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 array  */
  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 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 = array();
 102         }
 103
 104         /**
 105          * Search repositories for an image.
 106          * You can also use wfFindFile() to do this.
 107          *
 108          * @param $title Title|string 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 ( isset( $this->cache[$dbkey][$time] ) ) {
 141                                 wfDebug( __METHOD__ . ": got File:$dbkey from process cache\n" );
 142                                 # Move it to the end of the list so that we can delete the LRU entry later
 143                                 $this->pingCache( $dbkey );
 144
 145                                 # Return the entry
 146                                 return $this->cache[$dbkey][$time];
 147                         }
 148                         $useCache = true;
 149                 } else {
 150                         $useCache = false;
 151                 }
 152
 153                 # Check the local repo
 154                 $image = $this->localRepo->findFile( $title, $options );
 155
 156                 # Check the foreign repos
 157                 if ( !$image ) {
 158                         foreach ( $this->foreignRepos as $repo ) {
 159                                 $image = $repo->findFile( $title, $options );
 160                                 if ( $image ) {
 161                                         break;
 162                                 }
 163                         }
 164                 }
 165
 166                 $image = $image ? $image : false; // type sanity
 167                 # Cache file existence or non-existence
 168                 if ( $useCache && ( !$image || $image->isCacheable() ) ) {
 169                         $this->trimCache();
 170                         $this->cache[$dbkey][$time] = $image;
 171                 }
 172
 173                 return $image;
 174         }
 175
 176         /**
 177          * @param array $inputItems
 178          * @return array
 179          */
 180         function findFiles( $inputItems ) {
 181                 if ( !$this->reposInitialised ) {
 182                         $this->initialiseRepos();
 183                 }
 184
 185                 $items = array();
 186                 foreach ( $inputItems as $item ) {
 187                         if ( !is_array( $item ) ) {
 188                                 $item = array( 'title' => $item );
 189                         }
 190                         $item['title'] = File::normalizeTitle( $item['title'] );
 191                         if ( $item['title'] ) {
 192                                 $items[$item['title']->getDBkey()] = $item;
 193                         }
 194                 }
 195
 196                 $images = $this->localRepo->findFiles( $items );
 197
 198                 foreach ( $this->foreignRepos as $repo ) {
 199                         // Remove found files from $items
 200                         foreach ( $images as $name => $image ) {
 201                                 unset( $items[$name] );
 202                         }
 203
 204                         $images = array_merge( $images, $repo->findFiles( $items ) );
 205                 }
 206
 207                 return $images;
 208         }
 209
 210         /**
 211          * Interface for FileRepo::checkRedirect()
 212          * @param $title Title
 213          * @return bool
 214          */
 215         function checkRedirect( Title $title ) {
 216                 if ( !$this->reposInitialised ) {
 217                         $this->initialiseRepos();
 218                 }
 219
 220                 $redir = $this->localRepo->checkRedirect( $title );
 221                 if ( $redir ) {
 222                         return $redir;
 223                 }
 224
 225                 foreach ( $this->foreignRepos as $repo ) {
 226                         $redir = $repo->checkRedirect( $title );
 227                         if ( $redir ) {
 228                                 return $redir;
 229                         }
 230                 }
 231
 232                 return false;
 233         }
 234
 235         /**
 236          * Find an instance of the file with this key, created at the specified time
 237          * Returns false if the file does not exist.
 238          *
 239          * @param string $hash base 36 SHA-1 hash
 240          * @param array $options Option array, same as findFile()
 241          * @return File object or false if it is not found
 242          */
 243         function findFileFromKey( $hash, $options = array() ) {
 244                 if ( !$this->reposInitialised ) {
 245                         $this->initialiseRepos();
 246                 }
 247
 248                 $file = $this->localRepo->findFileFromKey( $hash, $options );
 249                 if ( !$file ) {
 250                         foreach ( $this->foreignRepos as $repo ) {
 251                                 $file = $repo->findFileFromKey( $hash, $options );
 252                                 if ( $file ) {
 253                                         break;
 254                                 }
 255                         }
 256                 }
 257
 258                 return $file;
 259         }
 260
 261         /**
 262          * Find all instances of files with this key
 263          *
 264          * @param string $hash base 36 SHA-1 hash
 265          * @return Array of File objects
 266          */
 267         function findBySha1( $hash ) {
 268                 if ( !$this->reposInitialised ) {
 269                         $this->initialiseRepos();
 270                 }
 271
 272                 $result = $this->localRepo->findBySha1( $hash );
 273                 foreach ( $this->foreignRepos as $repo ) {
 274                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 275                 }
 276                 usort( $result, 'File::compare' );
 277
 278                 return $result;
 279         }
 280
 281         /**
 282          * Find all instances of files with this keys
 283          *
 284          * @param array $hashes base 36 SHA-1 hashes
 285          * @return array of array of File objects
 286          */
 287         function findBySha1s( array $hashes ) {
 288                 if ( !$this->reposInitialised ) {
 289                         $this->initialiseRepos();
 290                 }
 291
 292                 $result = $this->localRepo->findBySha1s( $hashes );
 293                 foreach ( $this->foreignRepos as $repo ) {
 294                         $result = array_merge_recursive( $result, $repo->findBySha1s( $hashes ) );
 295                 }
 296                 //sort the merged (and presorted) sublist of each hash
 297                 foreach ( $result as $hash => $files ) {
 298                         usort( $result[$hash], 'File::compare' );
 299                 }
 300
 301                 return $result;
 302         }
 303
 304         /**
 305          * Get the repo instance with a given key.
