includes/filebackend/lockmanager/LockManagerGroup.php

   1 <?php
   2 /**
   3  * Lock manager registration handling.
   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 LockManager
  22  */
  23 use MediaWiki\MediaWikiServices;
  24 use MediaWiki\Logger\LoggerFactory;
  25
  26 /**
  27  * Class to handle file lock manager registration
  28  *
  29  * @ingroup LockManager
  30  * @author Aaron Schulz
  31  * @since 1.19
  32  */
  33 class LockManagerGroup {
  34         /** @var LockManagerGroup[] (domain => LockManagerGroup) */
  35         protected static $instances = [];
  36
  37         protected $domain; // string; domain (usually wiki ID)
  38
  39         /** @var array Array of (name => ('class' => ..., 'config' => ..., 'instance' => ...)) */
  40         protected $managers = [];
  41
  42         /**
  43          * @param string $domain Domain (usually wiki ID)
  44          */
  45         protected function __construct( $domain ) {
  46                 $this->domain = $domain;
  47         }
  48
  49         /**
  50          * @param bool|string $domain Domain (usually wiki ID). Default: false.
  51          * @return LockManagerGroup
  52          */
  53         public static function singleton( $domain = false ) {
  54                 $domain = ( $domain === false ) ? wfWikiID() : $domain;
  55                 if ( !isset( self::$instances[$domain] ) ) {
  56                         self::$instances[$domain] = new self( $domain );
  57                         self::$instances[$domain]->initFromGlobals();
  58                 }
  59
  60                 return self::$instances[$domain];
  61         }
  62
  63         /**
  64          * Destroy the singleton instances
  65          */
  66         public static function destroySingletons() {
  67                 self::$instances = [];
  68         }
  69
  70         /**
  71          * Register lock managers from the global variables
  72          */
  73         protected function initFromGlobals() {
  74                 global $wgLockManagers;
  75
  76                 $this->register( $wgLockManagers );
  77         }
  78
  79         /**
  80          * Register an array of file lock manager configurations
  81          *
  82          * @param array $configs
  83          * @throws Exception
  84          */
  85         protected function register( array $configs ) {
  86                 foreach ( $configs as $config ) {
  87                         $config['domain'] = $this->domain;
  88                         if ( !isset( $config['name'] ) ) {
  89                                 throw new Exception( "Cannot register a lock manager with no name." );
  90                         }
  91                         $name = $config['name'];
  92                         if ( !isset( $config['class'] ) ) {
  93                                 throw new Exception( "Cannot register lock manager `{$name}` with no class." );
  94                         }
  95                         $class = $config['class'];
  96                         unset( $config['class'] ); // lock manager won't need this
  97                         $this->managers[$name] = [
  98                                 'class' => $class,
  99                                 'config' => $config,
 100                                 'instance' => null
 101                         ];
 102                 }
 103         }
 104
 105         /**
 106          * Get the lock manager object with a given name
 107          *
 108          * @param string $name
 109          * @return LockManager
 110          * @throws Exception
 111          */
 112         public function get( $name ) {
 113                 if ( !isset( $this->managers[$name] ) ) {
 114                         throw new Exception( "No lock manager defined with the name `$name`." );
 115                 }
 116                 // Lazy-load the actual lock manager instance
 117                 if ( !isset( $this->managers[$name]['instance'] ) ) {
 118                         $class = $this->managers[$name]['class'];
 119                         $config = $this->managers[$name]['config'];
 120                         if ( $class === 'DBLockManager' ) {
 121                                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
 122                                 $lb = $lbFactory->newMainLB( $config['domain'] );
 123                                 $dbw = $lb->getLazyConnectionRef( DB_MASTER, [], $config['domain'] );
 124
 125                                 $config['dbServers']['localDBMaster'] = $dbw;
 126                                 $config['srvCache'] = ObjectCache::getLocalServerInstance( 'hash' );
 127                         }
 128                         $config['logger'] = LoggerFactory::getInstance( 'LockManager' );
 129
 130                         $this->managers[$name]['instance'] = new $class( $config );
 131                 }
 132
 133                 return $this->managers[$name]['instance'];
 134         }
 135
 136         /**
 137          * Get the config array for a lock manager object with a given name
 138          *
 139          * @param string $name
 140          * @return array
 141          * @throws Exception
 142          */
 143         public function config( $name ) {
 144                 if ( !isset( $this->managers[$name] ) ) {
 145                         throw new Exception( "No lock manager defined with the name `$name`." );
 146                 }
 147                 $class = $this->managers[$name]['class'];
 148
 149                 return [ 'class' => $class ] + $this->managers[$name]['config'];
 150         }
 151
 152         /**
 153          * Get the default lock manager configured for the site.
 154          * Returns NullLockManager if no lock manager could be found.
 155          *
 156          * @return LockManager
 157          */
 158         public function getDefault() {
 159                 return isset( $this->managers['default'] )
 160                         ? $this->get( 'default' )
 161                         : new NullLockManager( [] );
 162         }
 163
 164         /**
 165          * Get the default lock manager configured for the site
 166          * or at least some other effective configured lock manager.
 167          * Throws an exception if no lock manager could be found.
 168          *
 169          * @return LockManager
 170          * @throws Exception
 171          */
 172         public function getAny() {
 173                 return isset( $this->managers['default'] )
 174                         ? $this->get( 'default' )
 175                         : $this->get( 'fsLockManager' );
 176         }
 177 }