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