src/parquet/murmur3.cc

// 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.

//-----------------------------------------------------------------------------
// MurmurHash3 was written by Austin Appleby, and is placed in the public
// domain. The author hereby disclaims copyright to this source code.

// Note - The x86 and x64 versions do _not_ produce the same results, as the
// algorithms are optimized for their respective platforms. You can still
// compile and run any of them on any platform, but your performance with the
// non-native version will be less than optimal.

#include "parquet/murmur3.h"

namespace parquet {

#if defined(_MSC_VER)

#define FORCE_INLINE __forceinline
#define ROTL64(x, y) _rotl64(x, y)

#else  // defined(_MSC_VER)

#define FORCE_INLINE inline __attribute__((always_inline))
inline uint64_t rotl64(uint64_t x, int8_t r) { return (x << r) | (x >> (64 - r)); }
#define ROTL64(x, y) rotl64(x, y)

#endif  // !defined(_MSC_VER)

#define BIG_CONSTANT(x) (x##LLU)

//-----------------------------------------------------------------------------
// Block read - if your platform needs to do endian-swapping or can only
// handle aligned reads, do the conversion here

FORCE_INLINE uint32_t getblock32(const uint32_t* p, int i) { return p[i]; }

FORCE_INLINE uint64_t getblock64(const uint64_t* p, int i) { return p[i]; }

//-----------------------------------------------------------------------------
// Finalization mix - force all bits of a hash block to avalanche

FORCE_INLINE uint32_t fmix32(uint32_t h) {
  h ^= h >> 16;
  h *= 0x85ebca6b;
  h ^= h >> 13;
  h *= 0xc2b2ae35;
  h ^= h >> 16;

  return h;
}

//----------

FORCE_INLINE uint64_t fmix64(uint64_t k) {
  k ^= k >> 33;
  k *= BIG_CONSTANT(0xff51afd7ed558ccd);
  k ^= k >> 33;
  k *= BIG_CONSTANT(0xc4ceb9fe1a85ec53);
  k ^= k >> 33;

  return k;
}

//-----------------------------------------------------------------------------

void Hash_x64_128(const void* key, const int len, const uint32_t seed, uint64_t out[2]) {
  const uint8_t* data = (const uint8_t*)key;
  const int nblocks = len / 16;

  uint64_t h1 = seed;
  uint64_t h2 = seed;

  const uint64_t c1 = BIG_CONSTANT(0x87c37b91114253d5);
  const uint64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f);

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

  const uint64_t* blocks = (const uint64_t*)(data);

  for (int i = 0; i < nblocks; i++) {
    uint64_t k1 = getblock64(blocks, i * 2 + 0);
    uint64_t k2 = getblock64(blocks, 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

  const uint8_t* tail = (const uint8_t*)(data + nblocks * 16);

  uint64_t k1 = 0;
  uint64_t k2 = 0;

  switch (len & 15) {
    case 15:
      k2 ^= ((uint64_t)tail[14]) << 48;  // fall through
    case 14:
      k2 ^= ((uint64_t)tail[13]) << 40;  // fall through
    case 13:
      k2 ^= ((uint64_t)tail[12]) << 32;  // fall through
    case 12:
      k2 ^= ((uint64_t)tail[11]) << 24;  // fall through
    case 11:
      k2 ^= ((uint64_t)tail[10]) << 16;  // fall through
    case 10:
      k2 ^= ((uint64_t)tail[9]) << 8;  // fall through
    case 9:
      k2 ^= ((uint64_t)tail[8]) << 0;
      k2 *= c2;
      k2 = ROTL64(k2, 33);
      k2 *= c1;
      h2 ^= k2;  // fall through

    case 8:
      k1 ^= ((uint64_t)tail[7]) << 56;  // fall through
    case 7:
      k1 ^= ((uint64_t)tail[6]) << 48;  // fall through
    case 6:
      k1 ^= ((uint64_t)tail[5]) << 40;  // fall through
    case 5:
      k1 ^= ((uint64_t)tail[4]) << 32;  // fall through
    case 4:
      k1 ^= ((uint64_t)tail[3]) << 24;  // fall through
    case 3:
      k1 ^= ((uint64_t)tail[2]) << 16;  // fall through
    case 2:
      k1 ^= ((uint64_t)tail[1]) << 8;  // fall through
    case 1:
      k1 ^= ((uint64_t)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;

  reinterpret_cast<uint64_t*>(out)[0] = h1;
  reinterpret_cast<uint64_t*>(out)[1] = h2;
}

template <typename T>
uint64_t HashHelper(T value, uint32_t seed) {
  uint64_t output[2];
  Hash_x64_128(reinterpret_cast<void*>(&value), sizeof(T), seed, output);
  return output[0];
}

uint64_t MurmurHash3::Hash(int32_t value) const { return HashHelper(value, seed_); }

uint64_t MurmurHash3::Hash(int64_t value) const { return HashHelper(value, seed_); }

uint64_t MurmurHash3::Hash(float value) const { return HashHelper(value, seed_); }

uint64_t MurmurHash3::Hash(double value) const { return HashHelper(value, seed_); }

uint64_t MurmurHash3::Hash(const FLBA* value, uint32_t len) const {
  uint64_t out[2];
  Hash_x64_128(reinterpret_cast<const void*>(value->ptr), len, seed_, out);
  return out[0];
}

uint64_t MurmurHash3::Hash(const Int96* value) const {
  uint64_t out[2];
  Hash_x64_128(reinterpret_cast<const void*>(value->value), sizeof(value->value), seed_,
               out);
  return out[0];
}

uint64_t MurmurHash3::Hash(const ByteArray* value) const {
  uint64_t out[2];
  Hash_x64_128(reinterpret_cast<const void*>(value->ptr), value->len, seed_, out);
  return out[0];
}

}  // namespace parquet