Mercurial > hg
view mercurial/cffi/mpatch.py @ 50317:af776c3d5c3e stable
debugdeltachain: stop summing the same chain over and over
Before this patch, delta chain size was computed from scratch for each chain,
disregarding the fact very likely already computed the same of length-1 prefix
for another revisions.
We not cache delta chain size and shortcut the computation when we see them.
Just for my mercurial-devel clone, this move the computation from about 17.5
second to about 4.8 seconds.
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Tue, 21 Mar 2023 15:44:38 +0000 |
parents | 94a797032fc4 |
children | ecc3a893979d |
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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 typing import List 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: bytes, bins: List[bytes]) -> bytes: 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