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