/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is Bradley Baetz
 * Portions created by the Initial Developer are Copyright (C) 2001, 2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s): Bradley Baetz <bbaetz@student.usyd.edu.au>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or 
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsISupports.idl"
 
interface nsIStreamListener;

[scriptable, uuid(4ad136fa-83af-4a22-a76e-503642c0f4a8)]
interface nsIResumableChannel : nsISupports {
    /**
     * Prepare this channel for resuming. The request will not start until
     * asyncOpen or open is called. Calling resumeAt after open or asyncOpen
     * has been called has undefined behaviour.
     *
     * @param startPos the starting offset, in bytes, to use to download
     * @param entityID information about the file, to match before obtaining
     *  the file. Pass an empty string to use anything.
     *
     * During OnStartRequest, this channel will have a status of
     *  NS_ERROR_NOT_RESUMABLE if the file cannot be resumed, eg because the
     *  server doesn't support this. This error may occur even if startPos
     *  is 0, so that the front end can warn the user.
     * Similarly, the status of this channel during OnStartRequest may be
     *  NS_ERROR_ENTITY_CHANGED, which indicates that the entity has changed,
     *  as indicated by a changed entityID.
     * In both of these cases, no OnDataAvailable will be called, and
     *  OnStopRequest will immediately follow with the same status code.
     */
    void resumeAt(in unsigned long long startPos,
                  in ACString entityID);

    /**
     * The entity id for this URI. Available after OnStartRequest.
     * @throw NS_ERROR_NOT_RESUMABLE if this load is not resumable.
     */
    readonly attribute ACString entityID;
};