lidavidm commented on code in PR #31: URL: https://github.com/apache/iceberg-cpp/pull/31#discussion_r1929893856
########## src/iceberg/type.h: ########## @@ -0,0 +1,411 @@ +/* + * 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. + */ + +#pragma once + +/// \file iceberg/type.h +/// Data types for Iceberg. This header defines the data types, but see +/// iceberg/type_fwd.h for the enum defining the list of types. + +#include <array> +#include <cstdint> +#include <memory> +#include <optional> +#include <span> +#include <string> +#include <unordered_map> +#include <vector> + +#include "iceberg/iceberg_export.h" +#include "iceberg/schema_field.h" +#include "iceberg/util/formattable.h" + +namespace iceberg { + +/// \brief Interface for a data type for a field. +class ICEBERG_EXPORT Type : public iceberg::util::Formattable { + public: + virtual ~Type() = default; + + /// \brief Get the type ID. + [[nodiscard]] virtual TypeId type_id() const = 0; + + /// \brief Is this a primitive type (may not have child fields)? + [[nodiscard]] virtual bool is_primitive() const = 0; + + /// \brief Is this a nested type (may have child fields)? + [[nodiscard]] virtual bool is_nested() const = 0; + + /// \brief Compare two types for equality. + friend bool operator==(const Type& lhs, const Type& rhs) { return lhs.Equals(rhs); } + + /// \brief Compare two types for inequality. + friend bool operator!=(const Type& lhs, const Type& rhs) { return !(lhs == rhs); } + + protected: + /// \brief Compare two types for equality. + [[nodiscard]] virtual bool Equals(const Type& other) const = 0; +}; + +/// \brief A data type that may not have child fields. +class ICEBERG_EXPORT PrimitiveType : public Type { + public: + bool is_primitive() const override { return true; } + bool is_nested() const override { return false; } +}; + +/// \brief A data type that may have child fields. +class ICEBERG_EXPORT NestedType : public Type { + public: + bool is_primitive() const override { return false; } + bool is_nested() const override { return true; } + + /// \brief Get a view of the child fields. + [[nodiscard]] virtual std::span<const SchemaField> fields() const = 0; + /// \brief Get a field by field ID. + [[nodiscard]] virtual std::optional<std::reference_wrapper<const SchemaField>> + GetFieldById(int32_t field_id) const = 0; + /// \brief Get a field by index. + [[nodiscard]] virtual std::optional<std::reference_wrapper<const SchemaField>> + GetFieldByIndex(int32_t index) const = 0; + /// \brief Get a field by name. + [[nodiscard]] virtual std::optional<std::reference_wrapper<const SchemaField>> + GetFieldByName(std::string_view name) const = 0; +}; + +/// \defgroup type-primitive Primitive Types +/// Primitive types do not have nested fields. +/// @{ + +/// \brief A data type representing a boolean. +class ICEBERG_EXPORT BooleanType : public PrimitiveType { + public: + BooleanType() = default; + ~BooleanType() = default; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; +}; + +/// \brief A data type representing a 32-bit signed integer. +class ICEBERG_EXPORT Int32Type : public PrimitiveType { + public: + Int32Type() = default; + ~Int32Type() = default; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; +}; + +/// \brief A data type representing a 64-bit signed integer. +class ICEBERG_EXPORT Int64Type : public PrimitiveType { + public: + Int64Type() = default; + ~Int64Type() = default; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; +}; + +/// \brief A data type representing a 32-bit (single precision) float. +class ICEBERG_EXPORT Float32Type : public PrimitiveType { + public: + Float32Type() = default; + ~Float32Type() = default; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; +}; + +/// \brief A data type representing a 64-bit (double precision) float. +class ICEBERG_EXPORT Float64Type : public PrimitiveType { + public: + Float64Type() = default; + ~Float64Type() = default; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; +}; + +/// \brief A data type representing a fixed-precision decimal. +class ICEBERG_EXPORT DecimalType : public PrimitiveType { + public: + constexpr static const int32_t kMaxPrecision = 38; + + /// \brief Construct a decimal type with the given precision and scale. + DecimalType(int32_t precision, int32_t scale); + ~DecimalType() = default; + + /// \brief Get the precision (the number of decimal digits). + [[nodiscard]] int32_t precision() const; + /// \brief Get the scale (essentially, the number of decimal digits after + /// the decimal point; precisely, the value is scaled by $$10^{-s}$$.). + [[nodiscard]] int32_t scale() const; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; + + private: + int32_t precision_; + int32_t scale_; +}; + +/// \brief A data type representing a calendar date without reference to a +/// timezone or time. +class ICEBERG_EXPORT DateType : public PrimitiveType { + public: + DateType() = default; + ~DateType() = default; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; +}; + +/// \brief A data type representing a wall clock time in microseconds without +/// reference to a timezone or date. +class ICEBERG_EXPORT TimeType : public PrimitiveType { + public: + TimeType() = default; + ~TimeType() = default; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; +}; + +/// \brief A base class for any timestamp time (irrespective of unit or +/// timezone). +class ICEBERG_EXPORT TimestampBase : public PrimitiveType { + public: + /// \brief Is this type zoned or naive? + [[nodiscard]] virtual bool is_zoned() const = 0; + /// \brief The time resolution. + [[nodiscard]] virtual TimeUnit time_unit() const = 0; +}; + +/// \brief A data type representing a timestamp in microseconds without +/// reference to a timezone. +class ICEBERG_EXPORT TimestampType : public TimestampBase { + public: + TimestampType() = default; + ~TimestampType() = default; + + bool is_zoned() const override; + TimeUnit time_unit() const override; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; +}; + +/// \brief A data type representing a timestamp as microseconds since the +/// epoch in UTC. +class ICEBERG_EXPORT TimestampTzType : public TimestampBase { + public: + TimestampTzType() = default; + ~TimestampTzType() = default; + + bool is_zoned() const override; + TimeUnit time_unit() const override; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; +}; + +/// \brief A data type representing a bytestring. +class ICEBERG_EXPORT BinaryType : public PrimitiveType { + public: + BinaryType() = default; + ~BinaryType() = default; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; +}; + +/// \brief A data type representing a string. +class ICEBERG_EXPORT StringType : public PrimitiveType { + public: + StringType() = default; + ~StringType() = default; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; +}; + +/// \brief A data type representing a fixed-length bytestring. +class ICEBERG_EXPORT FixedType : public PrimitiveType { + public: + /// \brief Construct a fixed type with the given length. + FixedType(int32_t length); + ~FixedType() = default; + + /// \brief The length (the number of bytes to store). + [[nodiscard]] int32_t length() const; + + TypeId type_id() const override; + std::string ToString() const override; + + protected: + bool Equals(const Type& other) const override; + + private: + int32_t length_; Review Comment: Java uses a 32 bit int. https://github.com/apache/iceberg/blob/d693f83b6ad6e306550d117ff0bf0014356500b2/api/src/main/java/org/apache/iceberg/types/Types.java#L360 Are the Iceberg maintainers interested in making the spec actually lay out these details? I've mostly copied Java since the spec itself is extremely vague. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
