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