content: package com.clearspring.analytics.hash;
  
  /**
   * 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.
   * <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 ^= (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;
      }
  }
  