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 <utils/BlobCache.h> 24 #include <utils/String8.h> 25 #include <utils/StrongPointer.h> 26 27 // ---------------------------------------------------------------------------- 28 namespace android { 29 // ---------------------------------------------------------------------------- 30 31 class egl_display_t; 32 33 class EGLAPI egl_cache_t { 34 public: 35 36 // get returns a pointer to the singleton egl_cache_t object. This 37 // singleton object will never be destroyed. 38 static egl_cache_t* get(); 39 40 // initialize puts the egl_cache_t into an initialized state, such that it 41 // is able to insert and retrieve entries from the cache. This should be 42 // called when EGL is initialized. When not in the initialized state the 43 // getBlob and setBlob methods will return without performing any cache 44 // operations. 45 void initialize(egl_display_t* display); 46 47 // terminate puts the egl_cache_t back into the uninitialized state. When 48 // in this state the getBlob and setBlob methods will return without 49 // performing any cache operations. 50 void terminate(); 51 52 // setBlob attempts to insert a new key/value blob pair into the cache. 53 // This will be called by the hardware vendor's EGL implementation via the 54 // EGL_ANDROID_blob_cache extension. 55 void setBlob(const void* key, EGLsizeiANDROID keySize, const void* value, 56 EGLsizeiANDROID valueSize); 57 58 // getBlob attempts to retrieve the value blob associated with a given key 59 // blob from cache. This will be called by the hardware vendor's EGL 60 // implementation via the EGL_ANDROID_blob_cache extension. 61 EGLsizeiANDROID getBlob(const void* key, EGLsizeiANDROID keySize, 62 void* value, EGLsizeiANDROID valueSize); 63 64 // setCacheFilename sets the name of the file that should be used to store 65 // cache contents from one program invocation to another. 66 void setCacheFilename(const char* filename); 67 68 private: 69 // Creation and (the lack of) destruction is handled internally. 70 egl_cache_t(); 71 ~egl_cache_t(); 72 73 // Copying is disallowed. 74 egl_cache_t(const egl_cache_t&); // not implemented 75 void operator=(const egl_cache_t&); // not implemented 76 77 // getBlobCacheLocked returns the BlobCache object being used to store the 78 // key/value blob pairs. If the BlobCache object has not yet been created, 79 // this will do so, loading the serialized cache contents from disk if 80 // possible. 81 sp<BlobCache> getBlobCacheLocked(); 82 83 // saveBlobCache attempts to save the current contents of mBlobCache to 84 // disk. 85 void saveBlobCacheLocked(); 86 87 // loadBlobCache attempts to load the saved cache contents from disk into 88 // mBlobCache. 89 void loadBlobCacheLocked(); 90 91 // mInitialized indicates whether the egl_cache_t is in the initialized 92 // state. It is initialized to false at construction time, and gets set to 93 // true when initialize is called. It is set back to false when terminate 94 // is called. When in this state, the cache behaves as normal. When not, 95 // the getBlob and setBlob methods will return without performing any cache 96 // operations. 97 bool mInitialized; 98 99 // mBlobCache is the cache in which the key/value blob pairs are stored. It 100 // is initially NULL, and will be initialized by getBlobCacheLocked the 101 // first time it's needed. 102 sp<BlobCache> mBlobCache; 103 104 // mFilename is the name of the file for storing cache contents in between 105 // program invocations. It is initialized to an empty string at 106 // construction time, and can be set with the setCacheFilename method. An 107 // empty string indicates that the cache should not be saved to or restored 108 // from disk. 109 String8 mFilename; 110 111 // mSavePending indicates whether or not a deferred save operation is 112 // pending. Each time a key/value pair is inserted into the cache via 113 // setBlob, a deferred save is initiated if one is not already pending. 114 // This will wait some amount of time and then trigger a save of the cache 115 // contents to disk. 116 bool mSavePending; 117 118 // mMutex is the mutex used to prevent concurrent access to the member 119 // variables. It must be locked whenever the member variables are accessed. 120 mutable Mutex mMutex; 121 122 // sCache is the singleton egl_cache_t object. 123 static egl_cache_t sCache; 124 }; 125 126 // ---------------------------------------------------------------------------- 127 }; // namespace android 128 // ---------------------------------------------------------------------------- 129 130 #endif // ANDROID_EGL_CACHE_H 131