ClickHouse/dbms/Core/SortDescription.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

66 lines
2.5 KiB
C++

#pragma once
#include <vector>
#include <memory>
#include <cstddef>
#include <string>
#include <Core/Field.h>
class Collator;
namespace DB
{
struct FillColumnDescription
{
/// All missed values in range [FROM, TO) will be filled
/// Range [FROM, TO) respects sorting direction
Field fill_from; /// Fill value >= FILL_FROM
Field fill_to; /// Fill value + STEP < FILL_TO
Field fill_step; /// Default = 1 or -1 according to direction
};
/// Description of the sorting rule by one column.
struct SortColumnDescription
{
std::string column_name; /// The name of the column.
size_t column_number; /// Column number (used if no name is given).
int direction; /// 1 - ascending, -1 - descending.
int nulls_direction; /// 1 - NULLs and NaNs are greater, -1 - less.
/// To achieve NULLS LAST, set it equal to direction, to achieve NULLS FIRST, set it opposite.
std::shared_ptr<Collator> collator; /// Collator for locale-specific comparison of strings
bool with_fill;
FillColumnDescription fill_description;
SortColumnDescription(
size_t column_number_, int direction_, int nulls_direction_,
const std::shared_ptr<Collator> & collator_ = nullptr, bool with_fill_ = false,
const FillColumnDescription & fill_description_ = {})
: column_number(column_number_), direction(direction_), nulls_direction(nulls_direction_), collator(collator_)
, with_fill(with_fill_), fill_description(fill_description_) {}
SortColumnDescription(
const std::string & column_name_, int direction_, int nulls_direction_,
const std::shared_ptr<Collator> & collator_ = nullptr, bool with_fill_ = false,
const FillColumnDescription & fill_description_ = {})
: column_name(column_name_), column_number(0), direction(direction_), nulls_direction(nulls_direction_)
, collator(collator_), with_fill(with_fill_), fill_description(fill_description_) {}
bool operator == (const SortColumnDescription & other) const
{
return column_name == other.column_name && column_number == other.column_number
&& direction == other.direction && nulls_direction == other.nulls_direction;
}
bool operator != (const SortColumnDescription & other) const
{
return !(*this == other);
}
};
/// Description of the sorting rule for several columns.
using SortDescription = std::vector<SortColumnDescription>;
}