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          * Register lock managers from the global variables
  35          *
  36          * @return void
  37          */
  38         protected function initFromGlobals() {
  39                 global $wgLockManagers;
  40
  41                 $this->register( $wgLockManagers );
  42         }
  43
  44         /**
  45          * Register an array of file lock manager configurations
  46          *
  47          * @param $configs Array
  48          * @return void
  49          * @throws MWException
  50          */
  51         protected function register( array $configs ) {
  52                 foreach ( $configs as $config ) {
  53                         if ( !isset( $config['name'] ) ) {
  54                                 throw new MWException( "Cannot register a lock manager with no name." );
  55                         }
  56                         $name = $config['name'];
  57                         if ( !isset( $config['class'] ) ) {
  58                                 throw new MWException( "Cannot register lock manager `{$name}` with no class." );
  59                         }
  60                         $class = $config['class'];
  61                         unset( $config['class'] ); // lock manager won't need this
  62                         $this->managers[$name] = array(
  63                                 'class'    => $class,
  64                                 'config'   => $config,
  65                                 'instance' => null
  66                         );
  67                 }
  68         }
  69
  70         /**
  71          * Get the lock manager object with a given name
  72          *
  73          * @param $name string
  74          * @return LockManager
  75          * @throws MWException
  76          */
  77         public function get( $name ) {
  78                 if ( !isset( $this->managers[$name] ) ) {
  79                         throw new MWException( "No lock manager defined with the name `$name`." );
  80                 }
  81                 // Lazy-load the actual lock manager instance
  82                 if ( !isset( $this->managers[$name]['instance'] ) ) {
  83                         $class = $this->managers[$name]['class'];
  84                         $config = $this->managers[$name]['config'];
  85                         $this->managers[$name]['instance'] = new $class( $config );
  86                 }
  87                 return $this->managers[$name]['instance'];
  88         }
  89 }