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  */
  23 use \MediaWiki\Logger\LoggerFactory;
  24 use MediaWiki\MediaWikiServices;
  25
  26 /**
  27  * Class to handle file backend registration
  28  *
  29  * @ingroup FileBackend
  30  * @since 1.19
  31  */
  32 class FileBackendGroup {
  33         /** @var FileBackendGroup */
  34         protected static $instance = null;
  35
  36         /** @var array (name => ('class' => string, 'config' => array, 'instance' => object)) */
  37         protected $backends = [];
  38
  39         protected function __construct() {
  40         }
  41
  42         /**
  43          * @return FileBackendGroup
  44          */
  45         public static function singleton() {
  46                 if ( self::$instance == null ) {
  47                         self::$instance = new self();
  48                         self::$instance->initFromGlobals();
  49                 }
  50
  51                 return self::$instance;
  52         }
  53
  54         /**
  55          * Destroy the singleton instance
  56          */
  57         public static function destroySingleton() {
  58                 self::$instance = null;
  59         }
  60
  61         /**
  62          * Register file backends from the global variables
  63          */
  64         protected function initFromGlobals() {
  65                 global $wgLocalFileRepo, $wgForeignFileRepos, $wgFileBackends, $wgDirectoryMode;
  66
  67                 // Register explicitly defined backends
  68                 $this->register( $wgFileBackends, wfConfiguredReadOnlyReason() );
  69
  70                 $autoBackends = [];
  71                 // Automatically create b/c backends for file repos...
  72                 $repos = array_merge( $wgForeignFileRepos, [ $wgLocalFileRepo ] );
  73                 foreach ( $repos as $info ) {
  74                         $backendName = $info['backend'];
  75                         if ( is_object( $backendName ) || isset( $this->backends[$backendName] ) ) {
  76                                 continue; // already defined (or set to the object for some reason)
  77                         }
  78                         $repoName = $info['name'];
  79                         // Local vars that used to be FSRepo members...
  80                         $directory = $info['directory'];
  81                         $deletedDir = isset( $info['deletedDir'] )
  82                                 ? $info['deletedDir']
  83                                 : false; // deletion disabled
  84                         $thumbDir = isset( $info['thumbDir'] )
  85                                 ? $info['thumbDir']
  86                                 : "{$directory}/thumb";
  87                         $transcodedDir = isset( $info['transcodedDir'] )
  88                                 ? $info['transcodedDir']
  89                                 : "{$directory}/transcoded";
  90                         // Get the FS backend configuration
  91                         $autoBackends[] = [
  92                                 'name' => $backendName,
  93                                 'class' => 'FSFileBackend',
  94                                 'lockManager' => 'fsLockManager',
  95                                 'containerPaths' => [
  96                                         "{$repoName}-public" => "{$directory}",
  97                                         "{$repoName}-thumb" => $thumbDir,
  98                                         "{$repoName}-transcoded" => $transcodedDir,
  99                                         "{$repoName}-deleted" => $deletedDir,
 100                                         "{$repoName}-temp" => "{$directory}/temp"
 101                                 ],
 102                                 'fileMode' => isset( $info['fileMode'] ) ? $info['fileMode'] : 0644,
 103                                 'directoryMode' => $wgDirectoryMode,
 104                         ];
 105                 }
 106
 107                 // Register implicitly defined backends
 108                 $this->register( $autoBackends, wfConfiguredReadOnlyReason() );
 109         }
 110
 111         /**
 112          * Register an array of file backend configurations
 113          *
 114          * @param array $configs
 115          * @param string|null $readOnlyReason
 116          * @throws InvalidArgumentException
 117          */
 118         protected function register( array $configs, $readOnlyReason = null ) {
 119                 foreach ( $configs as $config ) {
 120                         if ( !isset( $config['name'] ) ) {
 121                                 throw new InvalidArgumentException( "Cannot register a backend with no name." );
 122                         }
 123                         $name = $config['name'];
 124                         if ( isset( $this->backends[$name] ) ) {
 125                                 throw new LogicException( "Backend with name `{$name}` already registered." );
 126                         } elseif ( !isset( $config['class'] ) ) {
 127                                 throw new InvalidArgumentException( "Backend with name `{$name}` has no class." );
 128                         }
 129                         $class = $config['class'];
 130
 131                         $config['readOnly'] = !empty( $config['readOnly'] )
 132                                 ? $config['readOnly']
 133                                 : $readOnlyReason;
 134
 135                         unset( $config['class'] ); // backend won't need this
 136                         $this->backends[$name] = [
 137                                 'class' => $class,
 138                                 'config' => $config,
 139                                 'instance' => null
 140                         ];
 141                 }
 142         }
 143
 144         /**
 145          * Get the backend object with a given name
 146          *
 147          * @param string $name
 148          * @return FileBackend
 149          * @throws InvalidArgumentException
 150          */
 151         public function get( $name ) {
 152                 // Lazy-load the actual backend instance
 153                 if ( !isset( $this->backends[$name]['instance'] ) ) {
 154                         $config = $this->config( $name );
 155
 156                         $class = $config['class'];
 157                         if ( $class === 'FileBackendMultiWrite' ) {
 158                                 foreach ( $config['backends'] as $index => $beConfig ) {
 159                                         if ( isset( $beConfig['template'] ) ) {
 160                                                 // Config is just a modified version of a registered backend's.
