1 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 2 // -*- mode: C++ -*- 3 // 4 // Copyright 2022-2024 Google LLC 5 // 6 // Licensed under the Apache License v2.0 with LLVM Exceptions (the 7 // "License"); you may not use this file except in compliance with the 8 // License. You may obtain a copy of the License at 9 // 10 // https://llvm.org/LICENSE.txt 11 // 12 // Unless required by applicable law or agreed to in writing, software 13 // distributed under the License is distributed on an "AS IS" BASIS, 14 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 // See the License for the specific language governing permissions and 16 // limitations under the License. 17 // 18 // Author: Siddharth Nayyar 19 20 #ifndef STG_STABLE_HASH_H_ 21 #define STG_STABLE_HASH_H_ 22 23 #include <unordered_map> 24 25 #include "graph.h" 26 #include "hashing.h" 27 28 namespace stg { 29 30 class StableHash { 31 public: StableHash(const Graph & graph)32 explicit StableHash(const Graph& graph) : graph_(graph) {} 33 HashValue operator()(Id); 34 35 private: 36 const Graph& graph_; 37 std::unordered_map<Id, HashValue> cache_; 38 }; 39 40 } // namespace stg 41 42 #endif // STG_STABLE_HASH_H_ 43