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   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  }