io.aeron.driver.CongestionControl Maven / Gradle / Ivy
/*
* Copyright 2017 Real Logic Ltd.
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.aeron.driver;
import java.net.InetSocketAddress;
/**
* Strategy for applying congestion control to determine the receiverWindowLength of the Status Messages
*/
public interface CongestionControl extends AutoCloseable
{
/**
* Polled by {@link Receiver} to determine when to initiate an RTT measurement to a Sender.
*
* @param nowNs in nanoseconds
* @return true for should measure RTT now or false for no measurement
*/
boolean shouldMeasureRtt(long nowNs);
/**
* Called by {@link Receiver} on reception of an RTT Measurement.
*
* @param nowNs in nanoseconds
* @param rttNs to the Sender in nanoseconds
* @param srcAddress of the Sender
*/
void onRttMeasurement(long nowNs, long rttNs, InetSocketAddress srcAddress);
/**
* Called by {@link DriverConductor} upon execution of {@link PublicationImage#trackRebuild(long, long)} to
* pass on current status.
*
* The return value must be packed using {@link CongestionControlUtil#packOutcome(int, boolean)}.
*
* @param nowNs in nanoseconds
* @param newConsumptionPosition of the Subscribers
* @param lastSmPosition of the image
* @param hwmPosition of the image
* @param startingRebuildPosition of the rebuild
* @param endingRebuildPosition of the rebuild
* @param lossOccurred during rebuild
* @return outcome of congestion control calculation containing window length and whether to force sending an SM.
*/
long onTrackRebuild(
long nowNs,
long newConsumptionPosition,
long lastSmPosition,
long hwmPosition,
long startingRebuildPosition,
long endingRebuildPosition,
boolean lossOccurred);
/**
* Called by {@link DriverConductor} to initialise window length for a new {@link PublicationImage}.
*
* @return new image window length
*/
int initialWindowLength();
void close();
}