Testing OpenStack upgrades
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
tobiko/tobiko/openstack/glance/_io.py

85 lines
2.4 KiB

# Copyright 2019 Red Hat
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
from __future__ import absolute_import
import bz2
import gzip
import io
import zipfile
from oslo_log import log
from tobiko.openstack.glance import _lzma
LOG = log.getLogger(__name__)
COMPRESSED_FILE_TYPES = {}
def comressed_file_type(cls):
COMPRESSED_FILE_TYPES[cls.compression_type] = cls
return cls
@comressed_file_type
class BZ2FileType(object):
file_magic = b'\x42\x5a\x68'
compression_type = 'bz2'
open_file = bz2.BZ2File
@comressed_file_type
class GzipFileType(gzip.GzipFile):
file_magic = b'\x1f\x8b\x08'
compression_type = 'gz'
open_file = gzip.GzipFile
@comressed_file_type
class XzFileType(object):
file_magic = b'\xfd7zXZ\x00'
compression_type = 'xz'
open_file = staticmethod(_lzma.open_file)
@comressed_file_type
class ZipFileType(object):
file_magic = b'\x50\x4b\x03\x04'
compression_type = 'zip'
open_file = zipfile.ZipFile
def open_image_file(filename, mode, compression_type=None):
if compression_type is None:
max_magic_len = max(len(cls.file_magic)
for cls in COMPRESSED_FILE_TYPES.values())
with io.open(filename, 'rb') as f:
magic = f.read(max_magic_len)
for cls in COMPRESSED_FILE_TYPES.values():
if magic.startswith(cls.file_magic):
compression_type = cls.compression_type
LOG.debug("Compression type %r of file %r got from file magic",
compression_type, filename)
break
if compression_type:
LOG.debug("Open compressed file %r (mode=%r, compression_type=%r)",
filename, mode, compression_type)
open_func = COMPRESSED_FILE_TYPES[compression_type].open_file
else:
LOG.debug("Open flat file %r (mode=%r)", filename, mode)
open_func = io.open
return open_func(filename, mode)