ClickHouse/dbms/include/DB/Columns/IColumnDummy.h
2016-07-11 13:09:16 +03:00

100 lines
3.4 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#pragma once
#include <DB/Columns/IColumn.h>
#include <DB/Columns/ColumnsCommon.h>
namespace DB
{
namespace ErrorCodes
{
extern const int SIZES_OF_COLUMNS_DOESNT_MATCH;
extern const int NOT_IMPLEMENTED;
}
/** Базовый класс для столбцов-констант, содержащих значение, не входящее в Field.
* Не является полноценым столбцом и используется особым образом.
*/
class IColumnDummy : public IColumn
{
public:
IColumnDummy(size_t s_) : s(s_) {}
virtual ColumnPtr cloneDummy(size_t s_) const = 0;
ColumnPtr cloneResized(size_t s_) const override { return cloneDummy(s_); }
bool isConst() const override { return true; }
size_t size() const override { return s; }
void insertDefault() override { ++s; }
void popBack(size_t n) override { s -= n; }
size_t byteSize() const override { return 0; }
int compareAt(size_t n, size_t m, const IColumn & rhs_, int nan_direction_hint) const override { return 0; }
Field operator[](size_t n) const override { throw Exception("Cannot get value from " + getName(), ErrorCodes::NOT_IMPLEMENTED); }
void get(size_t n, Field & res) const override { throw Exception("Cannot get value from " + getName(), ErrorCodes::NOT_IMPLEMENTED); };
void insert(const Field & x) override { throw Exception("Cannot insert element into " + getName(), ErrorCodes::NOT_IMPLEMENTED); }
StringRef getDataAt(size_t n) const override { throw Exception("Method getDataAt is not supported for " + getName(), ErrorCodes::NOT_IMPLEMENTED); }
void insertData(const char * pos, size_t length) override { throw Exception("Method insertData is not supported for " + getName(), ErrorCodes::NOT_IMPLEMENTED); }
StringRef serializeValueIntoArena(size_t n, Arena & arena, char const *& begin) const override
{
throw Exception("Method serializeValueIntoArena is not supported for " + getName(), ErrorCodes::NOT_IMPLEMENTED);
}
const char * deserializeAndInsertFromArena(const char * pos) override
{
throw Exception("Method deserializeAndInsertFromArena is not supported for " + getName(), ErrorCodes::NOT_IMPLEMENTED);
}
void updateHashWithValue(size_t n, SipHash & hash) const override
{
throw Exception("Method updateHashWithValue is not supported for " + getName(), ErrorCodes::NOT_IMPLEMENTED);
}
void insertRangeFrom(const IColumn & src, size_t start, size_t length) override
{
s += length;
}
ColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override
{
return cloneDummy(countBytesInFilter(filt));
}
ColumnPtr permute(const Permutation & perm, size_t limit) const override
{
if (s != perm.size())
throw Exception("Size of permutation doesn't match size of column.", ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
return cloneDummy(limit ? std::min(s, limit) : s);
}
void getPermutation(bool reverse, size_t limit, Permutation & res) const override
{
res.resize(s);
for (size_t i = 0; i < s; ++i)
res[i] = i;
}
ColumnPtr replicate(const Offsets_t & offsets) const override
{
if (s != offsets.size())
throw Exception("Size of offsets doesn't match size of column.", ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
return cloneDummy(s == 0 ? 0 : offsets.back());
}
private:
void getExtremesImpl(Field & min, Field & max, const PaddedPODArray<UInt8> * null_map_) const override
{
throw Exception("Method getExtremes is not supported for " + getName(), ErrorCodes::NOT_IMPLEMENTED);
}
private:
size_t s;
};
}