| // Copyright 2020 The Dawn Authors |
| // |
| // 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. |
| |
| #ifndef SRC_DAWN_NATIVE_OBJECTCONTENTHASHER_H_ |
| #define SRC_DAWN_NATIVE_OBJECTCONTENTHASHER_H_ |
| |
| #include <map> |
| #include <string> |
| #include <utility> |
| #include <vector> |
| |
| #include "dawn/common/HashUtils.h" |
| |
| namespace dawn::native { |
| |
| // ObjectContentHasher records a hash that can be used as a key to lookup a cached object in a |
| // cache. |
| class ObjectContentHasher { |
| public: |
| // Record calls the appropriate record function based on the type. |
| template <typename T, typename... Args> |
| void Record(const T& value, const Args&... args) { |
| RecordImpl<T, Args...>::Call(this, value, args...); |
| } |
| |
| size_t GetContentHash() const; |
| |
| private: |
| template <typename T, typename... Args> |
| struct RecordImpl { |
| static constexpr void Call(ObjectContentHasher* recorder, |
| const T& value, |
| const Args&... args) { |
| HashCombine(&recorder->mContentHash, value, args...); |
| } |
| }; |
| |
| template <typename T> |
| struct RecordImpl<T*> { |
| static constexpr void Call(ObjectContentHasher* recorder, T* obj) { |
| // Calling Record(objPtr) is not allowed. This check exists to only prevent such |
| // mistakes. |
| static_assert(obj == nullptr); |
| } |
| }; |
| |
| template <typename T> |
| struct RecordImpl<std::vector<T>> { |
| static constexpr void Call(ObjectContentHasher* recorder, const std::vector<T>& vec) { |
| recorder->RecordIterable<std::vector<T>>(vec); |
| } |
| }; |
| |
| template <typename T, typename E> |
| struct RecordImpl<std::map<T, E>> { |
| static constexpr void Call(ObjectContentHasher* recorder, const std::map<T, E>& map) { |
| recorder->RecordIterable<std::map<T, E>>(map); |
| } |
| }; |
| |
| template <typename IteratorT> |
| constexpr void RecordIterable(const IteratorT& iterable) { |
| for (auto it = iterable.begin(); it != iterable.end(); ++it) { |
| Record(*it); |
| } |
| } |
| |
| template <typename T, typename E> |
| struct RecordImpl<std::pair<T, E>> { |
| static constexpr void Call(ObjectContentHasher* recorder, const std::pair<T, E>& pair) { |
| recorder->Record(pair.first); |
| recorder->Record(pair.second); |
| } |
| }; |
| |
| size_t mContentHash = 0; |
| }; |
| |
| template <> |
| struct ObjectContentHasher::RecordImpl<std::string> { |
| static constexpr void Call(ObjectContentHasher* recorder, const std::string& str) { |
| recorder->RecordIterable<std::string>(str); |
| } |
| }; |
| |
| } // namespace dawn::native |
| |
| #endif // SRC_DAWN_NATIVE_OBJECTCONTENTHASHER_H_ |