| /** |
| * 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. |
| **/ |
| |
| #ifndef QUICKSTEP_EXPRESSIONS_TABLE_GENERATOR_GENERATOR_FUNCTION_FACTORY_HPP_ |
| #define QUICKSTEP_EXPRESSIONS_TABLE_GENERATOR_GENERATOR_FUNCTION_FACTORY_HPP_ |
| |
| #include <map> |
| #include <string> |
| |
| #include "utility/Macros.hpp" |
| |
| namespace quickstep { |
| |
| class GeneratorFunction; |
| class GeneratorFunctionHandle; |
| |
| namespace serialization { class GeneratorFunctionHandle; } |
| |
| /** \addtogroup Expressions |
| * @{ |
| */ |
| |
| /** |
| * @brief Singleton factory class that provides access to the various concrete |
| * implementations of GeneratorFunction. |
| * |
| * @note Generator functions are used for generating tables. A generator |
| * function takes a list of constant arguments at query compile time, |
| * and populates a table at query run time. See the documentation in |
| * GeneratorFunction.hpp for a detailed description and for how to |
| * implement a new generator function. |
| **/ |
| class GeneratorFunctionFactory { |
| public: |
| /** |
| * @brief Singleton instance of the GeneratorFunctionFactory class. |
| * @return A const reference to the singleton instance of the |
| * GeneratorFunctionFactory class. |
| */ |
| static const GeneratorFunctionFactory& Instance(); |
| |
| /** |
| * @brief Get a particular GeneratorFunction by its name. |
| * |
| * @param name The name of the desired GeneratorFunction. |
| * @return A pointer to the GeneratorFunction specified by name, or NULL if |
| * name does not match any known GeneratorFunction. |
| **/ |
| const GeneratorFunction* getByName(const std::string &name) const; |
| |
| /** |
| * @brief Reconstruct a particular GeneratorFunctionHandle by its protobuf |
| * message. |
| * |
| * @param proto A serialized protocol buffer representation of the |
| * GeneratorFunctionHandle. |
| * @return A new GeneratorFunctionHandle object constructed from the protobuf |
| * message. Caller is responsible for deleting the returned object. |
| */ |
| GeneratorFunctionHandle* reconstructFromProto( |
| const serialization::GeneratorFunctionHandle &proto) const; |
| |
| private: |
| /** |
| * @brief Constructor. All the implemented generator functions should be |
| * registered into GeneratorFunctionFactory inside the constructor. |
| */ |
| GeneratorFunctionFactory(); |
| |
| std::map<std::string, const GeneratorFunction *> func_map_; |
| |
| DISALLOW_COPY_AND_ASSIGN(GeneratorFunctionFactory); |
| }; |
| |
| /** @} */ |
| |
| } // namespace quickstep |
| |
| #endif // QUICKSTEP_EXPRESSIONS_TABLE_GENERATOR_GENERATOR_FUNCTION_FACTORY_HPP_ |