/[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 - (hide 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 dagobah 1.1 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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