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