Mercurial > hg
view mercurial/cffi/bdiff.py @ 37007:143219fc2620
debugcommands: introduce actions to perform deterministic reads
"readavailable" is useful as a debugging device to see what data is
available on a pipe. But the mechanism isn't deterministic because
what's available on a pipe is highly conditional on timing, system
load, OS behavior, etc. This makes it not suitable for tests.
We introduce "ereadline," "read," and "eread" for performing
deterministic I/O operations (at least on blocking file descriptors).
We stop short of converting existing consumers of "readavailable"
in tests because we're working out race conditions and deadlocks
on Windows. But the goal is to eventually move tests away from
"readavailable" to these new APIs.
Differential Revision: https://phab.mercurial-scm.org/D2720
author | Gregory Szorc <gregory.szorc@gmail.com> |
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date | Mon, 12 Mar 2018 15:49:02 -0700 |
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)