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         /**
  17          * @var LocalRepo
  18          */
  19         var $localRepo;
  20
  21         var $foreignRepos, $reposInitialised = false;
  22         var $localInfo, $foreignInfo;
  23         var $cache;
  24
  25         /**
  26          * @var RepoGroup
  27          */
  28         protected static $instance;
  29         const MAX_CACHE_SIZE = 1000;
  30
  31         /**
  32          * Get a RepoGroup instance. At present only one instance of RepoGroup is
  33          * needed in a MediaWiki invocation, this may change in the future.
  34          * @return RepoGroup
  35          */
  36         static function singleton() {
  37                 if ( self::$instance ) {
  38                         return self::$instance;
  39                 }
  40                 global $wgLocalFileRepo, $wgForeignFileRepos;
  41                 self::$instance = new RepoGroup( $wgLocalFileRepo, $wgForeignFileRepos );
  42                 return self::$instance;
  43         }
  44
  45         /**
  46          * Destroy the singleton instance, so that a new one will be created next
  47          * time singleton() is called.
  48          */
  49         static function destroySingleton() {
  50                 self::$instance = null;
  51         }
  52
  53         /**
  54          * Set the singleton instance to a given object
  55          * Used by extensions which hook into the Repo chain.
  56          * It's not enough to just create a superclass ... you have
  57          * to get people to call into it even though all they know is RepoGroup::singleton()
  58          *
  59          * @param $instance RepoGroup
  60          */
  61         static function setSingleton( $instance ) {
  62                 self::$instance = $instance;
  63         }
  64
  65         /**
  66          * Construct a group of file repositories.
  67          *
  68          * @param $localInfo array Associative array for local repo's info
  69          * @param $foreignInfo Array of repository info arrays.
  70          *     Each info array is an associative array with the 'class' member
  71          *     giving the class name. The entire array is passed to the repository
  72          *     constructor as the first parameter.
  73          */
  74         function __construct( $localInfo, $foreignInfo ) {
  75                 $this->localInfo = $localInfo;
  76                 $this->foreignInfo = $foreignInfo;
  77                 $this->cache = array();
  78         }
  79
  80         /**
  81          * Search repositories for an image.
  82          * You can also use wfFindFile() to do this.
  83          *
  84          * @param $title Title|string Title object or string
  85          * @param $options array Associative array of options:
  86          *     time:           requested time for an archived image, or false for the
  87          *                     current version. An image object will be returned which was
  88          *                     created at the specified time.
  89          *
  90          *     ignoreRedirect: If true, do not follow file redirects
  91          *
  92          *     private:        If true, return restricted (deleted) files if the current
  93          *                     user is allowed to view them. Otherwise, such files will not
  94          *                     be found.
  95          *
  96          *     bypassCache:    If true, do not use the process-local cache of File objects
  97          * @return File object or false if it is not found
  98          */
  99         function findFile( $title, $options = array() ) {
 100                 if ( !is_array( $options ) ) {
 101                         // MW 1.15 compat
 102                         $options = array( 'time' => $options );
 103                 }
 104                 if ( !$this->reposInitialised ) {
 105                         $this->initialiseRepos();
 106                 }
 107                 $title = File::normalizeTitle( $title );
 108                 if ( !$title ) {
 109                         return false;
 110                 }
 111
 112                 # Check the cache
 113                 if ( empty( $options['ignoreRedirect'] )
 114                         && empty( $options['private'] )
 115                         && empty( $options['bypassCache'] ) )
 116                 {
 117                         $useCache = true;
 118                         $time = isset( $options['time'] ) ? $options['time'] : '';
 119                         $dbkey = $title->getDBkey();
 120                         if ( isset( $this->cache[$dbkey][$time] ) ) {
 121                                 wfDebug( __METHOD__.": got File:$dbkey from process cache\n" );
 122                                 # Move it to the end of the list so that we can delete the LRU entry later
 123                                 $tmp = $this->cache[$dbkey];
 124                                 unset( $this->cache[$dbkey] );
 125                                 $this->cache[$dbkey] = $tmp;
 126                                 # Return the entry
 127                                 return $this->cache[$dbkey][$time];
 128                         } else {
