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         /**
  31          * @var LocalRepo
  32          */
  33         var $localRepo;
  34
  35         var $foreignRepos, $reposInitialised = false;
  36         var $localInfo, $foreignInfo;
  37         var $cache;
  38
  39         /**
  40          * @var RepoGroup
  41          */
  42         protected static $instance;
  43         const MAX_CACHE_SIZE = 500;
  44
  45         /**
  46          * Get a RepoGroup instance. At present only one instance of RepoGroup is
  47          * needed in a MediaWiki invocation, this may change in the future.
  48          * @return RepoGroup
  49          */
  50         static function singleton() {
  51                 if ( self::$instance ) {
  52                         return self::$instance;
  53                 }
  54                 global $wgLocalFileRepo, $wgForeignFileRepos;
  55                 self::$instance = new RepoGroup( $wgLocalFileRepo, $wgForeignFileRepos );
  56
  57                 return self::$instance;
  58         }
  59
  60         /**
  61          * Destroy the singleton instance, so that a new one will be created next
  62          * time singleton() is called.
  63          */
  64         static function destroySingleton() {
  65                 self::$instance = null;
  66         }
  67
  68         /**
  69          * Set the singleton instance to a given object
  70          * Used by extensions which hook into the Repo chain.
  71          * It's not enough to just create a superclass ... you have
  72          * to get people to call into it even though all they know is RepoGroup::singleton()
  73          *
  74          * @param $instance RepoGroup
  75          */
  76         static function setSingleton( $instance ) {
  77                 self::$instance = $instance;
  78         }
  79
  80         /**
  81          * Construct a group of file repositories.
  82          *
  83          * @param array $localInfo Associative array for local repo's info
  84          * @param array $foreignInfo of repository info arrays.
  85          *     Each info array is an associative array with the 'class' member
  86          *     giving the class name. The entire array is passed to the repository
  87          *     constructor as the first parameter.
  88          */
  89         function __construct( $localInfo, $foreignInfo ) {
  90                 $this->localInfo = $localInfo;
  91                 $this->foreignInfo = $foreignInfo;
  92                 $this->cache = array();
  93         }
  94
  95         /**
  96          * Search repositories for an image.
  97          * You can also use wfFindFile() to do this.
  98          *
  99          * @param $title Title|string Title object or string
 100          * @param array $options Associative array of options:
 101          *     time:           requested time for an archived image, or false for the
 102          *                     current version. An image object will be returned which was
 103          *                     created at the specified time.
 104          *
 105          *     ignoreRedirect: If true, do not follow file redirects
 106          *
 107          *     private:        If true, return restricted (deleted) files if the current
 108          *                     user is allowed to view them. Otherwise, such files will not
 109          *                     be found.
 110          *
 111          *     bypassCache:    If true, do not use the process-local cache of File objects
 112          * @return File object or false if it is not found
 113          */
 114         function findFile( $title, $options = array() ) {
 115                 if ( !is_array( $options ) ) {
 116                         // MW 1.15 compat
 117                         $options = array( 'time' => $options );
 118                 }
 119                 if ( !$this->reposInitialised ) {
 120                         $this->initialiseRepos();
 121                 }
 122                 $title = File::normalizeTitle( $title );
 123                 if ( !$title ) {
 124                         return false;
 125                 }
 126
 127                 # Check the cache
 128                 if ( empty( $options['ignoreRedirect'] )
 129                         && empty( $options['private'] )
 130                         && empty( $options['bypassCache'] )
 131                 ) {
 132                         $time = isset( $options['time'] ) ? $options['time'] : '';
 133                         $dbkey = $title->getDBkey();
 134                         if ( isset( $this->cache[$dbkey][$time] ) ) {
 135                                 wfDebug( __METHOD__ . ": got File:$dbkey from process cache\n" );
 136                                 # Move it to the end of the list so that we can delete the LRU entry later
 137                                 $this->pingCache( $dbkey );
 138
 139                                 # Return the entry
 140                                 return $this->cache[$dbkey][$time];
 141                         }
 142                         $useCache = true;
 143                 } else {
 144                         $useCache = false;
 145                 }
 146
 147                 # Check the local repo
 148                 $image = $this->localRepo->findFile( $title, $options );
 149
 150                 # Check the foreign repos
 151                 if ( !$image ) {
 152                         foreach ( $this->foreignRepos as $repo ) {
 153                                 $image = $repo->findFile( $title, $options );
 154                                 if ( $image ) {
