fix bugs in last few commits

[uccvend-vendserver.git] / sql-edition / servers / VendingMachine.py

diff --git a/sql-edition/servers/VendingMachine.py b/sql-edition/servers/VendingMachine.py
index 2574c6d..9506daf 100644 (file)
--- a/sql-edition/servers/VendingMachine.py
+++ b/sql-edition/servers/VendingMachine.py
@@ -1,6 +1,8 @@
-import re, pg
+# vim:ts=4
+import re
 from CRC import do_crc
 from select import select
+import socket
 
 asynchronous_responses = [     '400', '401', # door open/closed
                                '610',        # switches changed
@@ -11,6 +13,8 @@ DOOR = 1
 SWITCH = 2
 KEY = 3
 
+class VendingException(Exception): pass
+
 class VendingMachine:
        def __init__(self, rfh, wfh):
                self.events = []
@@ -26,7 +30,7 @@ class VendingMachine:
                self.wfh.write('PING\n')
                code = ''
                while code != '000':
-                       (code, _) = self.get_response()
+                       code = self.get_response()[0]
                self.get_switches()
 
        def await_prompt(self):
@@ -35,8 +39,12 @@ class VendingMachine:
                prefix = ''
                s = ''
                while True:
-                       s = self.rfh.read(1)
-                       if s == '': raise Exception
+                       try:
+                               s = self.rfh.read(1)
+                       except socket.error:
+                               print "Blah, seems DEC server has fallen over"
+                               raise VendingException('failed to read input from vending machine')
+                       if s == '': raise VendingException('nothing read!')
                        if s == '\n' or s == '\r':
                                state = 1
                                prefix = ''
@@ -49,18 +57,20 @@ class VendingMachine:
                                        self.challenge = int(prefix, 16)
                                        return
 
-       def get_response(self):
+       def get_response(self, async = False):
                self.wfh.flush()
                while True:
                        s = ''
                        while s == '':
                                s = self.rfh.readline()
-                               if s == '': return None
+                               if s == '':
+                                       raise VendingException('Input socket has closed!')
                                s = s.strip('\r\n')
                        code = s[0:3]
                        text = s[4:]
                        if code in asynchronous_responses:
                                self.handle_event(code, text)
+                               if async: return None
                        else:
                                self.await_prompt()
                                return (code, text)
@@ -82,7 +92,7 @@ class VendingMachine:
                elif code == '401':
                        self.events.append((DOOR, 1))
                elif code == '610':
-                       self.events_append((SWITCH, None))
+                       self.events.append((SWITCH, None))
                        self.interpret_switches(text)
                elif code[0] == '2':
                        self.events.append((KEY, int(code[1:3])))
@@ -129,8 +139,7 @@ class VendingMachine:
                        msg += '%02x'%duration
                self.wfh.write(msg+'\n')
                (code, string) = self.get_response()
-               # FIXME: workaround a bug in rom W. should be just: return (code == '500', code, string)
-               return (code == '500' or code == '501', code, string)
+               return (code == '501', code, string)
 
        def display(self, string):
                if len(string) > 10:
@@ -139,18 +148,18 @@ class VendingMachine:
                (code, string) = self.get_response()
                return (code == '300', code, string)
 
-       def next_event(self):
-               if len(self.events) > 0:
-                       ret = self.events[0]
-                       del self.events[0]
-                       return ret
-               return None
-
-       def wait_for_events(self, timeout = None):
-               (r, _, _) = select([self.rfh], [], [], timeout)
-               if not r: return False
-               event_added = False
+       def next_event(self, timeout = None):
+               # we don't want to buffer in the serial port, so we get all the events
+               # we can ASAP.
+               if len(self.events) > 0: timeout = 0
                while True:
-                   r.get_response()
-                   (r, _, _) = select([self.rfh], [], [], 0)
-                   if not r: return event_added
+                       (r, _, _) = select([self.rfh], [], [], timeout)
+                       if r:
+                               self.get_response(async = True)
+                               timeout = 0
+                       else:
+                               break
+               if len(self.events) == 0: return None
+               ret = self.events[0]
+               del self.events[0]
+               return ret