 129                                 # Add a negative cache entry, may be overridden
 130                                 $this->trimCache();
 131                                 $this->cache[$dbkey][$time] = false;
 132                                 $cacheEntry =& $this->cache[$dbkey][$time];
 133                         }
 134                 } else {
 135                         $useCache = false;
 136                 }
 137
 138                 # Check the local repo
 139                 $image = $this->localRepo->findFile( $title, $options );
 140                 if ( $image ) {
 141                         if ( $useCache ) {
 142                                 $cacheEntry = $image;
 143                         }
 144                         return $image;
 145                 }
 146
 147                 # Check the foreign repos
 148                 foreach ( $this->foreignRepos as $repo ) {
 149                         $image = $repo->findFile( $title, $options );
 150                         if ( $image ) {
 151                                 if ( $useCache ) {
 152                                         $cacheEntry = $image;
 153                                 }
 154                                 return $image;
 155                         }
 156                 }
 157                 # Not found, do not override negative cache
 158                 return false;
 159         }
 160
 161         function findFiles( $inputItems ) {
 162                 if ( !$this->reposInitialised ) {
 163                         $this->initialiseRepos();
 164                 }
 165
 166                 $items = array();
 167                 foreach ( $inputItems as $item ) {
 168                         if ( !is_array( $item ) ) {
 169                                 $item = array( 'title' => $item );
 170                         }
 171                         $item['title'] = File::normalizeTitle( $item['title'] );
 172                         if ( $item['title'] ) {
 173                                 $items[$item['title']->getDBkey()] = $item;
 174                         }
 175                 }
 176
 177                 $images = $this->localRepo->findFiles( $items );
 178
 179                 foreach ( $this->foreignRepos as $repo ) {
 180                         // Remove found files from $items
 181                         foreach ( $images as $name => $image ) {
 182                                 unset( $items[$name] );
 183                         }
 184
 185                         $images = array_merge( $images, $repo->findFiles( $items ) );
 186                 }
 187                 return $images;
 188         }
 189
 190         /**
 191          * Interface for FileRepo::checkRedirect()
 192          */
 193         function checkRedirect( Title $title ) {
 194                 if ( !$this->reposInitialised ) {
 195                         $this->initialiseRepos();
 196                 }
 197
 198                 $redir = $this->localRepo->checkRedirect( $title );
 199                 if( $redir ) {
 200                         return $redir;
 201                 }
 202                 foreach ( $this->foreignRepos as $repo ) {
 203                         $redir = $repo->checkRedirect( $title );
 204                         if ( $redir ) {
 205                                 return $redir;
 206                         }
 207                 }
 208                 return false;
 209         }
 210
 211         /**
 212          * Find an instance of the file with this key, created at the specified time
 213          * Returns false if the file does not exist.
 214          *
 215          * @param $hash String base 36 SHA-1 hash
 216          * @param $options Option array, same as findFile()
 217          * @return File object or false if it is not found
 218          */
 219         function findFileFromKey( $hash, $options = array() ) {
 220                 if ( !$this->reposInitialised ) {
 221                         $this->initialiseRepos();
 222                 }
 223
 224                 $file = $this->localRepo->findFileFromKey( $hash, $options );
 225                 if ( !$file ) {
 226                         foreach ( $this->foreignRepos as $repo ) {
 227                                 $file = $repo->findFileFromKey( $hash, $options );
 228                                 if ( $file ) break;
 229                         }
 230                 }
 231                 return $file;
 232         }
 233
 234         /**
 235          * Find all instances of files with this key
 236          *
 237          * @param $hash String base 36 SHA-1 hash
 238          * @return Array of File objects
 239          */
 240         function findBySha1( $hash ) {
 241                 if ( !$this->reposInitialised ) {
 242                         $this->initialiseRepos();
 243                 }
 244
 245                 $result = $this->localRepo->findBySha1( $hash );
 246                 foreach ( $this->foreignRepos as $repo ) {
 247                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 248                 }
 249                 return $result;
 250         }
 251
 252         /**
 253          * Get the repo instance with a given key.
