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  */
   8 class LockManagerGroup {
   9         protected static $instance = null;
  10
  11         /** @var Array of (name => ('class' =>, 'config' =>, 'instance' =>)) */
  12         protected $managers = array();
  13
  14         protected function __construct() {}
  15         protected function __clone() {}
  16
  17         /**
  18          * @return LockManagerGroup
  19          */
  20         public static function singleton() {
  21                 if ( self::$instance == null ) {
  22                         self::$instance = new self();
  23                         self::$instance->initFromGlobals();
  24                 }
  25                 return self::$instance;
  26         }
  27
  28         /**
  29          * Register lock managers from the global variables
  30          *
  31          * @return void
  32          */
  33         protected function initFromGlobals() {
  34                 global $wgLockManagers;
  35
  36                 $this->register( $wgLockManagers );
  37         }
  38
  39         /**
  40          * Register an array of file lock manager configurations
  41          *
  42          * @param $configs Array
  43          * @return void
  44          * @throws MWException
  45          */
  46         protected function register( array $configs ) {
  47                 foreach ( $configs as $config ) {
  48                         if ( !isset( $config['name'] ) ) {
  49                                 throw new MWException( "Cannot register a lock manager with no name." );
  50                         }
  51                         $name = $config['name'];
  52                         if ( !isset( $config['class'] ) ) {
  53                                 throw new MWException( "Cannot register lock manager `{$name}` with no class." );
  54                         }
  55                         $class = $config['class'];
  56                         unset( $config['class'] ); // lock manager won't need this
  57                         $this->managers[$name] = array(
  58                                 'class'    => $class,
  59                                 'config'   => $config,
  60                                 'instance' => null
  61                         );
  62                 }
  63         }
  64
  65         /**
  66          * Get the lock manager object with a given name
  67          *
  68          * @param $name string
  69          * @return LockManager
  70          * @throws MWException
  71          */
  72         public function get( $name ) {
  73                 if ( !isset( $this->managers[$name] ) ) {
  74                         throw new MWException( "No lock manager defined with the name `$name`." );
  75                 }
  76                 // Lazy-load the actual lock manager instance
  77                 if ( !isset( $this->managers[$name]['instance'] ) ) {
  78                         $class = $this->managers[$name]['class'];
  79                         $config = $this->managers[$name]['config'];
  80                         $this->managers[$name]['instance'] = new $class( $config );
  81                 }
  82                 return $this->managers[$name]['instance'];
  83         }
  84 }