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