Function BenchmarkBitmapWriter

cpp/src/arrow/util/bit_util_benchmark.cc:290–314

template <typename BitmapWriterType>
static void BenchmarkBitmapWriter(benchmark::State& state, int64_t nbytes) {
  std::shared_ptr<Buffer> buffer = CreateRandomBuffer(nbytes);

  const int64_t num_bits = nbytes * 8;
  uint8_t* bitmap = buffer->mutable_data();

  for (auto _ : state) {
    BitmapWriterType writer(bitmap, 0, num_bits);
    int64_t pattern_index = 0;
    for (int64_t i = 0; i < num_bits; i++) {
      if (pattern[pattern_index++]) {
        writer.Set();
      } else {
        writer.Clear();
      }
      if (pattern_index == sizeof(pattern) / sizeof(bool)) {
        pattern_index = 0;
      }
      writer.Next();
    }
    writer.Finish();
    benchmark::ClobberMemory();
  }
  state.SetBytesProcessed(state.iterations() * nbytes);
}

template <typename GenerateBitsFunctorType>
static void BenchmarkGenerateBits(benchmark::State& state, int64_t nbytes) {