ClickHouse/src/AggregateFunctions/AggregateFunctionEntropy.cpp
Alexey Milovidov be22a4b94e Checkpoint
2020-04-22 08:39:31 +03:00

46 lines
1.3 KiB
C++

#include <AggregateFunctions/AggregateFunctionFactory.h>
#include <AggregateFunctions/AggregateFunctionEntropy.h>
#include <AggregateFunctions/FactoryHelpers.h>
#include <AggregateFunctions/Helpers.h>
#include "registerAggregateFunctions.h"
namespace DB
{
namespace ErrorCodes
{
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
}
namespace
{
AggregateFunctionPtr createAggregateFunctionEntropy(const std::string & name, const DataTypes & argument_types, const Array & parameters)
{
assertNoParameters(name, parameters);
if (argument_types.empty())
throw Exception("Incorrect number of arguments for aggregate function " + name,
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
size_t num_args = argument_types.size();
if (num_args == 1)
{
/// Specialized implementation for single argument of numeric type.
if (auto * res = createWithNumericBasedType<AggregateFunctionEntropy>(*argument_types[0], argument_types))
return AggregateFunctionPtr(res);
}
/// Generic implementation for other types or for multiple arguments.
return std::make_shared<AggregateFunctionEntropy<UInt128>>(argument_types);
}
}
void registerAggregateFunctionEntropy(AggregateFunctionFactory & factory)
{
factory.registerFunction("entropy", createAggregateFunctionEntropy);
}
}