-
Notifications
You must be signed in to change notification settings - Fork 0
/
polling.py
67 lines (54 loc) · 2.1 KB
/
polling.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
# This file is part of mididump.
#
# mididump is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# mididump is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with mididump. If not, see <http://www.gnu.org/licenses/>.
import messages
import os
import select
class MIDIPoll:
def __init__(self, file_path):
self._file_path = file_path
self._poll = select.poll()
def _decode_message(self, buf):
try:
message = messages.MessageDecoder.get(buf)
except IndexError, e:
# Hit when the buffer is empty.
return None
except AssertionError, e:
print "Error while decoding message:", str(e)
print "Complete buffer data:", ','.join([hex(ord(b)) for b in buf])
return None
return message
def poll(self):
fd = os.open(self._file_path, os.O_RDONLY)
self._poll.register(fd, select.POLLIN)
buf = bytearray()
print "Starting polling device", self._file_path
while True:
try:
events = self._poll.poll()
for event in events:
if event[1] & select.POLLIN:
buf.extend(os.read(fd, 64))
while True:
message = self._decode_message(buf)
if message is None:
break
buf = buf[message.LENGTH:]
print "Message:", str(message)
except KeyboardInterrupt:
print
print "Stopping polling ..."
break
self._poll.unregister(fd)
os.close(fd)