includes/filerepo/backend/FileBackendGroup.php

   1 <?php
   2 /**
   3  * @file
   4  * @ingroup FileBackend
   5  * @author Aaron Schulz
   6  */
   7
   8 /**
   9  * Class to handle file backend registration
  10  *
  11  * @ingroup FileBackend
  12  * @since 1.19
  13  */
  14 class FileBackendGroup {
  15         /**
  16          * @var FileBackendGroup
  17          */
  18         protected static $instance = null;
  19
  20         /** @var Array (name => ('class' => string, 'config' => array, 'instance' => object)) */
  21         protected $backends = array();
  22
  23         protected function __construct() {}
  24
  25         /**
  26          * @return FileBackendGroup
  27          */
  28         public static function singleton() {
  29                 if ( self::$instance == null ) {
  30                         self::$instance = new self();
  31                         self::$instance->initFromGlobals();
  32                 }
  33                 return self::$instance;
  34         }
  35
  36         /**
  37          * Destroy the singleton instance
  38          *
  39          * @return void
  40          */
  41         public static function destroySingleton() {
  42                 self::$instance = null;
  43         }
  44
  45         /**
  46          * Register file backends from the global variables
  47          *
  48          * @return void
  49          */
  50         protected function initFromGlobals() {
  51                 global $wgLocalFileRepo, $wgForeignFileRepos, $wgFileBackends;
  52
  53                 // Register explicitly defined backends
  54                 $this->register( $wgFileBackends );
  55
  56                 $autoBackends = array();
  57                 // Automatically create b/c backends for file repos...
  58                 $repos = array_merge( $wgForeignFileRepos, array( $wgLocalFileRepo ) );
  59                 foreach ( $repos as $info ) {
  60                         $backendName = $info['backend'];
  61                         if ( is_object( $backendName ) || isset( $this->backends[$backendName] ) ) {
  62                                 continue; // already defined (or set to the object for some reason)
  63                         }
  64                         $repoName = $info['name'];
  65                         // Local vars that used to be FSRepo members...
  66                         $directory = $info['directory'];
  67                         $deletedDir = isset( $info['deletedDir'] )
  68                                 ? $info['deletedDir']
  69                                 : false; // deletion disabled
  70                         $thumbDir = isset( $info['thumbDir'] )
  71                                 ? $info['thumbDir']
  72                                 : "{$directory}/thumb";
  73                         $fileMode = isset( $info['fileMode'] )
  74                                 ? $info['fileMode']
  75                                 : 0644;
  76                         // Get the FS backend configuration
  77                         $autoBackends[] = array(
  78                                 'name'           => $backendName,
  79                                 'class'          => 'FSFileBackend',
  80                                 'lockManager'    => 'fsLockManager',
  81                                 'containerPaths' => array(
  82                                         "{$repoName}-public"  => "{$directory}",
  83                                         "{$repoName}-thumb"   => $thumbDir,
  84                                         "{$repoName}-deleted" => $deletedDir,
  85                                         "{$repoName}-temp"    => "{$directory}/temp"
  86                                 ),
  87                                 'fileMode'       => $fileMode,
  88                         );
  89                 }
  90
  91                 // Register implicitly defined backends
  92                 $this->register( $autoBackends );
  93         }
  94
  95         /**
  96          * Register an array of file backend configurations
  97          *
  98          * @param $configs Array
  99          * @return void
 100          * @throws MWException
 101          */
 102         protected function register( array $configs ) {
 103                 foreach ( $configs as $config ) {
 104                         if ( !isset( $config['name'] ) ) {
 105                                 throw new MWException( "Cannot register a backend with no name." );
 106                         }
 107                         $name = $config['name'];
 108                         if ( !isset( $config['class'] ) ) {
 109                                 throw new MWException( "Cannot register backend `{$name}` with no class." );
 110                         }
 111                         $class = $config['class'];
 112
 113                         unset( $config['class'] ); // backend won't need this
 114                         $this->backends[$name] = array(
 115                                 'class'    => $class,
 116                                 'config'   => $config,
 117                                 'instance' => null
 118                         );
 119                 }
 120         }
 121
 122         /**
 123          * Get the backend object with a given name
 124          *
 125          * @param $name string
 126          * @return FileBackend
 127          * @throws MWException
 128          */
 129         public function get( $name ) {
 130                 if ( !isset( $this->backends[$name] ) ) {
 131                         throw new MWException( "No backend defined with the name `$name`." );
 132                 }
 133                 // Lazy-load the actual backend instance
 134                 if ( !isset( $this->backends[$name]['instance'] ) ) {
 135                         $class = $this->backends[$name]['class'];
 136                         $config = $this->backends[$name]['config'];
 137                         $this->backends[$name]['instance'] = new $class( $config );
 138                 }
 139                 return $this->backends[$name]['instance'];
 140         }
 141
 142         /**
 143          * Get an appropriate backend object from a storage path
 144          *
 145          * @param $storagePath string
 146          * @return FileBackend|null Backend or null on failure
 147          */
 148         public function backendFromPath( $storagePath ) {
 149                 list( $backend, $c, $p ) = FileBackend::splitStoragePath( $storagePath );
 150                 if ( $backend !== null && isset( $this->backends[$backend] ) ) {
 151                         return $this->get( $backend );
 152                 }
 153                 return null;
 154         }
 155 }