com.orientechnologies.common.comparator.OUnsafeByteArrayComparator Maven / Gradle / Ivy
/*
*
* * Copyright 2014 Orient Technologies LTD (info(at)orientechnologies.com)
* *
* * 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.
* *
* * For more information: http://www.orientechnologies.com
*
*/
package com.orientechnologies.common.comparator;
import java.lang.reflect.Field;
import java.nio.ByteOrder;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Comparator;
import sun.misc.Unsafe;
/**
* Comparator for fast byte arrays comparison using {@link Unsafe} class. Bytes are compared like unsigned not like signed bytes.
*
*
* @author Andrey Lomakin
* @since 08.07.12
*/
@SuppressWarnings("restriction")
public class OUnsafeByteArrayComparator implements Comparator {
public static final OUnsafeByteArrayComparator INSTANCE = new OUnsafeByteArrayComparator();
private static final Unsafe unsafe;
private static final int BYTE_ARRAY_OFFSET;
private static final boolean littleEndian = ByteOrder.nativeOrder().equals(ByteOrder.LITTLE_ENDIAN);
private static final int LONG_SIZE = Long.SIZE / Byte.SIZE;
static {
unsafe = (Unsafe) AccessController.doPrivileged(new PrivilegedAction