# mpatch.py - CFFI implementation of mpatch.c
#
# Copyright 2016 Maciej Fijalkowski <fijall@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from ..pure.mpatch import *
from ..pure.mpatch import mpatchError # silence pyflakes
from . import _mpatch # pytype: disable=import-error
ffi = _mpatch.ffi
lib = _mpatch.lib
@ffi.def_extern()
def cffi_get_next_item(arg, pos):
all, bins = ffi.from_handle(arg)
container = ffi.new(b"struct mpatch_flist*[1]")
to_pass = ffi.new(b"char[]", str(bins[pos]))
all.append(to_pass)
r = lib.mpatch_decode(to_pass, len(to_pass) - 1, container)
if r < 0:
return ffi.NULL
return container[0]
def patches(text, bins):
lgt = len(bins)
all = []
if not lgt:
return text
arg = (all, bins)
patch = lib.mpatch_fold(ffi.new_handle(arg), lib.cffi_get_next_item, 0, lgt)
if not patch:
raise mpatchError(b"cannot decode chunk")
outlen = lib.mpatch_calcsize(len(text), patch)
if outlen < 0:
lib.mpatch_lfree(patch)
raise mpatchError(b"inconsistency detected")
buf = ffi.new(b"char[]", outlen)
if lib.mpatch_apply(buf, text, len(text), patch) < 0:
lib.mpatch_lfree(patch)
raise mpatchError(b"error applying patches")
res = ffi.buffer(buf, outlen)[:]
lib.mpatch_lfree(patch)
return res