Source code for kiwi.utils.compress

# Copyright (c) 2015 SUSE Linux GmbH.  All rights reserved.
#
# This file is part of kiwi.
#
# kiwi 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.
#
# kiwi 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 kiwi.  If not, see <http://www.gnu.org/licenses/>
#
import os
import logging
from tempfile import NamedTemporaryFile

# project
from kiwi.command import Command
from kiwi.defaults import Defaults

from kiwi.exceptions import (
    KiwiFileNotFound,
    KiwiCompressionFormatUnknown
)

log = logging.getLogger('kiwi')


[docs]class Compress: """ **File compression / decompression** :param bool keep_source: Request to keep the uncompressed source :param str source_filename: Source file name to compress :param list supported_zipper: List of supported compression tools :param str compressed_filename: Compressed file name path with compression suffix :param str uncompressed_filename: Uncompressed file name path """ def __init__(self, source_filename, keep_source_on_compress=False): if not os.path.exists(source_filename): raise KiwiFileNotFound( 'compression source file %s not found' % source_filename ) self.keep_source = keep_source_on_compress self.source_filename = source_filename self.supported_zipper = [ 'xz', 'gzip' ] self.compressed_filename = None self.uncompressed_filename = None
[docs] def xz(self, options=None): """ Create XZ compressed file :param list options: custom xz compression options """ if not options: options = Defaults.get_xz_compression_options() if self.keep_source: options.append('--keep') Command.run( ['xz', '-f'] + options + [self.source_filename] ) self.compressed_filename = self.source_filename + '.xz' return self.compressed_filename
[docs] def gzip(self): """ Create gzip(max compression) compressed file """ options = [ '-9' ] if self.keep_source: options.append('--keep') Command.run( ['gzip', '-f'] + options + [self.source_filename] ) self.compressed_filename = self.source_filename + '.gz' return self.compressed_filename
[docs] def uncompress(self, temporary=False): """ Uncompress with format autodetection By default the original source file will be changed into the uncompressed variant. If temporary is set to True a temporary file is created instead :param bool temporary: uncompress to a temporary file """ zipper = self.get_format() if not zipper: raise KiwiCompressionFormatUnknown( 'could not detect compression format for %s' % self.source_filename ) if not temporary: Command.run([zipper, '-d', self.source_filename]) self.uncompressed_filename = self.source_filename else: self.temp_file = NamedTemporaryFile() bash_command = [ zipper, '-c', '-d', self.source_filename, '>', self.temp_file.name ] Command.run(['bash', '-c', ' '.join(bash_command)]) self.uncompressed_filename = self.temp_file.name return self.uncompressed_filename
[docs] def get_format(self): """ Detect compression format :return: compression format name or None if it couldn't be inferred :rtype: Optional[str] """ for zipper in self.supported_zipper: cmd = [zipper, '-l', self.source_filename] try: Command.run(cmd) return zipper except Exception as exc: log.debug( 'Error running "{cmd:s}", got a {exc_t:s}: {exc:s}' .format( cmd=' '.join(cmd), exc_t=type(exc).__name__, exc=str(exc) ) )