Python Socket programming details

When programming socket with Python, you need to use the blocking (default) method to read the data stream, so you need to deal with the end of the data every time, which is too troublesome. And the Internet also did not find a good package, so I wrote a simple package.

Packaging ideas

1. Each request from the client sends an SocketRequest object, which encapsulates the specific data. json is used here. For the data to be sent, an end symbol is automatically added (EOF = '0x00').

2. When the server receives the data, it generates the complete data according to the identifier of the terminator and unpacks it into SocketRequest objects.

3. The server generates SocketResponse objects according to the content of SocketRequest. Here, an SimpleRequestHandler class is used for processing.

4. The server sends SocketResponse to the client. There is also a need to do a package encapsulation, will automatically add a terminal identifier (EOF = '0x00').

5. When the customer receives the data, it generates the complete data according to the identifier of the terminator, unpackages it into SocketResponse objects, and returns.

Wrapper class

sockets.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import socket
import pickle
import thread


PORT = 12345
EOF = '0x00'


class SocketServer(object):

  def __init__(self, port=None):
    self.port = port

  def startup(self):
    sock_server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock_server.bind(('0.0.0.0', self.port))
    sock_server.listen(0)

    while True:
      sock, address = sock_server.accept()
      thread.start_new_thread(self.__invoke, (sock, address))

  def shutdown(self):
    pass

  def __invoke(self, sock, address):
    try:
      full_data = ''
      while True:
        data = sock.recv(1024)
        if data is None:
          return

        full_data += data
        if full_data.endswith(EOF):
          full_data = full_data[0:len(full_data) - len(EOF)]
          request = pickle.loads(full_data)
          response = SimpleRequestHandler().handle(request)
          sock.sendall(pickle.dumps(response) + EOF)
          return
    except Exception as e:
      print e
    finally:
      sock.close()


class SocketClient(object):

  def __init__(self, host, port):
    self.host = host
    self.port = port

  def execute(self, request):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect((self.host, self.port))

    try:
      sock.sendall(pickle.dumps(request) + EOF)
      full_data = ''
      while True:
        data = sock.recv(1024)
        if data:
          full_data += data
          if full_data.endswith(EOF):
            full_data = full_data[0:len(full_data) - len(EOF)]
            response = pickle.loads(full_data)
            return response
        else:
          return None
    except Exception as e:
      print e
      return None
    finally:
      sock.close()


class SocketRequest(object):
  def __init__(self, data):
    self.data = data

  def __repr__(self):
    return repr(self.__dict__)


class SocketResponse(object):
  def __init__(self, data):
    self.data = data

  def __repr__(self):
    return repr(self.__dict__)


class SimpleRequestHandler(object):
  def __init__(self):
    pass

  def __repr__(self):
    return repr(self.__dict__)

  def handle(self, request):
    return SocketResponse(request.data)

test

socket_server.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from agent.sockets import *

ss = SocketServer(PORT)
ss.startup()

socket_client.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import pickle
from agent.sockets import *


sc = SocketClient('localhost', PORT)
request = SocketRequest('abc')
response = sc.execute(request)
print request
print response

Run the test

First, run socket_server.py

Then, run socket_client.py