1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/omx-plugin/include/froyo/utils/SharedBuffer.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,146 @@
1.4 +/*
1.5 + * Copyright (C) 2005 The Android Open Source Project
1.6 + *
1.7 + * Licensed under the Apache License, Version 2.0 (the "License");
1.8 + * you may not use this file except in compliance with the License.
1.9 + * You may obtain a copy of the License at
1.10 + *
1.11 + * http://www.apache.org/licenses/LICENSE-2.0
1.12 + *
1.13 + * Unless required by applicable law or agreed to in writing, software
1.14 + * distributed under the License is distributed on an "AS IS" BASIS,
1.15 + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
1.16 + * See the License for the specific language governing permissions and
1.17 + * limitations under the License.
1.18 + */
1.19 +
1.20 +#ifndef ANDROID_SHARED_BUFFER_H
1.21 +#define ANDROID_SHARED_BUFFER_H
1.22 +
1.23 +#include <stdint.h>
1.24 +#include <sys/types.h>
1.25 +
1.26 +// ---------------------------------------------------------------------------
1.27 +
1.28 +namespace android {
1.29 +
1.30 +class SharedBuffer
1.31 +{
1.32 +public:
1.33 +
1.34 + /* flags to use with release() */
1.35 + enum {
1.36 + eKeepStorage = 0x00000001
1.37 + };
1.38 +
1.39 + /*! allocate a buffer of size 'size' and acquire() it.
1.40 + * call release() to free it.
1.41 + */
1.42 + static SharedBuffer* alloc(size_t size);
1.43 +
1.44 + /*! free the memory associated with the SharedBuffer.
1.45 + * Fails if there are any users associated with this SharedBuffer.
1.46 + * In other words, the buffer must have been release by all its
1.47 + * users.
1.48 + */
1.49 + static ssize_t dealloc(const SharedBuffer* released);
1.50 +
1.51 + //! get the SharedBuffer from the data pointer
1.52 + static inline const SharedBuffer* sharedBuffer(const void* data);
1.53 +
1.54 + //! access the data for read
1.55 + inline const void* data() const;
1.56 +
1.57 + //! access the data for read/write
1.58 + inline void* data();
1.59 +
1.60 + //! get size of the buffer
1.61 + inline size_t size() const;
1.62 +
1.63 + //! get back a SharedBuffer object from its data
1.64 + static inline SharedBuffer* bufferFromData(void* data);
1.65 +
1.66 + //! get back a SharedBuffer object from its data
1.67 + static inline const SharedBuffer* bufferFromData(const void* data);
1.68 +
1.69 + //! get the size of a SharedBuffer object from its data
1.70 + static inline size_t sizeFromData(const void* data);
1.71 +
1.72 + //! edit the buffer (get a writtable, or non-const, version of it)
1.73 + SharedBuffer* edit() const;
1.74 +
1.75 + //! edit the buffer, resizing if needed
1.76 + SharedBuffer* editResize(size_t size) const;
1.77 +
1.78 + //! like edit() but fails if a copy is required
1.79 + SharedBuffer* attemptEdit() const;
1.80 +
1.81 + //! resize and edit the buffer, loose it's content.
1.82 + SharedBuffer* reset(size_t size) const;
1.83 +
1.84 + //! acquire/release a reference on this buffer
1.85 + void acquire() const;
1.86 +
1.87 + /*! release a reference on this buffer, with the option of not
1.88 + * freeing the memory associated with it if it was the last reference
1.89 + * returns the previous reference count
1.90 + */
1.91 + int32_t release(uint32_t flags = 0) const;
1.92 +
1.93 + //! returns wether or not we're the only owner
1.94 + inline bool onlyOwner() const;
1.95 +
1.96 +
1.97 +private:
1.98 + inline SharedBuffer() { }
1.99 + inline ~SharedBuffer() { }
1.100 + inline SharedBuffer(const SharedBuffer&);
1.101 +
1.102 + // 16 bytes. must be sized to preserve correct alingment.
1.103 + mutable int32_t mRefs;
1.104 + size_t mSize;
1.105 + uint32_t mReserved[2];
1.106 +};
1.107 +
1.108 +// ---------------------------------------------------------------------------
1.109 +
1.110 +const SharedBuffer* SharedBuffer::sharedBuffer(const void* data) {
1.111 + return data ? reinterpret_cast<const SharedBuffer *>(data)-1 : 0;
1.112 +}
1.113 +
1.114 +const void* SharedBuffer::data() const {
1.115 + return this + 1;
1.116 +}
1.117 +
1.118 +void* SharedBuffer::data() {
1.119 + return this + 1;
1.120 +}
1.121 +
1.122 +size_t SharedBuffer::size() const {
1.123 + return mSize;
1.124 +}
1.125 +
1.126 +SharedBuffer* SharedBuffer::bufferFromData(void* data)
1.127 +{
1.128 + return ((SharedBuffer*)data)-1;
1.129 +}
1.130 +
1.131 +const SharedBuffer* SharedBuffer::bufferFromData(const void* data)
1.132 +{
1.133 + return ((const SharedBuffer*)data)-1;
1.134 +}
1.135 +
1.136 +size_t SharedBuffer::sizeFromData(const void* data)
1.137 +{
1.138 + return (((const SharedBuffer*)data)-1)->mSize;
1.139 +}
1.140 +
1.141 +bool SharedBuffer::onlyOwner() const {
1.142 + return (mRefs == 1);
1.143 +}
1.144 +
1.145 +}; // namespace android
1.146 +
1.147 +// ---------------------------------------------------------------------------
1.148 +
1.149 +#endif // ANDROID_VECTOR_H
