ClickHouse/dbms/include/DB/AggregateFunctions/IBinaryAggregateFunction.h

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#pragma once
2015-12-23 05:31:51 +00:00
#include <DB/IO/WriteHelpers.h>
#include <DB/AggregateFunctions/IAggregateFunction.h>
namespace DB
{
template <typename T, typename Derived>
class IBinaryAggregateFunction : public IAggregateFunctionHelper<T>
{
private:
Derived & getDerived() { return static_cast<Derived &>(*this); }
const Derived & getDerived() const { return static_cast<const Derived &>(*this); }
public:
void setArguments(const DataTypes & arguments) override final
{
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, Arena * arena) const override final
{
getDerived().addImpl(place, *columns[0], *columns[1], row_num, arena);
}
static void addFree(const IAggregateFunction * that, AggregateDataPtr place, const IColumn ** columns, size_t row_num, Arena * arena)
{
static_cast<const Derived &>(*that).addImpl(place, *columns[0], *columns[1], row_num, arena);
}
IAggregateFunction::AddFunc getAddressOfAddFunction() const override final { return &addFree; }
};
}