static long murmurHash3_x64_64()

in src/main/java/com/spotify/sparkey/MurmurHash3.java [100:201]

• 77 lines of code
• 17 McCabe index (conditional complexity)

  static long murmurHash3_x64_64(byte[] data, int len, int seed) {
    final int nblocks = len / 16;

    long h1 = ((long) seed) & 0xFFFFFFFFL;
    long h2 = h1;

    final long c1 = 0x87c37b91114253d5L;
    final long c2 = 0x4cf5ad432745937fL;

    //----------
    // body

    for (int i = 0; i < nblocks; i++) {
      long k1 = getBlock64(data, 2 * i);
      long k2 = getBlock64(data, 2 * i + 1);

      k1 *= c1;
      k1 = ROTL64(k1, 31);
      k1 *= c2;
      h1 ^= k1;

      h1 = ROTL64(h1, 27);
      h1 += h2;
      h1 = h1 * 5 + 0x52dce729L;

      k2 *= c2;
      k2 = ROTL64(k2, 33);
      k2 *= c1;
      h2 ^= k2;

      h2 = ROTL64(h2, 31);
      h2 += h1;
      h2 = h2 * 5 + 0x38495ab5L;
    }

    //----------
    // tail

    int tail = 16 * nblocks;

    long k1 = 0;
    long k2 = 0;

    switch (len & 15) {
      case 15:
        k2 ^= (long) (Util.unsignedByte(data[tail + 14])) << 48;
      case 14:
        k2 ^= (long) (Util.unsignedByte(data[tail + 13])) << 40;
      case 13:
        k2 ^= (long) (Util.unsignedByte(data[tail + 12])) << 32;
      case 12:
        k2 ^= (long) (Util.unsignedByte(data[tail + 11])) << 24;
      case 11:
        k2 ^= (long) (Util.unsignedByte(data[tail + 10])) << 16;
      case 10:
        k2 ^= (long) (Util.unsignedByte(data[tail + 9])) << 8;
      case 9:
        k2 ^= (long) (Util.unsignedByte(data[tail + 8])) << 0;
        k2 *= c2;
        k2 = ROTL64(k2, 33);
        k2 *= c1;
        h2 ^= k2;

      case 8:
        k1 ^= (long) (Util.unsignedByte(data[tail + 7])) << 56;
      case 7:
        k1 ^= (long) (Util.unsignedByte(data[tail + 6])) << 48;
      case 6:
        k1 ^= (long) (Util.unsignedByte(data[tail + 5])) << 40;
      case 5:
        k1 ^= (long) (Util.unsignedByte(data[tail + 4])) << 32;
      case 4:
        k1 ^= (long) (Util.unsignedByte(data[tail + 3])) << 24;
      case 3:
        k1 ^= (long) (Util.unsignedByte(data[tail + 2])) << 16;
      case 2:
        k1 ^= (long) (Util.unsignedByte(data[tail + 1])) << 8;
      case 1:
        k1 ^= (long) (Util.unsignedByte(data[tail + 0])) << 0;
        k1 *= c1;
        k1 = ROTL64(k1, 31);
        k1 *= c2;
        h1 ^= k1;
    }

    //----------
    // finalization

    h1 ^= len;
    h2 ^= len;

    h1 += h2;
    h2 += h1;

    h1 = fmix64(h1);
    h2 = fmix64(h2);

    h1 += h2;
    h2 += h1;

    return h1;
  }