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         protected $foreignRepos;
  34
  35         /** @var bool */
  36         protected $reposInitialised = false;
  37
  38         protected $localInfo;
  39         protected $foreignInfo;
  40
  41         /** @var array  */
  42         protected $cache;
  43
  44         /** @var RepoGroup */
  45         protected static $instance;
  46
  47         /** Maximum number of cache items */
  48         const MAX_CACHE_SIZE = 500;
  49
  50         /**
  51          * Get a RepoGroup instance. At present only one instance of RepoGroup is
  52          * needed in a MediaWiki invocation, this may change in the future.
  53          * @return RepoGroup
  54          */
  55         static function singleton() {
  56                 if ( self::$instance ) {
  57                         return self::$instance;
  58                 }
  59                 global $wgLocalFileRepo, $wgForeignFileRepos;
  60                 self::$instance = new RepoGroup( $wgLocalFileRepo, $wgForeignFileRepos );
  61
  62                 return self::$instance;
  63         }
  64
  65         /**
  66          * Destroy the singleton instance, so that a new one will be created next
  67          * time singleton() is called.
  68          */
  69         static function destroySingleton() {
  70                 self::$instance = null;
  71         }
  72
  73         /**
  74          * Set the singleton instance to a given object
  75          * Used by extensions which hook into the Repo chain.
  76          * It's not enough to just create a superclass ... you have
  77          * to get people to call into it even though all they know is RepoGroup::singleton()
  78          *
  79          * @param $instance RepoGroup
  80          */
  81         static function setSingleton( $instance ) {
  82                 self::$instance = $instance;
  83         }
  84
  85         /**
  86          * Construct a group of file repositories.
  87          *
  88          * @param array $localInfo Associative array for local repo's info
  89          * @param array $foreignInfo of repository info arrays.
  90          *     Each info array is an associative array with the 'class' member
  91          *     giving the class name. The entire array is passed to the repository
  92          *     constructor as the first parameter.
  93          */
  94         function __construct( $localInfo, $foreignInfo ) {
  95                 $this->localInfo = $localInfo;
  96                 $this->foreignInfo = $foreignInfo;
  97                 $this->cache = array();
  98         }
  99
 100         /**
 101          * Search repositories for an image.
 102          * You can also use wfFindFile() to do this.
 103          *
 104          * @param $title Title|string Title object or string
 105          * @param array $options Associative array of options:
 106          *     time:           requested time for an archived image, or false for the
 107          *                     current version. An image object will be returned which was
 108          *                     created at the specified time.
 109          *
 110          *     ignoreRedirect: If true, do not follow file redirects
 111          *
 112          *     private:        If true, return restricted (deleted) files if the current
 113          *                     user is allowed to view them. Otherwise, such files will not
 114          *                     be found.
 115          *
 116          *     bypassCache:    If true, do not use the process-local cache of File objects
 117          * @return File object or false if it is not found
 118          */
 119         function findFile( $title, $options = array() ) {
 120                 if ( !is_array( $options ) ) {
 121                         // MW 1.15 compat
 122                         $options = array( 'time' => $options );
 123                 }
 124                 if ( !$this->reposInitialised ) {
 125                         $this->initialiseRepos();
 126                 }
 127                 $title = File::normalizeTitle( $title );
 128                 if ( !$title ) {
 129                         return false;
 130                 }
 131
 132                 # Check the cache
 133                 if ( empty( $options['ignoreRedirect'] )
 134                         && empty( $options['private'] )
 135                         && empty( $options['bypassCache'] )
 136                 ) {
 137                         $time = isset( $options['time'] ) ? $options['time'] : '';
 138                         $dbkey = $title->getDBkey();
 139                         if ( isset( $this->cache[$dbkey][$time] ) ) {
 140                                 wfDebug( __METHOD__ . ": got File:$dbkey from process cache\n" );
 141                                 # Move it to the end of the list so that we can delete the LRU entry later
 142                                 $this->pingCache( $dbkey );
 143
 144                                 # Return the entry
 145                                 return $this->cache[$dbkey][$time];
 146                         }
 147                         $useCache = true;
 148                 } else {
 149                         $useCache = false;
 150                 }
 151
 152                 # Check the local repo
 153                 $image = $this->localRepo->findFile( $title, $options );
 154
 155                 # Check the foreign repos
 156                 if ( !$image ) {
 157                         foreach ( $this->foreignRepos as $repo ) {
 158                                 $image = $repo->findFile( $title, $options );
 159                                 if ( $image ) {
