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                         $this->initialiseRepos();
 110                 }
 111                 if ( !($title instanceof Title) ) {
 112                         $title = Title::makeTitleSafe( NS_FILE, $title );
 113                         if ( !is_object( $title ) ) {
 114                                 return false;
 115                         }
 116                 }
 117
 118                 if ( $title->getNamespace() != NS_MEDIA && $title->getNamespace() != NS_FILE ) {
 119                         throw new MWException( __METHOD__ . ' received an Title object with incorrect namespace' );
 120                 }
 121
 122                 # Check the cache
 123                 if ( empty( $options['ignoreRedirect'] )
 124                         && empty( $options['private'] )
 125                         && empty( $options['bypassCache'] )
 126                         && $title->getNamespace() == NS_FILE )
 127                 {
 128                         $useCache = true;
 129                         $time = isset( $options['time'] ) ? $options['time'] : '';
 130                         $dbkey = $title->getDBkey();
 131                         if ( isset( $this->cache[$dbkey][$time] ) ) {
 132                                 wfDebug( __METHOD__.": got File:$dbkey from process cache\n" );
 133                                 # Move it to the end of the list so that we can delete the LRU entry later
 134                                 $tmp = $this->cache[$dbkey];
 135                                 unset( $this->cache[$dbkey] );
 136                                 $this->cache[$dbkey] = $tmp;
 137                                 # Return the entry
 138                                 return $this->cache[$dbkey][$time];
 139                         } else {
 140                                 # Add a negative cache entry, may be overridden
 141                                 $this->trimCache();
 142                                 $this->cache[$dbkey][$time] = false;
 143                                 $cacheEntry =& $this->cache[$dbkey][$time];
 144                         }
 145                 } else {
 146                         $useCache = false;
 147                 }
 148
 149                 # Check the local repo
 150                 $image = $this->localRepo->findFile( $title, $options );
 151                 if ( $image ) {
 152                         if ( $useCache ) {
 153                                 $cacheEntry = $image;
 154                         }
 155                         return $image;
 156                 }
 157
 158                 # Check the foreign repos
 159                 foreach ( $this->foreignRepos as $repo ) {
 160                         $image = $repo->findFile( $title, $options );
 161                         if ( $image ) {
 162                                 if ( $useCache ) {
 163                                         $cacheEntry = $image;
 164                                 }
 165                                 return $image;
 166                         }
 167                 }
 168                 # Not found, do not override negative cache
 169                 return false;
 170         }
 171
 172         function findFiles( $inputItems ) {
 173                 if ( !$this->reposInitialised ) {
 174                         $this->initialiseRepos();
 175                 }
 176
 177                 $items = array();
 178                 foreach ( $inputItems as $item ) {
 179                         if ( !is_array( $item ) ) {
 180                                 $item = array( 'title' => $item );
 181                         }
 182                         if ( !( $item['title'] instanceof Title ) )
 183                                 $item['title'] = Title::makeTitleSafe( NS_FILE, $item['title'] );
 184                         if ( $item['title'] )
 185                                 $items[$item['title']->getDBkey()] = $item;
 186                 }
 187
 188                 $images = $this->localRepo->findFiles( $items );
 189
 190                 foreach ( $this->foreignRepos as $repo ) {
 191                         // Remove found files from $items
 192                         foreach ( $images as $name => $image ) {
 193                                 unset( $items[$name] );
 194                         }
 195
 196                         $images = array_merge( $images, $repo->findFiles( $items ) );
 197                 }
 198                 return $images;
 199         }
 200
 201         /**
 202          * Interface for FileRepo::checkRedirect()
 203          */
 204         function checkRedirect( $title ) {
 205                 if ( !$this->reposInitialised ) {
 206                         $this->initialiseRepos();
 207                 }
 208
 209                 $redir = $this->localRepo->checkRedirect( $title );
 210                 if( $redir ) {
 211                         return $redir;
 212                 }
 213                 foreach ( $this->foreignRepos as $repo ) {
 214                         $redir = $repo->checkRedirect( $title );
 215                         if ( $redir ) {
 216                                 return $redir;
 217                         }
 218                 }
 219                 return false;
 220         }
 221
 222         /**
 223          * Find an instance of the file with this key, created at the specified time
 224          * Returns false if the file does not exist.
 225          *
 226          * @param $hash String base 36 SHA-1 hash
 227          * @param $options Option array, same as findFile()
 228          * @return File object or false if it is not found
 229          */
 230         function findFileFromKey( $hash, $options = array() ) {
 231                 if ( !$this->reposInitialised ) {
 232                         $this->initialiseRepos();
 233                 }
 234
 235                 $file = $this->localRepo->findFileFromKey( $hash, $options );
 236                 if ( !$file ) {
 237                         foreach ( $this->foreignRepos as $repo ) {
 238                                 $file = $repo->findFileFromKey( $hash, $options );
 239                                 if ( $file ) break;
 240                         }
 241                 }
 242                 return $file;
 243         }
 244
 245         /**
 246          * Find all instances of files with this key
 247          *
 248          * @param $hash String base 36 SHA-1 hash
 249          * @return Array of File objects
 250          */
 251         function findBySha1( $hash ) {
 252                 if ( !$this->reposInitialised ) {
 253                         $this->initialiseRepos();
 254                 }
 255
 256                 $result = $this->localRepo->findBySha1( $hash );
 257                 foreach ( $this->foreignRepos as $repo ) {
 258                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 259                 }
 260                 return $result;
 261         }
 262
 263         /**
 264          * Get the repo instance with a given key.
