/usr/lib/python3/dist-packages/diffoscope/comparators/fontconfig.py is in diffoscope 93ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 68 69 70 71 72 73 74 75 76 77 78 79 80 81 | # -*- coding: utf-8 -*-
#
# diffoscope: in-depth comparison of files, archives, and directories
#
# Copyright © 2017 Chris Lamb <lamby@debian.org>
#
# diffoscope 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.
#
# diffoscope 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 diffoscope. If not, see <https://www.gnu.org/licenses/>.
import struct
from diffoscope.difference import Difference
from .utils.file import File
class FontconfigCacheFile(File):
DESCRIPTION = "FreeDesktop Fontconfig cache files"
FILE_TYPE_HEADER_PREFIX = struct.pack('<H', 0xFC04)
FILE_EXTENSION_SUFFIX = '-le64.cache-4'
def compare_details(self, other, source=None):
return [Difference.from_text(
describe_cache_file(self.path),
describe_cache_file(other.path),
self.path,
other.path,
)]
def describe_cache_file(filename):
fmt = '<IIQQQQQQQ'
fields = (
'magic', 'version', 'size', 'dir', 'dirs', 'dirs_count', 'set',
'checksum', 'checksum_nano',
)
with open(filename, 'rb') as f:
data = struct.unpack(fmt, f.read(struct.calcsize(fmt)))
kwargs = {x: y for x, y in zip(fields, data)}
kwargs['dir_name'] = read_null_terminated_string(f, kwargs['dir'])
return """
struct FcCache {{
unsigned int magic = 0x{magic:08X}; /* FC_CACHE_MAGIC_MMAP or FC_CACHE_ALLOC */
int version = {version}; /* FC_CACHE_VERSION_NUMBER */
intptr_t size = {size}; /* size of file */
intptr_t dir = 0x{dir}; /* offset to dir name ("{dir_name}") */
intptr_t dirs = 0x{dirs:08X}; /* offset to subdirs */
int dirs_count = {dirs_count}; /* number of subdir strings */
intptr_t set = 0x{set:08X}; /* offset to font set */
int checksum = {checksum}; /* checksum of directory state */
int64_t checksum_nano = {checksum_nano}; /* checksum of directory state */
}};
""".format(**kwargs)
def read_null_terminated_string(fileobj, offset=None):
result = ''
if offset is not None:
fileobj.seek(offset)
while True:
x = fileobj.read(1).decode('ascii')
if x in ('', '\0'):
break
result += x
return result
|