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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef MEDIA_BASE_BYTE_QUEUE_H_
#define MEDIA_BASE_BYTE_QUEUE_H_
#include "base/basictypes.h"
#include "base/memory/scoped_ptr.h"
#include "media/base/media_export.h"
namespace media {
// Represents a queue of bytes.
// Data is added to the end of the queue via an Push() call and removed via
// Pop(). The contents of the queue can be observed via the Peek() method.
// This class manages the underlying storage of the queue and tries to minimize
// the number of buffer copies when data is appended and removed.
class MEDIA_EXPORT ByteQueue {
public:
ByteQueue();
~ByteQueue();
// Reset the queue to the empty state.
void Reset();
// Appends new bytes onto the end of the queue.
void Push(const uint8* data, int size);
// Get a pointer to the front of the queue and the queue size.
// These values are only valid until the next Push() or
// Pop() call.
void Peek(const uint8** data, int* size) const;
// Remove |count| bytes from the front of the queue.
void Pop(int count);
private:
// Returns a pointer to the front of the queue.
uint8* front() const;
scoped_array<uint8> buffer_;
// Size of |buffer_|.
size_t size_;
// Offset from the start of |buffer_| that marks the front of the queue.
size_t offset_;
// Number of bytes stored in the queue.
int used_;
DISALLOW_COPY_AND_ASSIGN(ByteQueue);
};
} // namespace media
#endif // MEDIA_BASE_BYTE_QUEUE_H_