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/*
 * This file from 
 *  https://github.com/addthis/stream-lib/blob/master/src/main/java/com/clearspring/analytics/hash/MurmurHash.java
 *
 *    This class modified by Scouter-Project
 *   - original  package :  com.clearspring.analytics.hash
 *
 */
  package scouter.server.util.cardinality;
 
/**
 * 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 is a very fast, non-cryptographic hash suitable for general hash-based
 * lookup. See http://murmurhash.googlepages.com/ for more details.
 * 

*

* The C version of MurmurHash 2.0 found at that site was ported to Java by * Andrzej Bialecki (ab at getopt org). *

*/ 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 ^= (int) data[length - 3] << 16; } if (left >= 2) { h ^= (int) data[length - 2] << 8; } if (left >= 1) { h ^= (int) 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 ^= (long) (data[length & ~7] & 0xff); h *= m; } ; h ^= h >>> r; h *= m; h ^= h >>> r; return h; } }




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