| /* |
| * 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.pig.impl.bloom; |
| |
| public abstract class Hash { |
| public static final int MURMUR = 1; |
| public static final int MURMUR3 = MURMUR; |
| public static final int MURMUR3KM = 2; |
| public static final int JENKINS = 3; |
| |
| public static int parseHashType(String hashType) { |
| if("murmur".equalsIgnoreCase(hashType)) { |
| return MURMUR3; |
| } else if("murmur3km".equalsIgnoreCase(hashType)) { |
| return MURMUR3KM; |
| } else if("jenkins".equalsIgnoreCase(hashType)) { |
| return JENKINS; |
| } |
| throw new IllegalArgumentException("Hash Algorithm values must be one of - murmur, murmur3km, jenkins"); |
| } |
| |
| public static Hash getInstance(int hashType) { |
| switch (hashType) { |
| case MURMUR: |
| return new Murmur3Hash(); |
| case MURMUR3KM: |
| return new KirschMitzenmacherHash(); |
| case JENKINS: |
| return new JenkinsHash(); |
| } |
| throw new IllegalArgumentException("Hash type values must be one of - 1 (murmur), 2 (murmur3km), 3 (jenkins)"); |
| } |
| |
| /** |
| * @param bytes |
| * @param maxValue The maximum hashed value |
| * @param nbHash The number of hashed values |
| * @return |
| */ |
| public abstract int[] hash(byte[] bytes, int maxValue, int nbHash); |
| |
| } |