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 array */
  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                 foreach ( $this->foreignRepos as $repo ) {
 225                         $redir = $repo->checkRedirect( $title );
 226                         if ( $redir ) {
 227                                 return $redir;
 228                         }
 229                 }
 230
 231                 return false;
 232         }
 233
 234         /**
 235          * Find an instance of the file with this key, created at the specified time
 236          * Returns false if the file does not exist.
 237          *
 238          * @param string $hash base 36 SHA-1 hash
 239          * @param array $options Option array, same as findFile()
 240          * @return File object or false if it is not found
 241          */
 242         function findFileFromKey( $hash, $options = array() ) {
 243                 if ( !$this->reposInitialised ) {
 244                         $this->initialiseRepos();
 245                 }
 246
 247                 $file = $this->localRepo->findFileFromKey( $hash, $options );
 248                 if ( !$file ) {
 249                         foreach ( $this->foreignRepos as $repo ) {
 250                                 $file = $repo->findFileFromKey( $hash, $options );
 251                                 if ( $file ) {
 252                                         break;
 253                                 }
 254                         }
 255                 }
 256
 257                 return $file;
 258         }
 259
 260         /**
 261          * Find all instances of files with this key
 262          *
 263          * @param string $hash base 36 SHA-1 hash
 264          * @return Array of File objects
 265          */
 266         function findBySha1( $hash ) {
 267                 if ( !$this->reposInitialised ) {
 268                         $this->initialiseRepos();
 269                 }
 270
 271                 $result = $this->localRepo->findBySha1( $hash );
 272                 foreach ( $this->foreignRepos as $repo ) {
 273                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 274                 }
 275                 usort( $result, 'File::compare' );
 276
 277                 return $result;
 278         }
 279
 280         /**
 281          * Find all instances of files with this keys
 282          *
 283          * @param array $hashes base 36 SHA-1 hashes
 284          * @return array of array of File objects
 285          */
 286         function findBySha1s( array $hashes ) {
 287                 if ( !$this->reposInitialised ) {
 288                         $this->initialiseRepos();
 289                 }
 290
 291                 $result = $this->localRepo->findBySha1s( $hashes );
 292                 foreach ( $this->foreignRepos as $repo ) {
 293                         $result = array_merge_recursive( $result, $repo->findBySha1s( $hashes ) );
 294                 }
 295                 //sort the merged (and presorted) sublist of each hash
 296                 foreach ( $result as $hash => $files ) {
 297                         usort( $result[$hash], 'File::compare' );
 298                 }
 299
 300                 return $result;
 301         }
 302
 303         /**
 304          * Get the repo instance with a given key.
 305          * @param string|int $index
 306          * @return bool|LocalRepo
 307          */
 308         function getRepo( $index ) {
 309                 if ( !$this->reposInitialised ) {
 310                         $this->initialiseRepos();
 311                 }
 312                 if ( $index === 'local' ) {
 313                         return $this->localRepo;
 314                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 315                         return $this->foreignRepos[$index];
 316                 } else {
 317                         return false;
 318                 }
 319         }
 320
 321         /**
 322          * Get the repo instance by its name
 323          * @param string $name
 324          * @return bool
 325          */
 326         function getRepoByName( $name ) {
 327                 if ( !$this->reposInitialised ) {
 328                         $this->initialiseRepos();
 329                 }
 330                 foreach ( $this->foreignRepos as $repo ) {
 331                         if ( $repo->name == $name ) {
 332                                 return $repo;
 333                         }
 334                 }
 335
 336                 return false;
 337         }
 338
 339         /**
 340          * Get the local repository, i.e. the one corresponding to the local image
 341          * table. Files are typically uploaded to the local repository.
 342          *
 343          * @return LocalRepo
 344          */
 345         function getLocalRepo() {
 346                 return $this->getRepo( 'local' );
 347         }
 348
 349         /**
 350          * Call a function for each foreign repo, with the repo object as the
 351          * first parameter.
