TcpServer Design

TcpServer Design

class TcpServer
* goal - implement a one thread TcpServer
* member variables
status - denotes the status of TcpServer - start, stop, running
logger - log each meaningful info/exception
config - denotes what conifg this TcpServer depends on
socket - denotes listening socket of TcpServer

* member functions
initialize (config, http)- according to config, init socket of TcpServer.
start - start TcpServer
   change server status to running
   one thread's processing loop
      uses IO.select to detect kinds of events
      when one client connects TcpServer, non-blocking accept it
      when clients' data comes, call HttpRequest.parse to parse Clients' request, then call HttpServer.process to pass the request to http, send the results back
   change server status to stop

shutdown - close TcpServer
   clear TcpServer socket