/[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 1.7 - (hide annotations) (download) (as text)
Sun Jun 27 18:38:29 2004 UTC (16 years, 11 months ago) by dagobah
Branch: MAIN
Changes since 1.6: +1 -1 lines
File MIME type: text/x-python
Unused module

1 dagobah 1.4 # vim:ts=4
2 dagobah 1.7 import re
3 dagobah 1.1 from CRC import do_crc
4 dagobah 1.2 from select import select
5 dagobah 1.1
6     asynchronous_responses = [ '400', '401', # door open/closed
7     '610', # switches changed
8 dagobah 1.2 '200', '201', '202', '203', '204', '205', '206',
9     '207', '208', '209', '211', # key presses
10 dagobah 1.1 ]
11 dagobah 1.2 DOOR = 1
12     SWITCH = 2
13     KEY = 3
14 dagobah 1.1
15     class VendingMachine:
16     def __init__(self, rfh, wfh):
17 dagobah 1.2 self.events = []
18 dagobah 1.1 self.secret = 'AAAAAAAAAAAAAAAA'
19     self.rfh = rfh
20     self.wfh = wfh
21     self.challenge = None
22     # Initialise ourselves into a known state
23     self.wfh.write('\n')
24     self.await_prompt()
25     self.wfh.write('echo off\n')
26     self.await_prompt()
27     self.wfh.write('PING\n')
28     code = ''
29     while code != '000':
30     (code, _) = self.get_response()
31 dagobah 1.2 self.get_switches()
32 dagobah 1.1
33     def await_prompt(self):
34     self.wfh.flush()
35     state = 1
36     prefix = ''
37     s = ''
38     while True:
39     s = self.rfh.read(1)
40 dagobah 1.3 if s == '': raise Exception('nothing read!')
41 dagobah 1.1 if s == '\n' or s == '\r':
42     state = 1
43     prefix = ''
44     if (s == '#' or s == '%') and state == 1: state = 2
45     if s == ' ' and state == 2:
46     if prefix == '':
47     self.challenge = None
48     return
49     if re.search('^[0-9a-fA-F]{4}$', prefix):
50 dagobah 1.2 self.challenge = int(prefix, 16)
51 dagobah 1.1 return
52    
53 dagobah 1.3 def get_response(self, async = False):
54 dagobah 1.1 self.wfh.flush()
55     while True:
56     s = ''
57     while s == '':
58     s = self.rfh.readline()
59     if s == '': return None
60     s = s.strip('\r\n')
61     code = s[0:3]
62     text = s[4:]
63     if code in asynchronous_responses:
64     self.handle_event(code, text)
65 dagobah 1.3 if async: return None
66 dagobah 1.1 else:
67     self.await_prompt()
68     return (code, text)
69    
70 dagobah 1.2 def get_switches(self):
71     self.wfh.write('S\n')
72     (code, text) = self.get_response()
73     if code != '600':
74     return (False, code, text)
75     self.interpret_switches(text)
76     return (True, code, text)
77    
78     def interpret_switches(self, text):
79     self.switches = (int(text[0:2], 16) << 8) | int(text[3:5], 16)
80    
81 dagobah 1.1 def handle_event(self, code, text):
82 dagobah 1.2 if code == '400':
83     self.events.append((DOOR, 0))
84     elif code == '401':
85     self.events.append((DOOR, 1))
86     elif code == '610':
87 dagobah 1.4 self.events.append((SWITCH, None))
88 dagobah 1.2 self.interpret_switches(text)
89     elif code[0] == '2':
90     self.events.append((KEY, int(code[1:3])))
91     else:
92     sys.stderr.write('WARNING: Unhandled event! (%s %s)\n'%(code,text))
93 dagobah 1.1
94     def authed_message(self, message):
95     if self.challenge == None:
96     return message
97     crc = do_crc('%c%c'%(self.challenge >> 8, self.challenge & 0xff))
98     crc = do_crc(self.secret, crc)
99     crc = do_crc(message, crc)
100     return message+'|'+('%04x'%crc)
101    
102     def ping(self):
103     self.wfh.write('PING\n')
104     (code, string) = self.get_response()
105     return (code == '000', code, string)
106    
107     def vend(self, item):
108     if not re.search('^[0-9][0-9]$', item):
109     return (False, 'Invalid item requested (%s)'%item)
110     self.wfh.write(self.authed_message(('V%s\n'%item)+'\n'))
111     (code, string) = self.get_response()
112 dagobah 1.2 return (code == '100', code, string)
113 dagobah 1.1
114     def beep(self, duration = None, synchronous = True):
115     msg = 'B'
116     if synchronous: msg += 'S'
117     if duration != None:
118     if duration > 255: duration = 255
119     if duration < 1: duration = 1
120     msg += '%02x'%duration
121     self.wfh.write(msg+'\n')
122     (code, string) = self.get_response()
123     return (code == '500', code, string)
124    
125     def silence(self, duration = None, synchronous = True):
126     msg = 'C'
127     if synchronous: msg += 'S'
128     if duration != None:
129     if duration > 255: duration = 255
130     if duration < 1: duration = 1
131     msg += '%02x'%duration
132     self.wfh.write(msg+'\n')
133     (code, string) = self.get_response()
134 dagobah 1.6 return (code == '501', code, string)
135 dagobah 1.1
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 1.4 def next_event(self, timeout = None):
144     # we don't want to buffer in the serial port, so we get all the events
145     # we can ASAP.
146     if len(self.events) > 0: timeout = 0
147 dagobah 1.2 while True:
148 dagobah 1.4 (r, _, _) = select([self.rfh], [], [], timeout)
149     if r:
150     self.get_response(async = True)
151 dagobah 1.5 timeout = 0
152 dagobah 1.4 else:
153     break
154     if len(self.events) == 0: return None
155     ret = self.events[0]
156     del self.events[0]
157     return ret

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