includes/ExternalStore.php

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