Under Linux, Download The Tools Of Multi-protocol Design And Implementation,

Network file download, which is also called Net File-sharing, is always one of primary impetuses of the development of network. People have designed many network protocols and developed various download tools, just for the higher performance of file transfer in speed, quality, and capacity. the early FlashGet and NetAnt with the feature of multithread HTTP/FTP download, and the following BitTorrent and eDonkey/eMule featured by multi-source transfer, and then the recently popular Thunder which has the advantages of the tools above and is known as the P2SP technology—Download tools and methods has experienced great reform.Based on the enough study of various download tools, this paper introduces the configurations of C/S and P2P MFTP network, which is used by HTTP, FTP or BT download technology. And then a brief analysis of P2SP basic model is given, which is a combination of FTP, HTTP and BT.Then this paper introduces in detail the working principle and process of HTTP/FTP, and the basal technique of realize multithread concurrent in Linux. And then the basic working principle and mode of BitTorrent is focused.And then analyses and comparisons are made for several existing download tools, the emphasis is a kind of BitTorrent client source program. On this basis, a basic frame and design of a multiprotocol file download tool under Linux is brought forward, which is called MDownLoader.In the end, this paper describes the pivotal parts of implementation of HTTP/FTP and BT download mode in MDownLoader. And the emphasis is given to several improvements of the existing download tools, which is used in MDownLoader and mainly includes the client supporting P2SP mode, the improved method of file multithread partition download, and the improved implementation of piece selection, peer selection and hard disk buffer management of BT download.