Method CheckArray

cpp/src/arrow/testing/random_test.cc:287–326

  }

  void CheckArray(const Array& array) {
    ASSERT_OK(array.ValidateFull());

    const auto& type = checked_cast<const DecimalType&>(*array.type());
    const auto& values = checked_cast<const ArrayType&>(array);

    const DecimalValue limit = DecimalValue::GetScaleMultiplier(type.precision());
    const DecimalValue neg_limit = DecimalValue(limit).Negate();
    const DecimalValue half_limit = limit / DecimalValue(2);
    const DecimalValue neg_half_limit = DecimalValue(half_limit).Negate();

    // Check that random-generated values:
    // - satisfy the requested precision
    // - at least sometimes are close to the max allowable values for precision
    // - sometimes are negative
    int64_t non_nulls = 0;
    int64_t over_half = 0;
    int64_t negative = 0;

    for (int64_t i = 0; i < values.length(); ++i) {
      if (values.IsNull(i)) {
        continue;
      }
      ++non_nulls;
      const DecimalValue value(values.GetValue(i));
      ASSERT_LT(value, limit);
      ASSERT_GT(value, neg_limit);
      if (value >= half_limit || value <= neg_half_limit) {
        ++over_half;
      }
      if (value.Sign() < 0) {
        ++negative;
      }
    }

    ASSERT_GE(over_half, non_nulls * 0.3);
    ASSERT_LE(over_half, non_nulls * 0.7);
    ASSERT_GE(negative, non_nulls * 0.3);
    ASSERT_LE(negative, non_nulls * 0.7);
  }
};

using DecimalTypes =