运行环境：Windows+Python3 实现功能：
- Go-Back-N
- 选择重传
- 丢包、失序、错误、重复，ack和sack两种模式一共八个测试
- 任意类型文件传输(base64)
使用方式：
python TestHarness.py -s Sender.py -r Receiver.py
# 可用-t指定超时时间，不指定则默认为0.5，例如-t 0.05(建议使用小的timeout以减少测试完成时间)
# 可用-f指定文件，不指定则默认为README.md，例如-f Calvin.jpg运行截图：
以下是原README：
In this folder you'll find the sample receiver, code for computing and validating checksums, as well as example sender code.
Sender.py is the file in which you will implement your reliable sender. Sender.py provides all the scaffolding you need to handle the command line arguments we will use in the grading of your project.
Receiver.py is the sample receiver.
The BasicSender class in BasicSender.py provides a skeleton upon which to build your reliable sender. It provides the following methods:
__init__(self,dest,port,filename,debug=False,sackMode=False): Creates a
BasicSender. Specify the destination's hostname, the port at which
the receiver is listening, and a filename to transmit. If no filename
is provided, it will read from STDIN.
receive(self, timeout): Receive a packet. Waits for a packet before
returning. Optionally you can specify a maximum timeout to wait for a
packet. Returns the received packet as a string, or None if receive
times out.
send(self,message): Sends message to the receiver specified when you
created the sender.
make_packet(self,msg_type,seqno,message): Creates a RUDP packet from
the specified message type, sequence number, and message. Generates the
appropriate checksum, and returns the full RUDP packet with
checksum appended.
split_packet(self,packet): Given a RUDP packet, splits a packet into a
tuple of the form (msg_type, seqno, data, checksum). For packets
without a data field, the data element will be the empty string.
In addition, it defines one method which you must implement:
start(self): Starts the Sender.
We provide two example senders that build upon the BasicSender; you are welcome to base your design upon these:
UnreliableSender.py: While it provides no reliability, it will read from a file or STDIN and send to a receiver using our protocol.
InteractiveSender.py: A simple interactive sender. It will send any message you type to the specified receiver. It then waits for a response before prompting you for a new message.
Checksum.py includes two functions for validating and generating checksums for your packets:
validate_checksum(message): Returns true if the message's checksum matches
the message, and false otherwise. This function assumes the last field
of the message the checksum.
generate_checksum(message): Returns the checksum string for a message. This
function assumes the message includes the trailing delimiter. The
checksum is ONLY valid if you simply append this function's result to
the message you pass in.
You are expected to write test cases for your own code to ensure compliance with the project specifications. To assist you, we've given you a simple test harness (TestHarness.py). The test harness is designed to intercept all packets sent between your sender and the receiver. It can modify the stream of packets and check to ensure the stream meets certain conditions. This is very similar to the grading script that we will use to evaluate your projects.
We have provided three test cases (BasicTest, DropRandomPackets, and SackDropRandomPackets) as examples of how to use the test harness. These test cases send this README file using the specified sender implementation to the specified receiver implementation, either passing all packets through the forwarder unmodified or dropping random packets. They both then verify that the file received by the receiver matches the input.
To run a test using this test harness, do the following:
python TestHarness.py -s YourSender.py -r Receiver.py
where "YourSender.py" is the path to your sender implementation, "Receiver.py" is the path to the receiver implementation. Inside TestHarness.py, you need to modify the function "tests_to_run" at the top of the script to include any test cases you add.
Passing the basic test cases we provide is a necessary but not sufficient condition for doing well on this project; there are still cases that they do not cover.