77 lines
2.3 KiB
C++
77 lines
2.3 KiB
C++
// Copyright 2014 Google Inc. All rights reserved.
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//
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file or at
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// https://developers.google.com/open-source/licenses/bsd
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#ifndef MEDIA_BASE_BUFFER_WRITER_H_
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#define MEDIA_BASE_BUFFER_WRITER_H_
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#include <vector>
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#include "base/stl_util.h"
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#include "media/base/status.h"
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namespace media {
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class File;
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/// A simple buffer writer implementation which appends various data types to
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/// buffer.
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class BufferWriter {
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public:
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BufferWriter();
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/// Construct the object with a reserved capacity.
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/// @param reserved_size_in_bytes is intended for optimization and is
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/// not a hard limit. It does not affect the actual size of the buffer,
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/// which still starts from zero.
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explicit BufferWriter(size_t reserved_size_in_bytes);
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~BufferWriter();
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/// These convenience functions append the integers (in network byte order,
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/// i.e. big endian) of various size and signedness to the end of the buffer.
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/// @{
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void AppendInt(uint8 v);
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void AppendInt(uint16 v);
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void AppendInt(uint32 v);
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void AppendInt(uint64 v);
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void AppendInt(int16 v);
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void AppendInt(int32 v);
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void AppendInt(int64 v);
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/// @}
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/// Append the least significant @a num_bytes of @a v to buffer.
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/// @param num_bytes should not be larger than sizeof(@a v), i.e. 8 on a
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/// 64-bit system.
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void AppendNBytes(uint64 v, size_t num_bytes);
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void AppendVector(const std::vector<uint8>& v);
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void AppendArray(const uint8* buf, size_t size);
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void AppendBuffer(const BufferWriter& buffer);
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void Swap(BufferWriter* buffer) { buf_.swap(buffer->buf_); }
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void Clear() { buf_.clear(); }
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size_t Size() const { return buf_.size(); }
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/// @return Underlying buffer. Behavior is undefined if the buffer size is 0.
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const uint8* Buffer() const { return vector_as_array(&buf_); }
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/// Write the buffer to file. The internal buffer will be cleared after
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/// writing.
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/// @param file should not be NULL.
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/// @return OK on success.
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Status WriteToFile(File* file);
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private:
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// Internal implementation of multi-byte write.
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template <typename T>
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void AppendInternal(T v);
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std::vector<uint8> buf_;
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DISALLOW_COPY_AND_ASSIGN(BufferWriter);
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};
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} // namespace media
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#endif // MEDIA_BASE_BUFFER_WRITER_H_
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