ClickHouse/dbms/DataStreams/TotalsHavingBlockInputStream.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

63 lines
1.8 KiB
C++

#pragma once
#include <DataStreams/IBlockInputStream.h>
namespace DB
{
class Arena;
using ArenaPtr = std::shared_ptr<Arena>;
class ExpressionActions;
enum class TotalsMode;
/** Takes blocks after grouping, with non-finalized aggregate functions.
* Calculates total values according to totals_mode.
* If necessary, evaluates the expression from HAVING and filters rows. Returns the finalized and filtered blocks.
*/
class TotalsHavingBlockInputStream : public IBlockInputStream
{
private:
using ExpressionActionsPtr = std::shared_ptr<ExpressionActions>;
public:
/// expression may be nullptr
TotalsHavingBlockInputStream(
const BlockInputStreamPtr & input_,
bool overflow_row_, const ExpressionActionsPtr & expression_,
const std::string & filter_column_, TotalsMode totals_mode_, double auto_include_threshold_, bool final_);
String getName() const override { return "TotalsHaving"; }
Block getTotals() override;
Block getHeader() const override;
protected:
Block readImpl() override;
private:
bool overflow_row;
ExpressionActionsPtr expression;
String filter_column_name;
TotalsMode totals_mode;
double auto_include_threshold;
bool final;
size_t passed_keys = 0;
size_t total_keys = 0;
/** Here are the values that did not pass max_rows_to_group_by.
* They are added or not added to the current_totals, depending on the totals_mode.
*/
Block overflow_aggregates;
/// Here, total values are accumulated. After the work is finished, they will be placed in IBlockInputStream::totals.
MutableColumns current_totals;
/// If filter == nullptr - add all rows. Otherwise, only the rows that pass the filter (HAVING).
void addToTotals(const Block & block, const IColumn::Filter * filter);
};
}