**
  45          * @param bool|string $wiki
  46          * @return LoadBalancer
  47          */
  48         public function newMainLB( $wiki = false ) {
  49                 global $wgDBservers;
  50
  51                 if ( is_array( $wgDBservers ) ) {
  52                         $servers = $wgDBservers;
  53                         foreach ( $servers as $i => &$server ) {
  54                                 if ( $i == 0 ) {
  55                                         $server['master'] = true;
  56                                 } else {
  57                                         $server['slave'] = true;
  58                                 }
  59                                 $server += [ 'flags' => DBO_DEFAULT ];
  60                         }
  61                 } else {
  62                         global $wgDBserver, $wgDBuser, $wgDBpassword, $wgDBname, $wgDBtype, $wgDebugDumpSql;
  63                         global $wgDBssl, $wgDBcompress;
  64
  65                         $flags = DBO_DEFAULT;
  66                         if ( $wgDebugDumpSql ) {
  67                                 $flags |= DBO_DEBUG;
  68                         }
  69                         if ( $wgDBssl ) {
  70                                 $flags |= DBO_SSL;
  71                         }
  72                         if ( $wgDBcompress ) {
  73                                 $flags |= DBO_COMPRESS;
  74                         }
  75
  76                         $servers = [ [
  77                                 'host' => $wgDBserver,
  78                                 'user' => $wgDBuser,
  79                                 'password' => $wgDBpassword,
  80                                 'dbname' => $wgDBname,
  81                                 'type' => $wgDBtype,
  82                                 'load' => 1,
  83                                 'flags' => $flags,
  84                                 'master' => true
  85                         ] ];
  86                 }
  87
  88                 return $this->newLoadBalancer( $servers );
  89         }
  90
  91         /**
  92          * @param bool|string $wiki
  93          * @return LoadBalancer
  94          */
  95         public function getMainLB( $wiki = false ) {
  96                 if ( !isset( $this->mainLB ) ) {
  97                         $this->mainLB = $this->newMainLB( $wiki );
  98                         $this->mainLB->parentInfo( [ 'id' => 'main' ] );
  99                         $this->chronProt->initLB( $this->mainLB );
 100                 }
 101
 102                 return $this->mainLB;
 103         }
 104
 105         /**
 106          * @throws MWException
 107          * @param string $cluster
 108          * @param bool|string $wiki
 109          * @return LoadBalancer
 110          */
 111         protected function newExternalLB( $cluster, $wiki = false ) {
 112                 global $wgExternalServers;
 113                 if ( !isset( $wgExternalServers[$cluster] ) ) {
 114                         throw new MWException( __METHOD__ . ": Unknown cluster \"$cluster\"" );
 115                 }
 116
 117                 return $this->newLoadBalancer( $wgExternalServers[$cluster] );
 118         }
 119
 120         /**
 121          * @param string $cluster
 122          * @param bool|string $wiki
 123          * @return array
 124          */
 125         public function &getExternalLB( $cluster, $wiki = false ) {
 126                 if ( !isset( $this->extLBs[$cluster] ) ) {
 127                         $this->extLBs[$cluster] = $this->newExternalLB( $cluster, $wiki );
 128                         $this->extLBs[$cluster]->parentInfo( [ 'id' => "ext-$cluster" ] );
 129                         $this->chronProt->initLB( $this->extLBs[$cluster] );
 130                 }
 131
 132                 return $this->extLBs[$cluster];
 133         }
 134
 135         private function newLoadBalancer( array $servers ) {
 136                 return new LoadBalancer( [
 137                         'servers' => $servers,
 138                         'loadMonitor' => $this->loadMonitorClass,
 139                         'readOnlyReason' => $this->readOnlyReason,
 140                         'trxProfiler' => $this->trxProfiler,
 141                         'srvCache' => $this->srvCache,
 142                         'wanCache' => $this->wanCache
 143                 ] );
 144         }
 145
 146         /**
 147          * Execute a function for each tracked load balancer
 148          * The callback is called with the load balancer as the first parameter,
 149          * and $params passed as the subsequent parameters.
 150          *
 151          * @param callable $callback
 152          * @param array $params
 153          */
 154         public function forEachLB( $callback, array $params = [] ) {
 155                 if ( isset( $this->mainLB ) ) {
 156                         call_user_func_array( $callback, array_merge( [ $this->mainLB ], $params ) );
 157                 }
 158                 foreach ( $this->extLBs as $lb ) {
 159                         call_user_func_array( $callback, array_merge( [ $lb ], $params ) );
 160                 }
 161         }
 162
 163         public function shutdown( $flags = 0 ) {
 164                 if ( !( $flags & self::SHUTDOWN_NO_CHRONPROT ) ) {
 165                         $this->shutdownChronologyProtector( $this->chronProt );
 166                 }
 167                 $this->commitMasterChanges( __METHOD__ ); // sanity
 168         }
 169 }