| /* |
| * 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.cassandra.utils; |
| |
| import java.nio.ByteBuffer; |
| import java.security.SecureRandom; |
| import java.util.Random; |
| |
| public class GuidGenerator |
| { |
| private static final Random myRand; |
| private static final SecureRandom mySecureRand; |
| private static final String s_id; |
| |
| static |
| { |
| if (System.getProperty("java.security.egd") == null) |
| { |
| System.setProperty("java.security.egd", "file:/dev/urandom"); |
| } |
| mySecureRand = new SecureRandom(); |
| long secureInitializer = mySecureRand.nextLong(); |
| myRand = new Random(secureInitializer); |
| try { |
| s_id = FBUtilities.getLocalAddress().toString(); |
| } |
| catch (RuntimeException e) { |
| throw new AssertionError(e); |
| } |
| } |
| |
| public static String guid() |
| { |
| ByteBuffer array = guidAsBytes(); |
| |
| StringBuilder sb = new StringBuilder(); |
| for (int j = array.position(); j < array.limit(); ++j) |
| { |
| int b = array.get(j) & 0xFF; |
| if (b < 0x10) sb.append('0'); |
| sb.append(Integer.toHexString(b)); |
| } |
| |
| return convertToStandardFormat( sb.toString() ); |
| } |
| |
| public static String guidToString(byte[] bytes) |
| { |
| StringBuilder sb = new StringBuilder(); |
| for (int j = 0; j < bytes.length; ++j) |
| { |
| int b = bytes[j] & 0xFF; |
| if (b < 0x10) sb.append('0'); |
| sb.append(Integer.toHexString(b)); |
| } |
| |
| return convertToStandardFormat( sb.toString() ); |
| } |
| |
| public static ByteBuffer guidAsBytes(Random random, String hostId, long time) |
| { |
| StringBuilder sbValueBeforeMD5 = new StringBuilder(); |
| long rand = random.nextLong(); |
| sbValueBeforeMD5.append(hostId) |
| .append(":") |
| .append(Long.toString(time)) |
| .append(":") |
| .append(Long.toString(rand)); |
| |
| String valueBeforeMD5 = sbValueBeforeMD5.toString(); |
| return ByteBuffer.wrap(FBUtilities.threadLocalMD5Digest().digest(valueBeforeMD5.getBytes())); |
| } |
| |
| public static ByteBuffer guidAsBytes() |
| { |
| return guidAsBytes(myRand, s_id, System.currentTimeMillis()); |
| } |
| |
| /* |
| * Convert to the standard format for GUID |
| * Example: C2FEEEAC-CFCD-11D1-8B05-00600806D9B6 |
| */ |
| |
| private static String convertToStandardFormat(String valueAfterMD5) |
| { |
| String raw = valueAfterMD5.toUpperCase(); |
| StringBuilder sb = new StringBuilder(); |
| sb.append(raw.substring(0, 8)) |
| .append("-") |
| .append(raw.substring(8, 12)) |
| .append("-") |
| .append(raw.substring(12, 16)) |
| .append("-") |
| .append(raw.substring(16, 20)) |
| .append("-") |
| .append(raw.substring(20)); |
| return sb.toString(); |
| } |
| } |
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