outgoing: rework the handling of the `missingroots` case to be faster
The previous implementation was slow, to the point it was taking a significant
amount of `hg bundle --type none-streamv2` call. We rework the code to compute
the same value much faster, making the operation disappear from the `hg bundle
--type none-streamv2` profile. Someone would remark that producing a streamclone
does not requires an `outgoing` object. However that is a matter for another
day. There is other user of `missingroots` (non stream `hg bundle` call for
example), and they will also benefit from this rework.
We implement an old TODO in the process, directly computing the missing and
common attribute as we have most element at hand already.
### benchmark.name = hg.command.bundle
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.revs = all
# benchmark.variants.type = none-streamv2
## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog
before: 7.750458
after: 6.665565 (-14.00%, -1.08)
## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog
before: 0.700229
after: 0.496050 (-29.16%, -0.20)
## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
before: 346.508952
after: 316.749699 (-8.59%, -29.76)
## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog
before: 3.401700
after: 2.915810 (-14.28%, -0.49)
## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog
before: 1.870798
after: 1.461583 (-21.87%, -0.41)
note: this whole `missingroots` of outgoing has a limited number of callers and
could likely be replace by something simpler (like taking an explicit
"missing_revs" set for example). However this is a wider change and we focus on
a small impact, quick rework that does not change the API for now.
#require no-windows
$ . "$TESTDIR/remotefilelog-library.sh"
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> server=True
> EOF
$ echo x > x
$ hg commit -qAm x
$ echo y >> x
$ hg commit -qAm y
$ echo z >> x
$ hg commit -qAm z
$ hg update 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo w >> x
$ hg commit -qAm w
$ cd ..
Shallow clone and activate getflogheads testing extension
$ hgcloneshallow ssh://user@dummy/master shallow --noupdate
streaming all changes
3 files to transfer, 908 bytes of data (no-rust !)
transferred 908 bytes in * seconds (*/sec) (glob) (no-rust !)
5 files to transfer, 1.01 KB of data (rust !)
transferred 1.01 KB in * seconds (* */sec) (glob) (rust !)
searching for changes
no changes found
$ cd shallow
$ cat >> .hg/hgrc <<EOF
> [extensions]
> getflogheads=$TESTDIR/remotefilelog-getflogheads.py
> EOF
Get heads of a remotefilelog
$ hg getflogheads x
2797809ca5e9c2f307d82b1345e832f655fb99a2
ca758b402ddc91e37e3113e1a97791b537e1b7bb
Get heads of a non-existing remotefilelog
$ hg getflogheads y
EMPTY