Differences

This shows you the differences between two versions of the page.

--- courses:ct30a6000:hw_01 [2012/01/22 20:37]
hevi
+++ courses:ct30a6000:hw_01 [2012/01/22 20:39] (current)
hevi
@@ Line 12: / Line 12: @@
 {{:courses:ct30a6000:main_server_sm.png|}}
-main_server statemachnine
+main_server state machine
+**exer_udb_b.main_client**
+<code>
+import socket
+import logging
+log = logging.getLogger(__name__)
+echo_host = "localhost"
+echo_port_client = 23456
+echo_port_server = 23456 + 1
+def run():
+  log.debug("client running ..")
+  s = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
+  s.bind( (echo_host,echo_port_client) )
+  ## send and receive a message
+  send_msg = "ECHO MESSAGE"
+  log.debug("Sending " + send_msg)
+  s.sendto(send_msg, (echo_host, echo_port_server) )
+  recv_msg = s.recv(4096)
+  log.debug("Received " + recv_msg)
+  s.close()
+if __name__ == '__main__':
+  logging.basicConfig(level=logging.DEBUG)
+  run()
+</code>
+**exer_udb_b.main_server**
+<code>
+'''
+Created on 9.1.2012
+@author: hevi
+concrete message coding (simple), messages
+character base coding as a ascii character set.
+message boundaries is based on one UDP message, ie.
+application message == UPD message.
+common message:
+type as char
+sid  as string (except on open_session)
+data as string
+- fields are separated by space
+open_session
+  type: 'o'
+  data: host and port
+number
+  type: 'n'
+  sid:  string
+  data: number
+result
+  type: 'r'
+  sid:  string
+  data: number
+close_session
+  type: 'c'
+  sid:  string
+  data: None
+set_sid
+  type: 's'
+  sid: string
+'''
+import socket
+import logging
+log = logging.getLogger(__name__)
+echo_host = "localhost"
+echo_port_client = 23456
+echo_port_server = 23456 + 1
+class Session(object):
+  def __init__(self,host,port,sid):
+    self.client_host = host
+    self.client_port = port
+    self.sid = sid
+  def open_session(self):
+    msg = "s " + str(self.sid)
+    sock.sendto(msg, (self.client_host, self.client_port) )
+  def number(self,n):
+    pass
+  def close_session(self):
+    pass
+sessions = list()
+sid_counter = 1
+sock = None
+# echo service
+def run():
+  log.debug("server running ..")
+  sock = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
+  sock.bind( (echo_host,echo_port_server) )
+  # loop
+  while True:
+    msg, sender = sock.recvfrom(4096)
+    log.debug("msg " + msg + " ip " + sender[0] + " port " + str(sender[1]))
+    #s.sendto(msg, (sender[0], echo_port_client) )
+    ## decoding
+    parts = msg.split()
+    type = parts[0]
+    if type == 'o':
+      client_host = parts[1]
+      client_port = int(parts[2])
+      sid = sid_counter
+      sid_counter += 1
+      session = Session(client_host,client_port,sid)
+      sessions.append(session)
+      session.open_session()
+    elif type == 'n':
+      sid = parts[1]
+      ## lookup
+      session = None
+      for s in sessions:
+        if s.sid == sid:
+          session = s
+      if session == None:
+        log.error("unknonw sid " + sid)
+        continue
+      ##
+      number = int(parts[2])
+      session.number(number)
+    elif type == 'r':
+      pass
+    elif type == 'c':
+      sid = parts[1]
+      ## lookup
+      session = None
+      for s in sessions:
+        if s.sid == sid:
+          session = s
+      if session == None:
+        log.error("unknonw sid " + sid)
+        continue
+      ##
+      session.close_session()
+      sessions.remove(session)
+    else:
+      log.error("unknown type " + type)
+  sock.close()
+if __name__ == '__main__':
+  logging.basicConfig(level=logging.DEBUG)
+  run()
+</code>

Tools

menus and quick search

quick search

site status

location indicator

Page Tools

meta data for this page

Differences