WinnyCheng / NetworkProject

Project 1 - QR Decoder, Client / Server

Contributors:

Jack Gerulskis and Winny Cheng

Overview

This project uses a TCP client / server model to let the user parse QR codes on the server side, and then get the QR codes URL as a response.

How to use

• run the makefile via 'make'

• run the server executable with the following options in any order

  • --PORT : the server port number (2000 <= PORT <= 3000)

    default is 2012

  • --RATE_MSG : the max amount of requests per RATE_TIME

    default is 3 requests

  • --RATE_TIME : the timespan of RATE_MSG

    default is 60 seconds

  • --MAX_USERS : the maximum amount of concurrent users

    default is 3 users

  • --TIME_OUT : the time until a connection times out

    default is 60 seconds

• Run as many client executables as necessary within server bounds using following options in any order

  • --PORT : the server port number (2000 <= PORT <= 3000)

    default is 2012

  • --ADDRESS : the server ip address

    default is 127.0.0.1

  • --FILE : (NOT OPTIONAL) the qr file to decode

Our Client Implementation

Our client is required to be given a image file to start as specified. In order to support timeout we allow client users the option to make multiple requests within one session. The client, after fulfilling the first request, will ask the user to make an additional request of enter 'q' to quit. When a client receives a timeout from the server, they will not see the message until the client makes an additional request.

Our Interpretation of Rate Throttling

We interpreted the rate throttling on the server as the amount of request a individual client can send within a time span. So after the first request a time span is initialized that starts at the time of the initial request and expires after MAX_TIME seconds have past. Once that period has expired, more requests can be sent within a new time span.

Concurrency

We utilized forking to support concurrent users. Writing to the log is protected by mutexes. Each forked server is given their own image file saved in memory so there will be no race conditions with decoding the QRs.

Logging

Our log is in the StdIO of the server as well as in a log.txt file.

Network Security

Max file size is 50kb, the client will receive an error when a file exceeds that size