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108 lines
2.9 KiB
C++
108 lines
2.9 KiB
C++
#pragma once
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#include <DB/DataTypes/DataTypeAggregateFunction.h>
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#include <DB/AggregateFunctions/IAggregateFunction.h>
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namespace DB
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{
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/** Не агрегатная функция, а адаптер агрегатных функций,
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* Агрегатные функции с суффиксом Merge принимают в качестве аргумента DataTypeAggregateFunction
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* (состояние агрегатной функции, полученное ранее с помощью применения агрегатной функции с суффиксом State)
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* и объединяют их при агрегации.
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*/
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class AggregateFunctionMerge final : public IAggregateFunction
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{
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private:
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AggregateFunctionPtr nested_func_owner;
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IAggregateFunction * nested_func;
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public:
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AggregateFunctionMerge(AggregateFunctionPtr nested_) : nested_func_owner(nested_), nested_func(nested_func_owner.get()) {}
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String getName() const
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{
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return nested_func->getName() + "Merge";
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}
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DataTypePtr getReturnType() const
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{
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return nested_func->getReturnType();
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}
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void setArguments(const DataTypes & arguments)
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{
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if (arguments.size() != 1)
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throw Exception("Passed " + toString(arguments.size()) + " arguments to unary aggregate function " + this->getName(),
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ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
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const DataTypeAggregateFunction * data_type = dynamic_cast<const DataTypeAggregateFunction *>(&*arguments[0]);
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if (!data_type || data_type->getFunctionName() != nested_func->getName())
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throw Exception("Illegal type " + arguments[0]->getName() + " of argument for aggregate function " + getName(),
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ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
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nested_func->setArguments(data_type->getArgumentsDataTypes());
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}
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void setParameters(const Array & params)
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{
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nested_func->setParameters(params);
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}
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void create(AggregateDataPtr place) const
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{
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nested_func->create(place);
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}
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void destroy(AggregateDataPtr place) const noexcept
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{
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nested_func->destroy(place);
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}
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bool hasTrivialDestructor() const
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{
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return nested_func->hasTrivialDestructor();
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}
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size_t sizeOfData() const
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{
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return nested_func->sizeOfData();
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}
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size_t alignOfData() const
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{
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return nested_func->alignOfData();
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}
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void add(AggregateDataPtr place, const IColumn ** columns, size_t row_num) const
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{
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nested_func->merge(place, static_cast<const ColumnAggregateFunction &>(*columns[0]).getData()[row_num]);
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}
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void merge(AggregateDataPtr place, ConstAggregateDataPtr rhs) const
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{
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nested_func->merge(place, rhs);
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}
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void serialize(ConstAggregateDataPtr place, WriteBuffer & buf) const
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{
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nested_func->serialize(place, buf);
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}
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void deserializeMerge(AggregateDataPtr place, ReadBuffer & buf) const
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{
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nested_func->deserializeMerge(place, buf);
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}
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void insertResultInto(ConstAggregateDataPtr place, IColumn & to) const
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{
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nested_func->insertResultInto(place, to);
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}
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};
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}
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