Mercurial > hg
view tests/test-revlog-v2.t @ 41247:a89b20a49c13
rust-cpython: using MissingAncestors from Python code
As precedently done with LazyAncestors on cpython.rs, we test for the
presence of the 'rustext' module.
incrementalmissingrevs() has two callers within the Mercurial core:
`setdiscovery.partialdiscovery` and the `only()` revset.
This move shows a significant discovery performance improvement
in cases where the baseline is slow: using perfdiscovery on the PyPy
repos, prepared with `contrib/discovery-helper <repo> 50 100`, we
get averaged medians of 403ms with the Rust version vs 742ms without
(about 45% better).
But there are still indications that performance can be worse in cases
the baseline is fast, possibly due to the conversion from Python to
Rust and back becoming the bottleneck. We could measure this on
mozilla-central in cases were the delta is just a few changesets.
This requires confirmation, but if that's the reason, then an
upcoming `partialdiscovery` fully in Rust should solve the problem.
Differential Revision: https://phab.mercurial-scm.org/D5551
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Fri, 30 Nov 2018 14:35:57 +0100 |
parents | e7a2cc84dbc0 |
children | 15d35f2ba474 |
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#require reporevlogstore A repo with unknown revlogv2 requirement string cannot be opened $ hg init invalidreq $ cd invalidreq $ echo exp-revlogv2.unknown >> .hg/requires $ hg log abort: repository requires features unknown to this Mercurial: exp-revlogv2.unknown! (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] $ cd .. Can create and open repo with revlog v2 requirement $ cat >> $HGRCPATH << EOF > [experimental] > revlogv2 = enable-unstable-format-and-corrupt-my-data > EOF $ hg init empty-repo $ cd empty-repo $ cat .hg/requires dotencode exp-revlogv2.1 fncache sparserevlog store $ hg log Unknown flags to revlog are rejected >>> with open('.hg/store/00changelog.i', 'wb') as fh: ... fh.write(b'\x00\x04\xde\xad') and None $ hg log abort: unknown flags (0x04) in version 57005 revlog 00changelog.i! [255] $ cd .. Writing a simple revlog v2 works $ hg init simple $ cd simple $ touch foo $ hg -q commit -A -m initial $ hg log changeset: 0:96ee1d7354c4 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: initial Header written as expected $ f --hexdump --bytes 4 .hg/store/00changelog.i .hg/store/00changelog.i: 0000: 00 01 de ad |....| $ f --hexdump --bytes 4 .hg/store/data/foo.i .hg/store/data/foo.i: 0000: 00 01 de ad |....|