1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef _LIBUNWINDSTACK_MEMORY_CACHE_H
18 #define _LIBUNWINDSTACK_MEMORY_CACHE_H
19 
20 #include <stdint.h>
21 
22 #include <memory>
23 #include <string>
24 #include <unordered_map>
25 
26 #include <unwindstack/Memory.h>
27 
28 namespace unwindstack {
29 
30 class MemoryCache : public Memory {
31  public:
MemoryCache(Memory * memory)32   MemoryCache(Memory* memory) : impl_(memory) {}
33   virtual ~MemoryCache() = default;
34 
35   size_t Read(uint64_t addr, void* dst, size_t size) override;
ReadTag(uint64_t addr)36   long ReadTag(uint64_t addr) override { return impl_->ReadTag(addr); }
37 
Clear()38   void Clear() override { cache_.clear(); }
39 
40  private:
41   constexpr static size_t kCacheBits = 12;
42   constexpr static size_t kCacheMask = (1 << kCacheBits) - 1;
43   constexpr static size_t kCacheSize = 1 << kCacheBits;
44   std::unordered_map<uint64_t, uint8_t[kCacheSize]> cache_;
45 
46   std::unique_ptr<Memory> impl_;
47 };
48 
49 }  // namespace unwindstack
50 
51 #endif  // _LIBUNWINDSTACK_MEMORY_CACHE_H
52