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         protected static $instance = null;
  11
  12         /** @var Array of (name => ('class' =>, 'config' =>, 'instance' =>)) */
  13         protected $managers = array();
  14
  15         protected function __construct() {}
  16         protected function __clone() {}
  17
  18         /**
  19          * @return LockManagerGroup
  20          */
  21         public static function singleton() {
  22                 if ( self::$instance == null ) {
  23                         self::$instance = new self();
  24                         self::$instance->initFromGlobals();
  25                 }
  26                 return self::$instance;
  27         }
  28
  29         /**
  30          * Register lock managers from the global variables
  31          *
  32          * @return void
  33          */
  34         protected function initFromGlobals() {
  35                 global $wgLockManagers;
  36
  37                 $this->register( $wgLockManagers );
  38         }
  39
  40         /**
  41          * Register an array of file lock manager configurations
  42          *
  43          * @param $configs Array
  44          * @return void
  45          * @throws MWException
  46          */
  47         protected function register( array $configs ) {
  48                 foreach ( $configs as $config ) {
  49                         if ( !isset( $config['name'] ) ) {
  50                                 throw new MWException( "Cannot register a lock manager with no name." );
  51                         }
  52                         $name = $config['name'];
  53                         if ( !isset( $config['class'] ) ) {
  54                                 throw new MWException( "Cannot register lock manager `{$name}` with no class." );
  55                         }
  56                         $class = $config['class'];
  57                         unset( $config['class'] ); // lock manager won't need this
  58                         $this->managers[$name] = array(
  59                                 'class'    => $class,
  60                                 'config'   => $config,
  61                                 'instance' => null
  62                         );
  63                 }
  64         }
  65
  66         /**
  67          * Get the lock manager object with a given name
  68          *
  69          * @param $name string
  70          * @return LockManager
  71          * @throws MWException
  72          */
  73         public function get( $name ) {
  74                 if ( !isset( $this->managers[$name] ) ) {
  75                         throw new MWException( "No lock manager defined with the name `$name`." );
  76                 }
  77                 // Lazy-load the actual lock manager instance
  78                 if ( !isset( $this->managers[$name]['instance'] ) ) {
  79                         $class = $this->managers[$name]['class'];
  80                         $config = $this->managers[$name]['config'];
  81                         $this->managers[$name]['instance'] = new $class( $config );
  82                 }
  83                 return $this->managers[$name]['instance'];
  84         }
  85 }