io.r2dbc.postgresql.KeepAliveMessage Maven / Gradle / Ivy
/*
* Copyright 2019-2020 the original author or authors.
*
* 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.r2dbc.postgresql;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.r2dbc.postgresql.message.frontend.CopyData;
import io.r2dbc.postgresql.replication.LogSequenceNumber;
/**
* Nested message for a Replication Stream using {@link CopyData} as carrier.
*/
final class KeepAliveMessage {
private static final byte KEEP_ALIVE_REPLY = 'r';
private static final int NO_REPLY_REQUIRED = 0;
private static final int REPLY_REQUIRED = 1;
private final LogSequenceNumber received;
private final LogSequenceNumber flushed;
private final LogSequenceNumber applied;
private final long systemClock;
private boolean replyRequired;
KeepAliveMessage(LogSequenceNumber received, LogSequenceNumber flushed, LogSequenceNumber applied, long systemClock, boolean replyRequired) {
this.received = received;
this.flushed = flushed;
this.applied = applied;
this.systemClock = systemClock;
this.replyRequired = replyRequired;
}
public ByteBuf encode(ByteBufAllocator allocator) {
ByteBuf out = allocator.buffer(34);
out.writeByte(KEEP_ALIVE_REPLY);
out.writeLong(this.received.asLong());
out.writeLong(this.flushed.asLong());
out.writeLong(this.applied.asLong());
out.writeLong(this.systemClock);
if (this.replyRequired) {
out.writeByte((byte) REPLY_REQUIRED);
} else {
out.writeByte(this.received == LogSequenceNumber.INVALID_LSN ? (byte) REPLY_REQUIRED : (byte) NO_REPLY_REQUIRED);
}
return out;
}
}