shaka-packager/media/base/byte_queue.h

60 lines
1.6 KiB
C++

// 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"
namespace edash_packager {
namespace media {
/// Represents a queue of bytes.
/// Data is added to the end of the queue via an Push() 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 ByteQueue {
public:
ByteQueue();
~ByteQueue();
/// Reset the queue to the empty state.
void Reset();
/// Append new bytes to 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 a number of bytes from the front of the queue.
/// @param count specifies number of bytes to be popped.
void Pop(int count);
private:
// Returns a pointer to the front of the queue.
uint8* front() const;
scoped_ptr<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
} // namespace edash_packager
#endif // MEDIA_BASE_BYTE_QUEUE_H_