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