/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** 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
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * 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 "nsIStreamListener.idl"

interface nsIRequest;
interface nsIStreamLoader;

[scriptable, uuid(359F7990-D4E9-11d3-A1A5-0050041CAF44)]
interface nsIStreamLoaderObserver : nsISupports
{
    /**
     * Called when the entire stream has been loaded.
     *
     * @param loader the stream loader that loaded the stream.
     * @param ctxt the context parameter of the underlying channel
     * @param status the status of the underlying channel
     * @param resultLength the length of the data loaded
     * @param result the data
     *
     * This method will always be called asynchronously by the
     * nsIStreamLoader involved, on the thread that called the
     * loader's init() method.
     *
     * If the observer wants to take over responsibility for the
     * data buffer (result), it returns NS_SUCCESS_ADOPTED_DATA
     * in place of NS_OK as its success code. The loader will then
     * "forget" about the data, and not NS_Free() it in its own
     * destructor; observer must call NS_Free() when the data is
     * no longer required.
     */
    void onStreamComplete(in nsIStreamLoader loader,
                          in nsISupports ctxt,
                          in nsresult status,
                          in unsigned long resultLength,
                          [const,array,size_is(resultLength)] in octet result);
};

/**
 * Asynchronously loads a channel into a memory buffer.
 *
 * To use this interface, first call init() with a nsIStreamLoaderObserver
 * that will be notified when the data has been loaded. Then call asyncOpen()
 * on the channel with the nsIStreamLoader as the listener. The context
 * argument in the asyncOpen() call will be passed to the onStreamComplete()
 * callback.
 *
 * XXX define behaviour for sizes >4 GB
 */
[scriptable, uuid(8ea7e890-8211-11d9-8bde-f66bad1e3f3a)]
interface nsIStreamLoader : nsIStreamListener
{
    /**
     * Initialize this stream loader, and start loading the data.
     *
     * @param aObserver
     *        An observer that will be notified when the data is complete.
     */
    void init(in nsIStreamLoaderObserver aObserver);

    /**
     * Gets the number of bytes read so far.
     */
    readonly attribute unsigned long numBytesRead;

    /**
     * Gets the request that loaded this file.
     * null after the request has finished loading.
     */
    readonly attribute nsIRequest request;
};
