<?php
  
  /**
   * This interface provides a way to modify only part of a target resource
   * It may be used to update a file chunk, upload big a file into smaller
   * chunks or resume an upload
   *
   * @package Sabre
   * @subpackage DAV
   * @copyright Copyright (C) 2007-2013 Rooftop Solutions. All rights reserved.
   * @author Jean-Tiare LE BIGOT (http://www.jtlebi.fr/)
   * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
   */
  interface Sabre_DAV_PartialUpdate_IFile extends Sabre_DAV_IFile {
  
      /**
       * Updates the data at a given offset
       *
       * The data argument is a readable stream resource.
       * The offset argument is an integer describing the offset. Contrary to
       * what's sent in the request, the offset here is a 0-based index.
       *
       * After a successful put operation, you may choose to return an ETag. The
       * etag must always be surrounded by double-quotes. These quotes must
       * appear in the actual string you're returning.
       *
       * Clients may use the ETag from a PUT request to later on make sure that
       * when they update the file, the contents haven't changed in the mean
       * time.
       *
       * @param resource $data
       * @param integer $offset
       * @return string|null
       */
      function putRange($data, $offset);
  
  }