 155                                         break;
 156                                 }
 157                         }
 158                 }
 159
 160                 $image = $image ? $image : false; // type sanity
 161                 # Cache file existence or non-existence
 162                 if ( $useCache && ( !$image || $image->isCacheable() ) ) {
 163                         $this->trimCache();
 164                         $this->cache[$dbkey][$time] = $image;
 165                 }
 166
 167                 return $image;
 168         }
 169
 170         /**
 171          * @param $inputItems array
 172          * @return array
 173          */
 174         function findFiles( $inputItems ) {
 175                 if ( !$this->reposInitialised ) {
 176                         $this->initialiseRepos();
 177                 }
 178
 179                 $items = array();
 180                 foreach ( $inputItems as $item ) {
 181                         if ( !is_array( $item ) ) {
 182                                 $item = array( 'title' => $item );
 183                         }
 184                         $item['title'] = File::normalizeTitle( $item['title'] );
 185                         if ( $item['title'] ) {
 186                                 $items[$item['title']->getDBkey()] = $item;
 187                         }
 188                 }
 189
 190                 $images = $this->localRepo->findFiles( $items );
 191
 192                 foreach ( $this->foreignRepos as $repo ) {
 193                         // Remove found files from $items
 194                         foreach ( $images as $name => $image ) {
 195                                 unset( $items[$name] );
 196                         }
 197
 198                         $images = array_merge( $images, $repo->findFiles( $items ) );
 199                 }
 200
 201                 return $images;
 202         }
 203
 204         /**
 205          * Interface for FileRepo::checkRedirect()
 206          * @param $title Title
 207          * @return bool
 208          */
 209         function checkRedirect( Title $title ) {
 210                 if ( !$this->reposInitialised ) {
 211                         $this->initialiseRepos();
 212                 }
 213
 214                 $redir = $this->localRepo->checkRedirect( $title );
 215                 if ( $redir ) {
 216                         return $redir;
 217                 }
 218                 foreach ( $this->foreignRepos as $repo ) {
 219                         $redir = $repo->checkRedirect( $title );
 220                         if ( $redir ) {
 221                                 return $redir;
 222                         }
 223                 }
 224
 225                 return false;
 226         }
 227
 228         /**
 229          * Find an instance of the file with this key, created at the specified time
 230          * Returns false if the file does not exist.
 231          *
 232          * @param string $hash base 36 SHA-1 hash
 233          * @param array $options Option array, same as findFile()
 234          * @return File object or false if it is not found
 235          */
 236         function findFileFromKey( $hash, $options = array() ) {
 237                 if ( !$this->reposInitialised ) {
 238                         $this->initialiseRepos();
 239                 }
 240
 241                 $file = $this->localRepo->findFileFromKey( $hash, $options );
 242                 if ( !$file ) {
 243                         foreach ( $this->foreignRepos as $repo ) {
 244                                 $file = $repo->findFileFromKey( $hash, $options );
 245                                 if ( $file ) {
 246                                         break;
 247                                 }
 248                         }
 249                 }
 250
 251                 return $file;
 252         }
 253
 254         /**
 255          * Find all instances of files with this key
 256          *
 257          * @param string $hash base 36 SHA-1 hash
 258          * @return Array of File objects
 259          */
 260         function findBySha1( $hash ) {
 261                 if ( !$this->reposInitialised ) {
 262                         $this->initialiseRepos();
 263                 }
 264
 265                 $result = $this->localRepo->findBySha1( $hash );
 266                 foreach ( $this->foreignRepos as $repo ) {
 267                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 268                 }
 269                 usort( $result, 'File::compare' );
 270
 271                 return $result;
 272         }
 273
 274         /**
 275          * Find all instances of files with this keys
 276          *
 277          * @param array $hashes base 36 SHA-1 hashes
 278          * @return Array of array of File objects
 279          */
 280         function findBySha1s( array $hashes ) {
 281                 if ( !$this->reposInitialised ) {
 282                         $this->initialiseRepos();
 283                 }
 284
 285                 $result = $this->localRepo->findBySha1s( $hashes );
 286                 foreach ( $this->foreignRepos as $repo ) {
 287                         $result = array_merge_recursive( $result, $repo->findBySha1s( $hashes ) );
 288                 }
 289                 //sort the merged (and presorted) sublist of each hash
 290                 foreach ( $result as $hash => $files ) {
 291                         usort( $result[$hash], 'File::compare' );
 292                 }
 293
 294                 return $result;
 295         }
 296
 297         /**
 298          * Get the repo instance with a given key.
