Mercurial > hg
view mercurial/cffi/bdiff.py @ 33822:42ad7cc645a4
copies: add more details to the documentation of mergecopies()
This documentation is very helpful for any developer to understand what
copytracing is and what the function does. Since this is the main function of
doing copytracing, I have also included bits about copytracing in it.
This additions are picked from a doc by Stash@Fb. So thanks to him.
Differential Revision: https://phab.mercurial-scm.org/D409
author | Pulkit Goyal <7895pulkit@gmail.com> |
---|---|
date | Wed, 16 Aug 2017 00:25:20 +0530 |
parents | 857876ebaed4 |
children | 2372284d9457 |
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# bdiff.py - CFFI implementation of bdiff.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 __future__ import absolute_import import struct from ..pure.bdiff import * from . import _bdiff ffi = _bdiff.ffi lib = _bdiff.lib def blocks(sa, sb): a = ffi.new("struct bdiff_line**") b = ffi.new("struct bdiff_line**") ac = ffi.new("char[]", str(sa)) bc = ffi.new("char[]", str(sb)) l = ffi.new("struct bdiff_hunk*") try: an = lib.bdiff_splitlines(ac, len(sa), a) bn = lib.bdiff_splitlines(bc, len(sb), b) if not a[0] or not b[0]: raise MemoryError count = lib.bdiff_diff(a[0], an, b[0], bn, l) if count < 0: raise MemoryError rl = [None] * count h = l.next i = 0 while h: rl[i] = (h.a1, h.a2, h.b1, h.b2) h = h.next i += 1 finally: lib.free(a[0]) lib.free(b[0]) lib.bdiff_freehunks(l.next) return rl def bdiff(sa, sb): a = ffi.new("struct bdiff_line**") b = ffi.new("struct bdiff_line**") ac = ffi.new("char[]", str(sa)) bc = ffi.new("char[]", str(sb)) l = ffi.new("struct bdiff_hunk*") try: an = lib.bdiff_splitlines(ac, len(sa), a) bn = lib.bdiff_splitlines(bc, len(sb), b) if not a[0] or not b[0]: raise MemoryError count = lib.bdiff_diff(a[0], an, b[0], bn, l) if count < 0: raise MemoryError rl = [] h = l.next la = lb = 0 while h: if h.a1 != la or h.b1 != lb: lgt = (b[0] + h.b1).l - (b[0] + lb).l rl.append(struct.pack(">lll", (a[0] + la).l - a[0].l, (a[0] + h.a1).l - a[0].l, lgt)) rl.append(str(ffi.buffer((b[0] + lb).l, lgt))) la = h.a2 lb = h.b2 h = h.next finally: lib.free(a[0]) lib.free(b[0]) lib.bdiff_freehunks(l.next) return "".join(rl)