includes/ExternalStore.php

   1 <?php
   2 /**
   3  * @defgroup ExternalStorage ExternalStorage
   4  */
   5
   6 /**
   7  * Constructor class for data kept in external repositories
   8  *
   9  * External repositories might be populated by maintenance/async
  10  * scripts, thus partial moving of data may be possible, as well
  11  * as possibility to have any storage format (i.e. for archives)
  12  *
  13  * @ingroup ExternalStorage
  14  */
  15 class ExternalStore {
  16         /* Fetch data from given URL */
  17         static function fetchFromURL($url) {
  18                 global $wgExternalStores;
  19
  20                 if (!$wgExternalStores)
  21                         return false;
  22
  23                 @list($proto,$path)=explode('://',$url,2);
  24                 /* Bad URL */
  25                 if ($path=="")
  26                         return false;
  27
  28                 $store =& ExternalStore::getStoreObject( $proto );
  29                 if ( $store === false )
  30                         return false;
  31                 return $store->fetchFromURL($url);
  32         }
  33
  34         /**
  35          * Get an external store object of the given type
  36          */
  37         static function &getStoreObject( $proto ) {
  38                 global $wgExternalStores;
  39                 if (!$wgExternalStores)
  40                         return false;
  41                 /* Protocol not enabled */
  42                 if (!in_array( $proto, $wgExternalStores ))
  43                         return false;
  44
  45                 $class='ExternalStore'.ucfirst($proto);
  46                 /* Any custom modules should be added to $wgAutoLoadClasses for on-demand loading */
  47                 if (!class_exists($class)) {
  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         static 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 }