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