| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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/AggregateFunctionCount.hpp" |
| |
| #include <vector> |
| |
| #include "expressions/aggregation/AggregationHandleCount.hpp" |
| #include "types/Type.hpp" |
| #include "types/TypeFactory.hpp" |
| #include "types/TypeID.hpp" |
| |
| #include "glog/logging.h" |
| |
| namespace quickstep { |
| |
| bool AggregateFunctionCount::canApplyToTypes( |
| const std::vector<const Type*> &argument_types) const { |
| // COUNT may be nullary (i.e. COUNT(*)) or unary. |
| return argument_types.size() <= 1; |
| } |
| |
| const Type* AggregateFunctionCount::resultTypeForArgumentTypes( |
| const std::vector<const Type*> &argument_types) const { |
| if (!canApplyToTypes(argument_types)) { |
| return nullptr; |
| } |
| |
| return &TypeFactory::GetType(kLong); |
| } |
| |
| AggregationHandle* AggregateFunctionCount::createHandle( |
| const std::vector<const Type*> &argument_types) const { |
| DCHECK(canApplyToTypes(argument_types)) |
| << "Attempted to create an AggregationHandleCount for argument Types " |
| << "that COUNT can not be applied to (> 1 argument)."; |
| |
| if (argument_types.empty()) { |
| // COUNT(*) |
| return new AggregationHandleCount<true, false>(); |
| } else if (argument_types.front()->isNullable()) { |
| // COUNT(some_nullable_argument) |
| return new AggregationHandleCount<false, true>(); |
| } else { |
| // COUNT(non_nullable_argument) |
| // |
| // TODO(chasseur): Modify query optimizer to optimize-away COUNT with a |
| // non-nullable argument and convert it to COUNT(*). |
| return new AggregationHandleCount<false, false>(); |
| } |
| } |
| |
| } // namespace quickstep |