2015年bt下载工具的设计和实现最终修订版大学学位论文.doc

BT下载工具设计与实现 BitTorrent协议；信号与槽机制；torrent文件解析；BT download tool design and Realization Abstract BitTorrent is very popular in todays Internet-based P2P content distribution system technology, it is able to quickly and efficiently distribute large files over the network nodes of the Internet, rather than the source server will bring excessive load. BitTorrent protocol is a network file transfer protocol that enables peer file sharing technology. BitTorrent protocol is used in peer to peer network file sharing network protocol procedures, it is the user group for users, download the same file more people, and after downloading, continue to maintain the status of the upload, you can share, as its clients node torrent file, download the file faster. The main content of the paper: in-depth study of the working principle of the BitTorrent protocol and BitTorrent protocol for communication, DHT network QT signals and slots mechanism, the seed file parsing process, the client and server communications Tracker, Peer and Peer between BTs key methods and the study of law and policy, the system design software are discussed. Key words:The BitTorrent protocol;Signal and slot mechanism;Torrent file parsing; 目 录 摘 要 I Abstract II 1 绪论 1 1.1 国内外BitTorrent的发展状况 1 1.2 发展BitTorrent的目的和意义 1 1.2.1 发展BitTorrent的目的 1 1.2.2 发展BitTorrent的意义 1 2 BitTorrent的原理分析 2 2.1 综述BitTorrent的相关技术 2 2.1.1 BitTorrent协议 2 2.1.2 BitTorrent的专业术语 2 2.1.3 种子的解析 3 2.1.4 BitTorrent运行原理 6 2.1.5 BitTorrent下载流程 7 2.1.6 BitTorrent协议的发展 7 2.2 BitTorrent的软件要求 8 2.2.1 软件系统设计要求 8 2.2.2 软件系统实现 8 3 需求分析 10 3.1 种子文件解析功能分析 10 3.2 Tracker服务器功能分析 10 3.3 Torrent服务器功能分析 10 3.4 软件需求分析 10 4 概要设计 11 4.1.1 种子解析模块 11 4.1.2 连接模块 11 4.1.3 Peer管理模块 11 4.1.4 出错处理模块 11 4.1.5 窗口界面模块 11 5 详细设计 13 5.1 系统功能模块 13 5.2 QT的信号与槽机制 14 5.3 BT的算法与策略 19 5.3.1 阻塞算法 19 5.3.2 超级种子算法 19 5.3.3 结束算法 20 5.3.4 防冷落算法 20 5.3.5 最佳无阻塞算法 20 5.3.6 最稀有算法 21 5.4 BT软件的模块的实现 21 5.4.1 种子解析模块的实现 21 5.4.2 Client与Traceker通信模块的实现 21 5.4.3 Peer之间的通信模块的实现 22 5.4.4 软件出错模块的实现