15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef MEDIA_BASE_BYTE_QUEUE_H_ 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define MEDIA_BASE_BYTE_QUEUE_H_ 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/basictypes.h" 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/memory/scoped_ptr.h" 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "media/base/media_export.h" 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace media { 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Represents a queue of bytes. 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Data is added to the end of the queue via an Push() call and removed via 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Pop(). The contents of the queue can be observed via the Peek() method. 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This class manages the underlying storage of the queue and tries to minimize 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// the number of buffer copies when data is appended and removed. 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class MEDIA_EXPORT ByteQueue { 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ByteQueue(); 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ~ByteQueue(); 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Reset the queue to the empty state. 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void Reset(); 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Appends new bytes onto the end of the queue. 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void Push(const uint8* data, int size); 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Get a pointer to the front of the queue and the queue size. 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // These values are only valid until the next Push() or 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Pop() call. 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void Peek(const uint8** data, int* size) const; 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Remove |count| bytes from the front of the queue. 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void Pop(int count); 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Returns a pointer to the front of the queue. 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8* front() const; 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 42c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) scoped_ptr<uint8[]> buffer_; 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Size of |buffer_|. 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_t size_; 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Offset from the start of |buffer_| that marks the front of the queue. 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_t offset_; 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Number of bytes stored in the queue. 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int used_; 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(ByteQueue); 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace media 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // MEDIA_BASE_BYTE_QUEUE_H_ 59