includes/filerepo/RepoGroup.php

   1 <?php
   2 /**
   3  * Prioritized list of file repositories
   4  *
   5  * @file
   6  * @ingroup FileRepo
   7  */
   8
   9 /**
  10  * Prioritized list of file repositories
  11  *
  12  * @ingroup FileRepo
  13  */
  14 class RepoGroup {
  15         /**
  16          * @var LocalRepo
  17          */
  18         var $localRepo;
  19
  20         var $foreignRepos, $reposInitialised = false;
  21         var $localInfo, $foreignInfo;
  22         var $cache;
  23
  24         /**
  25          * @var RepoGroup
  26          */
  27         protected static $instance;
  28         const MAX_CACHE_SIZE = 500;
  29
  30         /**
  31          * Get a RepoGroup instance. At present only one instance of RepoGroup is
  32          * needed in a MediaWiki invocation, this may change in the future.
  33          * @return RepoGroup
  34          */
  35         static function singleton() {
  36                 if ( self::$instance ) {
  37                         return self::$instance;
  38                 }
  39                 global $wgLocalFileRepo, $wgForeignFileRepos;
  40                 self::$instance = new RepoGroup( $wgLocalFileRepo, $wgForeignFileRepos );
  41                 return self::$instance;
  42         }
  43
  44         /**
  45          * Destroy the singleton instance, so that a new one will be created next
  46          * time singleton() is called.
  47          */
  48         static function destroySingleton() {
  49                 self::$instance = null;
  50         }
  51
  52         /**
  53          * Set the singleton instance to a given object
  54          * Used by extensions which hook into the Repo chain.
  55          * It's not enough to just create a superclass ... you have
  56          * to get people to call into it even though all they know is RepoGroup::singleton()
  57          *
  58          * @param $instance RepoGroup
  59          */
  60         static function setSingleton( $instance ) {
  61                 self::$instance = $instance;
  62         }
  63
  64         /**
  65          * Construct a group of file repositories.
  66          *
  67          * @param $localInfo array Associative array for local repo's info
  68          * @param $foreignInfo Array of repository info arrays.
  69          *     Each info array is an associative array with the 'class' member
  70          *     giving the class name. The entire array is passed to the repository
  71          *     constructor as the first parameter.
  72          */
  73         function __construct( $localInfo, $foreignInfo ) {
  74                 $this->localInfo = $localInfo;
  75                 $this->foreignInfo = $foreignInfo;
  76                 $this->cache = array();
  77         }
  78
  79         /**
  80          * Search repositories for an image.
  81          * You can also use wfFindFile() to do this.
  82          *
  83          * @param $title Title|string Title object or string
  84          * @param $options array Associative array of options:
  85          *     time:           requested time for an archived image, or false for the
  86          *                     current version. An image object will be returned which was
  87          *                     created at the specified time.
  88          *
  89          *     ignoreRedirect: If true, do not follow file redirects
  90          *
  91          *     private:        If true, return restricted (deleted) files if the current
  92          *                     user is allowed to view them. Otherwise, such files will not
  93          *                     be found.
  94          *
  95          *     bypassCache:    If true, do not use the process-local cache of File objects
  96          * @return File object or false if it is not found
  97          */
  98         function findFile( $title, $options = array() ) {
  99                 if ( !is_array( $options ) ) {
 100                         // MW 1.15 compat
 101                         $options = array( 'time' => $options );
 102                 }
 103                 if ( !$this->reposInitialised ) {
 104                         $this->initialiseRepos();
 105                 }
 106                 $title = File::normalizeTitle( $title );
 107                 if ( !$title ) {
 108                         return false;
 109                 }
 110
 111                 # Check the cache
 112                 if ( empty( $options['ignoreRedirect'] )
 113                         && empty( $options['private'] )
 114                         && empty( $options['bypassCache'] ) )
 115                 {
 116                         $time = isset( $options['time'] ) ? $options['time'] : '';
 117                         $dbkey = $title->getDBkey();
 118                         if ( isset( $this->cache[$dbkey][$time] ) ) {
 119                                 wfDebug( __METHOD__.": got File:$dbkey from process cache\n" );
 120                                 # Move it to the end of the list so that we can delete the LRU entry later
 121                                 $this->pingCache( $dbkey );
 122                                 # Return the entry
 123                                 return $this->cache[$dbkey][$time];
 124                         }
 125                         $useCache = true;
 126                 } else {
 127                         $useCache = false;
 128                 }
 129
 130                 # Check the local repo
 131                 $image = $this->localRepo->findFile( $title, $options );
 132
 133                 # Check the foreign repos
 134                 if ( !$image ) {
 135                         foreach ( $this->foreignRepos as $repo ) {
 136                                 $image = $repo->findFile( $title, $options );
