/* ***** 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.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Darin Fisher <darin@netscape.com>
 *
 * 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 nsITransport;
interface nsIInputStream;
interface nsIOutputStream;

/**
 * This service read/writes a stream on a background thread.
 *
 * Use this service to transform any blocking stream (e.g., file stream)
 * into a fully asynchronous stream that can be read/written without 
 * blocking the main thread.
 */
[scriptable, uuid(8268D474-EFBF-494f-A152-E8A8616F4E52)]
interface nsIStreamTransportService : nsISupports
{
    /**
     * CreateInputTransport
     *
     * @param aStream
     *        The input stream that will be read on a background thread.
     *        This stream must implement "blocking" stream semantics.
     * @param aStartOffset
     *        The input stream will be read starting from this offset.  Pass
     *        -1 to read from the current stream offset.  NOTE: this parameter
     *        is ignored if the stream does not support nsISeekableStream.
     * @param aReadLimit
     *        This parameter limits the number of bytes that will be read from
     *        the input stream.  Pass -1 to read everything.
     * @param aCloseWhenDone
     *        Specify this flag to have the input stream closed once its
     *        contents have been completely read.
     *
     * @return nsITransport instance.
     */
    nsITransport createInputTransport(in nsIInputStream aStream,
                                      in long long aStartOffset,
                                      in long long aReadLimit,
                                      in boolean aCloseWhenDone);

    /**
     * CreateOutputTransport
     *
     * @param aStream
     *        The output stream that will be written to on a background thread.
     *        This stream must implement "blocking" stream semantics.
     * @param aStartOffset
     *        The output stream will be written starting at this offset.  Pass
     *        -1 to write to the current stream offset.  NOTE: this parameter
     *        is ignored if the stream does not support nsISeekableStream.
     * @param aWriteLimit
     *        This parameter limits the number of bytes that will be written to
     *        the output stream.  Pass -1 for unlimited writing.
     * @param aCloseWhenDone
     *        Specify this flag to have the output stream closed once its
     *        contents have been completely written.
     *
     * @return nsITransport instance.
     */
    nsITransport createOutputTransport(in nsIOutputStream aStream,
                                       in long long aStartOffset,
                                       in long long aWriteLimit,
                                       in boolean aCloseWhenDone);
};