 254          */
 255         function getRepo( $index ) {
 256                 if ( !$this->reposInitialised ) {
 257                         $this->initialiseRepos();
 258                 }
 259                 if ( $index === 'local' ) {
 260                         return $this->localRepo;
 261                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 262                         return $this->foreignRepos[$index];
 263                 } else {
 264                         return false;
 265                 }
 266         }
 267         /**
 268          * Get the repo instance by its name
 269          */
 270         function getRepoByName( $name ) {
 271                 if ( !$this->reposInitialised ) {
 272                         $this->initialiseRepos();
 273                 }
 274                 foreach ( $this->foreignRepos as $repo ) {
 275                         if ( $repo->name == $name)
 276                                 return $repo;
 277                 }
 278                 return false;
 279         }
 280
 281         /**
 282          * Get the local repository, i.e. the one corresponding to the local image
 283          * table. Files are typically uploaded to the local repository.
 284          *
 285          * @return LocalRepo
 286          */
 287         function getLocalRepo() {
 288                 return $this->getRepo( 'local' );
 289         }
 290
 291         /**
 292          * Call a function for each foreign repo, with the repo object as the
 293          * first parameter.
 294          *
 295          * @param $callback Callback: the function to call
 296          * @param $params Array: optional additional parameters to pass to the function
 297          */
 298         function forEachForeignRepo( $callback, $params = array() ) {
 299                 foreach( $this->foreignRepos as $repo ) {
 300                         $args = array_merge( array( $repo ), $params );
 301                         if( call_user_func_array( $callback, $args ) ) {
 302                                 return true;
 303                         }
 304                 }
 305                 return false;
 306         }
 307
 308         /**
 309          * Does the installation have any foreign repos set up?
 310          * @return Boolean
 311          */
 312         function hasForeignRepos() {
 313                 return (bool)$this->foreignRepos;
 314         }
 315
 316         /**
 317          * Initialise the $repos array
 318          */
 319         function initialiseRepos() {
 320                 if ( $this->reposInitialised ) {
 321                         return;
 322                 }
 323                 $this->reposInitialised = true;
 324
 325                 $this->localRepo = $this->newRepo( $this->localInfo );
 326                 $this->foreignRepos = array();
 327                 foreach ( $this->foreignInfo as $key => $info ) {
 328                         $this->foreignRepos[$key] = $this->newRepo( $info );
 329                 }
 330         }
 331
 332         /**
 333          * Create a repo class based on an info structure
 334          */
 335         protected function newRepo( $info ) {
 336                 $class = $info['class'];
 337                 return new $class( $info );
 338         }
 339
 340         /**
 341          * Split a virtual URL into repo, zone and rel parts
 342          * @return an array containing repo, zone and rel
 343          */
 344         function splitVirtualUrl( $url ) {
 345                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 346                         throw new MWException( __METHOD__.': unknown protocol' );
 347                 }
 348
 349                 $bits = explode( '/', substr( $url, 9 ), 3 );
 350                 if ( count( $bits ) != 3 ) {
 351                         throw new MWException( __METHOD__.": invalid mwrepo URL: $url" );
 352                 }
 353                 return $bits;
 354         }
 355
 356         function getFileProps( $fileName ) {
 357                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 358                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 359                         if ( $repoName === '' ) {
 360                                 $repoName = 'local';
 361                         }
 362                         $repo = $this->getRepo( $repoName );
 363                         return $repo->getFileProps( $fileName );
 364                 } else {
 365                         return FSFile::getPropsFromPath( $fileName );
 366                 }
 367         }
 368
 369         /**
 370          * Limit cache memory
 371          */
 372         protected function trimCache() {
 373                 while ( count( $this->cache ) >= self::MAX_CACHE_SIZE ) {
 374                         reset( $this->cache );
 375                         $key = key( $this->cache );
 376                         wfDebug( __METHOD__.": evicting $key\n" );
 377                         unset( $this->cache[$key] );
 378                 }
 379         }
 380
 381         /**
 382          * Clear RepoGroup process cache used for finding a file
 383          * @param $title Title|null Title of the file or null to clear all files
 384          */
 385         public function clearCache( Title $title = null ) {
 386                 if ( $title == null ) {
 387                         $this->cache = array();
 388                 } else {
 389                         $dbKey = $title->getDBkey();
 390                         if ( isset( $this->cache[$dbKey] ) ) {
 391                                 unset( $this->cache[$dbKey] );
 392                         }
 393                 }
 394         }
 395 }