Mercurial > hg
view mercurial/cffi/mpatch.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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# 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 __future__ import absolute_import from ..pure.mpatch import * from ..pure.mpatch import mpatchError # silence pyflakes from . import _mpatch 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("struct mpatch_flist*[1]") to_pass = ffi.new("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("cannot decode chunk") outlen = lib.mpatch_calcsize(len(text), patch) if outlen < 0: lib.mpatch_lfree(patch) raise mpatchError("inconsistency detected") buf = ffi.new("char[]", outlen) if lib.mpatch_apply(buf, text, len(text), patch) < 0: lib.mpatch_lfree(patch) raise mpatchError("error applying patches") res = ffi.buffer(buf, outlen)[:] lib.mpatch_lfree(patch) return res