2022-05-23 00:16:32 +04:00

289 lines
9.2 KiB
C++

// 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
#include <cstdint>
#include <memory>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>
#include "arrow/array/data.h"
#include "arrow/scalar.h"
#include "arrow/type.h"
#include "arrow/type_traits.h"
#include "arrow/util/checked_cast.h"
#include "arrow/util/macros.h"
#include "arrow/util/variant.h" // IWYU pragma: export
#include "arrow/util/visibility.h"
namespace arrow {
class Array;
class ChunkedArray;
class RecordBatch;
class Table;
/// \brief A descriptor type that gives the shape (array or scalar) and
/// DataType of a Value, but without the data
struct ARROW_EXPORT ValueDescr {
std::shared_ptr<DataType> type;
enum Shape {
/// \brief Either Array or Scalar
ANY,
/// \brief Array type
ARRAY,
/// \brief Only Scalar arguments supported
SCALAR
};
Shape shape;
ValueDescr() : shape(ANY) {}
ValueDescr(std::shared_ptr<DataType> type, ValueDescr::Shape shape)
: type(std::move(type)), shape(shape) {}
ValueDescr(std::shared_ptr<DataType> type) // NOLINT implicit conversion
: type(std::move(type)), shape(ValueDescr::ANY) {}
/// \brief Convenience constructor for ANY descr
static ValueDescr Any(std::shared_ptr<DataType> type) {
return ValueDescr(std::move(type), ANY);
}
/// \brief Convenience constructor for Value::ARRAY descr
static ValueDescr Array(std::shared_ptr<DataType> type) {
return ValueDescr(std::move(type), ARRAY);
}
/// \brief Convenience constructor for Value::SCALAR descr
static ValueDescr Scalar(std::shared_ptr<DataType> type) {
return ValueDescr(std::move(type), SCALAR);
}
bool operator==(const ValueDescr& other) const {
if (shape != other.shape) return false;
if (type == other.type) return true;
return type && type->Equals(other.type);
}
bool operator!=(const ValueDescr& other) const { return !(*this == other); }
std::string ToString() const;
static std::string ToString(const std::vector<ValueDescr>&);
ARROW_EXPORT friend void PrintTo(const ValueDescr&, std::ostream*);
};
/// \brief For use with scalar functions, returns the broadcasted Value::Shape
/// given a vector of value descriptors. Return SCALAR unless any value is
/// ARRAY
ARROW_EXPORT
ValueDescr::Shape GetBroadcastShape(const std::vector<ValueDescr>& args);
/// \class Datum
/// \brief Variant type for various Arrow C++ data structures
struct ARROW_EXPORT Datum {
enum Kind { NONE, SCALAR, ARRAY, CHUNKED_ARRAY, RECORD_BATCH, TABLE };
struct Empty {};
// Datums variants may have a length. This special value indicate that the
// current variant does not have a length.
static constexpr int64_t kUnknownLength = -1;
util::Variant<Empty, std::shared_ptr<Scalar>, std::shared_ptr<ArrayData>,
std::shared_ptr<ChunkedArray>, std::shared_ptr<RecordBatch>,
std::shared_ptr<Table>>
value;
/// \brief Empty datum, to be populated elsewhere
Datum() = default;
Datum(const Datum& other) = default;
Datum& operator=(const Datum& other) = default;
Datum(Datum&& other) = default;
Datum& operator=(Datum&& other) = default;
Datum(std::shared_ptr<Scalar> value) // NOLINT implicit conversion
: value(std::move(value)) {}
Datum(std::shared_ptr<ArrayData> value) // NOLINT implicit conversion
: value(std::move(value)) {}
Datum(ArrayData arg) // NOLINT implicit conversion
: value(std::make_shared<ArrayData>(std::move(arg))) {}
Datum(const Array& value); // NOLINT implicit conversion
Datum(const std::shared_ptr<Array>& value); // NOLINT implicit conversion
Datum(std::shared_ptr<ChunkedArray> value); // NOLINT implicit conversion
Datum(std::shared_ptr<RecordBatch> value); // NOLINT implicit conversion
Datum(std::shared_ptr<Table> value); // NOLINT implicit conversion
// Explicit constructors from const-refs. Can be expensive, prefer the
// shared_ptr constructors
explicit Datum(const ChunkedArray& value);
explicit Datum(const RecordBatch& value);
explicit Datum(const Table& value);
// Cast from subtypes of Array or Scalar to Datum
template <typename T, bool IsArray = std::is_base_of<Array, T>::value,
