| /** |
| * Copyright 2015 Pivotal Software, Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| **/ |
| |
| #include "expressions/aggregation/AggregateFunctionMax.hpp" |
| |
| #include <vector> |
| |
| #include "expressions/aggregation/AggregationHandleMax.hpp" |
| #include "types/Type.hpp" |
| #include "types/operations/comparisons/Comparison.hpp" |
| #include "types/operations/comparisons/ComparisonFactory.hpp" |
| #include "types/operations/comparisons/ComparisonID.hpp" |
| |
| #include "glog/logging.h" |
| |
| namespace quickstep { |
| |
| bool AggregateFunctionMax::canApplyToTypes( |
| const std::vector<const Type*> &argument_types) const { |
| // MAX is unary. |
| if (argument_types.size() != 1) { |
| return false; |
| } |
| |
| // Argument must be comparable by '>'. |
| return ComparisonFactory::GetComparison(ComparisonID::kGreater).canCompareTypes( |
| *argument_types.front(), |
| *argument_types.front()); |
| } |
| |
| const Type* AggregateFunctionMax::resultTypeForArgumentTypes( |
| const std::vector<const Type*> &argument_types) const { |
| if (!canApplyToTypes(argument_types)) { |
| return nullptr; |
| } |
| |
| return &(argument_types.front()->getNullableVersion()); |
| } |
| |
| AggregationHandle* AggregateFunctionMax::createHandle( |
| const std::vector<const Type*> &argument_types) const { |
| DCHECK(canApplyToTypes(argument_types)) |
| << "Attempted to create an AggregationHandleMax for argument Type(s) " |
| << "that MAX can not be applied to."; |
| |
| return new AggregationHandleMax(*argument_types.front()); |
| } |
| |
| } // namespace quickstep |