includes/filebackend/FileBackendGroup.php

   1 <?php
   2 /**
   3  * File backend registration handling.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup FileBackend
  22  * @author Aaron Schulz
  23  */
  24
  25 /**
  26  * Class to handle file backend registration
  27  *
  28  * @ingroup FileBackend
  29  * @since 1.19
  30  */
  31 class FileBackendGroup {
  32         /** @var FileBackendGroup */
  33         protected static $instance = null;
  34
  35         /** @var array (name => ('class' => string, 'config' => array, 'instance' => object)) */
  36         protected $backends = array();
  37
  38         protected function __construct() {
  39         }
  40
  41         /**
  42          * @return FileBackendGroup
  43          */
  44         public static function singleton() {
  45                 if ( self::$instance == null ) {
  46                         self::$instance = new self();
  47                         self::$instance->initFromGlobals();
  48                 }
  49
  50                 return self::$instance;
  51         }
  52
  53         /**
  54          * Destroy the singleton instance
  55          */
  56         public static function destroySingleton() {
  57                 self::$instance = null;
  58         }
  59
  60         /**
  61          * Register file backends from the global variables
  62          */
  63         protected function initFromGlobals() {
  64                 global $wgLocalFileRepo, $wgForeignFileRepos, $wgFileBackends;
  65
  66                 // Register explicitly defined backends
  67                 $this->register( $wgFileBackends );
  68
  69                 $autoBackends = array();
  70                 // Automatically create b/c backends for file repos...
  71                 $repos = array_merge( $wgForeignFileRepos, array( $wgLocalFileRepo ) );
  72                 foreach ( $repos as $info ) {
  73                         $backendName = $info['backend'];
  74                         if ( is_object( $backendName ) || isset( $this->backends[$backendName] ) ) {
  75                                 continue; // already defined (or set to the object for some reason)
  76                         }
  77                         $repoName = $info['name'];
  78                         // Local vars that used to be FSRepo members...
  79                         $directory = $info['directory'];
  80                         $deletedDir = isset( $info['deletedDir'] )
  81                                 ? $info['deletedDir']
  82                                 : false; // deletion disabled
  83                         $thumbDir = isset( $info['thumbDir'] )
  84                                 ? $info['thumbDir']
  85                                 : "{$directory}/thumb";
  86                         $transcodedDir = isset( $info['transcodedDir'] )
  87                                 ? $info['transcodedDir']
  88                                 : "{$directory}/transcoded";
  89                         $fileMode = isset( $info['fileMode'] )
  90                                 ? $info['fileMode']
  91                                 : 0644;
  92                         // Get the FS backend configuration
  93                         $autoBackends[] = array(
  94                                 'name' => $backendName,
  95                                 'class' => 'FSFileBackend',
  96                                 'lockManager' => 'fsLockManager',
  97                                 'containerPaths' => array(
  98                                         "{$repoName}-public" => "{$directory}",
  99                                         "{$repoName}-thumb" => $thumbDir,
 100                                         "{$repoName}-transcoded" => $transcodedDir,
 101                                         "{$repoName}-deleted" => $deletedDir,
 102                                         "{$repoName}-temp" => "{$directory}/temp"
 103                                 ),
 104                                 'fileMode' => $fileMode,
 105                         );
 106                 }
 107
 108                 // Register implicitly defined backends
 109                 $this->register( $autoBackends );
 110         }
 111
 112         /**
 113          * Register an array of file backend configurations
 114          *
 115          * @param array $configs
 116          * @throws FileBackendException
 117          */
 118         protected function register( array $configs ) {
 119                 foreach ( $configs as $config ) {
 120                         if ( !isset( $config['name'] ) ) {
 121                                 throw new FileBackendException( "Cannot register a backend with no name." );
 122                         }
 123                         $name = $config['name'];
 124                         if ( isset( $this->backends[$name] ) ) {
 125                                 throw new FileBackendException( "Backend with name `{$name}` already registered." );
 126                         } elseif ( !isset( $config['class'] ) ) {
 127                                 throw new FileBackendException( "Backend with name `{$name}` has no class." );
 128                         }
 129                         $class = $config['class'];
 130
 131                         unset( $config['class'] ); // backend won't need this
 132                         $this->backends[$name] = array(
 133                                 'class' => $class,
 134                                 'config' => $config,
 135                                 'instance' => null
 136                         );
 137                 }
 138         }
 139
 140         /**
 141          * Get the backend object with a given name
 142          *
 143          * @param string $name
 144          * @return FileBackend
 145          * @throws FileBackendException
 146          */
 147         public function get( $name ) {
 148                 if ( !isset( $this->backends[$name] ) ) {
 149                         throw new FileBackendException( "No backend defined with the name `$name`." );
 150                 }
 151                 // Lazy-load the actual backend instance
 152                 if ( !isset( $this->backends[$name]['instance'] ) ) {
 153                         $class = $this->backends[$name]['class'];
 154                         $config = $this->backends[$name]['config'];
 155                         $config['wikiId'] = isset( $config['wikiId'] )
 156                                 ? $config['wikiId']
 157                                 : wfWikiID(); // e.g. "my_wiki-en_"
 158                         $config['lockManager'] =
 159                                 LockManagerGroup::singleton( $config['wikiId'] )->get( $config['lockManager'] );
 160                         $config['fileJournal'] = isset( $config['fileJournal'] )
 161                                 ? FileJournal::factory( $config['fileJournal'], $name )
 162                                 : FileJournal::factory( array( 'class' => 'NullFileJournal' ), $name );
 163                         $this->backends[$name]['instance'] = new $class( $config );
 164                 }
 165
 166                 return $this->backends[$name]['instance'];
 167         }
 168
 169         /**
 170          * Get the config array for a backend object with a given name
 171          *
 172          * @param string $name
 173          * @return array
 174          * @throws FileBackendException
 175          */
 176         public function config( $name ) {
 177                 if ( !isset( $this->backends[$name] ) ) {
 178                         throw new FileBackendException( "No backend defined with the name `$name`." );
 179                 }
 180                 $class = $this->backends[$name]['class'];
 181
 182                 return array( 'class' => $class ) + $this->backends[$name]['config'];
 183         }
 184
 185         /**
 186          * Get an appropriate backend object from a storage path
 187          *
 188          * @param string $storagePath
 189          * @return FileBackend|null Backend or null on failure
 190          */
 191         public function backendFromPath( $storagePath ) {
 192                 list( $backend, , ) = FileBackend::splitStoragePath( $storagePath );
 193                 if ( $backend !== null && isset( $this->backends[$backend] ) ) {
 194                         return $this->get( $backend );
 195                 }
 196
 197                 return null;
 198         }
 199 }