Introduction
用C语言编写一个P2P网络程序，从服务器上下载文件，注意处理好网络异常即可。
Requirement
This project creates a peer-to-peer network for file downloading. It resembles
some features of Bit-torrent, but much simplified. There are two pieces of
software – peer and file owner.
The file owner has a file, and it breaks the file into chunks of 100KB, each
stored as a separate file. The minimum size of the file is 5 chunks. The file
owner listens on a TCP port. It should be designed as a server that can run
multiple threads to serve multiple clients simultaneously.
Each peer should be able to connect to the file owner to download some chunks.
It then should have two threads of control, one acting as a server that
uploads the local chunks to another peer (referred to as upload neighbor), and
the other acting as a client that downloads chunks from a third peer (referred
to as download neighbor). So each peer has two neighbors, one of which will
get chunks from this peer and the other will send chunks to this peer. You can
arbitrarily decide on the neighboring relationship as long as the network is
connected — there is a direct path from any peer to any other peer. The
neighboring relationship may be encoded through input parameters (see below).
- Start the file owner process, giving a listening port
- Start five peer processes, one at a time, giving the file owner’s listening port, the peer’s listening port, and its download neighbor’s listening port.
- Each peer connects to the server’s listening port. The latter creates a new thread to download one or several file chunks to the peer, while its main thread goes back to listening for new peers.
- After receiving chunk(s) from the file owner, the peer stores them as separate file(s) and creates a summary file, listing the IDs of the chunks it has.
- The peer then proceeds with two new threads, with one thread listening to its upload neighbor to which it will upload file chunks, and the other thread connecting to its download neighbor.
- The peer requests for the chunk ID list from the download neighbor, compare with its own to find the missing ones, and download those from the neighbor. At the mean time, it sends its own chunk ID list to its upload neighbor, and upon request uploads chunks to the neighbor.
- After a peer has all file chunks, it combines them for a single file.
- A peer should output its activity to its console whenever it receives a chunk, sends a chunk, receives a chunk ID list, sends out a chunk ID list, requests for chunks, or receives such a request.
Other Information
Programming Environment
Programming language: Java, C, C++, C#
Operating System: Windows or Linux
Programming Tool: Jcreator, Kawa, Eclipse, Netbeans … whatever you like.
To use eclipse, please go through the following list:
- Download JDK from http://java.sun.com/javase/downloads/widget/jdk6.jsp
- Download Eclipse from http://www.eclipse.org/downloads/
- Here is a link for eclipse tutorial: http://eclipsetutorial.sourceforge.net/totalbeginner.html
- Here is a tutorial for socket programming in Java: http://java.sun.com/docs/books/tutorial/networking/sockets/
Submission
If you use Java, you will need to submit the following files: server.java,
client.java, server.class, client.class, README.txt in a zipped directory,
e.g., project1.rar. Please make sure to include server.class and client.class
in the submission.
