includes/filerepo/RepoGroup.php

   1 <?php
   2 /**
   3  * @defgroup FileRepo FileRepo
   4  *
   5  * @file
   6  * @ingroup FileRepo
   7  */
   8
   9 /**
  10  * @ingroup FileRepo
  11  * Prioritized list of file repositories
  12  */
  13 class RepoGroup {
  14         var $localRepo, $foreignRepos, $reposInitialised = false;
  15         var $localInfo, $foreignInfo;
  16         var $cache;
  17
  18         protected static $instance;
  19         const MAX_CACHE_SIZE = 1000;
  20
  21         /**
  22          * Get a RepoGroup instance. At present only one instance of RepoGroup is
  23          * needed in a MediaWiki invocation, this may change in the future.
  24          */
  25         static function singleton() {
  26                 if ( self::$instance ) {
  27                         return self::$instance;
  28                 }
  29                 global $wgLocalFileRepo, $wgForeignFileRepos;
  30                 self::$instance = new RepoGroup( $wgLocalFileRepo, $wgForeignFileRepos );
  31                 return self::$instance;
  32         }
  33
  34         /**
  35          * Destroy the singleton instance, so that a new one will be created next
  36          * time singleton() is called.
  37          */
  38         static function destroySingleton() {
  39                 self::$instance = null;
  40         }
  41
  42         /**
  43          * Set the singleton instance to a given object
  44          */
  45         static function setSingleton( $instance ) {
  46                 self::$instance = $instance;
  47         }
  48
  49         /**
  50          * Construct a group of file repositories.
  51          * @param array $data Array of repository info arrays.
  52          *     Each info array is an associative array with the 'class' member
  53          *     giving the class name. The entire array is passed to the repository
  54          *     constructor as the first parameter.
  55          */
  56         function __construct( $localInfo, $foreignInfo ) {
  57                 $this->localInfo = $localInfo;
  58                 $this->foreignInfo = $foreignInfo;
  59                 $this->cache = array();
  60         }
  61
  62         /**
  63          * Search repositories for an image.
  64          * You can also use wfFindFile() to do this.
  65          * @param mixed $title Title object or string
  66          * @param $options Associative array of options:
  67          *     time:           requested time for an archived image, or false for the
  68          *                     current version. An image object will be returned which was
  69          *                     created at the specified time.
  70          *
  71          *     ignoreRedirect: If true, do not follow file redirects
  72          *
  73          *     private:        If true, return restricted (deleted) files if the current
  74          *                     user is allowed to view them. Otherwise, such files will not
  75          *                     be found.
  76          *
  77          *     bypassCache:    If true, do not use the process-local cache of File objects
  78          * @return File object or false if it is not found
  79          */
  80         function findFile( $title, $options = array() ) {
  81                 if ( !is_array( $options ) ) {
  82                         // MW 1.15 compat
  83                         $options = array( 'time' => $options );
  84                 }
  85                 if ( !$this->reposInitialised ) {
  86                         $this->initialiseRepos();
  87                 }
  88                 if ( !($title instanceof Title) ) {
  89                         $title = Title::makeTitleSafe( NS_FILE, $title );
  90                         if ( !is_object( $title ) ) {
  91                                 return false;
  92                         }
  93                 }
  94
  95                 # Check the cache
  96                 if ( empty( $options['ignoreRedirect'] )
  97                         && empty( $options['private'] )
  98                         && empty( $options['bypassCache'] ) )
  99                 {
 100                         $useCache = true;
 101                         $time = isset( $options['time'] ) ? $options['time'] : '';
 102                         $dbkey = $title->getDBkey();
 103                         if ( isset( $this->cache[$dbkey][$time] ) ) {
 104                                 wfDebug( __METHOD__.": got File:$dbkey from process cache\n" );
 105                                 # Move it to the end of the list so that we can delete the LRU entry later
 106                                 $tmp = $this->cache[$dbkey];
 107                                 unset( $this->cache[$dbkey] );
 108                                 $this->cache[$dbkey] = $tmp;
 109                                 # Return the entry
 110                                 return $this->cache[$dbkey][$time];
 111                         } else {
 112                                 # Add a negative cache entry, may be overridden
 113                                 $this->trimCache();
 114                                 $this->cache[$dbkey][$time] = false;
 115                                 $cacheEntry =& $this->cache[$dbkey][$time];
 116                         }
 117                 } else {
 118                         $useCache = false;
 119                 }
 120
 121                 # Check the local repo
 122                 $image = $this->localRepo->findFile( $title, $options );
 123                 if ( $image ) {
 124                         if ( $useCache ) {
 125                                 $cacheEntry = $image;
 126                         }
 127                         return $image;
 128                 }
 129
 130                 # Check the foreign repos
 131                 foreach ( $this->foreignRepos as $repo ) {
 132                         $image = $repo->findFile( $title, $options );
 133                         if ( $image ) {
 134                                 if ( $useCache ) {
 135                                         $cacheEntry = $image;
 136                                 }
 137                                 return $image;
 138                         }
 139                 }
 140                 # Not found, do not override negative cache
 141                 return false;
 142         }
 143
 144         function findFiles( $inputItems ) {
 145                 if ( !$this->reposInitialised ) {
 146                         $this->initialiseRepos();
 147                 }
 148
 149                 $items = array();
 150                 foreach ( $inputItems as $item ) {
 151                         if ( !is_array( $item ) ) {
 152                                 $item = array( 'title' => $item );
 153                         }
 154                         if ( !( $item['title'] instanceof Title ) )
 155                                 $item['title'] = Title::makeTitleSafe( NS_FILE, $item['title'] );
 156                         if ( $item['title'] )
 157                                 $items[$item['title']->getDBkey()] = $item;
 158                 }
 159
 160                 $images = $this->localRepo->findFiles( $items );
 161
 162                 foreach ( $this->foreignRepos as $repo ) {
 163                         // Remove found files from $items
 164                         foreach ( $images as $name => $image ) {
 165                                 unset( $items[$name] );
 166                         }
 167
 168                         $images = array_merge( $images, $repo->findFiles( $items ) );
 169                 }
 170                 return $images;
 171         }
 172
 173         /**
 174          * Interface for FileRepo::checkRedirect()
 175          */
 176         function checkRedirect( $title ) {
 177                 if ( !$this->reposInitialised ) {
 178                         $this->initialiseRepos();
 179                 }
 180
 181                 $redir = $this->localRepo->checkRedirect( $title );
 182                 if( $redir ) {
 183                         return $redir;
 184                 }
 185                 foreach ( $this->foreignRepos as $repo ) {
 186                         $redir = $repo->checkRedirect( $title );
 187                         if ( $redir ) {
 188                                 return $redir;
 189                         }
 190                 }
 191                 return false;
 192         }
 193
 194         function findBySha1( $hash ) {
 195                 if ( !$this->reposInitialised ) {
 196                         $this->initialiseRepos();
 197                 }
 198
 199                 $result = $this->localRepo->findBySha1( $hash );
 200                 foreach ( $this->foreignRepos as $repo )
 201                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 202                 return $result;
 203         }
 204
 205         /**
 206          * Get the repo instance with a given key.
