tags-cache: directly perform a monimal walk for hgtagsfnodescache warming
We do something narrower than the path retrieving data. So lets use dedicated
code instead.
This provides further useful speedup:
### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
# benchmark.name = hg.debug.debug-update-cache
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.pre-state = warm
before-this-series: 19.947581
skip-fnode-filter: 18.916804 (-5.17%, -1.03)
use-rev-num: 17.493725 (-12.30%, -2.45)
this-changesets: 15.919466 (-20.19%, -4.03)
$ hg init repo
$ cd repo
$ echo 0 > a
$ hg ci -qAm 0
$ for i in 5 8 14 43 167; do
> hg up -q 0
> echo $i > a
> hg ci -qm $i
> done
$ cat <<EOF >> .hg/hgrc
> [alias]
> l = log -T '{rev}:{shortest(node,1)}\n'
> EOF
$ hg l
5:00f
4:7ba5d
3:7ba57
2:72
1:9
0:b
$ cat <<EOF >> .hg/hgrc
> [experimental]
> revisions.disambiguatewithin=not 4
> EOF
$ hg l
5:00
4:7ba5d
3:7b
2:72
1:9
0:b
9 was unambiguous and still is
$ hg l -r 9
1:9
7 was ambiguous and still is
$ hg l -r 7
abort: ambiguous revision identifier: 7
[10]
7b is no longer ambiguous
$ hg l -r 7b
3:7b
$ cd ..