ClickHouse/src/Interpreters/FillingRow.h
2020-04-03 18:14:31 +03:00

45 lines
1.5 KiB
C++

#pragma once
#include <Core/SortDescription.h>
#include <Columns/IColumn.h>
#include <Common/FieldVisitors.h>
namespace DB
{
/// Compares fields in terms of sorting order, considering direction.
bool less(const Field & lhs, const Field & rhs, int direction);
bool equals(const Field & lhs, const Field & rhs);
/** Helps to implement modifier WITH FILL for ORDER BY clause.
* Stores row as array of fields and provides functions to generate next row for filling gaps and for comparing rows.
* Used in FillingBlockInputStream and in FillingTransform.
*/
class FillingRow
{
public:
FillingRow(const SortDescription & sort_description);
/// Generates next row according to fill 'from', 'to' and 'step' values.
bool next(const FillingRow & to_row);
void initFromDefaults(size_t from_pos = 0);
Field & operator[](size_t ind) { return row[ind]; }
const Field & operator[](size_t ind) const { return row[ind]; }
size_t size() const { return row.size(); }
bool operator<(const FillingRow & other) const;
bool operator==(const FillingRow & other) const;
int getDirection(size_t ind) const { return description[ind].direction; }
FillColumnDescription & getFillDescription(size_t ind) { return description[ind].fill_description; }
private:
std::vector<Field> row;
SortDescription description;
};
void insertFromFillingRow(MutableColumns & filling_columns, MutableColumns & other_columns, const FillingRow & filling_row);
void copyRowFromColumns(MutableColumns & dest, const Columns & source, size_t row_num);
}