includes/ExternalStore.php

   1 <?php
   2 /**
   3  *
   4  * @package MediaWiki
   5  *
   6  * Constructor class for data kept in external repositories
   7  *
   8  * External repositories might be populated by maintenance/async
   9  * scripts, thus partial moving of data may be possible, as well
  10  * as possibility to have any storage format (i.e. for archives)
  11  *
  12  */
  13
  14 class ExternalStore {
  15         /* Fetch data from given URL */
  16         function fetchFromURL($url) {
  17                 global $wgExternalStores;
  18
  19                 if (!$wgExternalStores)
  20                         return false;
  21
  22                 @list($proto,$path)=explode('://',$url,2);
  23                 /* Bad URL */
  24                 if ($path=="")
  25                         return false;
  26
  27                 $store =& ExternalStore::getStoreObject( $proto );
  28                 if ( $store === false )
  29                         return false;
  30                 return $store->fetchFromURL($url);
  31         }
  32
  33         /**
  34          * Get an external store object of the given type
  35          */
  36         function &getStoreObject( $proto ) {
  37                 global $wgExternalStores;
  38                 if (!$wgExternalStores)
  39                         return false;
  40                 /* Protocol not enabled */
  41                 if (!in_array( $proto, $wgExternalStores ))
  42                         return false;
  43
  44                 $class='ExternalStore'.ucfirst($proto);
  45                 /* Preloaded modules might exist, especially ones serving multiple protocols */
  46                 if (!class_exists($class)) {
  47                         if (!include_once($class.'.php'))
  48                                 return false;
  49                 }
  50                 $store=new $class();
  51                 return $store;
  52         }
  53
  54         /**
  55          * Store a data item to an external store, identified by a partial URL
  56          * The protocol part is used to identify the class, the rest is passed to the
  57          * class itself as a parameter.
  58          * Returns the URL of the stored data item, or false on error
  59          */
  60         function insert( $url, $data ) {
  61                 list( $proto, $params ) = explode( '://', $url, 2 );
  62                 $store =& ExternalStore::getStoreObject( $proto );
  63                 if ( $store === false ) {
  64                         return false;
  65                 } else {
  66                         return $store->store( $params, $data );
  67                 }
  68         }
  69 }
  70 ?>