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)
#require no-symlink
# The following script was used to create the bundle:
#
# hg init symlinks
# cd symlinks
# echo a > a
# mkdir d
# echo b > d/b
# ln -s a a.lnk
# ln -s d/b d/b.lnk
# hg ci -Am t
# hg bundle --base null ../test-no-symlinks.hg
Extract a symlink on a platform not supporting them
$ hg init t
$ cd t
$ hg pull -q "$TESTDIR/bundles/test-no-symlinks.hg"
$ hg update
4 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat a.lnk && echo
a
$ cat d/b.lnk && echo
d/b
Copy a symlink and move another
$ hg copy a.lnk d/a2.lnk
$ hg mv d/b.lnk b2.lnk
$ hg ci -Am copy
$ cat d/a2.lnk && echo
a
$ cat b2.lnk && echo
d/b
Bundle and extract again
$ hg bundle --base null ../symlinks.hg
2 changesets found
$ cd ..
$ hg init t2
$ cd t2
$ hg pull ../symlinks.hg
pulling from ../symlinks.hg
requesting all changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 6 changes to 6 files
new changesets d326ae2d01ee:71d85cf3ba90 (2 drafts)
(run 'hg update' to get a working copy)
$ hg update
5 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat a.lnk && echo
a
$ cat d/a2.lnk && echo
a
$ cat b2.lnk && echo
d/b