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