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

121 lines
3.2 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#pragma once
#include <DB/Columns/ColumnArray.h>
#include <DB/DataTypes/DataTypeArray.h>
#include <DB/DataTypes/DataTypesNumberFixed.h>
#include <DB/AggregateFunctions/IAggregateFunction.h>
namespace DB
{
/** Не агрегатная функция, а адаптер агрегатных функций,
* который любую агрегатную функцию agg(x) делает агрегатной функцией вида aggArray(x).
* Адаптированная агрегатная функция вычисляет вложенную агрегатную функцию для каждого элемента массива.
*/
class AggregateFunctionArray final : public IAggregateFunction
{
private:
AggregateFunctionPtr nested_func_owner;
IAggregateFunction * nested_func;
int num_agruments;
public:
AggregateFunctionArray(AggregateFunctionPtr nested_) : nested_func_owner(nested_), nested_func(nested_func_owner.get()) {}
String getName() const
{
return nested_func->getName() + "Array";
}
DataTypePtr getReturnType() const
{
return nested_func->getReturnType();
}
void setArguments(const DataTypes & arguments)
{
num_agruments = arguments.size();
DataTypes nested_arguments;
for (int i = 0; i < num_agruments; ++i)
{
if (const DataTypeArray * array = typeid_cast<const DataTypeArray *>(&*arguments[i]))
nested_arguments.push_back(array->getNestedType());
else
throw Exception("Illegal type " + arguments[i]->getName() + " of argument #" + toString(i + 1) + " for aggregate function " + getName() + ". Must be array.", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
}
nested_func->setArguments(nested_arguments);
}
void setParameters(const Array & params)
{
nested_func->setParameters(params);
}
void create(AggregateDataPtr place) const
{
nested_func->create(place);
}
void destroy(AggregateDataPtr place) const noexcept
{
nested_func->destroy(place);
}
bool hasTrivialDestructor() const
{
return nested_func->hasTrivialDestructor();
}
size_t sizeOfData() const
{
return nested_func->sizeOfData();
}
size_t alignOfData() const
{
return nested_func->alignOfData();
}
void add(AggregateDataPtr place, const IColumn ** columns, size_t row_num) const
{
const IColumn * nested[num_agruments];
for (int i = 0; i < num_agruments; ++i)
nested[i] = &static_cast<const ColumnArray &>(*columns[i]).getData();
const ColumnArray & first_array_column = static_cast<const ColumnArray &>(*columns[0]);
const IColumn::Offsets_t & offsets = first_array_column.getOffsets();
size_t begin = row_num == 0 ? 0 : offsets[row_num - 1];
size_t end = offsets[row_num];
for (size_t i = begin; i < end; ++i)
nested_func->add(place, nested, i);
}
void merge(AggregateDataPtr place, ConstAggregateDataPtr rhs) const
{
nested_func->merge(place, rhs);
}
void serialize(ConstAggregateDataPtr place, WriteBuffer & buf) const
{
nested_func->serialize(place, buf);
}
void deserializeMerge(AggregateDataPtr place, ReadBuffer & buf) const
{
nested_func->deserializeMerge(place, buf);
}
void insertResultInto(ConstAggregateDataPtr place, IColumn & to) const
{
nested_func->insertResultInto(place, to);
}
};
}