Source code for daklib.compress
# Copyright (C) 2015, Ansgar Burchardt <ansgar@debian.org>
#
# 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 2 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, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
"""
Helper methods to deal with (de)compressing files
"""
import os
import shutil
import subprocess
from typing import IO, Optional
[docs]def decompress_zstd(input: IO, output: IO) -> None:
subprocess.check_call(["zstd", "--decompress"], stdin=input, stdout=output)
[docs]def decompress_xz(input: IO, output: IO) -> None:
subprocess.check_call(["xz", "--decompress", "-T0"], stdin=input, stdout=output)
[docs]def decompress_bz2(input: IO, output: IO) -> None:
subprocess.check_call(["bzip2", "--decompress"], stdin=input, stdout=output)
[docs]def decompress_gz(input: IO, output: IO) -> None:
subprocess.check_call(["gzip", "--decompress"], stdin=input, stdout=output)
decompressors = {
'.zst': decompress_zstd,
'.xz': decompress_xz,
'.bz2': decompress_bz2,
'.gz': decompress_gz,
}
[docs]def decompress(input: IO, output: IO, filename: Optional[str] = None) -> None:
if filename is None:
filename = input.name
base, ext = os.path.splitext(filename)
decompressor = decompressors.get(ext, None)
if decompressor is not None:
decompressor(input, output)
else:
shutil.copyfileobj(input, output)