gns3-server/gns3server/utils/images.py
2016-07-28 12:35:23 +02:00

73 lines
1.9 KiB
Python

# -*- coding: utf-8 -*-
#
# Copyright (C) 2014 GNS3 Technologies Inc.
#
# This program 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.
#
# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
import os
import hashlib
import logging
log = logging.getLogger(__name__)
def md5sum(path):
"""
Return the md5sum of an image and cache it on disk
:param path: Path to the image
:returns: Digest of the image
"""
if path is None or len(path) == 0 or not os.path.exists(path):
return None
try:
with open(path + '.md5sum') as f:
return f.read()
# Unicode error is when user rename an image to .md5sum ....
except (OSError, UnicodeDecodeError):
pass
try:
m = hashlib.md5()
with open(path, 'rb') as f:
while True:
buf = f.read(128)
if not buf:
break
m.update(buf)
digest = m.hexdigest()
except OSError as e:
log.error("Can't create digest of %s: %s", path, str(e))
return None
try:
with open('{}.md5sum'.format(path), 'w+') as f:
f.write(digest)
except OSError as e:
log.error("Can't write digest of %s: %s", path, str(e))
return digest
def remove_checksum(path):
"""
Remove the checksum of an image from cache if exists
"""
path = '{}.md5sum'.format(path)
if os.path.exists(path):
os.remove(path)