borg/setup.py

# borgbackup - main setup code (see also other setup_*.py files)

import os
import sys
from collections import defaultdict
from glob import glob

try:
    import multiprocessing
except ImportError:
    multiprocessing = None

from setuptools.command.build_ext import build_ext
from setuptools import setup, find_packages, Extension, Command
from setuptools.command.sdist import sdist

try:
    from Cython.Build import cythonize
except ImportError:
    cythonize = None

sys.path += [os.path.dirname(__file__)]
import setup_docs

is_win32 = sys.platform.startswith('win32')

# Number of threads to use for cythonize, not used on windows
cpu_threads = multiprocessing.cpu_count() if multiprocessing and multiprocessing.get_start_method() != 'spawn' else None

# Are we building on ReadTheDocs?
on_rtd = os.environ.get('READTHEDOCS')

# Extra cflags for all extensions, usually just warnings we want to explicitly enable
cflags = [
    '-Wall',
    '-Wextra',
    '-Wpointer-arith',
]

compress_source = 'src/borg/compress.pyx'
crypto_ll_source = 'src/borg/crypto/low_level.pyx'
crypto_helpers = 'src/borg/crypto/_crypto_helpers.c'
chunker_source = 'src/borg/chunker.pyx'
hashindex_source = 'src/borg/hashindex.pyx'
item_source = 'src/borg/item.pyx'
checksums_source = 'src/borg/checksums.pyx'
platform_posix_source = 'src/borg/platform/posix.pyx'
platform_linux_source = 'src/borg/platform/linux.pyx'
platform_syncfilerange_source = 'src/borg/platform/syncfilerange.pyx'
platform_darwin_source = 'src/borg/platform/darwin.pyx'
platform_freebsd_source = 'src/borg/platform/freebsd.pyx'
platform_windows_source = 'src/borg/platform/windows.pyx'

cython_sources = [
    compress_source,
    crypto_ll_source,
    chunker_source,
    hashindex_source,
    item_source,
    checksums_source,

    platform_posix_source,
    platform_linux_source,
    platform_syncfilerange_source,
    platform_freebsd_source,
    platform_darwin_source,
    platform_windows_source,
]

if cythonize:
    Sdist = sdist
else:
    class Sdist(sdist):
        def __init__(self, *args, **kwargs):
            raise Exception('Cython is required to run sdist')

    cython_c_files = [fn.replace('.pyx', '.c') for fn in cython_sources]
    if not on_rtd and not all(os.path.exists(path) for path in cython_c_files):
        raise ImportError('The GIT version of Borg needs Cython. Install Cython or use a released version.')


def rm(file):
    try:
        os.unlink(file)
        print('rm', file)
    except FileNotFoundError:
        pass


class Clean(Command):
    user_options = []

    def initialize_options(self):
        pass

    def finalize_options(self):
        pass

    def run(self):
        for source in cython_sources:
            genc = source.replace('.pyx', '.c')
            rm(genc)
            compiled_glob = source.replace('.pyx', '.cpython*')
            for compiled in sorted(glob(compiled_glob)):
                rm(compiled)


cmdclass = {
    'build_ext': build_ext,
    'build_usage': setup_docs.build_usage,
    'build_man': setup_docs.build_man,
    'sdist': Sdist,
    'clean2': Clean,
}


# How the build process finds the system libs:
#
# 1. if BORG_LIBXXX_PREFIX is set, it will use headers and libs from there.
# 2. if not and pkg-config can locate the lib, the lib located by
#    pkg-config will be used. We use the pkg-config tool via the pkgconfig
#    python package, which must be installed before invoking setup.py.
#    if pkgconfig is not installed, this step is skipped.
# 3. otherwise raise a fatal error.

ext_modules = []
if not on_rtd:

    def members_appended(*ds):
        result = defaultdict(list)
        for d in ds:
            for k, v in d.items():
                assert isinstance(v, list)
                result[k].extend(v)
        return result

    try:
        import pkgconfig as pc
    except ImportError:
        print('Warning: can not import pkgconfig python package.')
        pc = None

    def lib_ext_kwargs(pc, prefix_env_var, lib_name, lib_pkg_name, pc_version):
        system_prefix = os.environ.get(prefix_env_var)
        if system_prefix:
            print(f'Detected and preferring {lib_pkg_name} [via {prefix_env_var}]')
            return dict(include_dirs=[os.path.join(system_prefix, 'include')],
                        library_dirs=[os.path.join(system_prefix, 'lib')],
                        libraries=[lib_name])

