ClickHouse/dbms/include/DB/AggregateFunctions/IBinaryAggregateFunction.h
2015-11-11 05:04:23 +03:00

33 lines
849 B
C++

#pragma once
#include <DB/AggregateFunctions/IAggregateFunction.h>
namespace DB
{
template <typename T, typename Derived>
class IBinaryAggregateFunction : public IAggregateFunctionHelper<T>
{
Derived & getDerived() { return static_cast<Derived &>(*this); }
const Derived & getDerived() const { return static_cast<const Derived &>(*this); }
public:
void setArguments(const DataTypes & arguments) override
{
if (arguments.size() != 2)
throw Exception{
"Passed " + toString(arguments.size()) + " arguments to binary aggregate function " + this->getName(),
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH
};
getDerived().setArgumentsImpl(arguments);
}
void add(AggregateDataPtr place, const IColumn ** columns, const size_t row_num) const override
{
getDerived().addTwo(place, *columns[0], *columns[1], row_num);
}
};
}