includes/filerepo/RepoGroup.php

   1 <?php
   2 /**
   3  * Prioritized list of file repositories.
   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 FileRepo
  22  */
  23
  24 /**
  25  * Prioritized list of file repositories
  26  *
  27  * @ingroup FileRepo
  28  */
  29 class RepoGroup {
  30         /** @var LocalRepo */
  31         protected $localRepo;
  32
  33         /** @var FileRepo[] */
  34         protected $foreignRepos;
  35
  36         /** @var bool */
  37         protected $reposInitialised = false;
  38
  39         /** @var array */
  40         protected $localInfo;
  41
  42         /** @var array */
  43         protected $foreignInfo;
  44
  45         /** @var ProcessCacheLRU */
  46         protected $cache;
  47
  48         /** @var RepoGroup */
  49         protected static $instance;
  50
  51         /** Maximum number of cache items */
  52         const MAX_CACHE_SIZE = 500;
  53
  54         /**
  55          * Get a RepoGroup instance. At present only one instance of RepoGroup is
  56          * needed in a MediaWiki invocation, this may change in the future.
  57          * @return RepoGroup
  58          */
  59         static function singleton() {
  60                 if ( self::$instance ) {
  61                         return self::$instance;
  62                 }
  63                 global $wgLocalFileRepo, $wgForeignFileRepos;
  64                 self::$instance = new RepoGroup( $wgLocalFileRepo, $wgForeignFileRepos );
  65
  66                 return self::$instance;
  67         }
  68
  69         /**
  70          * Destroy the singleton instance, so that a new one will be created next
  71          * time singleton() is called.
  72          */
  73         static function destroySingleton() {
  74                 self::$instance = null;
  75         }
  76
  77         /**
  78          * Set the singleton instance to a given object
  79          * Used by extensions which hook into the Repo chain.
  80          * It's not enough to just create a superclass ... you have
  81          * to get people to call into it even though all they know is RepoGroup::singleton()
  82          *
  83          * @param RepoGroup $instance
  84          */
  85         static function setSingleton( $instance ) {
  86                 self::$instance = $instance;
  87         }
  88
  89         /**
  90          * Construct a group of file repositories.
  91          *
  92          * @param array $localInfo Associative array for local repo's info
  93          * @param array $foreignInfo Array of repository info arrays.
  94          *   Each info array is an associative array with the 'class' member
  95          *   giving the class name. The entire array is passed to the repository
  96          *   constructor as the first parameter.
  97          */
  98         function __construct( $localInfo, $foreignInfo ) {
  99                 $this->localInfo = $localInfo;
 100                 $this->foreignInfo = $foreignInfo;
 101                 $this->cache = new ProcessCacheLRU( self::MAX_CACHE_SIZE );
 102         }
 103
 104         /**
 105          * Search repositories for an image.
 106          * You can also use wfFindFile() to do this.
 107          *
 108          * @param Title|string $title Title object or string
 109          * @param array $options Associative array of options:
 110          *   time:           requested time for an archived image, or false for the
 111          *                   current version. An image object will be returned which was
 112          *                   created at the specified time.
 113          *   ignoreRedirect: If true, do not follow file redirects
 114          *   private:        If true, return restricted (deleted) files if the current
 115          *                   user is allowed to view them. Otherwise, such files will not
 116          *                   be found.
 117          *   bypassCache:    If true, do not use the process-local cache of File objects
 118          * @return File|bool False if title is not found
 119          */
 120         function findFile( $title, $options = array() ) {
 121                 if ( !is_array( $options ) ) {
 122                         // MW 1.15 compat
 123                         $options = array( 'time' => $options );
 124                 }
 125                 if ( !$this->reposInitialised ) {
 126                         $this->initialiseRepos();
 127                 }
 128                 $title = File::normalizeTitle( $title );
 129                 if ( !$title ) {
 130                         return false;
 131                 }
 132
 133                 # Check the cache
 134                 if ( empty( $options['ignoreRedirect'] )
 135                         && empty( $options['private'] )
 136                         && empty( $options['bypassCache'] )
 137                 ) {
 138                         $time = isset( $options['time'] ) ? $options['time'] : '';
 139                         $dbkey = $title->getDBkey();
 140                         if ( $this->cache->has( $dbkey, $time, 60 ) ) {
 141                                 return $this->cache->get( $dbkey, $time );
 142                         }
 143                         $useCache = true;
 144                 } else {
 145                         $useCache = false;
 146                 }
 147
 148                 # Check the local repo
 149                 $image = $this->localRepo->findFile( $title, $options );
 150
 151                 # Check the foreign repos
 152                 if ( !$image ) {
 153                         foreach ( $this->foreignRepos as $repo ) {
 154                                 $image = $repo->findFile( $title, $options );
 155                                 if ( $image ) {
 156                                         break;
 157                                 }
 158                         }
 159                 }
 160
 161                 $image = $image ? $image : false; // type sanity
 162                 # Cache file existence or non-existence
 163                 if ( $useCache && ( !$image || $image->isCacheable() ) ) {
 164                         $this->cache->set( $dbkey, $time, $image );
 165                 }
 166
 167                 return $image;
 168         }
 169
 170         /**
 171          * Search repositories for many files at once.
