Method DeltaBitPack

cpp/src/parquet/encoding_test.cc:1018–1045

  }

  void DeltaBitPack(int seed) {
    if (!std::is_same<ParquetType, Int32Type>::value &&
        !std::is_same<ParquetType, Int64Type>::value) {
      return;
    }
    auto values = GetValues(seed);
    auto encoder = MakeTypedEncoder<ParquetType>(
        Encoding::DELTA_BINARY_PACKED, /*use_dictionary=*/false, column_descr());
    auto decoder =
        MakeTypedDecoder<ParquetType>(Encoding::DELTA_BINARY_PACKED, column_descr());

    ASSERT_NO_THROW(encoder->Put(*values));
    auto buf = encoder->FlushValues();

    int num_values = static_cast<int>(values->length() - values->null_count());
    decoder->SetData(num_values, buf->data(), static_cast<int>(buf->size()));

    BuilderType acc(arrow_type(), ::arrow::default_memory_pool());
    ASSERT_EQ(num_values,
              decoder->DecodeArrow(static_cast<int>(values->length()),
                                   static_cast<int>(values->null_count()),
                                   values->null_bitmap_data(), values->offset(), &acc));

    std::shared_ptr<::arrow::Array> result;
    ASSERT_OK(acc.Finish(&result));
    ASSERT_EQ(50, result->length());
    ::arrow::AssertArraysEqual(*values, *result);
  }

  void Dict(int seed) {
    if (std::is_same<ParquetType, BooleanType>::value) {