/[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 - (hide annotations) (download) (as text)
Mon Mar 5 07:06:48 2007 UTC (14 years, 3 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 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 cameron 1.12 import socket, logging
6 mtearle 1.16 from time import time, sleep
7 dagobah 1.1
8     asynchronous_responses = [ '400', '401', # door open/closed
9     '610', # switches changed
10 dagobah 1.2 '200', '201', '202', '203', '204', '205', '206',
11     '207', '208', '209', '211', # key presses
12 dagobah 1.1 ]
13 dagobah 1.2 DOOR = 1
14     SWITCH = 2
15     KEY = 3
16 mtearle 1.16 TICK = 4
17 dagobah 1.1
18 cameron 1.8 class VendingException(Exception): pass
19    
20 dagobah 1.1 class VendingMachine:
21     def __init__(self, rfh, wfh):
22 dagobah 1.2 self.events = []
23 dagobah 1.19 # Secret
24     self.secret = 'SN4CKZ0RZZZZZZZZ'
25 dagobah 1.1 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 cameron 1.8 code = self.get_response()[0]
37 dagobah 1.2 self.get_switches()
38 dagobah 1.1
39     def await_prompt(self):
40     self.wfh.flush()
41     state = 1
42     prefix = ''
43     s = ''
44     while True:
45 cameron 1.8 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 dagobah 1.13 if (s != '#' and s != '%') and state == 1: prefix += s
51 dagobah 1.1 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 dagobah 1.2 self.challenge = int(prefix, 16)
61 dagobah 1.1 return
62    
63 dagobah 1.3 def get_response(self, async = False):
64 dagobah 1.1 self.wfh.flush()
65     while True:
66     s = ''
67     while s == '':
68     s = self.rfh.readline()
69 dagobah 1.9 if s == '':
70 cameron 1.10 raise VendingException('Input socket has closed!')
71 dagobah 1.1 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 dagobah 1.3 if async: return None
77 dagobah 1.1 else:
78     self.await_prompt()
79     return (code, text)
80    
81 dagobah 1.2 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 dagobah 1.1 def handle_event(self, code, text):
93 dagobah 1.2 if code == '400':
94 mtearle 1.14 self.events.append((DOOR, 1))
95     elif code == '401':
96 dagobah 1.2 self.events.append((DOOR, 0))
97     elif code == '610':
98 dagobah 1.18 # NOP this. Nothing handles this yet.
99     #self.events.append((SWITCH, None))
100 dagobah 1.2 self.interpret_switches(text)
101     elif code[0] == '2':
102     self.events.append((KEY, int(code[1:3])))
103     else:
104 cameron 1.12 logging.warning('Unhandled event! (%s %s)\n'%(code,text))
105 dagobah 1.1
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 dagobah 1.13 self.wfh.write(self.authed_message(('V%s'%item))+'\n')
123 dagobah 1.1 (code, string) = self.get_response()
124 dagobah 1.2 return (code == '100', code, string)
125 dagobah 1.1
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 dagobah 1.6 return (code == '501', code, string)
147 dagobah 1.1
148     def display(self, string):
149     if len(string) > 10:
150     string = string[0:10]
151 dagobah 1.15 string = re.sub('(.)\.', lambda match: '.'+match.group(1), string)
152 dagobah 1.1 self.wfh.write('D'+string+'\n')
153     (code, string) = self.get_response()
154     return (code == '300', code, string)
155    
156 dagobah 1.4 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 dagobah 1.17 if timeout < 0: timeout = 0
160 dagobah 1.4 if len(self.events) > 0: timeout = 0
161 dagobah 1.2 while True:
162 dagobah 1.4 (r, _, _) = select([self.rfh], [], [], timeout)
163     if r:
164     self.get_response(async = True)
165 dagobah 1.5 timeout = 0
166 dagobah 1.4 else:
167     break
168 mtearle 1.16 if len(self.events) == 0: return (TICK, time())
169 dagobah 1.4 ret = self.events[0]
170     del self.events[0]
171     return ret

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