.

Makefile

@@ -34,12 +34,12 @@ ifeq ($(CC),)
 $(error "Cannot defermine py-CC")
 endif
 
-all	: bigfile/_bigfile.so wcfs/wcfs
+all	: pyext wcfs/wcfs
 
 
 ccan_config := 3rdparty/ccan/config.h
 
-bigfile/_bigfile.so : $(ccan_config) FORCE
+pyext	: $(ccan_config) FORCE
 	$(PYTHON) setup.py ll_build_ext --inplace
 
 wcfs/wcfs: FORCE
@@ -173,14 +173,14 @@ test.vgdrd: $(TESTS:%=%.vgdrdrun)
 
 # run python tests
 PYTEST_IGNORE	:=  --ignore=3rdparty --ignore=build --ignore=t
-test.py	: bigfile/_bigfile.so wcfs/wcfs
+test.py	: pyext wcfs/wcfs
 	$(PYTEST) $(PYTEST_IGNORE)
 
 # test.py via Valgrind (very slow)
-test.py.vghel: bigfile/_bigfile.so wcfs/wcfs
+test.py.vghel: pyext wcfs/wcfs
 	$(call vgxrun,--tool=helgrind, $(PYTEST) $(PYTEST_IGNORE))
 
-test.py.drd: bigfile/_bigfile.so wcfs/wcfs
+test.py.drd: pyext wcfs/wcfs
 	$(call vgxrun,--tool=drd, $(PYTEST) $(PYTEST_IGNORE))
 
 
@@ -201,5 +201,5 @@ bench	: bench.t bench.py
 
 bench.t	: $(BENCHV.C:%=%.trun)
 
-bench.py: bigfile/_bigfile.so wcfs/wcfs
+bench.py: pyext wcfs/wcfs
 	$(PYBENCH) --count=3 --forked $(PYTEST_IGNORE)

setup.py

 # Wendelin.core | pythonic package setup
-# Copyright (C) 2014-2015  Nexedi SA and Contributors.
+# Copyright (C) 2014-2019  Nexedi SA and Contributors.
 #                          Kirill Smelkov <kirr@nexedi.com>
 #
 # This program is free software: you can Use, Study, Modify and Redistribute
@@ -20,6 +20,7 @@
 from setuptools import setup, Extension, Command, find_packages
 from setuptools.command.build_py import build_py as _build_py
 from setuptools.command.build_ext import build_ext as _build_ext
+from Cython.Build import cythonize
 from pkg_resources import working_set, EntryPoint
 from distutils.errors import DistutilsExecError
 from subprocess import Popen, PIPE
@@ -229,7 +230,7 @@ setup(
 
     keywords    = 'bigdata out-of-core numpy virtual-memory',
 
-    ext_modules = [_bigfile],
+    ext_modules = [_bigfile] + cythonize("wcfs/internal/*.pyx"),
 
     package_dir = {'wendelin': ''},
     packages    = ['wendelin'] + ['wendelin.%s' % _ for _ in