io.aeron.cluster.client.IngressSessionDecorator Maven / Gradle / Ivy
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/*
* Copyright 2014-2024 Real Logic Limited.
*
* 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
*
* https://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.cluster.client;
import io.aeron.Aeron;
import io.aeron.Publication;
import io.aeron.cluster.codecs.MessageHeaderEncoder;
import io.aeron.cluster.codecs.SessionMessageHeaderEncoder;
import org.agrona.DirectBuffer;
import org.agrona.concurrent.UnsafeBuffer;
/**
* Encapsulate applying a client message header for ingress to the cluster.
*
* The client message header is applied to the {@link Publication} before the offered buffer.
*
* Note: This class is NOT threadsafe for updating {@link #clusterSessionId(long)} or
* {@link #leadershipTermId(long)}. Each publisher thread requires its own instance.
*/
public final class IngressSessionDecorator
{
/**
* Length of the session header that will be prepended to the message.
*/
public static final int HEADER_LENGTH =
MessageHeaderEncoder.ENCODED_LENGTH + SessionMessageHeaderEncoder.BLOCK_LENGTH;
private final SessionMessageHeaderEncoder sessionMessageHeaderEncoder = new SessionMessageHeaderEncoder();
private final UnsafeBuffer headerBuffer = new UnsafeBuffer(new byte[HEADER_LENGTH]);
/**
* Construct a new ingress session header wrapper that defaults all fields to {@link Aeron#NULL_VALUE}.
*/
public IngressSessionDecorator()
{
this(Aeron.NULL_VALUE, Aeron.NULL_VALUE);
}
/**
* Construct a new session header wrapper.
*
* @param clusterSessionId that has been allocated by the cluster.
* @param leadershipTermId of the current leader.
*/
public IngressSessionDecorator(final long clusterSessionId, final long leadershipTermId)
{
sessionMessageHeaderEncoder
.wrapAndApplyHeader(headerBuffer, 0, new MessageHeaderEncoder())
.leadershipTermId(leadershipTermId)
.clusterSessionId(clusterSessionId)
.timestamp(Aeron.NULL_VALUE);
}
/**
* Reset the cluster session id in the header.
*
* @param clusterSessionId to be set in the header.
* @return this for a fluent API.
*/
public IngressSessionDecorator clusterSessionId(final long clusterSessionId)
{
sessionMessageHeaderEncoder.clusterSessionId(clusterSessionId);
return this;
}
/**
* Reset the leadership term id in the header.
*
* @param leadershipTermId to be set in the header.
* @return this for a fluent API.
*/
public IngressSessionDecorator leadershipTermId(final long leadershipTermId)
{
sessionMessageHeaderEncoder.leadershipTermId(leadershipTermId);
return this;
}
/**
* Non-blocking publish of a partial buffer containing a message plus session header to a cluster.
*
* This version of the method will set the timestamp value in the header to {@link Aeron#NULL_VALUE}.
*
* @param publication to be offered to.
* @param buffer containing message.
* @param offset offset in the buffer at which the encoded message begins.
* @param length in bytes of the encoded message.
* @return the same as {@link Publication#offer(DirectBuffer, int, int)}.
*/
public long offer(final Publication publication, final DirectBuffer buffer, final int offset, final int length)
{
return publication.offer(headerBuffer, 0, HEADER_LENGTH, buffer, offset, length, null);
}
}