| /* |
| * 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.codehaus.groovy.util; |
| |
| import java.util.Arrays; |
| |
| /** |
| * A utility class to help calculate hashcode values |
| * using an algorithm similar to that outlined in |
| * "Effective Java, Joshua Bloch, 2nd Edition". |
| */ |
| public class HashCodeHelper { |
| private static final int SEED = 127; |
| private static final int MULT = 59; |
| |
| public static int initHash() { |
| return SEED; |
| } |
| |
| public static int updateHash(int current, boolean var) { |
| return shift(current) + (var ? 79 : 97); |
| } |
| |
| public static int updateHash(int current, char var) { |
| return shift(current) + (int) var; |
| } |
| |
| public static int updateHash(int current, Character var) { |
| return updateHash(current, var == null ? 0 : var.charValue()); |
| } |
| |
| public static int updateHash(int current, int var) { |
| return shift(current) + var; |
| } |
| |
| public static int updateHash(int current, Integer var) { |
| return updateHash(current, var == null ? 0 : var); |
| } |
| |
| public static int updateHash(int current, long var) { |
| return shift(current) + (int) (var ^ (var >>> 32)); |
| } |
| |
| public static int updateHash(int current, Long var) { |
| return updateHash(current, var == null ? 0L : var); |
| } |
| |
| public static int updateHash(int current, float var) { |
| return updateHash(current, Float.floatToIntBits(var)); |
| } |
| |
| public static int updateHash(int current, Float var) { |
| return updateHash(current, var == null ? 0f : var); |
| } |
| |
| public static int updateHash(int current, double var) { |
| return updateHash(current, Double.doubleToLongBits(var)); |
| } |
| |
| public static int updateHash(int current, Double var) { |
| return updateHash(current, var == null ? 0d : var); |
| } |
| |
| public static int updateHash(int current, Object var) { |
| if (var == null) return updateHash(current, 0); |
| if (var.getClass().isArray()) |
| return shift(current) + Arrays.hashCode((Object[]) var); |
| return updateHash(current, var.hashCode()); |
| } |
| |
| public static int updateHash(int current, boolean[] var) { |
| if (var == null) return updateHash(current, 0); |
| return shift(current) + Arrays.hashCode(var); |
| } |
| |
| public static int updateHash(int current, char[] var) { |
| if (var == null) return updateHash(current, 0); |
| return shift(current) + Arrays.hashCode(var); |
| } |
| |
| public static int updateHash(int current, byte[] var) { |
| if (var == null) return updateHash(current, 0); |
| return shift(current) + Arrays.hashCode(var); |
| } |
| |
| public static int updateHash(int current, short[] var) { |
| if (var == null) return updateHash(current, 0); |
| return shift(current) + Arrays.hashCode(var); |
| } |
| |
| public static int updateHash(int current, int[] var) { |
| if (var == null) return updateHash(current, 0); |
| return shift(current) + Arrays.hashCode(var); |
| } |
| |
| public static int updateHash(int current, long[] var) { |
| if (var == null) return updateHash(current, 0); |
| return shift(current) + Arrays.hashCode(var); |
| } |
| |
| public static int updateHash(int current, float[] var) { |
| if (var == null) return updateHash(current, 0); |
| return shift(current) + Arrays.hashCode(var); |
| } |
| |
| public static int updateHash(int current, double[] var) { |
| if (var == null) return updateHash(current, 0); |
| return shift(current) + Arrays.hashCode(var); |
| } |
| |
| private static int shift(int current) { |
| return MULT * current; |
| } |
| |
| } |