net.openhft.chronicle.wire.channel.echo.EchoHandler Maven / Gradle / Ivy
/*
* Copyright 2016-2022 chronicle.software
*
* https://chronicle.software
*
* 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 net.openhft.chronicle.wire.channel.echo;
import net.openhft.affinity.AffinityLock;
import net.openhft.chronicle.core.io.ClosedIORuntimeException;
import net.openhft.chronicle.core.io.InvalidMarshallableException;
import net.openhft.chronicle.threads.Pauser;
import net.openhft.chronicle.wire.DocumentContext;
import net.openhft.chronicle.wire.channel.AbstractHandler;
import net.openhft.chronicle.wire.channel.ChronicleChannelCfg;
import net.openhft.chronicle.wire.channel.ChronicleContext;
import net.openhft.chronicle.wire.channel.echo.internal.EchoChannel;
/**
* An implementation of a channel handler that primarily echoes back any incoming data.
* The handler extends {@link AbstractHandler}, and implements the `run` and `asInternalChannel` methods
* for specific behavior.
*
* This handler acquires an {@link AffinityLock} before running, and releases it is closed.
* While the channel is open, it continuously reads incoming data, echoing it back to the sender.
*
* When there is no data available, it invokes the {@link Pauser} to pause execution,
* reducing the CPU usage when idle. If data is available, it resets the pauser to wake up immediately
* the next time it checks for data.
*/
@SuppressWarnings("deprecation")
public class EchoHandler extends AbstractHandler {
/**
* Executes the main logic of this EchoHandler, which continuously reads incoming data from the
* provided channel and echoes it back to the sender.
*
* @param context the ChronicleContext in which this handler operates
* @param channel the ChronicleChannel from which to read the data
* @throws ClosedIORuntimeException if the channel is closed unexpectedly
* @throws InvalidMarshallableException if there's an issue while processing the data
*/
@SuppressWarnings("try")
@Override
public void run(ChronicleContext context, net.openhft.chronicle.wire.channel.ChronicleChannel channel) throws ClosedIORuntimeException, InvalidMarshallableException {
try (AffinityLock lock = context.affinityLock()) {
Pauser pauser = Pauser.balanced();
while (!channel.isClosed()) {
try (DocumentContext dc = channel.readingDocument()) {
if (!dc.isPresent()) {
pauser.pause();
continue;
}
try (DocumentContext dc2 = channel.writingDocument(dc.isMetaData())) {
dc.wire().copyTo(dc2.wire());
}
pauser.reset();
}
}
}
}
/**
* Returns an {@link EchoChannel} as the internal channel for this handler.
*
* @param context the ChronicleContext in which this handler operates
* @param channelCfg the ChronicleChannelCfg that configures the channel
* @return a new EchoChannel instance
*/
@Override
public net.openhft.chronicle.wire.channel.ChronicleChannel asInternalChannel(ChronicleContext context, ChronicleChannelCfg channelCfg) {
return new EchoChannel(channelCfg);
}
}