includes/ExternalStore.php

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