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

84 lines
1.5 KiB
C++

#pragma once
#include <DB/IO/WriteHelpers.h>
#include <DB/IO/ReadHelpers.h>
#include <DB/AggregateFunctions/IUnaryAggregateFunction.h>
namespace DB
{
struct AggregateFunctionAnyLastData
{
Field value;
};
/// Берёт последнее попавшееся значение
class AggregateFunctionAnyLast : public IUnaryAggregateFunction<AggregateFunctionAnyLastData, AggregateFunctionAnyLast>
{
private:
DataTypePtr type;
public:
String getName() const { return "anyLast"; }
DataTypePtr getReturnType() const
{
return type;
}
void setArgument(const DataTypePtr & argument)
{
type = argument;
}
void addOne(AggregateDataPtr place, const IColumn & column, size_t row_num) const
{
column.get(row_num, data(place).value);
}
void merge(AggregateDataPtr place, ConstAggregateDataPtr rhs) const
{
if (!data(rhs).value.isNull())
data(place).value = data(rhs).value;
}
void serialize(ConstAggregateDataPtr place, WriteBuffer & buf) const
{
const Data & d = data(place);
if (unlikely(d.value.isNull()))
{
writeBinary(false, buf);
}
else
{
writeBinary(true, buf);
type->serializeBinary(data(place).value, buf);
}
}
void deserializeMerge(AggregateDataPtr place, ReadBuffer & buf) const
{
bool is_not_null = false;
readBinary(is_not_null, buf);
if (is_not_null)
type->deserializeBinary(data(place).value, buf);
}
void insertResultInto(ConstAggregateDataPtr place, IColumn & to) const
{
if (unlikely(data(place).value.isNull()))
to.insertDefault();
else
to.insert(data(place).value);
}
};
}