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comparison: media/omx-plugin/include/ics/utils/SharedBuffer.h
media/omx-plugin/include/ics/utils/SharedBuffer.h
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- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:8f817da85080 |
|---|---|
| 1 /* | |
| 2 * Copyright (C) 2005 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_SHARED_BUFFER_H | |
| 18 #define ANDROID_SHARED_BUFFER_H | |
| 19 | |
| 20 #include <stdint.h> | |
| 21 #include <sys/types.h> | |
| 22 | |
| 23 // --------------------------------------------------------------------------- | |
| 24 | |
| 25 namespace android { | |
| 26 | |
| 27 class SharedBuffer | |
| 28 { | |
| 29 public: | |
| 30 | |
| 31 /* flags to use with release() */ | |
| 32 enum { | |
| 33 eKeepStorage = 0x00000001 | |
| 34 }; | |
| 35 | |
| 36 /*! allocate a buffer of size 'size' and acquire() it. | |
| 37 * call release() to free it. | |
| 38 */ | |
| 39 static SharedBuffer* alloc(size_t size); | |
| 40 | |
| 41 /*! free the memory associated with the SharedBuffer. | |
| 42 * Fails if there are any users associated with this SharedBuffer. | |
| 43 * In other words, the buffer must have been release by all its | |
| 44 * users. | |
| 45 */ | |
| 46 static ssize_t dealloc(const SharedBuffer* released); | |
| 47 | |
| 48 //! get the SharedBuffer from the data pointer | |
| 49 static inline const SharedBuffer* sharedBuffer(const void* data); | |
| 50 | |
| 51 //! access the data for read | |
| 52 inline const void* data() const; | |
| 53 | |
| 54 //! access the data for read/write | |
| 55 inline void* data(); | |
| 56 | |
| 57 //! get size of the buffer | |
| 58 inline size_t size() const; | |
| 59 | |
| 60 //! get back a SharedBuffer object from its data | |
| 61 static inline SharedBuffer* bufferFromData(void* data); | |
| 62 | |
| 63 //! get back a SharedBuffer object from its data | |
| 64 static inline const SharedBuffer* bufferFromData(const void* data); | |
| 65 | |
| 66 //! get the size of a SharedBuffer object from its data | |
| 67 static inline size_t sizeFromData(const void* data); | |
| 68 | |
| 69 //! edit the buffer (get a writtable, or non-const, version of it) | |
| 70 SharedBuffer* edit() const; | |
| 71 | |
| 72 //! edit the buffer, resizing if needed | |
| 73 SharedBuffer* editResize(size_t size) const; | |
| 74 | |
| 75 //! like edit() but fails if a copy is required | |
| 76 SharedBuffer* attemptEdit() const; | |
| 77 | |
| 78 //! resize and edit the buffer, loose it's content. | |
| 79 SharedBuffer* reset(size_t size) const; | |
| 80 | |
| 81 //! acquire/release a reference on this buffer | |
| 82 void acquire() const; | |
| 83 | |
| 84 /*! release a reference on this buffer, with the option of not | |
| 85 * freeing the memory associated with it if it was the last reference | |
| 86 * returns the previous reference count | |
| 87 */ | |
| 88 int32_t release(uint32_t flags = 0) const; | |
| 89 | |
| 90 //! returns wether or not we're the only owner | |
| 91 inline bool onlyOwner() const; | |
| 92 | |
| 93 | |
| 94 private: | |
| 95 inline SharedBuffer() { } | |
| 96 inline ~SharedBuffer() { } | |
| 97 inline SharedBuffer(const SharedBuffer&); | |
| 98 | |
| 99 // 16 bytes. must be sized to preserve correct alingment. | |
| 100 mutable int32_t mRefs; | |
| 101 size_t mSize; | |
| 102 uint32_t mReserved[2]; | |
| 103 }; | |
| 104 | |
| 105 // --------------------------------------------------------------------------- | |
| 106 | |
| 107 const SharedBuffer* SharedBuffer::sharedBuffer(const void* data) { | |
| 108 return data ? reinterpret_cast<const SharedBuffer *>(data)-1 : 0; | |
| 109 } | |
| 110 | |
| 111 const void* SharedBuffer::data() const { | |
| 112 return this + 1; | |
| 113 } | |
| 114 | |
| 115 void* SharedBuffer::data() { | |
| 116 return this + 1; | |
| 117 } | |
| 118 | |
| 119 size_t SharedBuffer::size() const { | |
| 120 return mSize; | |
| 121 } | |
| 122 | |
| 123 SharedBuffer* SharedBuffer::bufferFromData(void* data) | |
| 124 { | |
| 125 return ((SharedBuffer*)data)-1; | |
| 126 } | |
| 127 | |
| 128 const SharedBuffer* SharedBuffer::bufferFromData(const void* data) | |
| 129 { | |
| 130 return ((const SharedBuffer*)data)-1; | |
| 131 } | |
| 132 | |
| 133 size_t SharedBuffer::sizeFromData(const void* data) | |
| 134 { | |
| 135 return (((const SharedBuffer*)data)-1)->mSize; | |
| 136 } | |
| 137 | |
| 138 bool SharedBuffer::onlyOwner() const { | |
| 139 return (mRefs == 1); | |
| 140 } | |
| 141 | |
| 142 }; // namespace android | |
| 143 | |
| 144 // --------------------------------------------------------------------------- | |
| 145 | |
| 146 #endif // ANDROID_VECTOR_H |
