ClickHouse/dbms/Columns/ColumnArray.h
Ivan 97f2a2213e
Move all folders inside /dbms one level up (#9974)
* Move some code outside dbms/src folder
* Fix paths
2020-04-02 02:51:21 +03:00

170 lines
6.9 KiB
C++

#pragma once
#include <Columns/IColumn.h>
#include <Columns/IColumnImpl.h>
#include <Columns/ColumnVector.h>
#include <Core/Defines.h>
#include <Common/typeid_cast.h>
#include <Common/assert_cast.h>
namespace DB
{
/** A column of array values.
* In memory, it is represented as one column of a nested type, whose size is equal to the sum of the sizes of all arrays,
* and as an array of offsets in it, which allows you to get each element.
*/
class ColumnArray final : public COWHelper<IColumn, ColumnArray>
{
private:
friend class COWHelper<IColumn, ColumnArray>;
/** Create an array column with specified values and offsets. */
ColumnArray(MutableColumnPtr && nested_column, MutableColumnPtr && offsets_column);
/** Create an empty column of arrays with the type of values as in the column `nested_column` */
explicit ColumnArray(MutableColumnPtr && nested_column);
ColumnArray(const ColumnArray &) = default;
public:
/** Create immutable column using immutable arguments. This arguments may be shared with other columns.
* Use IColumn::mutate in order to make mutable column and mutate shared nested columns.
*/
using Base = COWHelper<IColumn, ColumnArray>;
static Ptr create(const ColumnPtr & nested_column, const ColumnPtr & offsets_column)
{
return ColumnArray::create(nested_column->assumeMutable(), offsets_column->assumeMutable());
}
static Ptr create(const ColumnPtr & nested_column)
{
return ColumnArray::create(nested_column->assumeMutable());
}
template <typename ... Args, typename = typename std::enable_if<IsMutableColumns<Args ...>::value>::type>
static MutablePtr create(Args &&... args) { return Base::create(std::forward<Args>(args)...); }
/** On the index i there is an offset to the beginning of the i + 1 -th element. */
using ColumnOffsets = ColumnVector<Offset>;
std::string getName() const override;
const char * getFamilyName() const override { return "Array"; }
MutableColumnPtr cloneResized(size_t size) const override;
size_t size() const override;
Field operator[](size_t n) const override;
void get(size_t n, Field & res) const override;
StringRef getDataAt(size_t n) const override;
void insertData(const char * pos, size_t length) override;
StringRef serializeValueIntoArena(size_t n, Arena & arena, char const *& begin) const override;
const char * deserializeAndInsertFromArena(const char * pos) override;
void updateHashWithValue(size_t n, SipHash & hash) const override;
void updateWeakHash32(WeakHash32 & hash) const override;
void insertRangeFrom(const IColumn & src, size_t start, size_t length) override;
void insert(const Field & x) override;
void insertFrom(const IColumn & src_, size_t n) override;
void insertDefault() override;
void popBack(size_t n) override;
ColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
ColumnPtr permute(const Permutation & perm, size_t limit) const override;
ColumnPtr index(const IColumn & indexes, size_t limit) const override;
template <typename Type> ColumnPtr indexImpl(const PaddedPODArray<Type> & indexes, size_t limit) const;
int compareAt(size_t n, size_t m, const IColumn & rhs_, int nan_direction_hint) const override;
void getPermutation(bool reverse, size_t limit, int nan_direction_hint, Permutation & res) const override;
void reserve(size_t n) override;
size_t byteSize() const override;
size_t allocatedBytes() const override;
void protect() override;
ColumnPtr replicate(const Offsets & replicate_offsets) const override;
ColumnPtr convertToFullColumnIfConst() const override;
void getExtremes(Field & min, Field & max) const override;
bool hasEqualOffsets(const ColumnArray & other) const;
/** More efficient methods of manipulation */
IColumn & getData() { return *data; }
const IColumn & getData() const { return *data; }
IColumn & getOffsetsColumn() { return *offsets; }
const IColumn & getOffsetsColumn() const { return *offsets; }
Offsets & ALWAYS_INLINE getOffsets()
{
return assert_cast<ColumnOffsets &>(*offsets).getData();
}
const Offsets & ALWAYS_INLINE getOffsets() const
{
return assert_cast<const ColumnOffsets &>(*offsets).getData();
}
const ColumnPtr & getDataPtr() const { return data; }
ColumnPtr & getDataPtr() { return data; }
const ColumnPtr & getOffsetsPtr() const { return offsets; }
ColumnPtr & getOffsetsPtr() { return offsets; }
MutableColumns scatter(ColumnIndex num_columns, const Selector & selector) const override
{
return scatterImpl<ColumnArray>(num_columns, selector);
}
void gather(ColumnGathererStream & gatherer_stream) override;
void forEachSubcolumn(ColumnCallback callback) override
{
callback(offsets);
callback(data);
}
bool structureEquals(const IColumn & rhs) const override
{
if (auto rhs_concrete = typeid_cast<const ColumnArray *>(&rhs))
return data->structureEquals(*rhs_concrete->data);
return false;
}
private:
WrappedPtr data;
WrappedPtr offsets;
size_t ALWAYS_INLINE offsetAt(ssize_t i) const { return getOffsets()[i - 1]; }
size_t ALWAYS_INLINE sizeAt(ssize_t i) const { return getOffsets()[i] - getOffsets()[i - 1]; }
/// Multiply values if the nested column is ColumnVector<T>.
template <typename T>
ColumnPtr replicateNumber(const Offsets & replicate_offsets) const;
/// Multiply the values if the nested column is ColumnString. The code is too complicated.
ColumnPtr replicateString(const Offsets & replicate_offsets) const;
/** Non-constant arrays of constant values are quite rare.
* Most functions can not work with them, and does not create such columns as a result.
* An exception is the function `replicate` (see FunctionsMiscellaneous.h), which has service meaning for the implementation of lambda functions.
* Only for its sake is the implementation of the `replicate` method for ColumnArray(ColumnConst).
*/
ColumnPtr replicateConst(const Offsets & replicate_offsets) const;
/** The following is done by simply replicating of nested columns.
*/
ColumnPtr replicateTuple(const Offsets & replicate_offsets) const;
ColumnPtr replicateNullable(const Offsets & replicate_offsets) const;
ColumnPtr replicateGeneric(const Offsets & replicate_offsets) const;
/// Specializations for the filter function.
template <typename T>
ColumnPtr filterNumber(const Filter & filt, ssize_t result_size_hint) const;
ColumnPtr filterString(const Filter & filt, ssize_t result_size_hint) const;
ColumnPtr filterTuple(const Filter & filt, ssize_t result_size_hint) const;
ColumnPtr filterNullable(const Filter & filt, ssize_t result_size_hint) const;
ColumnPtr filterGeneric(const Filter & filt, ssize_t result_size_hint) const;
};
}