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 $backends = [];
  37
  38         protected function __construct() {
  39         }
  40
  41         /**
  42          * @return FileBackendGroup
  43          */
  44         public static function singleton() {
  45                 if ( self::$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, wfConfiguredReadOnlyReason() );
  68
  69                 $autoBackends = [];
  70                 // Automatically create b/c backends for file repos...
  71                 $repos = array_merge( $wgForeignFileRepos, [ $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[] = [
  94                                 'name' => $backendName,
  95                                 'class' => 'FSFileBackend',
  96                                 'lockManager' => 'fsLockManager',
  97                                 'containerPaths' => [
  98                                         "{$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, wfConfiguredReadOnlyReason() );
 110         }
 111
 112         /**
 113          * Register an array of file backend configurations
 114          *
 115          * @param array $configs
 116          * @param string|null $readOnlyReason
 117          * @throws FileBackendException
 118          */
 119         protected function register( array $configs, $readOnlyReason = null ) {
 120                 foreach ( $configs as $config ) {
 121                         if ( !isset( $config['name'] ) ) {
 122                                 throw new FileBackendException( "Cannot register a backend with no name." );
 123                         }
 124                         $name = $config['name'];
 125                         if ( isset( $this->backends[$name] ) ) {
 126                                 throw new FileBackendException( "Backend with name `{$name}` already registered." );
 127                         } elseif ( !isset( $config['class'] ) ) {
 128                                 throw new FileBackendException( "Backend with name `{$name}` has no class." );
 129                         }
 130                         $class = $config['class'];
 131
 132                         $config['readOnly'] = !empty( $config['readOnly'] )
 133                                 ? $config['readOnly']
 134                                 : $readOnlyReason;
 135
 136                         unset( $config['class'] ); // backend won't need this
 137                         $this->backends[$name] = [
 138                                 'class' => $class,
 139                                 'config' => $config,
 140                                 'instance' => null
 141                         ];
 142                 }
 143         }
 144
 145         /**
 146          * Get the backend object with a given name
 147          *
 148          * @param string $name
 149          * @return FileBackend
 150          * @throws FileBackendException
 151          */
 152         public function get( $name ) {
 153                 if ( !isset( $this->backends[$name] ) ) {
 154                         throw new FileBackendException( "No backend defined with the name `$name`." );
 155                 }
 156                 // Lazy-load the actual backend instance
 157                 if ( !isset( $this->backends[$name]['instance'] ) ) {
 158                         $class = $this->backends[$name]['class'];
 159                         $config = $this->backends[$name]['config'];
 160                         $config['wikiId'] = isset( $config['wikiId'] )
 161                                 ? $config['wikiId']
 162                                 : wfWikiID(); // e.g. "my_wiki-en_"
 163                         $config['lockManager'] =
 164                                 LockManagerGroup::singleton( $config['wikiId'] )->get( $config['lockManager'] );
 165                         $config['fileJournal'] = isset( $config['fileJournal'] )
 166                                 ? FileJournal::factory( $config['fileJournal'], $name )
 167                                 : FileJournal::factory( [ 'class' => 'NullFileJournal' ], $name );
 168                         $config['wanCache'] = ObjectCache::getMainWANInstance();
 169                         $config['mimeCallback'] = [ $this, 'guessMimeInternal' ];
 170
 171                         $this->backends[$name]['instance'] = new $class( $config );
 172                 }
 173
 174                 return $this->backends[$name]['instance'];
 175         }
 176
 177         /**
 178          * Get the config array for a backend object with a given name
 179          *
 180          * @param string $name
 181          * @return array
 182          * @throws FileBackendException
 183          */
 184         public function config( $name ) {
 185                 if ( !isset( $this->backends[$name] ) ) {
 186                         throw new FileBackendException( "No backend defined with the name `$name`." );
 187                 }
 188                 $class = $this->backends[$name]['class'];
 189
 190                 return [ 'class' => $class ] + $this->backends[$name]['config'];
 191         }
 192
 193         /**
 194          * Get an appropriate backend object from a storage path
 195          *
 196          * @param string $storagePath
 197          * @return FileBackend|null Backend or null on failure
 198          */
 199         public function backendFromPath( $storagePath ) {
 200                 list( $backend, , ) = FileBackend::splitStoragePath( $storagePath );
 201                 if ( $backend !== null && isset( $this->backends[$backend] ) ) {
 202                         return $this->get( $backend );
 203                 }
 204
 205                 return null;
 206         }
 207
 208         /**
 209          * @param string $storagePath
 210          * @param string|null $content
 211          * @param string|null $fsPath
 212          * @return string
 213          * @since 1.27
 214          */
 215         public function guessMimeInternal( $storagePath, $content, $fsPath ) {
 216                 $magic = MimeMagic::singleton();
 217                 // Trust the extension of the storage path (caller must validate)
 218                 $ext = FileBackend::extensionFromPath( $storagePath );
 219                 $type = $magic->guessTypesForExtension( $ext );
 220                 // For files without a valid extension (or one at all), inspect the contents
 221                 if ( !$type && $fsPath ) {
 222                         $type = $magic->guessMimeType( $fsPath, false );
 223                 } elseif ( !$type && strlen( $content ) ) {
 224                         $tmpFile = TempFSFile::factory( 'mime_' );
 225                         file_put_contents( $tmpFile->getPath(), $content );
 226                         $type = $magic->guessMimeType( $tmpFile->getPath(), false );
 227                 }
 228                 return $type ?: 'unknown/unknown';
 229         }
 230 }