 137                                 if ( $image ) {
 138                                         break;
 139                                 }
 140                         }
 141                 }
 142
 143                 $image = $image ? $image : false; // type sanity
 144                 # Cache file existence or non-existence
 145                 if ( $useCache && ( !$image || $image->isCacheable() ) ) {
 146                         $this->trimCache();
 147                         $this->cache[$dbkey][$time] = $image;
 148                 }
 149
 150                 return $image;
 151         }
 152
 153         function findFiles( $inputItems ) {
 154                 if ( !$this->reposInitialised ) {
 155                         $this->initialiseRepos();
 156                 }
 157
 158                 $items = array();
 159                 foreach ( $inputItems as $item ) {
 160                         if ( !is_array( $item ) ) {
 161                                 $item = array( 'title' => $item );
 162                         }
 163                         $item['title'] = File::normalizeTitle( $item['title'] );
 164                         if ( $item['title'] ) {
 165                                 $items[$item['title']->getDBkey()] = $item;
 166                         }
 167                 }
 168
 169                 $images = $this->localRepo->findFiles( $items );
 170
 171                 foreach ( $this->foreignRepos as $repo ) {
 172                         // Remove found files from $items
 173                         foreach ( $images as $name => $image ) {
 174                                 unset( $items[$name] );
 175                         }
 176
 177                         $images = array_merge( $images, $repo->findFiles( $items ) );
 178                 }
 179                 return $images;
 180         }
 181
 182         /**
 183          * Interface for FileRepo::checkRedirect()
 184          * @return bool
 185          */
 186         function checkRedirect( Title $title ) {
 187                 if ( !$this->reposInitialised ) {
 188                         $this->initialiseRepos();
 189                 }
 190
 191                 $redir = $this->localRepo->checkRedirect( $title );
 192                 if( $redir ) {
 193                         return $redir;
 194                 }
 195                 foreach ( $this->foreignRepos as $repo ) {
 196                         $redir = $repo->checkRedirect( $title );
 197                         if ( $redir ) {
 198                                 return $redir;
 199                         }
 200                 }
 201                 return false;
 202         }
 203
 204         /**
 205          * Find an instance of the file with this key, created at the specified time
 206          * Returns false if the file does not exist.
 207          *
 208          * @param $hash String base 36 SHA-1 hash
 209          * @param $options array Option array, same as findFile()
 210          * @return File object or false if it is not found
 211          */
 212         function findFileFromKey( $hash, $options = array() ) {
 213                 if ( !$this->reposInitialised ) {
 214                         $this->initialiseRepos();
 215                 }
 216
 217                 $file = $this->localRepo->findFileFromKey( $hash, $options );
 218                 if ( !$file ) {
 219                         foreach ( $this->foreignRepos as $repo ) {
 220                                 $file = $repo->findFileFromKey( $hash, $options );
 221                                 if ( $file ) break;
 222                         }
 223                 }
 224                 return $file;
 225         }
 226
 227         /**
 228          * Find all instances of files with this key
 229          *
 230          * @param $hash String base 36 SHA-1 hash
 231          * @return Array of File objects
 232          */
 233         function findBySha1( $hash ) {
 234                 if ( !$this->reposInitialised ) {
 235                         $this->initialiseRepos();
 236                 }
 237
 238                 $result = $this->localRepo->findBySha1( $hash );
 239                 foreach ( $this->foreignRepos as $repo ) {
 240                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 241                 }
 242                 return $result;
 243         }
 244
 245         /**
 246          * Get the repo instance with a given key.
 247          * @return bool|LocalRepo
 248          */
 249         function getRepo( $index ) {
 250                 if ( !$this->reposInitialised ) {
 251                         $this->initialiseRepos();
 252                 }
 253                 if ( $index === 'local' ) {
 254                         return $this->localRepo;
 255                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 256                         return $this->foreignRepos[$index];
 257                 } else {
 258                         return false;
 259                 }
 260         }
 261         /**
 262          * Get the repo instance by its name
 263          * @return bool
 264          */
 265         function getRepoByName( $name ) {
 266                 if ( !$this->reposInitialised ) {
 267                         $this->initialiseRepos();
 268                 }
 269                 foreach ( $this->foreignRepos as $repo ) {
 270                         if ( $repo->name == $name)
 271                                 return $repo;
 272                 }
 273                 return false;
 274         }
 275
 276         /**
 277          * Get the local repository, i.e. the one corresponding to the local image
 278          * table. Files are typically uploaded to the local repository.
