/[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 1.1 - (show annotations) (download) (as text)
Fri Jun 25 15:33:12 2004 UTC (17 years ago) by dagobah
Branch: MAIN
File MIME type: text/x-python
Split this code out.

1 import re
2 from CRC import do_crc
3 from binascii import unhexlify
4
5 asynchronous_responses = [ '400', '401', # door open/closed
6 '610', # switches changed
7 ]
8
9 class VendingMachine:
10 def __init__(self, rfh, wfh):
11 self.secret = 'AAAAAAAAAAAAAAAA'
12 self.rfh = rfh
13 self.wfh = wfh
14 self.challenge = None
15 # Initialise ourselves into a known state
16 self.wfh.write('\n')
17 self.await_prompt()
18 self.wfh.write('echo off\n')
19 self.await_prompt()
20 self.wfh.write('PING\n')
21 code = ''
22 while code != '000':
23 (code, _) = self.get_response()
24
25 def await_prompt(self):
26 self.wfh.flush()
27 state = 1
28 prefix = ''
29 s = ''
30 while True:
31 s = self.rfh.read(1)
32 if s == '': raise Exception
33 if s == '\n' or s == '\r':
34 state = 1
35 prefix = ''
36 if (s == '#' or s == '%') and state == 1: state = 2
37 if s == ' ' and state == 2:
38 if prefix == '':
39 self.challenge = None
40 return
41 if re.search('^[0-9a-fA-F]{4}$', prefix):
42 self.challenge = unhexlify(prefix)
43 return
44
45 def get_response(self):
46 self.wfh.flush()
47 while True:
48 s = ''
49 while s == '':
50 s = self.rfh.readline()
51 if s == '': return None
52 s = s.strip('\r\n')
53 code = s[0:3]
54 text = s[4:]
55 if code in asynchronous_responses:
56 self.handle_event(code, text)
57 else:
58 self.await_prompt()
59 return (code, text)
60
61 def handle_event(self, code, text):
62 pass
63
64 def authed_message(self, message):
65 if self.challenge == None:
66 return message
67 crc = do_crc('%c%c'%(self.challenge >> 8, self.challenge & 0xff))
68 crc = do_crc(self.secret, crc)
69 crc = do_crc(message, crc)
70 return message+'|'+('%04x'%crc)
71
72 def ping(self):
73 self.wfh.write('PING\n')
74 (code, string) = self.get_response()
75 return (code == '000', code, string)
76
77 def vend(self, item):
78 if not re.search('^[0-9][0-9]$', item):
79 return (False, 'Invalid item requested (%s)'%item)
80 self.wfh.write(self.authed_message(('V%s\n'%item)+'\n'))
81 (code, string) = self.get_response()
82 return (code, string)
83
84 def beep(self, duration = None, synchronous = True):
85 msg = 'B'
86 if synchronous: msg += 'S'
87 if duration != None:
88 if duration > 255: duration = 255
89 if duration < 1: duration = 1
90 msg += '%02x'%duration
91 self.wfh.write(msg+'\n')
92 (code, string) = self.get_response()
93 return (code == '500', code, string)
94
95 def silence(self, duration = None, synchronous = True):
96 msg = 'C'
97 if synchronous: msg += 'S'
98 if duration != None:
99 if duration > 255: duration = 255
100 if duration < 1: duration = 1
101 msg += '%02x'%duration
102 self.wfh.write(msg+'\n')
103 (code, string) = self.get_response()
104 # FIXME: workaround a bug in rom W. should be just: return (code == '500', code, string)
105 return (code == '500' or code == '501', code, string)
106
107 def display(self, string):
108 if len(string) > 10:
109 string = string[0:10]
110 self.wfh.write('D'+string+'\n')
111 (code, string) = self.get_response()
112 return (code == '300', code, string)
113

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