1 /* 2 ** Copyright 2011, 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 ANDROID_EGL_CACHE_H 18 #define ANDROID_EGL_CACHE_H 19 20 #include <EGL/egl.h> 21 #include <EGL/eglext.h> 22 23 #include <memory> 24 #include <mutex> 25 #include <string> 26 27 #include "FileBlobCache.h" 28 29 namespace android { 30 31 class egl_display_t; 32 33 class EGLAPI egl_cache_t { 34 public: 35 // get returns a pointer to the singleton egl_cache_t object. This 36 // singleton object will never be destroyed. 37 static egl_cache_t* get(); 38 39 // initialize puts the egl_cache_t into an initialized state, such that it 40 // is able to insert and retrieve entries from the cache. This should be 41 // called when EGL is initialized. When not in the initialized state the 42 // getBlob and setBlob methods will return without performing any cache 43 // operations. 44 void initialize(egl_display_t* display); 45 46 // terminate puts the egl_cache_t back into the uninitialized state. When 47 // in this state the getBlob and setBlob methods will return without 48 // performing any cache operations. 49 void terminate(); 50 51 // setBlob attempts to insert a new key/value blob pair into the cache. 52 // This will be called by the hardware vendor's EGL implementation via the 53 // EGL_ANDROID_blob_cache extension. 54 void setBlob(const void* key, EGLsizeiANDROID keySize, const void* value, 55 EGLsizeiANDROID valueSize); 56 57 // getBlob attempts to retrieve the value blob associated with a given key 58 // blob from cache. This will be called by the hardware vendor's EGL 59 // implementation via the EGL_ANDROID_blob_cache extension. 60 EGLsizeiANDROID getBlob(const void* key, EGLsizeiANDROID keySize, 61 void* value, EGLsizeiANDROID valueSize); 62 63 // setCacheFilename sets the name of the file that should be used to store 64 // cache contents from one program invocation to another. 65 void setCacheFilename(const char* filename); 66 67 private: 68 // Creation and (the lack of) destruction is handled internally. 69 egl_cache_t(); 70 ~egl_cache_t(); 71 72 // Copying is disallowed. 73 egl_cache_t(const egl_cache_t&); // not implemented 74 void operator=(const egl_cache_t&); // not implemented 75 76 // getBlobCacheLocked returns the BlobCache object being used to store the 77 // key/value blob pairs. If the BlobCache object has not yet been created, 78 // this will do so, loading the serialized cache contents from disk if 79 // possible. 80 BlobCache* getBlobCacheLocked(); 81 82 // mInitialized indicates whether the egl_cache_t is in the initialized 83 // state. It is initialized to false at construction time, and gets set to 84 // true when initialize is called. It is set back to false when terminate 85 // is called. When in this state, the cache behaves as normal. When not, 86 // the getBlob and setBlob methods will return without performing any cache 87 // operations. 88 bool mInitialized; 89 90 // mBlobCache is the cache in which the key/value blob pairs are stored. It 91 // is initially NULL, and will be initialized by getBlobCacheLocked the 92 // first time it's needed. 93 std::unique_ptr<FileBlobCache> mBlobCache; 94 95 // mFilename is the name of the file for storing cache contents in between 96 // program invocations. It is initialized to an empty string at 97 // construction time, and can be set with the setCacheFilename method. An 98 // empty string indicates that the cache should not be saved to or restored 99 // from disk. 100 std::string mFilename; 101 102 // mSavePending indicates whether or not a deferred save operation is 103 // pending. Each time a key/value pair is inserted into the cache via 104 // setBlob, a deferred save is initiated if one is not already pending. 105 // This will wait some amount of time and then trigger a save of the cache 106 // contents to disk. 107 bool mSavePending; 108 109 // mMutex is the mutex used to prevent concurrent access to the member 110 // variables. It must be locked whenever the member variables are accessed. 111 mutable std::mutex mMutex; 112 113 // sCache is the singleton egl_cache_t object. 114 static egl_cache_t sCache; 115 }; 116 117 }; // namespace android 118 119 #endif // ANDROID_EGL_CACHE_H 120