 279          *
 280          * @return LocalRepo
 281          */
 282         function getLocalRepo() {
 283                 return $this->getRepo( 'local' );
 284         }
 285
 286         /**
 287          * Call a function for each foreign repo, with the repo object as the
 288          * first parameter.
 289          *
 290          * @param $callback Callback: the function to call
 291          * @param $params Array: optional additional parameters to pass to the function
 292          * @return bool
 293          */
 294         function forEachForeignRepo( $callback, $params = array() ) {
 295                 foreach( $this->foreignRepos as $repo ) {
 296                         $args = array_merge( array( $repo ), $params );
 297                         if( call_user_func_array( $callback, $args ) ) {
 298                                 return true;
 299                         }
 300                 }
 301                 return false;
 302         }
 303
 304         /**
 305          * Does the installation have any foreign repos set up?
 306          * @return Boolean
 307          */
 308         function hasForeignRepos() {
 309                 return (bool)$this->foreignRepos;
 310         }
 311
 312         /**
 313          * Initialise the $repos array
 314          */
 315         function initialiseRepos() {
 316                 if ( $this->reposInitialised ) {
 317                         return;
 318                 }
 319                 $this->reposInitialised = true;
 320
 321                 $this->localRepo = $this->newRepo( $this->localInfo );
 322                 $this->foreignRepos = array();
 323                 foreach ( $this->foreignInfo as $key => $info ) {
 324                         $this->foreignRepos[$key] = $this->newRepo( $info );
 325                 }
 326         }
 327
 328         /**
 329          * Create a repo class based on an info structure
 330          */
 331         protected function newRepo( $info ) {
 332                 $class = $info['class'];
 333                 return new $class( $info );
 334         }
 335
 336         /**
 337          * Split a virtual URL into repo, zone and rel parts
 338          * @param $url string
 339          * @return array containing repo, zone and rel
 340          */
 341         function splitVirtualUrl( $url ) {
 342                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 343                         throw new MWException( __METHOD__.': unknown protocol' );
 344                 }
 345
 346                 $bits = explode( '/', substr( $url, 9 ), 3 );
 347                 if ( count( $bits ) != 3 ) {
 348                         throw new MWException( __METHOD__.": invalid mwrepo URL: $url" );
 349                 }
 350                 return $bits;
 351         }
 352
 353         function getFileProps( $fileName ) {
 354                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 355                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 356                         if ( $repoName === '' ) {
 357                                 $repoName = 'local';
 358                         }
 359                         $repo = $this->getRepo( $repoName );
 360                         return $repo->getFileProps( $fileName );
 361                 } else {
 362                         return FSFile::getPropsFromPath( $fileName );
 363                 }
 364         }
 365
 366         /**
 367          * Move a cache entry to the top (such as when accessed)
 368          */
 369         protected function pingCache( $key ) {
 370                 if ( isset( $this->cache[$key] ) ) {
 371                         $tmp = $this->cache[$key];
 372                         unset( $this->cache[$key] );
 373                         $this->cache[$key] = $tmp;
 374                 }
 375         }
 376
 377         /**
 378          * Limit cache memory
 379          */
 380         protected function trimCache() {
 381                 while ( count( $this->cache ) >= self::MAX_CACHE_SIZE ) {
 382                         reset( $this->cache );
 383                         $key = key( $this->cache );
 384                         wfDebug( __METHOD__.": evicting $key\n" );
 385                         unset( $this->cache[$key] );
 386                 }
 387         }
 388
 389         /**
 390          * Clear RepoGroup process cache used for finding a file
 391          * @param $title Title|null Title of the file or null to clear all files
 392          */
 393         public function clearCache( Title $title = null ) {
 394                 if ( $title == null ) {
 395                         $this->cache = array();
 396                 } else {
 397                         $dbKey = $title->getDBkey();
 398                         if ( isset( $this->cache[$dbKey] ) ) {
 399                                 unset( $this->cache[$dbKey] );
 400                         }
 401                 }
 402         }
 403 }