includes/db/loadbalancer/LBFactoryMW.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 use MediaWiki\MediaWikiServices;
  25 use MediaWiki\Services\DestructibleService;
  26 use MediaWiki\Logger\LoggerFactory;
  27
  28 /**
  29  * Legacy MediaWiki-specific class for generating database load balancers
  30  * @ingroup Database
  31  */
  32 abstract class LBFactoryMW extends LBFactory implements DestructibleService {
  33         /** @noinspection PhpMissingParentConstructorInspection */
  34         /**
  35          * Construct a factory based on a configuration array (typically from $wgLBFactoryConf)
  36          * @param array $conf
  37          * @TODO: inject objects via dependency framework
  38          */
  39         public function __construct( array $conf ) {
  40                 global $wgCommandLineMode;
  41
  42                 $defaults = [
  43                         'domain' => wfWikiID(),
  44                         'hostname' => wfHostname(),
  45                         'trxProfiler' => Profiler::instance()->getTransactionProfiler(),
  46                         'replLogger' => LoggerFactory::getInstance( 'DBReplication' ),
  47                         'queryLogger' => LoggerFactory::getInstance( 'wfLogDBError' ),
  48                         'connLogger' => LoggerFactory::getInstance( 'wfLogDBError' ),
  49                         'perfLogger' => LoggerFactory::getInstance( 'DBPerformance' ),
  50                         'errorLogger' => [ MWExceptionHandler::class, 'logException' ]
  51                 ];
  52                 // Use APC/memcached style caching, but avoids loops with CACHE_DB (T141804)
  53                 $sCache = ObjectCache::getLocalServerInstance();
  54                 if ( $sCache->getQoS( $sCache::ATTR_EMULATION ) > $sCache::QOS_EMULATION_SQL ) {
  55                         $defaults['srvCache'] = $sCache;
  56                 }
  57                 $cCache = ObjectCache::getLocalClusterInstance();
  58                 if ( $cCache->getQoS( $cCache::ATTR_EMULATION ) > $cCache::QOS_EMULATION_SQL ) {
  59                         $defaults['memCache'] = $cCache;
  60                 }
  61                 $wCache = ObjectCache::getMainWANInstance();
  62                 if ( $wCache->getQoS( $wCache::ATTR_EMULATION ) > $wCache::QOS_EMULATION_SQL ) {
  63                         $defaults['wanCache'] = $wCache;
  64                 }
  65
  66                 $this->agent = isset( $params['agent'] ) ? $params['agent'] : '';
  67                 $this->cliMode = isset( $params['cliMode'] ) ? $params['cliMode'] : $wgCommandLineMode;
  68
  69                 parent::__construct( $conf + $defaults );
  70         }
  71
  72         /**
  73          * Returns the LBFactory class to use and the load balancer configuration.
  74          *
  75          * @todo instead of this, use a ServiceContainer for managing the different implementations.
  76          *
  77          * @param array $config (e.g. $wgLBFactoryConf)
  78          * @return string Class name
  79          */
  80         public static function getLBFactoryClass( array $config ) {
  81                 // For configuration backward compatibility after removing
  82                 // underscores from class names in MediaWiki 1.23.
  83                 $bcClasses = [
  84                         'LBFactory_Simple' => 'LBFactorySimple',
  85                         'LBFactory_Single' => 'LBFactorySingle',
  86                         'LBFactory_Multi' => 'LBFactoryMulti'
  87                 ];
  88
  89                 $class = $config['class'];
  90
  91                 if ( isset( $bcClasses[$class] ) ) {
  92                         $class = $bcClasses[$class];
  93                         wfDeprecated(
  94                                 '$wgLBFactoryConf must be updated. See RELEASE-NOTES for details',
  95                                 '1.23'
  96                         );
  97                 }
  98
  99                 return $class;
 100         }
 101
 102         /**
 103          * @return bool
 104          * @since 1.27
 105          * @deprecated Since 1.28; use laggedReplicaUsed()
 106          */
 107         public function laggedSlaveUsed() {
 108                 return $this->laggedReplicaUsed();
 109         }
 110
 111         protected function newChronologyProtector() {
 112                 $request = RequestContext::getMain()->getRequest();
 113                 $chronProt = new ChronologyProtector(
 114                         ObjectCache::getMainStashInstance(),
 115                         [
 116                                 'ip' => $request->getIP(),
 117                                 'agent' => $request->getHeader( 'User-Agent' ),
 118                         ],
 119                         $request->getFloat( 'cpPosTime', $request->getCookie( 'cpPosTime', '' ) )
 120                 );
 121                 if ( PHP_SAPI === 'cli' ) {
 122                         $chronProt->setEnabled( false );
 123                 } elseif ( $request->getHeader( 'ChronologyProtection' ) === 'false' ) {
 124                         // Request opted out of using position wait logic. This is useful for requests
 125                         // done by the job queue or background ETL that do not have a meaningful session.
 126                         $chronProt->setWaitEnabled( false );
 127                 }
 128
 129                 return $chronProt;
 130         }
 131
 132         /**
 133          * Append ?cpPosTime parameter to a URL for ChronologyProtector purposes if needed
 134          *
 135          * Note that unlike cookies, this works accross domains
 136          *
 137          * @param string $url
 138          * @param float $time UNIX timestamp just before shutdown() was called
 139          * @return string
 140          * @since 1.28
 141          */
 142         public function appendPreShutdownTimeAsQuery( $url, $time ) {
 143                 $usedCluster = 0;
 144                 $this->forEachLB( function ( LoadBalancer $lb ) use ( &$usedCluster ) {
 145                         $usedCluster |= ( $lb->getServerCount() > 1 );
 146                 } );
 147
 148                 if ( !$usedCluster ) {
 149                         return $url; // no master/replica clusters touched
 150                 }
 151
 152                 return wfAppendQuery( $url, [ 'cpPosTime' => $time ] );
 153         }
 154 }