/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"

interface nsIInputStream;
interface nsIAsyncInputStream;

/**
 * An instance of this interface can be used to throttle the uploads
 * of a group of associated channels.
 */
[scriptable, uuid(6b4b96fe-3c67-4587-af7b-58b6b17da411)]
interface nsIInputChannelThrottleQueue : nsISupports
{
    /**
     * Initialize this object with the mean and maximum bytes per
     * second that will be allowed.  Neither value may be zero, and
     * the maximum must not be less than the mean.
     *
     * @param aMeanBytesPerSecond
     *        Mean number of bytes per second.
     * @param aMaxBytesPerSecond
     *        Maximum number of bytes per second.
     */
    void init(in unsigned long aMeanBytesPerSecond, in unsigned long aMaxBytesPerSecond);

    /**
     * Internal use only. Get the values set by init method.
     */
    [noscript] readonly attribute unsigned long meanBytesPerSecond;
    [noscript] readonly attribute unsigned long maxBytesPerSecond;


    /**
     * Return the number of bytes that are available to the caller in
     * this time slice.
     *
     * @param aRemaining
     *        The number of bytes available to be processed
     * @return the number of bytes allowed to be processed during this
     *        time slice; this will never be greater than aRemaining.
     */
    unsigned long available(in unsigned long aRemaining);

    /**
     * Record a successful read.
     *
     * @param aBytesRead
     *        The number of bytes actually read.
     */
    void recordRead(in unsigned long aBytesRead);

    /**
     * Return the number of bytes allowed through this queue.  This is
     * the sum of all the values passed to recordRead.  This method is
     * primarily useful for testing.
     */
    unsigned long long bytesProcessed();

    /**
     * Wrap the given input stream in a new input stream which
     * throttles the incoming data.
     *
     * @param aInputStream the input stream to wrap
     * @return a new input stream that throttles the data.
     */
    nsIAsyncInputStream wrapStream(in nsIInputStream aInputStream);
};

/**
 * A throttled input channel can be managed by an
 * nsIInputChannelThrottleQueue to limit how much data is sent during
 * a given time slice.
 */
[scriptable, uuid(0a32a100-c031-45b6-9e8b-0444c7d4a143)]
interface nsIThrottledInputChannel : nsISupports
{
    /**
     * The queue that manages this channel.  Multiple channels can
     * share a single queue.  A null value means that no throttling
     * will be done.
     */
    attribute nsIInputChannelThrottleQueue throttleQueue;
};