Commit 699b1375 authored by Kirill Smelkov's avatar Kirill Smelkov

lib/mem: Python utilities to zero, set & copy memory

Like C bzero / memset & memcopy - but work on python buffers. We
leverage NumPy for doing actual work, and this way NumPy becomes a

Having NumPy as a dependency is ok - we'll for sure need it later as we
are trying to build out-of-core ndarrays.
parent 3e5e78cd
# -*- coding: utf-8 -*-
# Wendelin. Memory helpers
# Copyright (C) 2014-2015 Nexedi SA and Contributors.
# Kirill Smelkov <>
# This program is free software: you can Use, Study, Modify and Redistribute
# it under the terms of the GNU General Public License version 3, or (at your
# option) any later version, as published by the Free Software Foundation.
# You can also Link and Combine this program with other software covered by
# the terms of any of the Open Source Initiative approved licenses and Convey
# the resulting work. Corresponding source of such a combination shall include
# the source code for all other software used.
# This program is distributed WITHOUT ANY WARRANTY; without even the implied
# See COPYING file for full licensing terms.
from numpy import ndarray, uint64, copyto
# zero buffer memory
def bzero(buf):
assert len(buf)%8 == 0 # XXX for simplicity
a = ndarray(len(buf)//8, buffer=buf, dtype=uint64)
a[:] = 0
# set bytes in memory
def memset(buf, c):
assert 0 <= c <= 0xff
assert len(buf)%8 == 0 # XXX for simplicity
a = ndarray(len(buf)//8, buffer=buf, dtype=uint64)
a[:] = (c * 0x0101010101010101)
# copy src buffer memory to dst
# precondition: len(dst) == len(src)
def memcpy(dst, src):
l = len(src)
assert len(dst) == l
assert l % 8 == 0 # XXX for simplicity
adst = ndarray(l//8, buffer=dst, dtype=uint64)
asrc = ndarray(l//8, buffer=src, dtype=uint64)
copyto(adst, asrc)
......@@ -175,6 +175,10 @@ setup(
package_dir = {'wendelin': ''},
packages = ['wendelin'] + ['wendelin.%s' % _ for _ in
install_requires = [
'numpy', # lib/mem
cmdclass = {'build_ext': build_ext,
'll_build_ext': _build_ext, # original build_ext for Makefile
'build_py': build_py,
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