 161                                                 // This should only be used when that config is used only by this backend.
 162                                                 $config['backends'][$index] += $this->config( $beConfig['template'] );
 163                                         }
 164                                 }
 165                         }
 166
 167                         $this->backends[$name]['instance'] = new $class( $config );
 168                 }
 169
 170                 return $this->backends[$name]['instance'];
 171         }
 172
 173         /**
 174          * Get the config array for a backend object with a given name
 175          *
 176          * @param string $name
 177          * @return array Parameters to FileBackend::__construct()
 178          * @throws InvalidArgumentException
 179          */
 180         public function config( $name ) {
 181                 if ( !isset( $this->backends[$name] ) ) {
 182                         throw new InvalidArgumentException( "No backend defined with the name `$name`." );
 183                 }
 184                 $class = $this->backends[$name]['class'];
 185
 186                 $config = $this->backends[$name]['config'];
 187                 $config['class'] = $class;
 188                 $config += [ // set defaults
 189                         'wikiId' => wfWikiID(), // e.g. "my_wiki-en_"
 190                         'mimeCallback' => [ $this, 'guessMimeInternal' ],
 191                         'obResetFunc' => 'wfResetOutputBuffers',
 192                         'streamMimeFunc' => [ 'StreamFile', 'contentTypeFromPath' ],
 193                         'tmpDirectory' => wfTempDir(),
 194                         'statusWrapper' => [ 'Status', 'wrap' ],
 195                         'wanCache' => MediaWikiServices::getInstance()->getMainWANObjectCache(),
 196                         'srvCache' => ObjectCache::getLocalServerInstance( 'hash' ),
 197                         'logger' => LoggerFactory::getInstance( 'FileOperation' ),
 198                         'profiler' => Profiler::instance()
 199                 ];
 200                 $config['lockManager'] =
 201                         LockManagerGroup::singleton( $config['wikiId'] )->get( $config['lockManager'] );
 202                 $config['fileJournal'] = isset( $config['fileJournal'] )
 203                         ? FileJournal::factory( $config['fileJournal'], $name )
 204                         : FileJournal::factory( [ 'class' => 'NullFileJournal' ], $name );
 205
 206                 return $config;
 207         }
 208
 209         /**
 210          * Get an appropriate backend object from a storage path
 211          *
 212          * @param string $storagePath
 213          * @return FileBackend|null Backend or null on failure
 214          */
 215         public function backendFromPath( $storagePath ) {
 216                 list( $backend, , ) = FileBackend::splitStoragePath( $storagePath );
 217                 if ( $backend !== null && isset( $this->backends[$backend] ) ) {
 218                         return $this->get( $backend );
 219                 }
 220
 221                 return null;
 222         }
 223
 224         /**
 225          * @param string $storagePath
 226          * @param string|null $content
 227          * @param string|null $fsPath
 228          * @return string
 229          * @since 1.27
 230          */
 231         public function guessMimeInternal( $storagePath, $content, $fsPath ) {
 232                 $magic = MimeMagic::singleton();
 233                 // Trust the extension of the storage path (caller must validate)
 234                 $ext = FileBackend::extensionFromPath( $storagePath );
 235                 $type = $magic->guessTypesForExtension( $ext );
 236                 // For files without a valid extension (or one at all), inspect the contents
 237                 if ( !$type && $fsPath ) {
 238                         $type = $magic->guessMimeType( $fsPath, false );
 239                 } elseif ( !$type && strlen( $content ) ) {
 240                         $tmpFile = TempFSFile::factory( 'mime_', '', wfTempDir() );
 241                         file_put_contents( $tmpFile->getPath(), $content );
 242                         $type = $magic->guessMimeType( $tmpFile->getPath(), false );
 243                 }
 244                 return $type ?: 'unknown/unknown';
 245         }
 246 }