Initial import of virtualRelay

git-svn-id: https://subversion.xray.aps.anl.gov/kmp/virtualRelay@25 f095f811-4e88-6c84-d33e-e382bdb4531c

virtualRelay.py

+#!/usr/bin/env python
+
+#
+# Based on simulated XIA PFCU-4 filter controller.
+#
+# For usage, see my printUsage function or run me with my -h option.
+#
+
+import getopt
+import asynchat
+import asyncore
+import os
+#import re
+import signal
+import socket
+import sys
+#import time
+
+DEFAULT_PORT = 31337
+
+def main(args):
+	(port, isDebugOutputEnabled) = parseCommandLineArgs(args)
+	d = ConnectionDispatcher(port, isDebugOutputEnabled)
+	asyncore.loop()
+
+def getProgramName(args=None):
+  if args == None: args = sys.argv
+  if len(args) == 0 or args[0] == "-c": return "PROGRAM_NAME"
+  return os.path.basename(args[0])
+
+def parseCommandLineArgs(args):
+  (options, extra) = getopt.getopt(args[1:], "dp:h", ["debug", "port=",
+    "help"])
+
+  port = DEFAULT_PORT
+  isDebugOutputEnabled = False
+
+  for eachOptName, eachOptValue in options:
+    if eachOptName in ("-d", "--debug"):
+      isDebugOutputEnabled = True
+    elif eachOptName in ("-p", "--port"):
+      port = int(eachOptValue)
+    elif eachOptName in ("-h", "--help"):
+      printUsage(sys.stdout)
+      sys.exit(0)
+
+  if len(extra) > 0:
+    print >> sys.stderr, "Error: unexpected command line argument \"%s\"" % \
+      extra[0]
+    printUsage(sys.stderr)
+    sys.exit(1)
+
+  return (port, isDebugOutputEnabled)
+
+def printUsage(outStream):
+  print >> outStream, """\
+Usage: %s [-dph]
+
+Options:
+  -d,--debug        Print debug messages to stderr
+  -p,--port=NUMBER  Listen on the specified port NUMBER for incoming
+                    connections (default: %d)
+  -h,--help         Print usage message and exit\
+""" % (getProgramName(), DEFAULT_PORT)
+
+class ConnectionDispatcher(asyncore.dispatcher):
+  def __init__(self, port, debugOutputEnabled=False):
+    asyncore.dispatcher.__init__(self)
+    self.port = port
+    self.debugOutputEnabled = debugOutputEnabled
+    # xia pfcu 4 example used 16 devices
+    self.device = KevinRelay()
+    self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
+    self.set_reuse_addr()
+    self.bind(("", port))
+    self.listen(5)
+  
+  def handle_accept(self):
+    ConnectionSession(self.accept(), self.device, self.debugOutputEnabled)
+
+class ConnectionSession(asynchat.async_chat):
+  ## regular expressions, if necessary, can go here
+  
+  def __init__(self, (conn, addr), device, debugOutputEnabled=False):
+    asynchat.async_chat.__init__(self, conn)
+    self.debugOutputEnabled = debugOutputEnabled
+    self.set_terminator("\r")
+    self.outputTerminator = "\r\n"
+    self.device = device
+    self.buffer = ""
+    
+  def collect_incoming_data(self, data):
+    self.buffer = self.buffer + data
+    
+  def found_terminator(self):
+    data = self.buffer
+    self.buffer = ""
+    if self.debugOutputEnabled:
+      print >> sys.stderr, "< \"%s\"" % \
+        (data + self.get_terminator()).encode("string_escape")
+    self.handleClientRequest(data)
+    
+  def handleClientRequest(self, request):
+    request = request.strip()
+
+    #print request
+    ## handle actual commands here
+    
+    if len(request) >= 2:
+      if request[0] == chr(254):
+        ## NOTE chr(254) is 376 in octal
+        if request[1] == chr(0):
+          # turn off relay 1
+          print("Turn off relay 1")
+          self.device.setRelayState(0, 0)
+        
+        elif request[1] == chr(1):
+          # turn on relay 1
+          print("Turn on relay 1")
+          self.device.setRelayState(0, 1)
+          
+        elif request[1] == chr(2):
+          # turn off relay 2
+          print("Turn off relay 2")
+          self.device.setRelayState(1, 0)
+        
+        elif request[1] == chr(3):
+          # turn on relay 2
+          print("Turn on relay 2")
+          self.device.setRelayState(1, 1)
+          
+        elif request[1] == chr(4):
+          # get relay 1 status
+          print("Get relay 1 status")
+          status = self.device.getRelayState(0)
+          self.sendClientResponse("%i" % status)
+          
+        elif request[1] == chr(5):
+          # get relay 2 status
+          print("Get relay 2 status")
+          status = self.device.getRelayState(1)
+          self.sendClientResponse("%i" % status)
+          
+        else:
+          print("Other commands not implemented yet")
+
+      else:
+        print("First char wasn't the 254")
+
+    else:
+      print("Command wasn't at least two characters")
+      ##
+    return
+
+  def sendClientResponse(self, response=""):
+    data = response + self.outputTerminator
+    self.push(data)
+    if self.debugOutputEnabled:
+      print >> sys.stderr, "> \"%s\"" % data.encode("string_escape")
+
+class KevinRelay:
+
+  def __init__(self):
+    self.relayStates = [0, 0]
+    
+  def getRelayState(self, relay):
+    return self.relayStates[relay]
+  
+  def setRelayState(self, relay, state):
+    self.relayStates[relay] = state
+
+
+if __name__ == '__main__':
+  try:
+    # command omitted
+  	main(sys.argv)
+  except Exception, e:
+    if isinstance(e, SystemExit):
+      raise e
+    else:
+      print >> sys.stderr
+      print >> sys.stderr, "Error: %s" % e
+      sys.exit(1)