includes/filerepo/RepoGroup.php

   1 <?php
   2 /**
   3  * Prioritized list of file repositories
   4  *
   5  * @file
   6  * @ingroup FileRepo
   7  */
   8
   9 /**
  10  * @defgroup FileRepo FileRepo
  11  */
  12
  13 /**
  14  * Prioritized list of file repositories
  15  *
  16  * @ingroup FileRepo
  17  */
  18 class RepoGroup {
  19
  20         /**
  21          * @var LocalRepo
  22          */
  23         var $localRepo;
  24
  25         var $foreignRepos, $reposInitialised = false;
  26         var $localInfo, $foreignInfo;
  27         var $cache;
  28
  29         /**
  30          * @var RepoGroup
  31          */
  32         protected static $instance;
  33         const MAX_CACHE_SIZE = 1000;
  34
  35         /**
  36          * Get a RepoGroup instance. At present only one instance of RepoGroup is
  37          * needed in a MediaWiki invocation, this may change in the future.
  38          * @return RepoGroup
  39          */
  40         static function singleton() {
  41                 if ( self::$instance ) {
  42                         return self::$instance;
  43                 }
  44                 global $wgLocalFileRepo, $wgForeignFileRepos;
  45                 self::$instance = new RepoGroup( $wgLocalFileRepo, $wgForeignFileRepos );
  46                 return self::$instance;
  47         }
  48
  49         /**
  50          * Destroy the singleton instance, so that a new one will be created next
  51          * time singleton() is called.
  52          */
  53         static function destroySingleton() {
  54                 self::$instance = null;
  55         }
  56
  57         /**
  58          * Set the singleton instance to a given object
  59          * Used by extensions which hook into the Repo chain.
  60          * It's not enough to just create a superclass ... you have
  61          * to get people to call into it even though all they know is RepoGroup::singleton()
  62          *
  63          * @param $instance RepoGroup
  64          */
  65         static function setSingleton( $instance ) {
  66                 self::$instance = $instance;
  67         }
  68
  69         /**
  70          * Construct a group of file repositories.
  71          *
  72          * @param $localInfo Associative array for local repo's info
  73          * @param $foreignInfo Array of repository info arrays.
  74          *     Each info array is an associative array with the 'class' member
  75          *     giving the class name. The entire array is passed to the repository
  76          *     constructor as the first parameter.
  77          */
  78         function __construct( $localInfo, $foreignInfo ) {
  79                 $this->localInfo = $localInfo;
  80                 $this->foreignInfo = $foreignInfo;
  81                 $this->cache = array();
  82         }
  83
  84         /**
  85          * Search repositories for an image.
  86          * You can also use wfFindFile() to do this.
  87          *
  88          * @param $title Title|string Title object or string
  89          * @param $options array Associative array of options:
  90          *     time:           requested time for an archived image, or false for the
  91          *                     current version. An image object will be returned which was
  92          *                     created at the specified time.
  93          *
  94          *     ignoreRedirect: If true, do not follow file redirects
  95          *
  96          *     private:        If true, return restricted (deleted) files if the current
  97          *                     user is allowed to view them. Otherwise, such files will not
  98          *                     be found.
