com.hazelcast.internal.serialization.impl.DataSerializableHeader Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2024, Hazelcast, Inc. All Rights Reserved.
*
* 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 com.hazelcast.internal.serialization.impl;
/**
* The serializaion header consists of one java byte primitive value.
* Bits are used in the following way (from the least significant to the most significant)
* 0.) 0=data_serializable, 1=identified_data_serializable
* 1.) 0=non-versioned, 1=versioned
* 2.) unused
* 3.) unused
* 4.) unused
* 5.) unused
* 6.) unused
* 7.) unused
*
* Earlier the header was just a byte holding boolean value:
* - 0=data_serializable, 1=identified_data_serializable
* thus the new format is fully backward compatible.
*/
final class DataSerializableHeader {
public static final int FACTORY_AND_CLASS_ID_BYTE_LENGTH = 8;
public static final int EE_BYTE_LENGTH = 2;
private static final byte IDENTIFIED_DATA_SERIALIZABLE = 1 << 0;
private static final byte VERSIONED = 1 << 1;
private DataSerializableHeader() {
}
static boolean isIdentifiedDataSerializable(byte header) {
return (header & IDENTIFIED_DATA_SERIALIZABLE) != 0;
}
static boolean isVersioned(byte header) {
return (header & VERSIONED) != 0;
}
static byte createHeader(boolean identified, boolean versioned) {
byte header = 0;
if (identified) {
header |= IDENTIFIED_DATA_SERIALIZABLE;
}
if (versioned) {
header |= VERSIONED;
}
return header;
}
}