File: bit.py

package info (click to toggle)
checkbox-support 0.22-1
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 5,620 kB
  • sloc: xml: 14,952; python: 7,921; sh: 4; makefile: 3
file content (51 lines) | stat: -rw-r--r-- 1,376 bytes parent folder | download
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
#
# This file is part of Checkbox.
#
# Copyright 2008 Canonical Ltd.
#
# Checkbox is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 3,
# as published by the Free Software Foundation.

#
# Checkbox 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 Checkbox.  If not, see <http://www.gnu.org/licenses/>.

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals

from struct import calcsize


def get_bitmask(key):
    bitmask = []
    for value in reversed(key.split()):
        value = int(value, 16)
        bitmask.append(value)
    return bitmask


def get_bitcount(bitmask):
    bitcount = 0
    for value in bitmask:
        while value:
            bitcount += 1
            value &= (value - 1)
    return bitcount


def test_bit(bit, bitmask, bits=None):
    if bits is None:
        bits = calcsize("l") * 8
    offset = bit % bits
    long = int(bit / bits)
    if long >= len(bitmask):
        return 0
    return (bitmask[long] >> offset) & 1