 172          *
 173          * @param array $inputItems An array of titles, or an array of findFile() options with
 174          *    the "title" option giving the title. Example:
 175          *
 176          *     $findItem = array( 'title' => $title, 'private' => true );
 177          *     $findBatch = array( $findItem );
 178          *     $repo->findFiles( $findBatch );
 179          *
 180          *    No title should appear in $items twice, as the result use titles as keys
 181          * @param int $flags Supports:
 182          *     - FileRepo::NAME_AND_TIME_ONLY : return a (search title => (title,timestamp)) map.
 183          *       The search title uses the input titles; the other is the final post-redirect title.
 184          *       All titles are returned as string DB keys and the inner array is associative.
 185          * @return array Map of (file name => File objects) for matches
 186          */
 187         function findFiles( array $inputItems, $flags = 0 ) {
 188                 if ( !$this->reposInitialised ) {
 189                         $this->initialiseRepos();
 190                 }
 191
 192                 $items = array();
 193                 foreach ( $inputItems as $item ) {
 194                         if ( !is_array( $item ) ) {
 195                                 $item = array( 'title' => $item );
 196                         }
 197                         $item['title'] = File::normalizeTitle( $item['title'] );
 198                         if ( $item['title'] ) {
 199                                 $items[$item['title']->getDBkey()] = $item;
 200                         }
 201                 }
 202
 203                 $images = $this->localRepo->findFiles( $items, $flags );
 204
 205                 foreach ( $this->foreignRepos as $repo ) {
 206                         // Remove found files from $items
 207                         foreach ( $images as $name => $image ) {
 208                                 unset( $items[$name] );
 209                         }
 210
 211                         $images = array_merge( $images, $repo->findFiles( $items, $flags ) );
 212                 }
 213
 214                 return $images;
 215         }
 216
 217         /**
 218          * Interface for FileRepo::checkRedirect()
 219          * @param Title $title
 220          * @return bool|Title
 221          */
 222         function checkRedirect( Title $title ) {
 223                 if ( !$this->reposInitialised ) {
 224                         $this->initialiseRepos();
 225                 }
 226
 227                 $redir = $this->localRepo->checkRedirect( $title );
 228                 if ( $redir ) {
 229                         return $redir;
 230                 }
 231
 232                 foreach ( $this->foreignRepos as $repo ) {
 233                         $redir = $repo->checkRedirect( $title );
 234                         if ( $redir ) {
 235                                 return $redir;
 236                         }
 237                 }
 238
 239                 return false;
 240         }
 241
 242         /**
 243          * Find an instance of the file with this key, created at the specified time
 244          * Returns false if the file does not exist.
 245          *
 246          * @param string $hash Base 36 SHA-1 hash
 247          * @param array $options Option array, same as findFile()
 248          * @return File|bool File object or false if it is not found
 249          */
 250         function findFileFromKey( $hash, $options = array() ) {
 251                 if ( !$this->reposInitialised ) {
 252                         $this->initialiseRepos();
 253                 }
 254
 255                 $file = $this->localRepo->findFileFromKey( $hash, $options );
 256                 if ( !$file ) {
 257                         foreach ( $this->foreignRepos as $repo ) {
 258                                 $file = $repo->findFileFromKey( $hash, $options );
 259                                 if ( $file ) {
 260                                         break;
 261                                 }
 262                         }
 263                 }
 264
 265                 return $file;
 266         }
 267
 268         /**
 269          * Find all instances of files with this key
 270          *
 271          * @param string $hash Base 36 SHA-1 hash
 272          * @return File[]
 273          */
 274         function findBySha1( $hash ) {
 275                 if ( !$this->reposInitialised ) {
 276                         $this->initialiseRepos();
 277                 }
 278
 279                 $result = $this->localRepo->findBySha1( $hash );
 280                 foreach ( $this->foreignRepos as $repo ) {
 281                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 282                 }
 283                 usort( $result, 'File::compare' );
 284
 285                 return $result;
 286         }
 287
 288         /**
 289          * Find all instances of files with this keys
 290          *
 291          * @param array $hashes Base 36 SHA-1 hashes
 292          * @return array Array of array of File objects
 293          */
 294         function findBySha1s( array $hashes ) {
 295                 if ( !$this->reposInitialised ) {
 296                         $this->initialiseRepos();
 297                 }
 298
 299                 $result = $this->localRepo->findBySha1s( $hashes );
 300                 foreach ( $this->foreignRepos as $repo ) {
 301                         $result = array_merge_recursive( $result, $repo->findBySha1s( $hashes ) );
 302                 }
 303                 //sort the merged (and presorted) sublist of each hash
 304                 foreach ( $result as $hash => $files ) {
 305                         usort( $result[$hash], 'File::compare' );
 306                 }
 307
 308                 return $result;
 309         }
 310
 311         /**
 312          * Get the repo instance with a given key.