        if pc and pc.installed(lib_pkg_name, pc_version):
            print(f'Detected and preferring {lib_pkg_name} [via pkg-config]')
            return pc.parse(lib_pkg_name)
        raise Exception(f'Could not find {lib_name} lib/headers, please set {prefix_env_var}')


    crypto_ext_kwargs = members_appended(
        dict(sources=[crypto_ll_source, crypto_helpers]),
        lib_ext_kwargs(pc, 'BORG_OPENSSL_PREFIX', 'crypto', 'libcrypto', '>=1.1.1'),
        dict(extra_compile_args=cflags),
    )

    compress_ext_kwargs = members_appended(
        dict(sources=[compress_source]),
        lib_ext_kwargs(pc, 'BORG_LIBLZ4_PREFIX', 'lz4', 'liblz4', '>= 1.7.0'),
        lib_ext_kwargs(pc, 'BORG_LIBZSTD_PREFIX', 'zstd', 'libzstd', '>= 1.3.0'),
        dict(extra_compile_args=cflags),
    )

    checksums_ext_kwargs = members_appended(
        dict(sources=[checksums_source]),
        lib_ext_kwargs(pc, 'BORG_LIBXXHASH_PREFIX', 'xxhash', 'libxxhash', '>= 0.7.3'),
        lib_ext_kwargs(pc, 'BORG_LIBDEFLATE_PREFIX', 'deflate', 'libdeflate', '>= 1.5'),
        dict(extra_compile_args=cflags),
    )

    ext_modules += [
        Extension('borg.crypto.low_level', **crypto_ext_kwargs),
        Extension('borg.compress', **compress_ext_kwargs),
        Extension('borg.hashindex', [hashindex_source], extra_compile_args=cflags),
        Extension('borg.item', [item_source], extra_compile_args=cflags),
        Extension('borg.chunker', [chunker_source], extra_compile_args=cflags),
        Extension('borg.checksums', **checksums_ext_kwargs),
    ]

    posix_ext = Extension('borg.platform.posix', [platform_posix_source], extra_compile_args=cflags)
    linux_ext = Extension('borg.platform.linux', [platform_linux_source], libraries=['acl'], extra_compile_args=cflags)
    syncfilerange_ext = Extension('borg.platform.syncfilerange', [platform_syncfilerange_source], extra_compile_args=cflags)
    freebsd_ext = Extension('borg.platform.freebsd', [platform_freebsd_source], extra_compile_args=cflags)
    darwin_ext = Extension('borg.platform.darwin', [platform_darwin_source], extra_compile_args=cflags)
    windows_ext = Extension('borg.platform.windows', [platform_windows_source], extra_compile_args=cflags)

    if not is_win32:
        ext_modules.append(posix_ext)
    else:
        ext_modules.append(windows_ext)
    if sys.platform == 'linux':
        ext_modules.append(linux_ext)
        ext_modules.append(syncfilerange_ext)
    elif sys.platform.startswith('freebsd'):
        ext_modules.append(freebsd_ext)
    elif sys.platform == 'darwin':
        ext_modules.append(darwin_ext)

    # sometimes there's no need to cythonize
    # this breaks chained commands like 'clean sdist'
    cythonizing = len(sys.argv) > 1 and sys.argv[1] not in (
        ('clean', 'clean2', 'egg_info', '--help-commands', '--version')) and '--help' not in sys.argv[1:]

    if cythonize and cythonizing:
        cython_opts = dict(
            # default language_level will be '3str' starting from Cython 3.0.0,
            # but old cython versions (< 0.29) do not know that, thus we use 3 for now.
            compiler_directives={'language_level': 3},
        )
        if not is_win32:
            # compile .pyx extensions to .c in parallel, does not work on windows
            cython_opts['nthreads'] = cpu_threads

        # generate C code from Cython for ALL supported platforms, so we have them in the sdist.
        # the sdist does not require Cython at install time, so we need all as C.
        cythonize([posix_ext, linux_ext, syncfilerange_ext, freebsd_ext, darwin_ext, windows_ext], **cython_opts)
        # generate C code from Cython for THIS platform (and for all platform-independent Cython parts).
        ext_modules = cythonize(ext_modules, **cython_opts)


setup(
    use_scm_version={
        'write_to': 'src/borg/_version.py',
    },
    cmdclass=cmdclass,
    ext_modules=ext_modules,
)