| /** |
| * 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_QUERY_OPTIMIZER_EXPRESSIONS_COMMON_SUBEXPRESSION_HPP_ |
| #define QUICKSTEP_QUERY_OPTIMIZER_EXPRESSIONS_COMMON_SUBEXPRESSION_HPP_ |
| |
| #include <memory> |
| #include <string> |
| #include <unordered_map> |
| #include <vector> |
| |
| #include "query_optimizer/expressions/AttributeReference.hpp" |
| #include "query_optimizer/expressions/ExprId.hpp" |
| #include "query_optimizer/expressions/Expression.hpp" |
| #include "query_optimizer/expressions/ExpressionType.hpp" |
| #include "query_optimizer/expressions/Scalar.hpp" |
| #include "utility/Macros.hpp" |
| |
| #include "glog/logging.h" |
| |
| namespace quickstep { |
| |
| class Scalar; |
| class Type; |
| |
| namespace optimizer { |
| namespace expressions { |
| |
| /** \addtogroup OptimizerExpressions |
| * @{ |
| */ |
| |
| class CommonSubexpression; |
| typedef std::shared_ptr<const CommonSubexpression> CommonSubexpressionPtr; |
| |
| /** |
| * @brief A wrapper expression that represents a common subexpression. |
| */ |
| class CommonSubexpression : public Scalar { |
| public: |
| ExpressionType getExpressionType() const override { |
| return ExpressionType::kCommonSubexpression; |
| } |
| |
| std::string getName() const override { |
| return "CommonSubexpression"; |
| } |
| |
| bool isConstant() const override { |
| return operand_->isConstant(); |
| } |
| |
| /** |
| * @return The unique ID for the equivalence class that this common subexpression |
| * belongs to. |
| */ |
| inline ExprId common_subexpression_id() const { |
| return common_subexpression_id_; |
| } |
| |
| /** |
| * @return The operand that represents the underlying subexpression. |
| */ |
| const ScalarPtr& operand() const { |
| return operand_; |
| } |
| |
| const Type& getValueType() const override { |
| return operand_->getValueType(); |
| } |
| |
| ExpressionPtr copyWithNewChildren( |
| const std::vector<ExpressionPtr> &new_children) const override; |
| |
| std::vector<AttributeReferencePtr> getReferencedAttributes() const override { |
| return operand_->getReferencedAttributes(); |
| } |
| |
| ::quickstep::Scalar* concretize( |
| const std::unordered_map<ExprId, const CatalogAttribute*> &substitution_map) const override; |
| |
| /** |
| * @brief Creates an immutable CommonSubexpression. |
| * |
| * @param common_subexpression_id A unique ID for the equivalence class that |
| * this common subexpressions belongs to. |
| * @param operand The operand that represents the underlying subexpression. |
| * @return An immutable CommonSubexpression. |
| */ |
| static CommonSubexpressionPtr Create(const ExprId common_subexpression_id, |
| const ScalarPtr &operand) { |
| return CommonSubexpressionPtr( |
| new CommonSubexpression(common_subexpression_id, operand)); |
| } |
| |
| protected: |
| void getFieldStringItems( |
| std::vector<std::string> *inline_field_names, |
| std::vector<std::string> *inline_field_values, |
| std::vector<std::string> *non_container_child_field_names, |
| std::vector<OptimizerTreeBaseNodePtr> *non_container_child_fields, |
| std::vector<std::string> *container_child_field_names, |
| std::vector<std::vector<OptimizerTreeBaseNodePtr>> *container_child_fields) const override; |
| |
| private: |
| CommonSubexpression(const ExprId common_subexpression_id, |
| const ScalarPtr &operand) |
| : common_subexpression_id_(common_subexpression_id), |
| operand_(operand) { |
| addChild(operand); |
| } |
| |
| const ExprId common_subexpression_id_; |
| const ScalarPtr operand_; |
| |
| DISALLOW_COPY_AND_ASSIGN(CommonSubexpression); |
| }; |
| |
| /** @} */ |
| |
| } // namespace expressions |
| } // namespace optimizer |
| } // namespace quickstep |
| |
| #endif // QUICKSTEP_QUERY_OPTIMIZER_EXPRESSIONS_COMMON_SUBEXPRESSION_HPP_ |