 306          * @param string|int $index
 307          * @return bool|LocalRepo
 308          */
 309         function getRepo( $index ) {
 310                 if ( !$this->reposInitialised ) {
 311                         $this->initialiseRepos();
 312                 }
 313                 if ( $index === 'local' ) {
 314                         return $this->localRepo;
 315                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 316                         return $this->foreignRepos[$index];
 317                 } else {
 318                         return false;
 319                 }
 320         }
 321
 322         /**
 323          * Get the repo instance by its name
 324          * @param string $name
 325          * @return bool
 326          */
 327         function getRepoByName( $name ) {
 328                 if ( !$this->reposInitialised ) {
 329                         $this->initialiseRepos();
 330                 }
 331                 foreach ( $this->foreignRepos as $repo ) {
 332                         if ( $repo->name == $name ) {
 333                                 return $repo;
 334                         }
 335                 }
 336
 337                 return false;
 338         }
 339
 340         /**
 341          * Get the local repository, i.e. the one corresponding to the local image
 342          * table. Files are typically uploaded to the local repository.
 343          *
 344          * @return LocalRepo
 345          */
 346         function getLocalRepo() {
 347                 return $this->getRepo( 'local' );
 348         }
 349
 350         /**
 351          * Call a function for each foreign repo, with the repo object as the
 352          * first parameter.
 353          *
 354          * @param callable $callback The function to call
 355          * @param array $params Optional additional parameters to pass to the function
 356          * @return bool
 357          */
 358         function forEachForeignRepo( $callback, $params = array() ) {
 359                 foreach ( $this->foreignRepos as $repo ) {
 360                         $args = array_merge( array( $repo ), $params );
 361                         if ( call_user_func_array( $callback, $args ) ) {
 362                                 return true;
 363                         }
 364                 }
 365
 366                 return false;
 367         }
 368
 369         /**
 370          * Does the installation have any foreign repos set up?
 371          * @return bool
 372          */
 373         function hasForeignRepos() {
 374                 return (bool)$this->foreignRepos;
 375         }
 376
 377         /**
 378          * Initialise the $repos array
 379          */
 380         function initialiseRepos() {
 381                 if ( $this->reposInitialised ) {
 382                         return;
 383                 }
 384                 $this->reposInitialised = true;
 385
 386                 $this->localRepo = $this->newRepo( $this->localInfo );
 387                 $this->foreignRepos = array();
 388                 foreach ( $this->foreignInfo as $key => $info ) {
 389                         $this->foreignRepos[$key] = $this->newRepo( $info );
 390                 }
 391         }
 392
 393         /**
 394          * Create a repo class based on an info structure
 395          */
 396         protected function newRepo( $info ) {
 397                 $class = $info['class'];
 398
 399                 return new $class( $info );
 400         }
 401
 402         /**
 403          * Split a virtual URL into repo, zone and rel parts
 404          * @param string $url
 405          * @throws MWException
 406          * @return array containing repo, zone and rel
 407          */
 408         function splitVirtualUrl( $url ) {
 409                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 410                         throw new MWException( __METHOD__ . ': unknown protocol' );
 411                 }
 412
 413                 $bits = explode( '/', substr( $url, 9 ), 3 );
 414                 if ( count( $bits ) != 3 ) {
 415                         throw new MWException( __METHOD__ . ": invalid mwrepo URL: $url" );
 416                 }
 417
 418                 return $bits;
 419         }
 420
 421         /**
 422          * @param string $fileName
 423          * @return array
 424          */
 425         function getFileProps( $fileName ) {
 426                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 427                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 428                         if ( $repoName === '' ) {
 429                                 $repoName = 'local';
 430                         }
 431                         $repo = $this->getRepo( $repoName );
 432
 433                         return $repo->getFileProps( $fileName );
 434                 } else {
 435                         return FSFile::getPropsFromPath( $fileName );
 436                 }
 437         }
 438
 439         /**
 440          * Move a cache entry to the top (such as when accessed)
 441          */
 442         protected function pingCache( $key ) {
 443                 if ( isset( $this->cache[$key] ) ) {
 444                         $tmp = $this->cache[$key];
 445                         unset( $this->cache[$key] );
 446                         $this->cache[$key] = $tmp;
 447                 }
 448         }
 449
 450         /**
 451          * Limit cache memory
 452          */
 453         protected function trimCache() {
 454                 while ( count( $this->cache ) >= self::MAX_CACHE_SIZE ) {
 455                         reset( $this->cache );
 456                         $key = key( $this->cache );
 457                         wfDebug( __METHOD__ . ": evicting $key\n" );
 458                         unset( $this->cache[$key] );
 459                 }
 460         }
 461
 462         /**
 463          * Clear RepoGroup process cache used for finding a file
 464          * @param Title|null $title Title of the file or null to clear all files
 465          */
 466         public function clearCache( Title $title = null ) {
 467                 if ( $title == null ) {
 468                         $this->cache = array();
 469                 } else {
 470                         $dbKey = $title->getDBkey();
 471                         if ( isset( $this->cache[$dbKey] ) ) {
 472                                 unset( $this->cache[$dbKey] );
 473                         }
 474                 }
 475         }
 476 }