bool IsScalar = std::is_base_of<Scalar, T>::value,
typename = enable_if_t<IsArray || IsScalar>>
Datum(std::shared_ptr<T> value) // NOLINT implicit conversion
: Datum(std::shared_ptr<typename std::conditional<IsArray, Array, Scalar>::type>(
std::move(value))) {}
// Cast from subtypes of Array or Scalar to Datum
template <typename T, typename TV = typename std::remove_reference<T>::type,
bool IsArray = std::is_base_of<Array, T>::value,
bool IsScalar = std::is_base_of<Scalar, T>::value,
typename = enable_if_t<IsArray || IsScalar>>
Datum(T&& value) // NOLINT implicit conversion
: Datum(std::make_shared<TV>(std::forward<T>(value))) {}
// Convenience constructors
explicit Datum(bool value);
explicit Datum(int8_t value);
explicit Datum(uint8_t value);
explicit Datum(int16_t value);
explicit Datum(uint16_t value);
explicit Datum(int32_t value);
explicit Datum(uint32_t value);
explicit Datum(int64_t value);
explicit Datum(uint64_t value);
explicit Datum(float value);
explicit Datum(double value);
explicit Datum(std::string value);
explicit Datum(const char* value);
Datum::Kind kind() const {
switch (this->value.index()) {
case 0:
return Datum::NONE;
case 1:
return Datum::SCALAR;
case 2:
return Datum::ARRAY;
case 3:
return Datum::CHUNKED_ARRAY;
case 4:
return Datum::RECORD_BATCH;
case 5:
return Datum::TABLE;
default:
return Datum::NONE;
}
}
const std::shared_ptr<ArrayData>& array() const {
return util::get<std::shared_ptr<ArrayData>>(this->value);
}
/// \brief The sum of bytes in each buffer referenced by the datum
/// Note: Scalars report a size of 0
/// \see arrow::util::TotalBufferSize for caveats
int64_t TotalBufferSize() const;
ArrayData* mutable_array() const { return this->array().get(); }
std::shared_ptr<Array> make_array() const;
const std::shared_ptr<ChunkedArray>& chunked_array() const {
return util::get<std::shared_ptr<ChunkedArray>>(this->value);
}
const std::shared_ptr<RecordBatch>& record_batch() const {
return util::get<std::shared_ptr<RecordBatch>>(this->value);
}
const std::shared_ptr<Table>& table() const {
return util::get<std::shared_ptr<Table>>(this->value);
}
const std::shared_ptr<Scalar>& scalar() const {
return util::get<std::shared_ptr<Scalar>>(this->value);
}
template <typename ExactType>
std::shared_ptr<ExactType> array_as() const {
return internal::checked_pointer_cast<ExactType>(this->make_array());
}
template <typename ExactType>
const ExactType& scalar_as() const {
return internal::checked_cast<const ExactType&>(*this->scalar());
}
bool is_array() const { return this->kind() == Datum::ARRAY; }
bool is_arraylike() const {
return this->kind() == Datum::ARRAY || this->kind() == Datum::CHUNKED_ARRAY;
}
bool is_scalar() const { return this->kind() == Datum::SCALAR; }
/// \brief True if Datum contains a scalar or array-like data
bool is_value() const { return this->is_arraylike() || this->is_scalar(); }
int64_t null_count() const;
/// \brief Return the shape (array or scalar) and type for supported kinds
/// (ARRAY, CHUNKED_ARRAY, and SCALAR). Debug asserts otherwise
ValueDescr descr() const;
/// \brief Return the shape (array or scalar) for supported kinds (ARRAY,
/// CHUNKED_ARRAY, and SCALAR). Debug asserts otherwise
ValueDescr::Shape shape() const;
/// \brief The value type of the variant, if any
///
/// \return nullptr if no type
const std::shared_ptr<DataType>& type() const;
/// \brief The schema of the variant, if any
///
/// \return nullptr if no schema
const std::shared_ptr<Schema>& schema() const;
/// \brief The value length of the variant, if any
///
/// \return kUnknownLength if no type
int64_t length() const;
/// \brief The array chunks of the variant, if any
///
/// \return empty if not arraylike
ArrayVector chunks() const;
bool Equals(const Datum& other) const;
bool operator==(const Datum& other) const { return Equals(other); }
bool operator!=(const Datum& other) const { return !Equals(other); }
std::string ToString() const;
ARROW_EXPORT friend void PrintTo(const Datum&, std::ostream*);
};
} // namespace arrow