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.
$ cat >> $HGRCPATH << EOF
> [extensions]
> blackbox=
> rebase=
> mock=$TESTDIR/mockblackbox.py
>
> [blackbox]
> track = command, commandfinish, tagscache
>
> [experimental]
> evolution.createmarkers=True
> EOF
Create a repo with some tags
$ hg init repo
$ cd repo
$ echo initial > foo
$ hg -q commit -A -m initial
$ hg tag -m 'test tag' test1
$ echo first > first
$ hg -q commit -A -m first
$ hg tag -m 'test2 tag' test2
$ hg -q up -r 0
$ echo newhead > newhead
$ hg commit -A -m newhead
adding newhead
created new head
$ hg tag -m 'test head 2 tag' head2
$ hg log -G -T '{rev}:{node|short} {tags} {desc}\n'
@ 5:2942a772f72a tip test head 2 tag
|
o 4:042eb6bfcc49 head2 newhead
|
| o 3:c3cb30f2d2cd test2 tag
| |
| o 2:d75775ffbc6b test2 first
| |
| o 1:5f97d42da03f test tag
|/
o 0:55482a6fb4b1 test1 initial
Trigger tags cache population by doing something that accesses tags info
$ hg tags
tip 5:2942a772f72a
head2 4:042eb6bfcc49
test2 2:d75775ffbc6b
test1 0:55482a6fb4b1
$ cat .hg/cache/tags2-visible
5 2942a772f72a444bef4bef13874d515f50fa27b6
042eb6bfcc4909bad84a1cbf6eb1ddf0ab587d41 head2
55482a6fb4b1881fa8f746fd52cf6f096bb21c89 test1
d75775ffbc6bca1794d300f5571272879bd280da test2
Hiding a non-tip changeset should change filtered hash and cause tags recompute
$ hg debugobsolete -d '0 0' c3cb30f2d2cd0aae008cc91a07876e3c5131fd22 -u dummyuser
1 new obsolescence markers
obsoleted 1 changesets
$ hg tags
tip 5:2942a772f72a
head2 4:042eb6bfcc49
test1 0:55482a6fb4b1
$ cat .hg/cache/tags2-visible
5 2942a772f72a444bef4bef13874d515f50fa27b6 f34fbc9a9769ba9eff5aff3d008a6b49f85c08b1
042eb6bfcc4909bad84a1cbf6eb1ddf0ab587d41 head2
55482a6fb4b1881fa8f746fd52cf6f096bb21c89 test1
$ hg blackbox -l 5
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> tags
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> 2/2 cache hits/lookups in * seconds (glob)
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> writing .hg/cache/tags2-visible with 2 tags
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> tags exited 0 after * seconds (glob)
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> blackbox -l 5
Hiding another changeset should cause the filtered hash to change
$ hg debugobsolete -d '0 0' d75775ffbc6bca1794d300f5571272879bd280da -u dummyuser
1 new obsolescence markers
obsoleted 1 changesets
$ hg debugobsolete -d '0 0' 5f97d42da03fd56f3b228b03dfe48af5c0adf75b -u dummyuser
1 new obsolescence markers
obsoleted 1 changesets
$ hg tags
tip 5:2942a772f72a
head2 4:042eb6bfcc49
$ cat .hg/cache/tags2-visible
5 2942a772f72a444bef4bef13874d515f50fa27b6 2fce1eec33263d08a4d04293960fc73a555230e4
042eb6bfcc4909bad84a1cbf6eb1ddf0ab587d41 head2
$ hg blackbox -l 5
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> tags
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> 1/1 cache hits/lookups in * seconds (glob)
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> writing .hg/cache/tags2-visible with 1 tags
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> tags exited 0 after * seconds (glob)
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> blackbox -l 5
Resolving tags on an unfiltered repo writes a separate tags cache
$ hg --hidden tags
tip 5:2942a772f72a
head2 4:042eb6bfcc49
test2 2:d75775ffbc6b
test1 0:55482a6fb4b1
$ cat .hg/cache/tags2
5 2942a772f72a444bef4bef13874d515f50fa27b6
042eb6bfcc4909bad84a1cbf6eb1ddf0ab587d41 head2
55482a6fb4b1881fa8f746fd52cf6f096bb21c89 test1
d75775ffbc6bca1794d300f5571272879bd280da test2
$ hg blackbox -l 5
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> --hidden tags
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> 2/2 cache hits/lookups in * seconds (glob)
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> writing .hg/cache/tags2 with 3 tags
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> --hidden tags exited 0 after * seconds (glob)
1970-01-01 00:00:00.000 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> blackbox -l 5