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 ProcessCacheLRU  */
  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 = new ProcessCacheLRU( self::MAX_CACHE_SIZE );
  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 ( $this->cache->has( $dbkey, $time, 60 ) ) {
 140                                 return $this->cache->get( $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->cache->set( $dbkey, $time, $image );
 164                 }
 165
 166                 return $image;
 167         }
 168
 169         /**
 170          * @param $inputItems array
 171          * @return array
 172          */
 173         function findFiles( $inputItems ) {
 174                 if ( !$this->reposInitialised ) {
 175                         $this->initialiseRepos();
 176                 }
 177
 178                 $items = array();
 179                 foreach ( $inputItems as $item ) {
 180                         if ( !is_array( $item ) ) {
 181                                 $item = array( 'title' => $item );
 182                         }
 183                         $item['title'] = File::normalizeTitle( $item['title'] );
 184                         if ( $item['title'] ) {
 185                                 $items[$item['title']->getDBkey()] = $item;
 186                         }
 187                 }
 188
 189                 $images = $this->localRepo->findFiles( $items );
 190
 191                 foreach ( $this->foreignRepos as $repo ) {
 192                         // Remove found files from $items
 193                         foreach ( $images as $name => $image ) {
 194                                 unset( $items[$name] );
 195                         }
 196
 197                         $images = array_merge( $images, $repo->findFiles( $items ) );
 198                 }
 199
 200                 return $images;
 201         }
 202
 203         /**
 204          * Interface for FileRepo::checkRedirect()
 205          * @param $title Title
 206          * @return bool
 207          */
 208         function checkRedirect( Title $title ) {
 209                 if ( !$this->reposInitialised ) {
 210                         $this->initialiseRepos();
 211                 }
 212
 213                 $redir = $this->localRepo->checkRedirect( $title );
 214                 if ( $redir ) {
 215                         return $redir;
 216                 }
 217                 foreach ( $this->foreignRepos as $repo ) {
 218                         $redir = $repo->checkRedirect( $title );
 219                         if ( $redir ) {
 220                                 return $redir;
 221                         }
 222                 }
 223
 224                 return false;
 225         }
 226
 227         /**
 228          * Find an instance of the file with this key, created at the specified time
 229          * Returns false if the file does not exist.
 230          *
 231          * @param string $hash base 36 SHA-1 hash
 232          * @param array $options Option array, same as findFile()
 233          * @return File object or false if it is not found
 234          */
 235         function findFileFromKey( $hash, $options = array() ) {
 236                 if ( !$this->reposInitialised ) {
 237                         $this->initialiseRepos();
 238                 }
 239
 240                 $file = $this->localRepo->findFileFromKey( $hash, $options );
 241                 if ( !$file ) {
 242                         foreach ( $this->foreignRepos as $repo ) {
 243                                 $file = $repo->findFileFromKey( $hash, $options );
 244                                 if ( $file ) {
 245                                         break;
 246                                 }
 247                         }
 248                 }
 249
 250                 return $file;
 251         }
 252
 253         /**
 254          * Find all instances of files with this key
 255          *
 256          * @param string $hash base 36 SHA-1 hash
 257          * @return Array of File objects
 258          */
 259         function findBySha1( $hash ) {
 260                 if ( !$this->reposInitialised ) {
 261                         $this->initialiseRepos();
 262                 }
 263
 264                 $result = $this->localRepo->findBySha1( $hash );
 265                 foreach ( $this->foreignRepos as $repo ) {
 266                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 267                 }
 268                 usort( $result, 'File::compare' );
 269
 270                 return $result;
 271         }
 272
 273         /**
 274          * Find all instances of files with this keys
 275          *
 276          * @param array $hashes base 36 SHA-1 hashes
 277          * @return Array of array of File objects
 278          */
 279         function findBySha1s( array $hashes ) {
 280                 if ( !$this->reposInitialised ) {
 281                         $this->initialiseRepos();
 282                 }
 283
 284                 $result = $this->localRepo->findBySha1s( $hashes );
 285                 foreach ( $this->foreignRepos as $repo ) {
 286                         $result = array_merge_recursive( $result, $repo->findBySha1s( $hashes ) );
 287                 }
 288                 //sort the merged (and presorted) sublist of each hash
 289                 foreach ( $result as $hash => $files ) {
 290                         usort( $result[$hash], 'File::compare' );
 291                 }
 292
 293                 return $result;
 294         }
 295
 296         /**
 297          * Get the repo instance with a given key.
