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 "BlobCache.h" 24 25 #include <memory> 26 #include <mutex> 27 #include <string> 28 29 // ---------------------------------------------------------------------------- 30 namespace android { 31 // ---------------------------------------------------------------------------- 32 33 class egl_display_t; 34 35 class EGLAPI egl_cache_t { 36 public: 37 38 // get returns a pointer to the singleton egl_cache_t object. This 39 // singleton object will never be destroyed. 40 static egl_cache_t* get(); 41 42 // initialize puts the egl_cache_t into an initialized state, such that it 43 // is able to insert and retrieve entries from the cache. This should be 44 // called when EGL is initialized. When not in the initialized state the 45 // getBlob and setBlob methods will return without performing any cache 46 // operations. 47 void initialize(egl_display_t* display); 48 49 // terminate puts the egl_cache_t back into the uninitialized state. When 50 // in this state the getBlob and setBlob methods will return without 51 // performing any cache operations. 52 void terminate(); 53 54 // setBlob attempts to insert a new key/value blob pair into the cache. 55 // This will be called by the hardware vendor's EGL implementation via the 56 // EGL_ANDROID_blob_cache extension. 57 void setBlob(const void* key, EGLsizeiANDROID keySize, const void* value, 58 EGLsizeiANDROID valueSize); 59 60 // getBlob attempts to retrieve the value blob associated with a given key 61 // blob from cache. This will be called by the hardware vendor's EGL 62 // implementation via the EGL_ANDROID_blob_cache extension. 63 EGLsizeiANDROID getBlob(const void* key, EGLsizeiANDROID keySize, 64 void* value, EGLsizeiANDROID valueSize); 65 66 // setCacheFilename sets the name of the file that should be used to store 67 // cache contents from one program invocation to another. 68 void setCacheFilename(const char* filename); 69 70 private: 71 // Creation and (the lack of) destruction is handled internally. 72 egl_cache_t(); 73 ~egl_cache_t(); 74 75 // Copying is disallowed. 76 egl_cache_t(const egl_cache_t&); // not implemented 77 void operator=(const egl_cache_t&); // not implemented 78 79 // getBlobCacheLocked returns the BlobCache object being used to store the 80 // key/value blob pairs. If the BlobCache object has not yet been created, 81 // this will do so, loading the serialized cache contents from disk if 82 // possible. 83 BlobCache* getBlobCacheLocked(); 84 85 // saveBlobCache attempts to save the current contents of mBlobCache to 86 // disk. 87 void saveBlobCacheLocked(); 88 89 // loadBlobCache attempts to load the saved cache contents from disk into 90 // mBlobCache. 91 void loadBlobCacheLocked(); 92 93 // mInitialized indicates whether the egl_cache_t is in the initialized 94 // state. It is initialized to false at construction time, and gets set to 95 // true when initialize is called. It is set back to false when terminate 96 // is called. When in this state, the cache behaves as normal. When not, 97 // the getBlob and setBlob methods will return without performing any cache 98 // operations. 99 bool mInitialized; 100 101 // mBlobCache is the cache in which the key/value blob pairs are stored. It 102 // is initially NULL, and will be initialized by getBlobCacheLocked the 103 // first time it's needed. 104 std::unique_ptr<BlobCache> mBlobCache; 105 106 // mFilename is the name of the file for storing cache contents in between 107 // program invocations. It is initialized to an empty string at 108 // construction time, and can be set with the setCacheFilename method. An 109 // empty string indicates that the cache should not be saved to or restored 110 // from disk. 111 std::string mFilename; 112 113 // mSavePending indicates whether or not a deferred save operation is 114 // pending. Each time a key/value pair is inserted into the cache via 115 // setBlob, a deferred save is initiated if one is not already pending. 116 // This will wait some amount of time and then trigger a save of the cache 117 // contents to disk. 118 bool mSavePending; 119 120 // mMutex is the mutex used to prevent concurrent access to the member 121 // variables. It must be locked whenever the member variables are accessed. 122 mutable std::mutex mMutex; 123 124 // sCache is the singleton egl_cache_t object. 125 static egl_cache_t sCache; 126 }; 127 128 // ---------------------------------------------------------------------------- 129 }; // namespace android 130 // ---------------------------------------------------------------------------- 131 132 #endif // ANDROID_EGL_CACHE_H 133