  99          *
 100          *     bypassCache:    If true, do not use the process-local cache of File objects
 101          * @return File object or false if it is not found
 102          */
 103         function findFile( $title, $options = array() ) {
 104                 if ( !is_array( $options ) ) {
 105                         // MW 1.15 compat
 106                         $options = array( 'time' => $options );
 107                 }
 108                 if ( !$this->reposInitialised ) {
 109                         $this->initialiseRepos();
 110                 }
 111                 $title = File::normalizeTitle( $title );
 112                 if ( !$title ) {
 113                         return false;
 114                 }
 115
 116                 # Check the cache
 117                 if ( empty( $options['ignoreRedirect'] )
 118                         && empty( $options['private'] )
 119                         && empty( $options['bypassCache'] ) )
 120                 {
 121                         $useCache = true;
 122                         $time = isset( $options['time'] ) ? $options['time'] : '';
 123                         $dbkey = $title->getDBkey();
 124                         if ( isset( $this->cache[$dbkey][$time] ) ) {
 125                                 wfDebug( __METHOD__.": got File:$dbkey from process cache\n" );
 126                                 # Move it to the end of the list so that we can delete the LRU entry later
 127                                 $tmp = $this->cache[$dbkey];
 128                                 unset( $this->cache[$dbkey] );
 129                                 $this->cache[$dbkey] = $tmp;
 130                                 # Return the entry
 131                                 return $this->cache[$dbkey][$time];
 132                         } else {
 133                                 # Add a negative cache entry, may be overridden
 134                                 $this->trimCache();
 135                                 $this->cache[$dbkey][$time] = false;
 136                                 $cacheEntry =& $this->cache[$dbkey][$time];
 137                         }
 138                 } else {
 139                         $useCache = false;
 140                 }
 141
 142                 # Check the local repo
 143                 $image = $this->localRepo->findFile( $title, $options );
 144                 if ( $image ) {
 145                         if ( $useCache ) {
 146                                 $cacheEntry = $image;
 147                         }
 148                         return $image;
 149                 }
 150
 151                 # Check the foreign repos
 152                 foreach ( $this->foreignRepos as $repo ) {
 153                         $image = $repo->findFile( $title, $options );
 154                         if ( $image ) {
 155                                 if ( $useCache ) {
 156                                         $cacheEntry = $image;
 157                                 }
 158                                 return $image;
 159                         }
 160                 }
 161                 # Not found, do not override negative cache
 162                 return false;
 163         }
 164
 165         function findFiles( $inputItems ) {
 166                 if ( !$this->reposInitialised ) {
 167                         $this->initialiseRepos();
 168                 }
 169
 170                 $items = array();
 171                 foreach ( $inputItems as $item ) {
 172                         if ( !is_array( $item ) ) {
 173                                 $item = array( 'title' => $item );
 174                         }
 175                         $item['title'] = File::normalizeTitle( $item['title'] );
 176                         if ( $item['title'] ) {
 177                                 $items[$item['title']->getDBkey()] = $item;
 178                         }
 179                 }
 180
 181                 $images = $this->localRepo->findFiles( $items );
 182
 183                 foreach ( $this->foreignRepos as $repo ) {
 184                         // Remove found files from $items
 185                         foreach ( $images as $name => $image ) {
 186                                 unset( $items[$name] );
 187                         }
 188
 189                         $images = array_merge( $images, $repo->findFiles( $items ) );
 190                 }
 191                 return $images;
 192         }
 193
 194         /**
 195          * Interface for FileRepo::checkRedirect()
 196          */
 197         function checkRedirect( Title $title ) {
 198                 if ( !$this->reposInitialised ) {
 199                         $this->initialiseRepos();
 200                 }
 201
 202                 $redir = $this->localRepo->checkRedirect( $title );
 203                 if( $redir ) {
 204                         return $redir;
 205                 }
 206                 foreach ( $this->foreignRepos as $repo ) {
 207                         $redir = $repo->checkRedirect( $title );
 208                         if ( $redir ) {
 209                                 return $redir;
 210                         }
 211                 }
 212                 return false;
 213         }
 214
 215         /**
 216          * Find an instance of the file with this key, created at the specified time
 217          * Returns false if the file does not exist.
 218          *
 219          * @param $hash String base 36 SHA-1 hash
 220          * @param $options Option array, same as findFile()
 221          * @return File object or false if it is not found
 222          */
 223         function findFileFromKey( $hash, $options = array() ) {
 224                 if ( !$this->reposInitialised ) {
 225                         $this->initialiseRepos();
 226                 }
 227
 228                 $file = $this->localRepo->findFileFromKey( $hash, $options );
 229                 if ( !$file ) {
 230                         foreach ( $this->foreignRepos as $repo ) {
 231                                 $file = $repo->findFileFromKey( $hash, $options );
 232                                 if ( $file ) break;
 233                         }
 234                 }
 235                 return $file;
 236         }
 237
 238         /**
 239          * Find all instances of files with this key
 240          *
 241          * @param $hash String base 36 SHA-1 hash
 242          * @return Array of File objects
 243          */
 244         function findBySha1( $hash ) {
 245                 if ( !$this->reposInitialised ) {
 246                         $this->initialiseRepos();
 247                 }
 248
 249                 $result = $this->localRepo->findBySha1( $hash );
 250                 foreach ( $this->foreignRepos as $repo ) {
 251                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 252                 }
 253                 return $result;
 254         }
 255
 256         /**
 257          * Get the repo instance with a given key.
