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 use \MediaWiki\Logger\LoggerFactory;
  25 use MediaWiki\MediaWikiServices;
  26
  27 /**
  28  * Class to handle file backend registration
  29  *
  30  * @ingroup FileBackend
  31  * @since 1.19
  32  */
  33 class FileBackendGroup {
  34         /** @var FileBackendGroup */
  35         protected static $instance = null;
  36
  37         /** @var array (name => ('class' => string, 'config' => array, 'instance' => object)) */
  38         protected $backends = [];
  39
  40         protected function __construct() {
  41         }
  42
  43         /**
  44          * @return FileBackendGroup
  45          */
  46         public static function singleton() {
  47                 if ( self::$instance == null ) {
  48                         self::$instance = new self();
  49                         self::$instance->initFromGlobals();
  50                 }
  51
  52                 return self::$instance;
  53         }
  54
  55         /**
  56          * Destroy the singleton instance
  57          */
  58         public static function destroySingleton() {
  59                 self::$instance = null;
  60         }
  61
  62         /**
  63          * Register file backends from the global variables
  64          */
  65         protected function initFromGlobals() {
  66                 global $wgLocalFileRepo, $wgForeignFileRepos, $wgFileBackends, $wgDirectoryMode;
  67
  68                 // Register explicitly defined backends
  69                 $this->register( $wgFileBackends, wfConfiguredReadOnlyReason() );
  70
  71                 $autoBackends = [];
  72                 // Automatically create b/c backends for file repos...
  73                 $repos = array_merge( $wgForeignFileRepos, [ $wgLocalFileRepo ] );
  74                 foreach ( $repos as $info ) {
  75                         $backendName = $info['backend'];
  76                         if ( is_object( $backendName ) || isset( $this->backends[$backendName] ) ) {
  77                                 continue; // already defined (or set to the object for some reason)
  78                         }
  79                         $repoName = $info['name'];
  80                         // Local vars that used to be FSRepo members...
  81                         $directory = $info['directory'];
  82                         $deletedDir = isset( $info['deletedDir'] )
  83                                 ? $info['deletedDir']
  84                                 : false; // deletion disabled
  85                         $thumbDir = isset( $info['thumbDir'] )
  86                                 ? $info['thumbDir']
  87                                 : "{$directory}/thumb";
  88                         $transcodedDir = isset( $info['transcodedDir'] )
  89                                 ? $info['transcodedDir']
  90                                 : "{$directory}/transcoded";
  91                         // Get the FS backend configuration
  92                         $autoBackends[] = [
  93                                 'name' => $backendName,
  94                                 'class' => 'FSFileBackend',
  95                                 'lockManager' => 'fsLockManager',
  96                                 'containerPaths' => [
  97                                         "{$repoName}-public" => "{$directory}",
  98                                         "{$repoName}-thumb" => $thumbDir,
  99                                         "{$repoName}-transcoded" => $transcodedDir,
 100                                         "{$repoName}-deleted" => $deletedDir,
 101                                         "{$repoName}-temp" => "{$directory}/temp"
 102                                 ],
 103                                 'fileMode' => isset( $info['fileMode'] ) ? $info['fileMode'] : 0644,
 104                                 'directoryMode' => $wgDirectoryMode,
 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 InvalidArgumentException
 118          */
 119         protected function register( array $configs, $readOnlyReason = null ) {
 120                 foreach ( $configs as $config ) {
 121                         if ( !isset( $config['name'] ) ) {
 122                                 throw new InvalidArgumentException( "Cannot register a backend with no name." );
 123                         }
 124                         $name = $config['name'];
 125                         if ( isset( $this->backends[$name] ) ) {
 126                                 throw new LogicException( "Backend with name `{$name}` already registered." );
 127                         } elseif ( !isset( $config['class'] ) ) {
 128                                 throw new InvalidArgumentException( "Backend with name `{$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 InvalidArgumentException
 151          */
 152         public function get( $name ) {
 153                 // Lazy-load the actual backend instance
 154                 if ( !isset( $this->backends[$name]['instance'] ) ) {
 155                         $config = $this->config( $name );
 156
 157                         $class = $config['class'];
 158                         if ( $class === 'FileBackendMultiWrite' ) {
 159                                 foreach ( $config['backends'] as $index => $beConfig ) {
 160                                         if ( isset( $beConfig['template'] ) ) {
 161                                                 // Config is just a modified version of a registered backend's.