 265          */
 266         function getRepo( $index ) {
 267                 if ( !$this->reposInitialised ) {
 268                         $this->initialiseRepos();
 269                 }
 270                 if ( $index === 'local' ) {
 271                         return $this->localRepo;
 272                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 273                         return $this->foreignRepos[$index];
 274                 } else {
 275                         return false;
 276                 }
 277         }
 278         /**
 279          * Get the repo instance by its name
 280          */
 281         function getRepoByName( $name ) {
 282                 if ( !$this->reposInitialised ) {
 283                         $this->initialiseRepos();
 284                 }
 285                 foreach ( $this->foreignRepos as $repo ) {
 286                         if ( $repo->name == $name)
 287                                 return $repo;
 288                 }
 289                 return false;
 290         }
 291
 292         /**
 293          * Get the local repository, i.e. the one corresponding to the local image
 294          * table. Files are typically uploaded to the local repository.
 295          *
 296          * @return LocalRepo
 297          */
 298         function getLocalRepo() {
 299                 return $this->getRepo( 'local' );
 300         }
 301
 302         /**
 303          * Call a function for each foreign repo, with the repo object as the
 304          * first parameter.
 305          *
 306          * @param $callback Callback: the function to call
 307          * @param $params Array: optional additional parameters to pass to the function
 308          */
 309         function forEachForeignRepo( $callback, $params = array() ) {
 310                 foreach( $this->foreignRepos as $repo ) {
 311                         $args = array_merge( array( $repo ), $params );
 312                         if( call_user_func_array( $callback, $args ) ) {
 313                                 return true;
 314                         }
 315                 }
 316                 return false;
 317         }
 318
 319         /**
 320          * Does the installation have any foreign repos set up?
 321          * @return Boolean
 322          */
 323         function hasForeignRepos() {
 324                 return (bool)$this->foreignRepos;
 325         }
 326
 327         /**
 328          * Initialise the $repos array
 329          */
 330         function initialiseRepos() {
 331                 if ( $this->reposInitialised ) {
 332                         return;
 333                 }
 334                 $this->reposInitialised = true;
 335
 336                 $this->localRepo = $this->newRepo( $this->localInfo );
 337                 $this->foreignRepos = array();
 338                 foreach ( $this->foreignInfo as $key => $info ) {
 339                         $this->foreignRepos[$key] = $this->newRepo( $info );
 340                 }
 341         }
 342
 343         /**
 344          * Create a repo class based on an info structure
 345          */
 346         protected function newRepo( $info ) {
 347                 $class = $info['class'];
 348                 return new $class( $info );
 349         }
 350
 351         /**
 352          * Split a virtual URL into repo, zone and rel parts
 353          * @return an array containing repo, zone and rel
 354          */
 355         function splitVirtualUrl( $url ) {
 356                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 357                         throw new MWException( __METHOD__.': unknown protocol' );
 358                 }
 359
 360                 $bits = explode( '/', substr( $url, 9 ), 3 );
 361                 if ( count( $bits ) != 3 ) {
 362                         throw new MWException( __METHOD__.": invalid mwrepo URL: $url" );
 363                 }
 364                 return $bits;
 365         }
 366
 367         function getFileProps( $fileName ) {
 368                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 369                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 370                         if ( $repoName === '' ) {
 371                                 $repoName = 'local';
 372                         }
 373                         $repo = $this->getRepo( $repoName );
 374                         return $repo->getFileProps( $fileName );
 375                 } else {
 376                         return File::getPropsFromPath( $fileName );
 377                 }
 378         }
 379
 380         /**
 381          * Limit cache memory
 382          */
 383         protected function trimCache() {
 384                 while ( count( $this->cache ) >= self::MAX_CACHE_SIZE ) {
 385                         reset( $this->cache );
 386                         $key = key( $this->cache );
 387                         wfDebug( __METHOD__.": evicting $key\n" );
 388                         unset( $this->cache[$key] );
 389                 }
 390         }
 391
 392         /**
 393          * Clear RepoGroup process cache used for finding a file
 394          * @param $title Title|null Title of the file or null to clear all files
 395          */
 396         public function clearCache( Title $title = null ) {
 397                 if ( $title == null ) {
 398                         $this->cache = array();
 399                 } else {
 400                         $dbKey = $title->getDBkey();
 401                         if ( isset( $this->cache[$dbKey] ) ) {
 402                                 unset( $this->cache[$dbKey] );
 403                         }
 404                 }
 405         }
 406 }