1 /** 2 * 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, software 14 * distributed under the License is distributed on an "AS IS" BASIS, 15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 * See the License for the specific language governing permissions and 17 * limitations under the License. 18 */ 19 package org.apache.hadoop.hbase.client; 20 21 import java.util.Arrays; 22 import java.util.Random; 23 24 import org.apache.hadoop.hbase.classification.InterfaceAudience; 25 import org.apache.hadoop.hbase.HConstants; 26 27 /** 28 * NonceGenerator implementation that uses client ID hash + random int as nonce group, 29 * and random numbers as nonces. 30 */ 31 @InterfaceAudience.Private 32 public class PerClientRandomNonceGenerator implements NonceGenerator { 33 private final Random rdm = new Random(); 34 private final long clientId; 35 36 public PerClientRandomNonceGenerator() { 37 byte[] clientIdBase = ClientIdGenerator.generateClientId(); 38 this.clientId = (((long)Arrays.hashCode(clientIdBase)) << 32) + rdm.nextInt(); 39 } 40 41 public long getNonceGroup() { 42 return this.clientId; 43 } 44 45 public long newNonce() { 46 long result = HConstants.NO_NONCE; 47 do { 48 result = rdm.nextLong(); 49 } while (result == HConstants.NO_NONCE); 50 return result; 51 } 52 }