sviolet.thistle.util.conversion.HashUtils Maven / Gradle / Ivy
/*
* Copyright (C) 2015-2019 S.Violet
*
* Licensed 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.
*
* Project GitHub: https://github.com/shepherdviolet/thistle
* Email: [email protected]
*/
package sviolet.thistle.util.conversion;
/**
* Hash算法工具
*
* @author S.Violet
*/
public class HashUtils {
public static int fnv1(byte[] data) {
final int p = 16777619;
int hash = (int) 2166136261L;
for (byte b : data) {
hash = (hash ^ b) * p;
}
hash += hash << 13;
hash ^= hash >> 7;
hash += hash << 3;
hash ^= hash >> 17;
hash += hash << 5;
return (hash & 0x7FFFFFFF);
}
public static int sdbm(byte[] data) {
int hash = 0;
for (byte b : data) {
hash = b + (hash << 6) + (hash << 16) - hash;
}
return (hash & 0x7FFFFFFF);
}
public static int djb2(byte[] data) {
int hash = 5381;
for (byte b : data) {
hash = ((hash << 5) + hash) + b;
}
return (hash & 0x7FFFFFFF);
}
}