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