includes/filerepo/backend/lockmanager/LockManagerGroup.php

   1 <?php
   2 /**
   3  * Class to handle file lock manager registration
   4  *
   5  * @ingroup LockManager
   6  * @author Aaron Schulz
   7  * @since 1.19
   8  */
   9 class LockManagerGroup {
  10
  11         /**
  12          * @var LockManagerGroup
  13          */
  14         protected static $instance = null;
  15
  16         /** @var Array of (name => ('class' =>, 'config' =>, 'instance' =>)) */
  17         protected $managers = array();
  18
  19         protected function __construct() {}
  20         protected function __clone() {}
  21
  22         /**
  23          * @return LockManagerGroup
  24          */
  25         public static function singleton() {
  26                 if ( self::$instance == null ) {
  27                         self::$instance = new self();
  28                         self::$instance->initFromGlobals();
  29                 }
  30                 return self::$instance;
  31         }
  32
  33         /**
  34          * Destroy the singleton instance, so that a new one will be created next
  35          * time singleton() is called.
  36          */
  37         public static function destroySingleton() {
  38                 self::$instance = null;
  39         }
  40
  41         /**
  42          * Register lock managers from the global variables
  43          *
  44          * @return void
  45          */
  46         protected function initFromGlobals() {
  47                 global $wgLockManagers;
  48
  49                 $this->register( $wgLockManagers );
  50         }
  51
  52         /**
  53          * Register an array of file lock manager configurations
  54          *
  55          * @param $configs Array
  56          * @return void
  57          * @throws MWException
  58          */
  59         protected function register( array $configs ) {
  60                 foreach ( $configs as $config ) {
  61                         if ( !isset( $config['name'] ) ) {
  62                                 throw new MWException( "Cannot register a lock manager with no name." );
  63                         }
  64                         $name = $config['name'];
  65                         if ( !isset( $config['class'] ) ) {
  66                                 throw new MWException( "Cannot register lock manager `{$name}` with no class." );
  67                         }
  68                         $class = $config['class'];
  69                         unset( $config['class'] ); // lock manager won't need this
  70                         $this->managers[$name] = array(
  71                                 'class'    => $class,
  72                                 'config'   => $config,
  73                                 'instance' => null
  74                         );
  75                 }
  76         }
  77
  78         /**
  79          * Get the lock manager object with a given name
  80          *
  81          * @param $name string
  82          * @return LockManager
  83          * @throws MWException
  84          */
  85         public function get( $name ) {
  86                 if ( !isset( $this->managers[$name] ) ) {
  87                         throw new MWException( "No lock manager defined with the name `$name`." );
  88                 }
  89                 // Lazy-load the actual lock manager instance
  90                 if ( !isset( $this->managers[$name]['instance'] ) ) {
  91                         $class = $this->managers[$name]['class'];
  92                         $config = $this->managers[$name]['config'];
  93                         $this->managers[$name]['instance'] = new $class( $config );
  94                 }
  95                 return $this->managers[$name]['instance'];
  96         }
  97 }