package org.apache.cassandra.utils;
/*
*
* 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.
*
*/
import java.net.InetAddress;
import java.nio.ByteBuffer;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.UUID;
import org.safehaus.uuid.EthernetAddress;
import org.safehaus.uuid.UUIDGenerator;
/**
* Generates type 1 (time-based) UUIDs
*/
public class UUIDGen
{
/** creates a type1 uuid but substitutes hash of the IP where the mac would go. */
public static synchronized UUID makeType1UUIDFromHost(InetAddress addr)
{
try
{
MessageDigest digest = MessageDigest.getInstance("MD5");
digest.update(addr.getAddress());
byte[] md5 = digest.digest();
byte[] fauxMac = new byte[6];
System.arraycopy(md5, 0, fauxMac, 0, Math.min(md5.length, fauxMac.length));
return getUUID(ByteBuffer.wrap(UUIDGenerator.getInstance().generateTimeBasedUUID(new EthernetAddress(fauxMac)).toByteArray()));
}
catch (NoSuchAlgorithmException ex)
{
throw new RuntimeException("Your platform has no support for generating MD5 sums");
}
}
/** creates a type 1 uuid from raw bytes. */
public static UUID getUUID(ByteBuffer raw)
{
return new UUID(raw.getLong(raw.position() + raw.arrayOffset()), raw.getLong(raw.position() + raw.arrayOffset() + 8));
}
/** decomposes a uuid into raw bytes. */
public static byte[] decompose(UUID uuid)
{
long most = uuid.getMostSignificantBits();
long least = uuid.getLeastSignificantBits();
byte[] b = new byte[16];
for (int i = 0; i < 8; i++)
{
b[i] = (byte)(most >>> ((7-i) * 8));
b[8+i] = (byte)(least >>> ((7-i) * 8));
}
return b;
}
}