 258          */
 259         function getRepo( $index ) {
 260                 if ( !$this->reposInitialised ) {
 261                         $this->initialiseRepos();
 262                 }
 263                 if ( $index === 'local' ) {
 264                         return $this->localRepo;
 265                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 266                         return $this->foreignRepos[$index];
 267                 } else {
 268                         return false;
 269                 }
 270         }
 271         /**
 272          * Get the repo instance by its name
 273          */
 274         function getRepoByName( $name ) {
 275                 if ( !$this->reposInitialised ) {
 276                         $this->initialiseRepos();
 277                 }
 278                 foreach ( $this->foreignRepos as $repo ) {
 279                         if ( $repo->name == $name)
 280                                 return $repo;
 281                 }
 282                 return false;
 283         }
 284
 285         /**
 286          * Get the local repository, i.e. the one corresponding to the local image
 287          * table. Files are typically uploaded to the local repository.
 288          *
 289          * @return LocalRepo
 290          */
 291         function getLocalRepo() {
 292                 return $this->getRepo( 'local' );
 293         }
 294
 295         /**
 296          * Call a function for each foreign repo, with the repo object as the
 297          * first parameter.
 298          *
 299          * @param $callback Callback: the function to call
 300          * @param $params Array: optional additional parameters to pass to the function
 301          */
 302         function forEachForeignRepo( $callback, $params = array() ) {
 303                 foreach( $this->foreignRepos as $repo ) {
 304                         $args = array_merge( array( $repo ), $params );
 305                         if( call_user_func_array( $callback, $args ) ) {
 306                                 return true;
 307                         }
 308                 }
 309                 return false;
 310         }
 311
 312         /**
 313          * Does the installation have any foreign repos set up?
 314          * @return Boolean
 315          */
 316         function hasForeignRepos() {
 317                 return (bool)$this->foreignRepos;
 318         }
 319
 320         /**
 321          * Initialise the $repos array
 322          */
 323         function initialiseRepos() {
 324                 if ( $this->reposInitialised ) {
 325                         return;
 326                 }
 327                 $this->reposInitialised = true;
 328
 329                 $this->localRepo = $this->newRepo( $this->localInfo );
 330                 $this->foreignRepos = array();
 331                 foreach ( $this->foreignInfo as $key => $info ) {
 332                         $this->foreignRepos[$key] = $this->newRepo( $info );
 333                 }
 334         }
 335
 336         /**
 337          * Create a repo class based on an info structure
 338          */
 339         protected function newRepo( $info ) {
 340                 $class = $info['class'];
 341                 return new $class( $info );
 342         }
 343
 344         /**
 345          * Split a virtual URL into repo, zone and rel parts
 346          * @return an array containing repo, zone and rel
 347          */
 348         function splitVirtualUrl( $url ) {
 349                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 350                         throw new MWException( __METHOD__.': unknown protocol' );
 351                 }
 352
 353                 $bits = explode( '/', substr( $url, 9 ), 3 );
 354                 if ( count( $bits ) != 3 ) {
 355                         throw new MWException( __METHOD__.": invalid mwrepo URL: $url" );
 356                 }
 357                 return $bits;
 358         }
 359
 360         function getFileProps( $fileName ) {
 361                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 362                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 363                         if ( $repoName === '' ) {
 364                                 $repoName = 'local';
 365                         }
 366                         $repo = $this->getRepo( $repoName );
 367                         return $repo->getFileProps( $fileName );
 368                 } else {
 369                         return File::getPropsFromPath( $fileName );
 370                 }
 371         }
 372
 373         /**
 374          * Limit cache memory
 375          */
 376         protected function trimCache() {
 377                 while ( count( $this->cache ) >= self::MAX_CACHE_SIZE ) {
 378                         reset( $this->cache );
 379                         $key = key( $this->cache );
 380                         wfDebug( __METHOD__.": evicting $key\n" );
 381                         unset( $this->cache[$key] );
 382                 }
 383         }
 384
 385         /**
 386          * Clear RepoGroup process cache used for finding a file
 387          * @param $title Title|null Title of the file or null to clear all files
 388          */
 389         public function clearCache( Title $title = null ) {
 390                 if ( $title == null ) {
 391                         $this->cache = array();
 392                 } else {
 393                         $dbKey = $title->getDBkey();
 394                         if ( isset( $this->cache[$dbKey] ) ) {
 395                                 unset( $this->cache[$dbKey] );
 396                         }
 397                 }
 398         }
 399 }