/[anoncvs]/projects/dispense2/sql-edition/servers/VendingMachine.py


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Contents of /projects/dispense2/sql-edition/servers/VendingMachine.py

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Revision 1.3 - (hide annotations) (download) (as text)
Sat Jun 26 09:38:39 2004 UTC (17 years ago) by dagobah
Branch: MAIN
Changes since 1.2: +5 -3 lines
File MIME type: text/x-python
Usable but ugly!

1 dagobah 1.2 import re, pg
2 dagobah 1.1 from CRC import do_crc
3 dagobah 1.2 from select import select
4 dagobah 1.1
5     asynchronous_responses = [ '400', '401', # door open/closed
6     '610', # switches changed
7 dagobah 1.2 '200', '201', '202', '203', '204', '205', '206',
8     '207', '208', '209', '211', # key presses
9 dagobah 1.1 ]
10 dagobah 1.2 DOOR = 1
11     SWITCH = 2
12     KEY = 3
13 dagobah 1.1
14     class VendingMachine:
15     def __init__(self, rfh, wfh):
16 dagobah 1.2 self.events = []
17 dagobah 1.1 self.secret = 'AAAAAAAAAAAAAAAA'
18     self.rfh = rfh
19     self.wfh = wfh
20     self.challenge = None
21     # Initialise ourselves into a known state
22     self.wfh.write('\n')
23     self.await_prompt()
24     self.wfh.write('echo off\n')
25     self.await_prompt()
26     self.wfh.write('PING\n')
27     code = ''
28     while code != '000':
29     (code, _) = self.get_response()
30 dagobah 1.2 self.get_switches()
31 dagobah 1.1
32     def await_prompt(self):
33     self.wfh.flush()
34     state = 1
35     prefix = ''
36     s = ''
37     while True:
38     s = self.rfh.read(1)
39 dagobah 1.3 if s == '': raise Exception('nothing read!')
40 dagobah 1.1 if s == '\n' or s == '\r':
41     state = 1
42     prefix = ''
43     if (s == '#' or s == '%') and state == 1: state = 2
44     if s == ' ' and state == 2:
45     if prefix == '':
46     self.challenge = None
47     return
48     if re.search('^[0-9a-fA-F]{4}$', prefix):
49 dagobah 1.2 self.challenge = int(prefix, 16)
50 dagobah 1.1 return
51    
52 dagobah 1.3 def get_response(self, async = False):
53 dagobah 1.1 self.wfh.flush()
54     while True:
55     s = ''
56     while s == '':
57     s = self.rfh.readline()
58     if s == '': return None
59     s = s.strip('\r\n')
60     code = s[0:3]
61     text = s[4:]
62     if code in asynchronous_responses:
63     self.handle_event(code, text)
64 dagobah 1.3 if async: return None
65 dagobah 1.1 else:
66     self.await_prompt()
67     return (code, text)
68    
69 dagobah 1.2 def get_switches(self):
70     self.wfh.write('S\n')
71     (code, text) = self.get_response()
72     if code != '600':
73     return (False, code, text)
74     self.interpret_switches(text)
75     return (True, code, text)
76    
77     def interpret_switches(self, text):
78     self.switches = (int(text[0:2], 16) << 8) | int(text[3:5], 16)
79    
80 dagobah 1.1 def handle_event(self, code, text):
81 dagobah 1.2 if code == '400':
82     self.events.append((DOOR, 0))
83     elif code == '401':
84     self.events.append((DOOR, 1))
85     elif code == '610':
86     self.events_append((SWITCH, None))
87     self.interpret_switches(text)
88     elif code[0] == '2':
89     self.events.append((KEY, int(code[1:3])))
90     else:
91     sys.stderr.write('WARNING: Unhandled event! (%s %s)\n'%(code,text))
92 dagobah 1.1
93     def authed_message(self, message):
94     if self.challenge == None:
95     return message
96     crc = do_crc('%c%c'%(self.challenge >> 8, self.challenge & 0xff))
97     crc = do_crc(self.secret, crc)
98     crc = do_crc(message, crc)
99     return message+'|'+('%04x'%crc)
100    
101     def ping(self):
102     self.wfh.write('PING\n')
103     (code, string) = self.get_response()
104     return (code == '000', code, string)
105    
106     def vend(self, item):
107     if not re.search('^[0-9][0-9]$', item):
108     return (False, 'Invalid item requested (%s)'%item)
109     self.wfh.write(self.authed_message(('V%s\n'%item)+'\n'))
110     (code, string) = self.get_response()
111 dagobah 1.2 return (code == '100', code, string)
112 dagobah 1.1
113     def beep(self, duration = None, synchronous = True):
114     msg = 'B'
115     if synchronous: msg += 'S'
116     if duration != None:
117     if duration > 255: duration = 255
118     if duration < 1: duration = 1
119     msg += '%02x'%duration
120     self.wfh.write(msg+'\n')
121     (code, string) = self.get_response()
122     return (code == '500', code, string)
123    
124     def silence(self, duration = None, synchronous = True):
125     msg = 'C'
126     if synchronous: msg += 'S'
127     if duration != None:
128     if duration > 255: duration = 255
129     if duration < 1: duration = 1
130     msg += '%02x'%duration
131     self.wfh.write(msg+'\n')
132     (code, string) = self.get_response()
133     # FIXME: workaround a bug in rom W. should be just: return (code == '500', code, string)
134     return (code == '500' or code == '501', code, string)
135    
136     def display(self, string):
137     if len(string) > 10:
138     string = string[0:10]
139     self.wfh.write('D'+string+'\n')
140     (code, string) = self.get_response()
141     return (code == '300', code, string)
142    
143 dagobah 1.2 def next_event(self):
144     if len(self.events) > 0:
145     ret = self.events[0]
146     del self.events[0]
147     return ret
148     return None
149    
150     def wait_for_events(self, timeout = None):
151 dagobah 1.3 if self.events: return True
152 dagobah 1.2 (r, _, _) = select([self.rfh], [], [], timeout)
153     if not r: return False
154     event_added = False
155     while True:
156 dagobah 1.3 self.get_response(async = True)
157 dagobah 1.2 (r, _, _) = select([self.rfh], [], [], 0)
158     if not r: return event_added

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