private static long innerHash()

in java/tsfile/src/main/java/org/apache/tsfile/utils/Murmur128Hash.java [82:183]

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

  private static long innerHash(byte[] key, int offset, int length, long seed) {
    final int nblocks = length >> 4; // Process as 128-bit blocks.
    long h1 = seed;
    long h2 = seed;
    long c1 = 0x87c37b91114253d5L;
    long c2 = 0x4cf5ad432745937fL;
    // ----------
    // body
    for (int i = 0; i < nblocks; i++) {
      long k1 = getBlock(key, offset, i * 2);
      long k2 = getBlock(key, offset, i * 2 + 1);
      k1 *= c1;
      k1 = rotl64(k1, 31);
      k1 *= c2;
      h1 ^= k1;
      h1 = rotl64(h1, 27);
      h1 += h2;
      h1 = h1 * 5 + 0x52dce729;
      k2 *= c2;
      k2 = rotl64(k2, 33);
      k2 *= c1;
      h2 ^= k2;
      h2 = rotl64(h2, 31);
      h2 += h1;
      h2 = h2 * 5 + 0x38495ab5;
    }
    // ----------
    // tail
    // Advance offset to the unprocessed tail of the data.
    offset += nblocks * 16;
    long k1 = 0;
    long k2 = 0;
    switch (length & 15) {
      case 15:
        k2 ^= ((long) key[offset + 14]) << 48;
        // fallthrough
      case 14:
        k2 ^= ((long) key[offset + 13]) << 40;
        // fallthrough
      case 13:
        k2 ^= ((long) key[offset + 12]) << 32;
        // fallthrough
      case 12:
        k2 ^= ((long) key[offset + 11]) << 24;
        // fallthrough
      case 11:
        k2 ^= ((long) key[offset + 10]) << 16;
        // fallthrough
      case 10:
        k2 ^= ((long) key[offset + 9]) << 8;
        // fallthrough
      case 9:
        k2 ^= key[offset + 8];
        k2 *= c2;
        k2 = rotl64(k2, 33);
        k2 *= c1;
        h2 ^= k2;
        // fallthrough
      case 8:
        k1 ^= ((long) key[offset + 7]) << 56;
        // fallthrough
      case 7:
        k1 ^= ((long) key[offset + 6]) << 48;
        // fallthrough
      case 6:
        k1 ^= ((long) key[offset + 5]) << 40;
        // fallthrough
      case 5:
        k1 ^= ((long) key[offset + 4]) << 32;
        // fallthrough
      case 4:
        k1 ^= ((long) key[offset + 3]) << 24;
        // fallthrough
      case 3:
        k1 ^= ((long) key[offset + 2]) << 16;
        // fallthrough
      case 2:
        k1 ^= ((long) key[offset + 1]) << 8;
        // fallthrough
      case 1:
        k1 ^= (key[offset]);
        k1 *= c1;
        k1 = rotl64(k1, 31);
        k1 *= c2;
        h1 ^= k1;
        break;
      default: // 0
        // do nothing

    }
    // ----------
    // finalization
    h1 ^= length;
    h2 ^= length;
    h1 += h2;
    h2 += h1;
    h1 = fmix(h1);
    h2 = fmix(h2);
    h1 += h2;
    h2 += h1;
    return h1 + h2;
  }