ClickHouse/dbms/src/AggregateFunctions/AggregateFunctionUniqUpTo.cpp
2019-02-11 22:26:32 +03:00

92 lines
3.4 KiB
C++

#include <AggregateFunctions/AggregateFunctionFactory.h>
#include <AggregateFunctions/Helpers.h>
#include <AggregateFunctions/AggregateFunctionUniqUpTo.h>
#include <DataTypes/DataTypeDate.h>
#include <DataTypes/DataTypeDateTime.h>
#include <DataTypes/DataTypeString.h>
#include <DataTypes/DataTypeFixedString.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
extern const int ARGUMENT_OUT_OF_BOUND;
}
namespace
{
static constexpr UInt8 uniq_upto_max_threshold = 100;
AggregateFunctionPtr createAggregateFunctionUniqUpTo(const std::string & name, const DataTypes & argument_types, const Array & params)
{
UInt8 threshold = 5; /// default value
if (!params.empty())
{
if (params.size() != 1)
throw Exception("Aggregate function " + name + " requires one parameter or less.", ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
UInt64 threshold_param = applyVisitor(FieldVisitorConvertToNumber<UInt64>(), params[0]);
if (threshold_param > uniq_upto_max_threshold)
throw Exception("Too large parameter for aggregate function " + name + ". Maximum: " + toString(uniq_upto_max_threshold),
ErrorCodes::ARGUMENT_OUT_OF_BOUND);
threshold = threshold_param;
}
if (argument_types.empty())
throw Exception("Incorrect number of arguments for aggregate function " + name,
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
bool use_exact_hash_function = !isAllArgumentsContiguousInMemory(argument_types);
if (argument_types.size() == 1)
{
const IDataType & argument_type = *argument_types[0];
AggregateFunctionPtr res(createWithNumericType<AggregateFunctionUniqUpTo>(*argument_types[0], threshold, argument_types, params));
WhichDataType which(argument_type);
if (res)
return res;
else if (which.isDate())
return std::make_shared<AggregateFunctionUniqUpTo<DataTypeDate::FieldType>>(threshold, argument_types, params);
else if (which.isDateTime())
return std::make_shared<AggregateFunctionUniqUpTo<DataTypeDateTime::FieldType>>(threshold, argument_types, params);
else if (which.isStringOrFixedString())
return std::make_shared<AggregateFunctionUniqUpTo<String>>(threshold, argument_types, params);
else if (which.isUUID())
return std::make_shared<AggregateFunctionUniqUpTo<DataTypeUUID::FieldType>>(threshold, argument_types, params);
else if (which.isTuple())
{
if (use_exact_hash_function)
return std::make_shared<AggregateFunctionUniqUpToVariadic<true, true>>(argument_types, params, threshold);
else
return std::make_shared<AggregateFunctionUniqUpToVariadic<false, true>>(argument_types, params, threshold);
}
}
/// "Variadic" method also works as a fallback generic case for single argument.
if (use_exact_hash_function)
return std::make_shared<AggregateFunctionUniqUpToVariadic<true, false>>(argument_types, params, threshold);
else
return std::make_shared<AggregateFunctionUniqUpToVariadic<false, false>>(argument_types, params, threshold);
}
}
void registerAggregateFunctionUniqUpTo(AggregateFunctionFactory & factory)
{
factory.registerFunction("uniqUpTo", createAggregateFunctionUniqUpTo);
}
}