 162                                                 // This should only be used when that config is used only by this backend.
 163                                                 $config['backends'][$index] += $this->config( $beConfig['template'] );
 164                                         }
 165                                 }
 166                         }
 167
 168                         $this->backends[$name]['instance'] = new $class( $config );
 169                 }
 170
 171                 return $this->backends[$name]['instance'];
 172         }
 173
 174         /**
 175          * Get the config array for a backend object with a given name
 176          *
 177          * @param string $name
 178          * @return array Parameters to FileBackend::__construct()
 179          * @throws InvalidArgumentException
 180          */
 181         public function config( $name ) {
 182                 if ( !isset( $this->backends[$name] ) ) {
 183                         throw new InvalidArgumentException( "No backend defined with the name `$name`." );
 184                 }
 185                 $class = $this->backends[$name]['class'];
 186
 187                 $config = $this->backends[$name]['config'];
 188                 $config['class'] = $class;
 189                 $config += [ // set defaults
 190                         'wikiId' => wfWikiID(), // e.g. "my_wiki-en_"
 191                         'mimeCallback' => [ $this, 'guessMimeInternal' ],
 192                         'obResetFunc' => 'wfResetOutputBuffers',
 193                         'streamMimeFunc' => [ 'StreamFile', 'contentTypeFromPath' ],
 194                         'tmpDirectory' => wfTempDir(),
 195                         'statusWrapper' => [ 'Status', 'wrap' ],
 196                         'wanCache' => MediaWikiServices::getInstance()->getMainWANObjectCache(),
 197                         'srvCache' => ObjectCache::getLocalServerInstance( 'hash' ),
 198                         'logger' => LoggerFactory::getInstance( 'FileOperation' ),
 199                         'profiler' => Profiler::instance()
 200                 ];
 201                 $config['lockManager'] =
 202                         LockManagerGroup::singleton( $config['wikiId'] )->get( $config['lockManager'] );
 203                 $config['fileJournal'] = isset( $config['fileJournal'] )
 204                         ? FileJournal::factory( $config['fileJournal'], $name )
 205                         : FileJournal::factory( [ 'class' => 'NullFileJournal' ], $name );
 206
 207                 return $config;
 208         }
 209
 210         /**
 211          * Get an appropriate backend object from a storage path
 212          *
 213          * @param string $storagePath
 214          * @return FileBackend|null Backend or null on failure
 215          */
 216         public function backendFromPath( $storagePath ) {
 217                 list( $backend, , ) = FileBackend::splitStoragePath( $storagePath );
 218                 if ( $backend !== null && isset( $this->backends[$backend] ) ) {
 219                         return $this->get( $backend );
 220                 }
 221
 222                 return null;
 223         }
 224
 225         /**
 226          * @param string $storagePath
 227          * @param string|null $content
 228          * @param string|null $fsPath
 229          * @return string
 230          * @since 1.27
 231          */
 232         public function guessMimeInternal( $storagePath, $content, $fsPath ) {
 233                 $magic = MimeMagic::singleton();
 234                 // Trust the extension of the storage path (caller must validate)
 235                 $ext = FileBackend::extensionFromPath( $storagePath );
 236                 $type = $magic->guessTypesForExtension( $ext );
 237                 // For files without a valid extension (or one at all), inspect the contents
 238                 if ( !$type && $fsPath ) {
 239                         $type = $magic->guessMimeType( $fsPath, false );
 240                 } elseif ( !$type && strlen( $content ) ) {
 241                         $tmpFile = TempFSFile::factory( 'mime_', '', wfTempDir() );
 242                         file_put_contents( $tmpFile->getPath(), $content );
 243                         $type = $magic->guessMimeType( $tmpFile->getPath(), false );
 244                 }
 245                 return $type ?: 'unknown/unknown';
 246         }
 247 }