 160                                         break;
 161                                 }
 162                         }
 163                 }
 164
 165                 $image = $image ? $image : false; // type sanity
 166                 # Cache file existence or non-existence
 167                 if ( $useCache && ( !$image || $image->isCacheable() ) ) {
 168                         $this->trimCache();
 169                         $this->cache[$dbkey][$time] = $image;
 170                 }
 171
 172                 return $image;
 173         }
 174
 175         /**
 176          * @param $inputItems array
 177          * @return array
 178          */
 179         function findFiles( $inputItems ) {
 180                 if ( !$this->reposInitialised ) {
 181                         $this->initialiseRepos();
 182                 }
 183
 184                 $items = array();
 185                 foreach ( $inputItems as $item ) {
 186                         if ( !is_array( $item ) ) {
 187                                 $item = array( 'title' => $item );
 188                         }
 189                         $item['title'] = File::normalizeTitle( $item['title'] );
 190                         if ( $item['title'] ) {
 191                                 $items[$item['title']->getDBkey()] = $item;
 192                         }
 193                 }
 194
 195                 $images = $this->localRepo->findFiles( $items );
 196
 197                 foreach ( $this->foreignRepos as $repo ) {
 198                         // Remove found files from $items
 199                         foreach ( $images as $name => $image ) {
 200                                 unset( $items[$name] );
 201                         }
 202
 203                         $images = array_merge( $images, $repo->findFiles( $items ) );
 204                 }
 205
 206                 return $images;
 207         }
 208
 209         /**
 210          * Interface for FileRepo::checkRedirect()
 211          * @param $title Title
 212          * @return bool
 213          */
 214         function checkRedirect( Title $title ) {
 215                 if ( !$this->reposInitialised ) {
 216                         $this->initialiseRepos();
 217                 }
 218
 219                 $redir = $this->localRepo->checkRedirect( $title );
 220                 if ( $redir ) {
 221                         return $redir;
 222                 }
 223                 foreach ( $this->foreignRepos as $repo ) {
 224                         $redir = $repo->checkRedirect( $title );
 225                         if ( $redir ) {
 226                                 return $redir;
 227                         }
 228                 }
 229
 230                 return false;
 231         }
 232
 233         /**
 234          * Find an instance of the file with this key, created at the specified time
 235          * Returns false if the file does not exist.
 236          *
 237          * @param string $hash base 36 SHA-1 hash
 238          * @param array $options Option array, same as findFile()
 239          * @return File object or false if it is not found
 240          */
 241         function findFileFromKey( $hash, $options = array() ) {
 242                 if ( !$this->reposInitialised ) {
 243                         $this->initialiseRepos();
 244                 }
 245
 246                 $file = $this->localRepo->findFileFromKey( $hash, $options );
 247                 if ( !$file ) {
 248                         foreach ( $this->foreignRepos as $repo ) {
 249                                 $file = $repo->findFileFromKey( $hash, $options );
 250                                 if ( $file ) {
 251                                         break;
 252                                 }
 253                         }
 254                 }
 255
 256                 return $file;
 257         }
 258
 259         /**
 260          * Find all instances of files with this key
 261          *
 262          * @param string $hash base 36 SHA-1 hash
 263          * @return Array of File objects
 264          */
 265         function findBySha1( $hash ) {
 266                 if ( !$this->reposInitialised ) {
 267                         $this->initialiseRepos();
 268                 }
 269
 270                 $result = $this->localRepo->findBySha1( $hash );
 271                 foreach ( $this->foreignRepos as $repo ) {
 272                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 273                 }
 274                 usort( $result, 'File::compare' );
 275
 276                 return $result;
 277         }
 278
 279         /**
 280          * Find all instances of files with this keys
 281          *
 282          * @param array $hashes base 36 SHA-1 hashes
 283          * @return Array of array of File objects
 284          */
 285         function findBySha1s( array $hashes ) {
 286                 if ( !$this->reposInitialised ) {
 287                         $this->initialiseRepos();
 288                 }
 289
 290                 $result = $this->localRepo->findBySha1s( $hashes );
 291                 foreach ( $this->foreignRepos as $repo ) {
 292                         $result = array_merge_recursive( $result, $repo->findBySha1s( $hashes ) );
 293                 }
 294                 //sort the merged (and presorted) sublist of each hash
 295                 foreach ( $result as $hash => $files ) {
 296                         usort( $result[$hash], 'File::compare' );
 297                 }
 298
 299                 return $result;
 300         }
 301
 302         /**
 303          * Get the repo instance with a given key.
