org.apache.hadoop.ipc.RpcConstants Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.hadoop.ipc;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import org.apache.hadoop.classification.InterfaceAudience;
@InterfaceAudience.Private
public class RpcConstants {
private RpcConstants() {
// Hidden Constructor
}
public static final int AUTHORIZATION_FAILED_CALL_ID = -1;
public static final int INVALID_CALL_ID = -2;
public static final int CONNECTION_CONTEXT_CALL_ID = -3;
public static final int PING_CALL_ID = -4;
public static final byte[] DUMMY_CLIENT_ID = new byte[0];
public static final int INVALID_RETRY_COUNT = -1;
/**
* The Rpc-connection header is as follows
* +----------------------------------+
* | "hrpc" 4 bytes |
* +----------------------------------+
* | Version (1 byte) |
* +----------------------------------+
* | Service Class (1 byte) |
* +----------------------------------+
* | AuthProtocol (1 byte) |
* +----------------------------------+
*/
/**
* The first four bytes of Hadoop RPC connections
*/
public static final ByteBuffer HEADER =
ByteBuffer.wrap("hrpc".getBytes(StandardCharsets.UTF_8));
public static final int HEADER_LEN_AFTER_HRPC_PART = 3; // 3 bytes that follow
// 1 : Introduce ping and server does not throw away RPCs
// 3 : Introduce the protocol into the RPC connection header
// 4 : Introduced SASL security layer
// 5 : Introduced use of {@link ArrayPrimitiveWritable$Internal}
// in ObjectWritable to efficiently transmit arrays of primitives
// 6 : Made RPC Request header explicit
// 7 : Changed Ipc Connection Header to use Protocol buffers
// 8 : SASL server always sends a final response
// 9 : Changes to protocol for HADOOP-8990
public static final byte CURRENT_VERSION = 9;
}