 313          * @param string|int $index
 314          * @return bool|LocalRepo
 315          */
 316         function getRepo( $index ) {
 317                 if ( !$this->reposInitialised ) {
 318                         $this->initialiseRepos();
 319                 }
 320                 if ( $index === 'local' ) {
 321                         return $this->localRepo;
 322                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 323                         return $this->foreignRepos[$index];
 324                 } else {
 325                         return false;
 326                 }
 327         }
 328
 329         /**
 330          * Get the repo instance by its name
 331          * @param string $name
 332          * @return bool
 333          */
 334         function getRepoByName( $name ) {
 335                 if ( !$this->reposInitialised ) {
 336                         $this->initialiseRepos();
 337                 }
 338                 foreach ( $this->foreignRepos as $repo ) {
 339                         if ( $repo->name == $name ) {
 340                                 return $repo;
 341                         }
 342                 }
 343
 344                 return false;
 345         }
 346
 347         /**
 348          * Get the local repository, i.e. the one corresponding to the local image
 349          * table. Files are typically uploaded to the local repository.
 350          *
 351          * @return LocalRepo
 352          */
 353         function getLocalRepo() {
 354                 return $this->getRepo( 'local' );
 355         }
 356
 357         /**
 358          * Call a function for each foreign repo, with the repo object as the
 359          * first parameter.
 360          *
 361          * @param callable $callback The function to call
 362          * @param array $params Optional additional parameters to pass to the function
 363          * @return bool
 364          */
 365         function forEachForeignRepo( $callback, $params = array() ) {
 366                 if ( !$this->reposInitialised ) {
 367                         $this->initialiseRepos();
 368                 }
 369                 foreach ( $this->foreignRepos as $repo ) {
 370                         $args = array_merge( array( $repo ), $params );
 371                         if ( call_user_func_array( $callback, $args ) ) {
 372                                 return true;
 373                         }
 374                 }
 375
 376                 return false;
 377         }
 378
 379         /**
 380          * Does the installation have any foreign repos set up?
 381          * @return bool
 382          */
 383         function hasForeignRepos() {
 384                 if ( !$this->reposInitialised ) {
 385                         $this->initialiseRepos();
 386                 }
 387                 return (bool)$this->foreignRepos;
 388         }
 389
 390         /**
 391          * Initialise the $repos array
 392          */
 393         function initialiseRepos() {
 394                 if ( $this->reposInitialised ) {
 395                         return;
 396                 }
 397                 $this->reposInitialised = true;
 398
 399                 $this->localRepo = $this->newRepo( $this->localInfo );
 400                 $this->foreignRepos = array();
 401                 foreach ( $this->foreignInfo as $key => $info ) {
 402                         $this->foreignRepos[$key] = $this->newRepo( $info );
 403                 }
 404         }
 405
 406         /**
 407          * Create a repo class based on an info structure
 408          * @param array $info
 409          * @return FileRepo
 410          */
 411         protected function newRepo( $info ) {
 412                 $class = $info['class'];
 413
 414                 return new $class( $info );
 415         }
 416
 417         /**
 418          * Split a virtual URL into repo, zone and rel parts
 419          * @param string $url
 420          * @throws MWException
 421          * @return array Containing repo, zone and rel
 422          */
 423         function splitVirtualUrl( $url ) {
 424                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 425                         throw new MWException( __METHOD__ . ': unknown protocol' );
 426                 }
 427
 428                 $bits = explode( '/', substr( $url, 9 ), 3 );
 429                 if ( count( $bits ) != 3 ) {
 430                         throw new MWException( __METHOD__ . ": invalid mwrepo URL: $url" );
 431                 }
 432
 433                 return $bits;
 434         }
 435
 436         /**
 437          * @param string $fileName
 438          * @return array
 439          */
 440         function getFileProps( $fileName ) {
 441                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 442                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 443                         if ( $repoName === '' ) {
 444                                 $repoName = 'local';
 445                         }
 446                         $repo = $this->getRepo( $repoName );
 447
 448                         return $repo->getFileProps( $fileName );
 449                 } else {
 450                         return FSFile::getPropsFromPath( $fileName );
 451                 }
 452         }
 453
 454         /**
 455          * Clear RepoGroup process cache used for finding a file
 456          * @param Title|null $title Title of the file or null to clear all files
 457          */
 458         public function clearCache( Title $title = null ) {
 459                 if ( $title == null ) {
 460                         $this->cache->clear();
 461                 } else {
 462                         $this->cache->clear( $title->getDBkey() );
 463                 }
 464         }
 465 }