 304          * @param $index string|int
 305          * @return bool|LocalRepo
 306          */
 307         function getRepo( $index ) {
 308                 if ( !$this->reposInitialised ) {
 309                         $this->initialiseRepos();
 310                 }
 311                 if ( $index === 'local' ) {
 312                         return $this->localRepo;
 313                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 314                         return $this->foreignRepos[$index];
 315                 } else {
 316                         return false;
 317                 }
 318         }
 319
 320         /**
 321          * Get the repo instance by its name
 322          * @param $name string
 323          * @return bool
 324          */
 325         function getRepoByName( $name ) {
 326                 if ( !$this->reposInitialised ) {
 327                         $this->initialiseRepos();
 328                 }
 329                 foreach ( $this->foreignRepos as $repo ) {
 330                         if ( $repo->name == $name ) {
 331                                 return $repo;
 332                         }
 333                 }
 334
 335                 return false;
 336         }
 337
 338         /**
 339          * Get the local repository, i.e. the one corresponding to the local image
 340          * table. Files are typically uploaded to the local repository.
 341          *
 342          * @return LocalRepo
 343          */
 344         function getLocalRepo() {
 345                 return $this->getRepo( 'local' );
 346         }
 347
 348         /**
 349          * Call a function for each foreign repo, with the repo object as the
 350          * first parameter.
 351          *
 352          * @param $callback Callback: the function to call
 353          * @param array $params optional additional parameters to pass to the function
 354          * @return bool
 355          */
 356         function forEachForeignRepo( $callback, $params = array() ) {
 357                 foreach ( $this->foreignRepos as $repo ) {
 358                         $args = array_merge( array( $repo ), $params );
 359                         if ( call_user_func_array( $callback, $args ) ) {
 360                                 return true;
 361                         }
 362                 }
 363
 364                 return false;
 365         }
 366
 367         /**
 368          * Does the installation have any foreign repos set up?
 369          * @return Boolean
 370          */
 371         function hasForeignRepos() {
 372                 return (bool)$this->foreignRepos;
 373         }
 374
 375         /**
 376          * Initialise the $repos array
 377          */
 378         function initialiseRepos() {
 379                 if ( $this->reposInitialised ) {
 380                         return;
 381                 }
 382                 $this->reposInitialised = true;
 383
 384                 $this->localRepo = $this->newRepo( $this->localInfo );
 385                 $this->foreignRepos = array();
 386                 foreach ( $this->foreignInfo as $key => $info ) {
 387                         $this->foreignRepos[$key] = $this->newRepo( $info );
 388                 }
 389         }
 390
 391         /**
 392          * Create a repo class based on an info structure
 393          */
 394         protected function newRepo( $info ) {
 395                 $class = $info['class'];
 396
 397                 return new $class( $info );
 398         }
 399
 400         /**
 401          * Split a virtual URL into repo, zone and rel parts
 402          * @param $url string
 403          * @throws MWException
 404          * @return array containing repo, zone and rel
 405          */
 406         function splitVirtualUrl( $url ) {
 407                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 408                         throw new MWException( __METHOD__ . ': unknown protocol' );
 409                 }
 410
 411                 $bits = explode( '/', substr( $url, 9 ), 3 );
 412                 if ( count( $bits ) != 3 ) {
 413                         throw new MWException( __METHOD__ . ": invalid mwrepo URL: $url" );
 414                 }
 415
 416                 return $bits;
 417         }
 418
 419         /**
 420          * @param $fileName string
 421          * @return array
 422          */
 423         function getFileProps( $fileName ) {
 424                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 425                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 426                         if ( $repoName === '' ) {
 427                                 $repoName = 'local';
 428                         }
 429                         $repo = $this->getRepo( $repoName );
 430
 431                         return $repo->getFileProps( $fileName );
 432                 } else {
 433                         return FSFile::getPropsFromPath( $fileName );
 434                 }
 435         }
 436
 437         /**
 438          * Move a cache entry to the top (such as when accessed)
 439          */
 440         protected function pingCache( $key ) {
 441                 if ( isset( $this->cache[$key] ) ) {
 442                         $tmp = $this->cache[$key];
 443                         unset( $this->cache[$key] );
 444                         $this->cache[$key] = $tmp;
 445                 }
 446         }
 447
 448         /**
 449          * Limit cache memory
 450          */
 451         protected function trimCache() {
 452                 while ( count( $this->cache ) >= self::MAX_CACHE_SIZE ) {
 453                         reset( $this->cache );
 454                         $key = key( $this->cache );
 455                         wfDebug( __METHOD__ . ": evicting $key\n" );
 456                         unset( $this->cache[$key] );
 457                 }
 458         }
 459
 460         /**
 461          * Clear RepoGroup process cache used for finding a file
 462          * @param $title Title|null Title of the file or null to clear all files
 463          */
 464         public function clearCache( Title $title = null ) {
 465                 if ( $title == null ) {
 466                         $this->cache = array();
 467                 } else {
 468                         $dbKey = $title->getDBkey();
 469                         if ( isset( $this->cache[$dbKey] ) ) {
 470                                 unset( $this->cache[$dbKey] );
 471                         }
 472                 }
 473         }
 474 }