 298          * @param $index string|int
 299          * @return bool|LocalRepo
 300          */
 301         function getRepo( $index ) {
 302                 if ( !$this->reposInitialised ) {
 303                         $this->initialiseRepos();
 304                 }
 305                 if ( $index === 'local' ) {
 306                         return $this->localRepo;
 307                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 308                         return $this->foreignRepos[$index];
 309                 } else {
 310                         return false;
 311                 }
 312         }
 313
 314         /**
 315          * Get the repo instance by its name
 316          * @param $name string
 317          * @return bool
 318          */
 319         function getRepoByName( $name ) {
 320                 if ( !$this->reposInitialised ) {
 321                         $this->initialiseRepos();
 322                 }
 323                 foreach ( $this->foreignRepos as $repo ) {
 324                         if ( $repo->name == $name ) {
 325                                 return $repo;
 326                         }
 327                 }
 328
 329                 return false;
 330         }
 331
 332         /**
 333          * Get the local repository, i.e. the one corresponding to the local image
 334          * table. Files are typically uploaded to the local repository.
 335          *
 336          * @return LocalRepo
 337          */
 338         function getLocalRepo() {
 339                 return $this->getRepo( 'local' );
 340         }
 341
 342         /**
 343          * Call a function for each foreign repo, with the repo object as the
 344          * first parameter.
 345          *
 346          * @param $callback Callback: the function to call
 347          * @param array $params optional additional parameters to pass to the function
 348          * @return bool
 349          */
 350         function forEachForeignRepo( $callback, $params = array() ) {
 351                 foreach ( $this->foreignRepos as $repo ) {
 352                         $args = array_merge( array( $repo ), $params );
 353                         if ( call_user_func_array( $callback, $args ) ) {
 354                                 return true;
 355                         }
 356                 }
 357
 358                 return false;
 359         }
 360
 361         /**
 362          * Does the installation have any foreign repos set up?
 363          * @return Boolean
 364          */
 365         function hasForeignRepos() {
 366                 return (bool)$this->foreignRepos;
 367         }
 368
 369         /**
 370          * Initialise the $repos array
 371          */
 372         function initialiseRepos() {
 373                 if ( $this->reposInitialised ) {
 374                         return;
 375                 }
 376                 $this->reposInitialised = true;
 377
 378                 $this->localRepo = $this->newRepo( $this->localInfo );
 379                 $this->foreignRepos = array();
 380                 foreach ( $this->foreignInfo as $key => $info ) {
 381                         $this->foreignRepos[$key] = $this->newRepo( $info );
 382                 }
 383         }
 384
 385         /**
 386          * Create a repo class based on an info structure
 387          */
 388         protected function newRepo( $info ) {
 389                 $class = $info['class'];
 390
 391                 return new $class( $info );
 392         }
 393
 394         /**
 395          * Split a virtual URL into repo, zone and rel parts
 396          * @param $url string
 397          * @throws MWException
 398          * @return array containing repo, zone and rel
 399          */
 400         function splitVirtualUrl( $url ) {
 401                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 402                         throw new MWException( __METHOD__ . ': unknown protocol' );
 403                 }
 404
 405                 $bits = explode( '/', substr( $url, 9 ), 3 );
 406                 if ( count( $bits ) != 3 ) {
 407                         throw new MWException( __METHOD__ . ": invalid mwrepo URL: $url" );
 408                 }
 409
 410                 return $bits;
 411         }
 412
 413         /**
 414          * @param $fileName string
 415          * @return array
 416          */
 417         function getFileProps( $fileName ) {
 418                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 419                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 420                         if ( $repoName === '' ) {
 421                                 $repoName = 'local';
 422                         }
 423                         $repo = $this->getRepo( $repoName );
 424
 425                         return $repo->getFileProps( $fileName );
 426                 } else {
 427                         return FSFile::getPropsFromPath( $fileName );
 428                 }
 429         }
 430
 431         /**
 432          * Clear RepoGroup process cache used for finding a file
 433          * @param $title Title|null Title of the file or null to clear all files
 434          */
 435         public function clearCache( Title $title = null ) {
 436                 if ( $title == null ) {
 437                         $this->cache->clear();
 438                 } else {
 439                         $this->cache->clear( $title->getDBkey() );
 440                 }
 441         }
 442 }