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
  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 = $info['deletedDir'] ?? false; // deletion disabled
  83                         $thumbDir = $info['thumbDir'] ?? "{$directory}/thumb";
  84                         $transcodedDir = $info['transcodedDir'] ?? "{$directory}/transcoded";
  85                         // Get the FS backend configuration
  86                         $autoBackends[] = [
  87                                 'name' => $backendName,
  88                                 'class' => FSFileBackend::class,
  89                                 'lockManager' => 'fsLockManager',
  90                                 'containerPaths' => [
  91                                         "{$repoName}-public" => "{$directory}",
  92                                         "{$repoName}-thumb" => $thumbDir,
  93                                         "{$repoName}-transcoded" => $transcodedDir,
  94                                         "{$repoName}-deleted" => $deletedDir,
  95                                         "{$repoName}-temp" => "{$directory}/temp"
  96                                 ],
  97                                 'fileMode' => $info['fileMode'] ?? 0644,
  98                                 'directoryMode' => $wgDirectoryMode,
  99                         ];
 100                 }
 101
 102                 // Register implicitly defined backends
 103                 $this->register( $autoBackends, wfConfiguredReadOnlyReason() );
 104         }
 105
 106         /**
 107          * Register an array of file backend configurations
 108          *
 109          * @param array[] $configs
 110          * @param string|null $readOnlyReason
 111          * @throws InvalidArgumentException
 112          */
 113         protected function register( array $configs, $readOnlyReason = null ) {
 114                 foreach ( $configs as $config ) {
 115                         if ( !isset( $config['name'] ) ) {
 116                                 throw new InvalidArgumentException( "Cannot register a backend with no name." );
 117                         }
 118                         $name = $config['name'];
 119                         if ( isset( $this->backends[$name] ) ) {
 120                                 throw new LogicException( "Backend with name '$name' already registered." );
 121                         } elseif ( !isset( $config['class'] ) ) {
 122                                 throw new InvalidArgumentException( "Backend with name '$name' has no class." );
 123                         }
 124                         $class = $config['class'];
 125
 126                         // @FIXME: ideally this would default to the DB domain (which includes the schema)
 127                         $config['domainId'] = $config['domainId'] ?? ( $config['wikiId'] ?? wfWikiID() );
 128                         $config['readOnly'] = $config['readOnly'] ?? $readOnlyReason;
 129
 130                         unset( $config['class'] ); // backend won't need this
 131                         $this->backends[$name] = [
 132                                 'class' => $class,
 133                                 'config' => $config,
 134                                 'instance' => null
 135                         ];
 136                 }
 137         }
 138
 139         /**
 140          * Get the backend object with a given name
 141          *
 142          * @param string $name
 143          * @return FileBackend
 144          * @throws InvalidArgumentException
 145          */
 146         public function get( $name ) {
 147                 // Lazy-load the actual backend instance
 148                 if ( !isset( $this->backends[$name]['instance'] ) ) {
 149                         $config = $this->config( $name );
 150
 151                         $class = $config['class'];
 152                         if ( $class === FileBackendMultiWrite::class ) {
 153                                 // @todo How can we test this? What's the intended use-case?
 154                                 foreach ( $config['backends'] as $index => $beConfig ) {
 155                                         if ( isset( $beConfig['template'] ) ) {
 156                                                 // Config is just a modified version of a registered backend's.
 157                                                 // This should only be used when that config is used only by this backend.
 158                                                 $config['backends'][$index] += $this->config( $beConfig['template'] );
 159                                         }
 160                                 }
 161                         }
 162
 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 Parameters to FileBackend::__construct()
 174          * @throws InvalidArgumentException
 175          */
 176         public function config( $name ) {
 177                 if ( !isset( $this->backends[$name] ) ) {
 178                         throw new InvalidArgumentException( "No backend defined with the name '$name'." );
 179                 }
 180
 181                 $config = $this->backends[$name]['config'];
 182                 $services = MediaWikiServices::getInstance();
 183
 184                 return array_merge(
 185                         // Default backend parameters
 186                         [
 187                                 'mimeCallback' => [ $this, 'guessMimeInternal' ],
 188                                 'obResetFunc' => 'wfResetOutputBuffers',
 189                                 'streamMimeFunc' => [ StreamFile::class, 'contentTypeFromPath' ],
 190                                 'tmpFileFactory' => $services->getTempFSFileFactory(),
 191                                 'statusWrapper' => [ Status::class, 'wrap' ],
 192                                 'wanCache' => $services->getMainWANObjectCache(),
 193                                 'srvCache' => ObjectCache::getLocalServerInstance( 'hash' ),
 194                                 'logger' => LoggerFactory::getInstance( 'FileOperation' ),
 195                                 'profiler' => function ( $section ) {
 196                                         return Profiler::instance()->scopedProfileIn( $section );
 197                                 }
 198                         ],
 199                         // Configured backend parameters
 200                         $config,
 201                         // Resolved backend parameters
 202                         [
 203                                 'class' => $this->backends[$name]['class'],
 204                                 'lockManager' =>
 205                                         LockManagerGroup::singleton( $config['domainId'] )
 206                                                 ->get( $config['lockManager'] ),
 207                                 'fileJournal' => isset( $config['fileJournal'] )
 208                                         ? FileJournal::factory( $config['fileJournal'], $name )
 209                                         : FileJournal::factory( [ 'class' => NullFileJournal::class ], $name )
 210                         ]
 211                 );
 212         }
 213
 214         /**
 215          * Get an appropriate backend object from a storage path
 216          *
 217          * @param string $storagePath
 218          * @return FileBackend|null Backend or null on failure
 219          */
 220         public function backendFromPath( $storagePath ) {
 221                 list( $backend, , ) = FileBackend::splitStoragePath( $storagePath );
 222                 if ( $backend !== null && isset( $this->backends[$backend] ) ) {
 223                         return $this->get( $backend );
 224                 }
 225
 226                 return null;
 227         }
 228
 229         /**
 230          * @param string $storagePath
 231          * @param string|null $content
 232          * @param string|null $fsPath
 233          * @return string
 234          * @since 1.27
 235          */
 236         public function guessMimeInternal( $storagePath, $content, $fsPath ) {
 237                 $magic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
 238                 // Trust the extension of the storage path (caller must validate)
 239                 $ext = FileBackend::extensionFromPath( $storagePath );
 240                 $type = $magic->guessTypesForExtension( $ext );
 241                 // For files without a valid extension (or one at all), inspect the contents
 242                 if ( !$type && $fsPath ) {
 243                         $type = $magic->guessMimeType( $fsPath, false );
 244                 } elseif ( !$type && strlen( $content ) ) {
 245                         $tmpFile = MediaWikiServices::getInstance()->getTempFSFileFactory()
 246                                 ->newTempFSFile( 'mime_', '' );
 247                         file_put_contents( $tmpFile->getPath(), $content );
 248                         $type = $magic->guessMimeType( $tmpFile->getPath(), false );
 249                 }
 250                 return $type ?: 'unknown/unknown';
 251         }
 252 }