/[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 1.19 - (show annotations) (download) (as text)
Mon Mar 5 07:06:48 2007 UTC (14 years, 6 months ago) by dagobah
Branch: MAIN
Changes since 1.18: +2 -1 lines
File MIME type: text/x-python
Price check on key 9 when not logged in.

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 # Secret
24 self.secret = 'SN4CKZ0RZZZZZZZZ'
25 self.rfh = rfh
26 self.wfh = wfh
27 self.challenge = None
28 # Initialise ourselves into a known state
29 self.wfh.write('\n')
30 self.await_prompt()
31 self.wfh.write('echo off\n')
32 self.await_prompt()
33 self.wfh.write('PING\n')
34 code = ''
35 while code != '000':
36 code = self.get_response()[0]
37 self.get_switches()
38
39 def await_prompt(self):
40 self.wfh.flush()
41 state = 1
42 prefix = ''
43 s = ''
44 while True:
45 try:
46 s = self.rfh.read(1)
47 except socket.error:
48 raise VendingException('failed to read input from vending machine')
49 if s == '': raise VendingException('nothing read!')
50 if (s != '#' and s != '%') and state == 1: prefix += s
51 if s == '\n' or s == '\r':
52 state = 1
53 prefix = ''
54 if (s == '#' or s == '%') and state == 1: state = 2
55 if s == ' ' and state == 2:
56 if prefix == '':
57 self.challenge = None
58 return
59 if re.search('^[0-9a-fA-F]{4}$', prefix):
60 self.challenge = int(prefix, 16)
61 return
62
63 def get_response(self, async = False):
64 self.wfh.flush()
65 while True:
66 s = ''
67 while s == '':
68 s = self.rfh.readline()
69 if s == '':
70 raise VendingException('Input socket has closed!')
71 s = s.strip('\r\n')
72 code = s[0:3]
73 text = s[4:]
74 if code in asynchronous_responses:
75 self.handle_event(code, text)
76 if async: return None
77 else:
78 self.await_prompt()
79 return (code, text)
80
81 def get_switches(self):
82 self.wfh.write('S\n')
83 (code, text) = self.get_response()
84 if code != '600':
85 return (False, code, text)
86 self.interpret_switches(text)
87 return (True, code, text)
88
89 def interpret_switches(self, text):
90 self.switches = (int(text[0:2], 16) << 8) | int(text[3:5], 16)
91
92 def handle_event(self, code, text):
93 if code == '400':
94 self.events.append((DOOR, 1))
95 elif code == '401':
96 self.events.append((DOOR, 0))
97 elif code == '610':
98 # NOP this. Nothing handles this yet.
99 #self.events.append((SWITCH, None))
100 self.interpret_switches(text)
101 elif code[0] == '2':
102 self.events.append((KEY, int(code[1:3])))
103 else:
104 logging.warning('Unhandled event! (%s %s)\n'%(code,text))
105
106 def authed_message(self, message):
107 if self.challenge == None:
108 return message
109 crc = do_crc('%c%c'%(self.challenge >> 8, self.challenge & 0xff))
110 crc = do_crc(self.secret, crc)
111 crc = do_crc(message, crc)
112 return message+'|'+('%04x'%crc)
113
114 def ping(self):
115 self.wfh.write('PING\n')
116 (code, string) = self.get_response()
117 return (code == '000', code, string)
118
119 def vend(self, item):
120 if not re.search('^[0-9][0-9]$', item):
121 return (False, 'Invalid item requested (%s)'%item)
122 self.wfh.write(self.authed_message(('V%s'%item))+'\n')
123 (code, string) = self.get_response()
124 return (code == '100', code, string)
125
126 def beep(self, duration = None, synchronous = True):
127 msg = 'B'
128 if synchronous: msg += 'S'
129 if duration != None:
130 if duration > 255: duration = 255
131 if duration < 1: duration = 1
132 msg += '%02x'%duration
133 self.wfh.write(msg+'\n')
134 (code, string) = self.get_response()
135 return (code == '500', code, string)
136
137 def silence(self, duration = None, synchronous = True):
138 msg = 'C'
139 if synchronous: msg += 'S'
140 if duration != None:
141 if duration > 255: duration = 255
142 if duration < 1: duration = 1
143 msg += '%02x'%duration
144 self.wfh.write(msg+'\n')
145 (code, string) = self.get_response()
146 return (code == '501', code, string)
147
148 def display(self, string):
149 if len(string) > 10:
150 string = string[0:10]
151 string = re.sub('(.)\.', lambda match: '.'+match.group(1), string)
152 self.wfh.write('D'+string+'\n')
153 (code, string) = self.get_response()
154 return (code == '300', code, string)
155
156 def next_event(self, timeout = None):
157 # we don't want to buffer in the serial port, so we get all the events
158 # we can ASAP.
159 if timeout < 0: timeout = 0
160 if len(self.events) > 0: timeout = 0
161 while True:
162 (r, _, _) = select([self.rfh], [], [], timeout)
163 if r:
164 self.get_response(async = True)
165 timeout = 0
166 else:
167 break
168 if len(self.events) == 0: return (TICK, time())
169 ret = self.events[0]
170 del self.events[0]
171 return ret

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