/[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 1.18 - (show annotations) (download) (as text)
Fri Mar 2 12:33:13 2007 UTC (14 years, 3 months ago) by dagobah
Branch: MAIN
Changes since 1.17: +2 -1 lines
File MIME type: text/x-python
fix bugs and solve world poverty.

1 # vim:ts=4
2 import re
3 from CRC import do_crc
4 from select import select
5 import socket, logging
6 from time import time, sleep
7
8 asynchronous_responses = [ '400', '401', # door open/closed
9 '610', # switches changed
10 '200', '201', '202', '203', '204', '205', '206',
11 '207', '208', '209', '211', # key presses
12 ]
13 DOOR = 1
14 SWITCH = 2
15 KEY = 3
16 TICK = 4
17
18 class VendingException(Exception): pass
19
20 class VendingMachine:
21 def __init__(self, rfh, wfh):
22 self.events = []
23 self.secret = 'AAAAAAAAAAAAAAAA'
24 self.rfh = rfh
25 self.wfh = wfh
26 self.challenge = None
27 # Initialise ourselves into a known state
28 self.wfh.write('\n')
29 self.await_prompt()
30 self.wfh.write('echo off\n')
31 self.await_prompt()
32 self.wfh.write('PING\n')
33 code = ''
34 while code != '000':
35 code = self.get_response()[0]
36 self.get_switches()
37
38 def await_prompt(self):
39 self.wfh.flush()
40 state = 1
41 prefix = ''
42 s = ''
43 while True:
44 try:
45 s = self.rfh.read(1)
46 except socket.error:
47 raise VendingException('failed to read input from vending machine')
48 if s == '': raise VendingException('nothing read!')
49 if (s != '#' and s != '%') and state == 1: prefix += s
50 if s == '\n' or s == '\r':
51 state = 1
52 prefix = ''
53 if (s == '#' or s == '%') and state == 1: state = 2
54 if s == ' ' and state == 2:
55 if prefix == '':
56 self.challenge = None
57 return
58 if re.search('^[0-9a-fA-F]{4}$', prefix):
59 self.challenge = int(prefix, 16)
60 return
61
62 def get_response(self, async = False):
63 self.wfh.flush()
64 while True:
65 s = ''
66 while s == '':
67 s = self.rfh.readline()
68 if s == '':
69 raise VendingException('Input socket has closed!')
70 s = s.strip('\r\n')
71 code = s[0:3]
72 text = s[4:]
73 if code in asynchronous_responses:
74 self.handle_event(code, text)
75 if async: return None
76 else:
77 self.await_prompt()
78 return (code, text)
79
80 def get_switches(self):
81 self.wfh.write('S\n')
82 (code, text) = self.get_response()
83 if code != '600':
84 return (False, code, text)
85 self.interpret_switches(text)
86 return (True, code, text)
87
88 def interpret_switches(self, text):
89 self.switches = (int(text[0:2], 16) << 8) | int(text[3:5], 16)
90
91 def handle_event(self, code, text):
92 if code == '400':
93 self.events.append((DOOR, 1))
94 elif code == '401':
95 self.events.append((DOOR, 0))
96 elif code == '610':
97 # NOP this. Nothing handles this yet.
98 #self.events.append((SWITCH, None))
99 self.interpret_switches(text)
100 elif code[0] == '2':
101 self.events.append((KEY, int(code[1:3])))
102 else:
103 logging.warning('Unhandled event! (%s %s)\n'%(code,text))
104
105 def authed_message(self, message):
106 if self.challenge == None:
107 return message
108 crc = do_crc('%c%c'%(self.challenge >> 8, self.challenge & 0xff))
109 crc = do_crc(self.secret, crc)
110 crc = do_crc(message, crc)
111 return message+'|'+('%04x'%crc)
112
113 def ping(self):
114 self.wfh.write('PING\n')
115 (code, string) = self.get_response()
116 return (code == '000', code, string)
117
118 def vend(self, item):
119 if not re.search('^[0-9][0-9]$', item):
120 return (False, 'Invalid item requested (%s)'%item)
121 self.wfh.write(self.authed_message(('V%s'%item))+'\n')
122 (code, string) = self.get_response()
123 return (code == '100', code, string)
124
125 def beep(self, duration = None, synchronous = True):
126 msg = 'B'
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 return (code == '500', code, string)
135
136 def silence(self, duration = None, synchronous = True):
137 msg = 'C'
138 if synchronous: msg += 'S'
139 if duration != None:
140 if duration > 255: duration = 255
141 if duration < 1: duration = 1
142 msg += '%02x'%duration
143 self.wfh.write(msg+'\n')
144 (code, string) = self.get_response()
145 return (code == '501', code, string)
146
147 def display(self, string):
148 if len(string) > 10:
149 string = string[0:10]
150 string = re.sub('(.)\.', lambda match: '.'+match.group(1), string)
151 self.wfh.write('D'+string+'\n')
152 (code, string) = self.get_response()
153 return (code == '300', code, string)
154
155 def next_event(self, timeout = None):
156 # we don't want to buffer in the serial port, so we get all the events
157 # we can ASAP.
158 if timeout < 0: timeout = 0
159 if len(self.events) > 0: timeout = 0
160 while True:
161 (r, _, _) = select([self.rfh], [], [], timeout)
162 if r:
163 self.get_response(async = True)
164 timeout = 0
165 else:
166 break
167 if len(self.events) == 0: return (TICK, time())
168 ret = self.events[0]
169 del self.events[0]
170 return ret

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