/* This file is part of VoltDB.
* Copyright (C) 2008-2017 VoltDB Inc.
*
* This file contains original code and/or modifications of original code.
* Any modifications made by VoltDB Inc. are licensed under the following
* terms and conditions:
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
/**
* 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.
*/
/* This code was originally sourced from https://github.com/addthis/stream-lib
in December 2014. */
package org.voltdb_hll;
/**
* This is a very fast, non-cryptographic hash suitable for general hash-based
* lookup. See http://murmurhash.googlepages.com/ for more details.
* <p/>
* <p>
* The C version of MurmurHash 2.0 found at that site was ported to Java by
* Andrzej Bialecki (ab at getopt org).
* </p>
*/
public class MurmurHash {
public static int hash(Object o) {
if (o == null) {
return 0;
}
if (o instanceof Long) {
return hashLong((Long) o);
}
if (o instanceof Integer) {
return hashLong((Integer) o);
}
if (o instanceof Double) {
return hashLong(Double.doubleToRawLongBits((Double) o));
}
if (o instanceof Float) {
return hashLong(Float.floatToRawIntBits((Float) o));
}
if (o instanceof String) {
return hash(((String) o).getBytes());
}
if (o instanceof byte[]) {
return hash((byte[]) o);
}
return hash(o.toString());
}
public static int hash(byte[] data) {
return hash(data, data.length, -1);
}
public static int hash(byte[] data, int seed) {
return hash(data, data.length, seed);
}
public static int hash(byte[] data, int length, int seed) {
int m = 0x5bd1e995;
int r = 24;
int h = seed ^ length;
int len_4 = length >> 2;
for (int i = 0; i < len_4; i++) {
int i_4 = i << 2;
int k = data[i_4 + 3];
k = k << 8;
k = k | (data[i_4 + 2] & 0xff);
k = k << 8;
k = k | (data[i_4 + 1] & 0xff);
k = k << 8;
k = k | (data[i_4 + 0] & 0xff);
k *= m;
k ^= k >>> r;
k *= m;
h *= m;
h ^= k;
}
// avoid calculating modulo
int len_m = len_4 << 2;
int left = length - len_m;
if (left != 0) {
if (left >= 3) {
h ^= data[length - 3] << 16;
}
if (left >= 2) {
h ^= data[length - 2] << 8;
}
if (left >= 1) {
h ^= data[length - 1];
}
h *= m;
}
h ^= h >>> 13;
h *= m;
h ^= h >>> 15;
return h;
}
public static int hashLong(long data) {
int m = 0x5bd1e995;
int r = 24;
int h = 0;
int k = (int) data * m;
k ^= k >>> r;
h ^= k * m;
k = (int) (data >> 32) * m;
k ^= k >>> r;
h *= m;
h ^= k * m;
h ^= h >>> 13;
h *= m;
h ^= h >>> 15;
return h;
}
public static long hash64(Object o) {
if (o == null) {
return 0l;
} else if (o instanceof String) {
final byte[] bytes = ((String) o).getBytes();
return hash64(bytes, bytes.length);
} else if (o instanceof byte[]) {
final byte[] bytes = (byte[]) o;
return hash64(bytes, bytes.length);
}
return hash64(o.toString());
}
// 64 bit implementation copied from here: https://github.com/tnm/murmurhash-java
/**
* Generates 64 bit hash from byte array with default seed value.
*
* @param data byte array to hash
* @param length length of the array to hash
* @return 64 bit hash of the given string
*/
public static long hash64(final byte[] data, int length) {
return hash64(data, length, 0xe17a1465);
}
/**
* Generates 64 bit hash from byte array of the given length and seed.
*
* @param data byte array to hash
* @param length length of the array to hash
* @param seed initial seed value
* @return 64 bit hash of the given array
*/
public static long hash64(final byte[] data, int length, int seed) {
final long m = 0xc6a4a7935bd1e995L;
final int r = 47;
long h = (seed & 0xffffffffl) ^ (length * m);
int length8 = length / 8;
for (int i = 0; i < length8; i++) {
final int i8 = i * 8;
long k = ((long) data[i8 + 0] & 0xff) + (((long) data[i8 + 1] & 0xff) << 8)
+ (((long) data[i8 + 2] & 0xff) << 16) + (((long) data[i8 + 3] & 0xff) << 24)
+ (((long) data[i8 + 4] & 0xff) << 32) + (((long) data[i8 + 5] & 0xff) << 40)
+ (((long) data[i8 + 6] & 0xff) << 48) + (((long) data[i8 + 7] & 0xff) << 56);
k *= m;
k ^= k >>> r;
k *= m;
h ^= k;
h *= m;
}
switch (length % 8) {
case 7:
h ^= (long) (data[(length & ~7) + 6] & 0xff) << 48;
case 6:
h ^= (long) (data[(length & ~7) + 5] & 0xff) << 40;
case 5:
h ^= (long) (data[(length & ~7) + 4] & 0xff) << 32;
case 4:
h ^= (long) (data[(length & ~7) + 3] & 0xff) << 24;
case 3:
h ^= (long) (data[(length & ~7) + 2] & 0xff) << 16;
case 2:
h ^= (long) (data[(length & ~7) + 1] & 0xff) << 8;
case 1:
h ^= data[length & ~7] & 0xff;
h *= m;
}
;
h ^= h >>> r;
h *= m;
h ^= h >>> r;
return h;
}
}