borg/setup_lz4.py

73 lines
2.4 KiB
Python

# Support code for building a C extension with lz4 files
#
# Copyright (c) 2016-present, Gregory Szorc (original code for zstd)
# 2017-present, Thomas Waldmann (mods to make it more generic, code for lz4)
# All rights reserved.
#
# This software may be modified and distributed under the terms
# of the BSD license. See the LICENSE file for details.
import os
# lz4 files, structure as seen in lz4 project repository:
lz4_sources = [
'lib/lz4.c',
]
lz4_includes = [
'lib',
]
def lz4_system_prefix(prefixes):
for prefix in prefixes:
filename = os.path.join(prefix, 'include', 'lz4.h')
if os.path.exists(filename):
with open(filename, 'rb') as fd:
if b'LZ4_compress_default' in fd.read(): # requires lz4 >= 1.7.0 (r129)
return prefix
def lz4_ext_kwargs(bundled_path, system_prefix=None, system=False, **kwargs):
"""amend kwargs with lz4 stuff for a distutils.extension.Extension initialization.
bundled_path: relative (to this file) path to the bundled library source code files
system_prefix: where the system-installed library can be found
system: True: use the system-installed shared library, False: use the bundled library code
kwargs: distutils.extension.Extension kwargs that should be amended
returns: amended kwargs
"""
def multi_join(paths, *path_segments):
"""apply os.path.join on a list of paths"""
return [os.path.join(*(path_segments + (path, ))) for path in paths]
use_system = system and system_prefix is not None
sources = kwargs.get('sources', [])
if not use_system:
sources += multi_join(lz4_sources, bundled_path)
include_dirs = kwargs.get('include_dirs', [])
if use_system:
include_dirs += multi_join(['include'], system_prefix)
else:
include_dirs += multi_join(lz4_includes, bundled_path)
library_dirs = kwargs.get('library_dirs', [])
if use_system:
library_dirs += multi_join(['lib'], system_prefix)
libraries = kwargs.get('libraries', [])
if use_system:
libraries += ['lz4', ]
extra_compile_args = kwargs.get('extra_compile_args', [])
if not use_system:
extra_compile_args += [] # not used yet
ret = dict(**kwargs)
ret.update(dict(sources=sources, extra_compile_args=extra_compile_args,
include_dirs=include_dirs, library_dirs=library_dirs, libraries=libraries))
return ret