 299          * @param $index string|int
 300          * @return bool|LocalRepo
 301          */
 302         function getRepo( $index ) {
 303                 if ( !$this->reposInitialised ) {
 304                         $this->initialiseRepos();
 305                 }
 306                 if ( $index === 'local' ) {
 307                         return $this->localRepo;
 308                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 309                         return $this->foreignRepos[$index];
 310                 } else {
 311                         return false;
 312                 }
 313         }
 314
 315         /**
 316          * Get the repo instance by its name
 317          * @param $name string
 318          * @return bool
 319          */
 320         function getRepoByName( $name ) {
 321                 if ( !$this->reposInitialised ) {
 322                         $this->initialiseRepos();
 323                 }
 324                 foreach ( $this->foreignRepos as $repo ) {
 325                         if ( $repo->name == $name ) {
 326                                 return $repo;
 327                         }
 328                 }
 329
 330                 return false;
 331         }
 332
 333         /**
 334          * Get the local repository, i.e. the one corresponding to the local image
 335          * table. Files are typically uploaded to the local repository.
 336          *
 337          * @return LocalRepo
 338          */
 339         function getLocalRepo() {
 340                 return $this->getRepo( 'local' );
 341         }
 342
 343         /**
 344          * Call a function for each foreign repo, with the repo object as the
 345          * first parameter.
 346          *
 347          * @param $callback Callback: the function to call
 348          * @param array $params optional additional parameters to pass to the function
 349          * @return bool
 350          */
 351         function forEachForeignRepo( $callback, $params = array() ) {
 352                 foreach ( $this->foreignRepos as $repo ) {
 353                         $args = array_merge( array( $repo ), $params );
 354                         if ( call_user_func_array( $callback, $args ) ) {
 355                                 return true;
 356                         }
 357                 }
 358
 359                 return false;
 360         }
 361
 362         /**
 363          * Does the installation have any foreign repos set up?
 364          * @return Boolean
 365          */
 366         function hasForeignRepos() {
 367                 return (bool)$this->foreignRepos;
 368         }
 369
 370         /**
 371          * Initialise the $repos array
 372          */
 373         function initialiseRepos() {
 374                 if ( $this->reposInitialised ) {
 375                         return;
 376                 }
 377                 $this->reposInitialised = true;
 378
 379                 $this->localRepo = $this->newRepo( $this->localInfo );
 380                 $this->foreignRepos = array();
 381                 foreach ( $this->foreignInfo as $key => $info ) {
 382                         $this->foreignRepos[$key] = $this->newRepo( $info );
 383                 }
 384         }
 385
 386         /**
 387          * Create a repo class based on an info structure
 388          */
 389         protected function newRepo( $info ) {
 390                 $class = $info['class'];
 391
 392                 return new $class( $info );
 393         }
 394
 395         /**
 396          * Split a virtual URL into repo, zone and rel parts
 397          * @param $url string
 398          * @throws MWException
 399          * @return array containing repo, zone and rel
 400          */
 401         function splitVirtualUrl( $url ) {
 402                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 403                         throw new MWException( __METHOD__ . ': unknown protocol' );
 404                 }
 405
 406                 $bits = explode( '/', substr( $url, 9 ), 3 );
 407                 if ( count( $bits ) != 3 ) {
 408                         throw new MWException( __METHOD__ . ": invalid mwrepo URL: $url" );
 409                 }
 410
 411                 return $bits;
 412         }
 413
 414         /**
 415          * @param $fileName string
 416          * @return array
 417          */
 418         function getFileProps( $fileName ) {
 419                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 420                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 421                         if ( $repoName === '' ) {
 422                                 $repoName = 'local';
 423                         }
 424                         $repo = $this->getRepo( $repoName );
 425
 426                         return $repo->getFileProps( $fileName );
 427                 } else {
 428                         return FSFile::getPropsFromPath( $fileName );
 429                 }
 430         }
 431
 432         /**
 433          * Move a cache entry to the top (such as when accessed)
 434          */
 435         protected function pingCache( $key ) {
 436                 if ( isset( $this->cache[$key] ) ) {
 437                         $tmp = $this->cache[$key];
 438                         unset( $this->cache[$key] );
 439                         $this->cache[$key] = $tmp;
 440                 }
 441         }
 442
 443         /**
 444          * Limit cache memory
 445          */
 446         protected function trimCache() {
 447                 while ( count( $this->cache ) >= self::MAX_CACHE_SIZE ) {
 448                         reset( $this->cache );
 449                         $key = key( $this->cache );
 450                         wfDebug( __METHOD__ . ": evicting $key\n" );
 451                         unset( $this->cache[$key] );
 452                 }
 453         }
 454
 455         /**
 456          * Clear RepoGroup process cache used for finding a file
 457          * @param $title Title|null Title of the file or null to clear all files
 458          */
 459         public function clearCache( Title $title = null ) {
 460                 if ( $title == null ) {
 461                         $this->cache = array();
 462                 } else {
 463                         $dbKey = $title->getDBkey();
 464                         if ( isset( $this->cache[$dbKey] ) ) {
 465                                 unset( $this->cache[$dbKey] );
 466                         }
 467                 }
 468         }
 469 }