 352          *
 353          * @param callable $callback The function to call
 354          * @param array $params Optional additional parameters to pass to the function
 355          * @return bool
 356          */
 357         function forEachForeignRepo( $callback, $params = array() ) {
 358                 foreach ( $this->foreignRepos as $repo ) {
 359                         $args = array_merge( array( $repo ), $params );
 360                         if ( call_user_func_array( $callback, $args ) ) {
 361                                 return true;
 362                         }
 363                 }
 364
 365                 return false;
 366         }
 367
 368         /**
 369          * Does the installation have any foreign repos set up?
 370          * @return bool
 371          */
 372         function hasForeignRepos() {
 373                 return (bool)$this->foreignRepos;
 374         }
 375
 376         /**
 377          * Initialise the $repos array
 378          */
 379         function initialiseRepos() {
 380                 if ( $this->reposInitialised ) {
 381                         return;
 382                 }
 383                 $this->reposInitialised = true;
 384
 385                 $this->localRepo = $this->newRepo( $this->localInfo );
 386                 $this->foreignRepos = array();
 387                 foreach ( $this->foreignInfo as $key => $info ) {
 388                         $this->foreignRepos[$key] = $this->newRepo( $info );
 389                 }
 390         }
 391
 392         /**
 393          * Create a repo class based on an info structure
 394          */
 395         protected function newRepo( $info ) {
 396                 $class = $info['class'];
 397
 398                 return new $class( $info );
 399         }
 400
 401         /**
 402          * Split a virtual URL into repo, zone and rel parts
 403          * @param string $url
 404          * @throws MWException
 405          * @return array containing repo, zone and rel
 406          */
 407         function splitVirtualUrl( $url ) {
 408                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 409                         throw new MWException( __METHOD__ . ': unknown protocol' );
 410                 }
 411
 412                 $bits = explode( '/', substr( $url, 9 ), 3 );
 413                 if ( count( $bits ) != 3 ) {
 414                         throw new MWException( __METHOD__ . ": invalid mwrepo URL: $url" );
 415                 }
 416
 417                 return $bits;
 418         }
 419
 420         /**
 421          * @param string $fileName
 422          * @return array
 423          */
 424         function getFileProps( $fileName ) {
 425                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 426                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 427                         if ( $repoName === '' ) {
 428                                 $repoName = 'local';
 429                         }
 430                         $repo = $this->getRepo( $repoName );
 431
 432                         return $repo->getFileProps( $fileName );
 433                 } else {
 434                         return FSFile::getPropsFromPath( $fileName );
 435                 }
 436         }
 437
 438         /**
 439          * Move a cache entry to the top (such as when accessed)
 440          */
 441         protected function pingCache( $key ) {
 442                 if ( isset( $this->cache[$key] ) ) {
 443                         $tmp = $this->cache[$key];
 444                         unset( $this->cache[$key] );
 445                         $this->cache[$key] = $tmp;
 446                 }
 447         }
 448
 449         /**
 450          * Limit cache memory
 451          */
 452         protected function trimCache() {
 453                 while ( count( $this->cache ) >= self::MAX_CACHE_SIZE ) {
 454                         reset( $this->cache );
 455                         $key = key( $this->cache );
 456                         wfDebug( __METHOD__ . ": evicting $key\n" );
 457                         unset( $this->cache[$key] );
 458                 }
 459         }
 460
 461         /**
 462          * Clear RepoGroup process cache used for finding a file
 463          * @param Title|null $title Title of the file or null to clear all files
 464          */
 465         public function clearCache( Title $title = null ) {
 466                 if ( $title == null ) {
 467                         $this->cache = array();
 468                 } else {
 469                         $dbKey = $title->getDBkey();
 470                         if ( isset( $this->cache[$dbKey] ) ) {
 471                                 unset( $this->cache[$dbKey] );
 472                         }
 473                 }
 474         }
 475 }