 207          */
 208         function getRepo( $index ) {
 209                 if ( !$this->reposInitialised ) {
 210                         $this->initialiseRepos();
 211                 }
 212                 if ( $index === 'local' ) {
 213                         return $this->localRepo;
 214                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 215                         return $this->foreignRepos[$index];
 216                 } else {
 217                         return false;
 218                 }
 219         }
 220         /**
 221          * Get the repo instance by its name
 222          */
 223         function getRepoByName( $name ) {
 224                 if ( !$this->reposInitialised ) {
 225                         $this->initialiseRepos();
 226                 }
 227                 foreach ( $this->foreignRepos as $key => $repo ) {
 228                         if ( $repo->name == $name)
 229                                 return $repo;
 230                 }
 231                 return false;
 232         }
 233
 234         /**
 235          * Get the local repository, i.e. the one corresponding to the local image
 236          * table. Files are typically uploaded to the local repository.
 237          */
 238         function getLocalRepo() {
 239                 return $this->getRepo( 'local' );
 240         }
 241
 242         /**
 243          * Call a function for each foreign repo, with the repo object as the
 244          * first parameter.
 245          *
 246          * @param $callback callback The function to call
 247          * @param $params array Optional additional parameters to pass to the function
 248          */
 249         function forEachForeignRepo( $callback, $params = array() ) {
 250                 foreach( $this->foreignRepos as $repo ) {
 251                         $args = array_merge( array( $repo ), $params );
 252                         if( call_user_func_array( $callback, $args ) ) {
 253                                 return true;
 254                         }
 255                 }
 256                 return false;
 257         }
 258
 259         /**
 260          * Does the installation have any foreign repos set up?
 261          * @return bool
 262          */
 263         function hasForeignRepos() {
 264                 return (bool)$this->foreignRepos;
 265         }
 266
 267         /**
 268          * Initialise the $repos array
 269          */
 270         function initialiseRepos() {
 271                 if ( $this->reposInitialised ) {
 272                         return;
 273                 }
 274                 $this->reposInitialised = true;
 275
 276                 $this->localRepo = $this->newRepo( $this->localInfo );
 277                 $this->foreignRepos = array();
 278                 foreach ( $this->foreignInfo as $key => $info ) {
 279                         $this->foreignRepos[$key] = $this->newRepo( $info );
 280                 }
 281         }
 282
 283         /**
 284          * Create a repo class based on an info structure
 285          */
 286         protected function newRepo( $info ) {
 287                 $class = $info['class'];
 288                 return new $class( $info );
 289         }
 290
 291         /**
 292          * Split a virtual URL into repo, zone and rel parts
 293          * @return an array containing repo, zone and rel
 294          */
 295         function splitVirtualUrl( $url ) {
 296                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 297                         throw new MWException( __METHOD__.': unknown protoocl' );
 298                 }
 299
 300                 $bits = explode( '/', substr( $url, 9 ), 3 );
 301                 if ( count( $bits ) != 3 ) {
 302                         throw new MWException( __METHOD__.": invalid mwrepo URL: $url" );
 303                 }
 304                 return $bits;
 305         }
 306
 307         function getFileProps( $fileName ) {
 308                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 309                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 310                         if ( $repoName === '' ) {
 311                                 $repoName = 'local';
 312                         }
 313                         $repo = $this->getRepo( $repoName );
 314                         return $repo->getFileProps( $fileName );
 315                 } else {
 316                         return File::getPropsFromPath( $fileName );
 317                 }
 318         }
 319
 320         /**
 321          * Limit cache memory
 322          */
 323         function trimCache() {
 324                 while ( count( $this->cache ) >= self::MAX_CACHE_SIZE ) {
 325                         reset( $this->cache );
 326                         $key = key( $this->cache );
 327                         wfDebug( __METHOD__.": evicting $key\n" );
 328                         unset( $this->cache[$key] );
 329                 }
 330         }
 331 }