1 /*
2  * Copyright 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 #pragma once
18 
19 #include <android-base/thread_annotations.h>
20 #include <binder/IBinder.h>
21 #include <gui/LayerState.h>
22 #include <ui/GraphicBuffer.h>
23 #include <utils/RefBase.h>
24 #include <utils/Singleton.h>
25 
26 #include <map>
27 #include <mutex>
28 #include <set>
29 #include <unordered_map>
30 
31 #define BUFFER_CACHE_MAX_SIZE 64
32 
33 namespace android {
34 
35 class ClientCache : public Singleton<ClientCache> {
36 public:
37     ClientCache();
38 
39     bool add(const client_cache_t& cacheId, const sp<GraphicBuffer>& buffer);
40     void erase(const client_cache_t& cacheId);
41 
42     sp<GraphicBuffer> get(const client_cache_t& cacheId);
43 
44     void removeProcess(const wp<IBinder>& processToken);
45 
46     class ErasedRecipient : public virtual RefBase {
47     public:
48         virtual void bufferErased(const client_cache_t& clientCacheId) = 0;
49     };
50 
51     bool registerErasedRecipient(const client_cache_t& cacheId,
52                                  const wp<ErasedRecipient>& recipient);
53     void unregisterErasedRecipient(const client_cache_t& cacheId,
54                                    const wp<ErasedRecipient>& recipient);
55 
56 private:
57     std::mutex mMutex;
58 
59     struct ClientCacheBuffer {
60         sp<GraphicBuffer> buffer;
61         std::set<wp<ErasedRecipient>> recipients;
62     };
63     std::map<wp<IBinder> /*caching process*/,
64              std::pair<sp<IBinder> /*strong ref to caching process*/,
65                        std::unordered_map<uint64_t /*cache id*/, ClientCacheBuffer>>>
66             mBuffers GUARDED_BY(mMutex);
67 
68     class CacheDeathRecipient : public IBinder::DeathRecipient {
69     public:
70         void binderDied(const wp<IBinder>& who) override;
71     };
72 
73     sp<CacheDeathRecipient> mDeathRecipient;
74 
75     bool getBuffer(const client_cache_t& cacheId, ClientCacheBuffer** outClientCacheBuffer)
76             REQUIRES(mMutex);
77 };
78 
79 }; // namespace android
80