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