mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-13 11:04:10 +00:00
77 lines
2.3 KiB
C++
77 lines
2.3 KiB
C++
#pragma once
|
||
|
||
#include <DB/Columns/IColumn.h>
|
||
#include <DB/Interpreters/Set.h>
|
||
|
||
|
||
namespace DB
|
||
{
|
||
|
||
/** 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 { return cloneDummy(s_); }
|
||
bool isConst() { return true; }
|
||
size_t size() const { return s; }
|
||
void insertDefault() { ++s; }
|
||
size_t byteSize() const { return 0; }
|
||
int compareAt(size_t n, size_t m, const IColumn & rhs_) const { return 0; }
|
||
|
||
Field operator[](size_t n) const { throw Exception("Cannot get value from " + getName(), ErrorCodes::NOT_IMPLEMENTED); }
|
||
void get(size_t n, Field & res) const { throw Exception("Cannot get value from " + getName(), ErrorCodes::NOT_IMPLEMENTED); };
|
||
void insert(const Field & x) { throw Exception("Cannot insert element into " + getName(), ErrorCodes::NOT_IMPLEMENTED); }
|
||
StringRef getDataAt(size_t n) const { throw Exception("Method getDataAt is not supported for " + getName(), ErrorCodes::NOT_IMPLEMENTED); }
|
||
void insertData(const char * pos, size_t length) { throw Exception("Method insertData is not supported for " + getName(), ErrorCodes::NOT_IMPLEMENTED); }
|
||
|
||
ColumnPtr cut(size_t start, size_t length) const
|
||
{
|
||
return cloneDummy(length);
|
||
}
|
||
|
||
ColumnPtr filter(const Filter & filt) const
|
||
{
|
||
size_t new_size = 0;
|
||
for (Filter::const_iterator it = filt.begin(); it != filt.end(); ++it)
|
||
if (*it)
|
||
++new_size;
|
||
|
||
return cloneDummy(new_size);
|
||
}
|
||
|
||
ColumnPtr permute(const Permutation & perm) const
|
||
{
|
||
if (s != perm.size())
|
||
throw Exception("Size of permutation doesn't match size of column.", ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
|
||
|
||
return cloneDummy(s);
|
||
}
|
||
|
||
Permutation getPermutation() const
|
||
{
|
||
Permutation res(s);
|
||
for (size_t i = 0; i < s; ++i)
|
||
res[i] = i;
|
||
return res;
|
||
}
|
||
|
||
ColumnPtr replicate(const Offsets_t & offsets) const
|
||
{
|
||
if (s != offsets.size())
|
||
throw Exception("Size of offsets doesn't match size of column.", ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
|
||
|
||
return cloneDummy(offsets.back());
|
||
}
|
||
|
||
private:
|
||
size_t s;
|
||
};
|
||
|
||
}
|