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.
$ hg init
$ echo foo > a
$ echo foo > b
$ hg add a b
$ hg ci -m "test"
$ echo blah > a
$ hg ci -m "branch a"
$ hg co 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo blah > b
$ hg ci -m "branch b"
created new head
$ HGMERGE=true hg merge 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merge b/a -> blah"
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ HGMERGE=true hg merge 2
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merge a/b -> blah"
created new head
$ hg log
changeset: 4:2ee31f665a86
tag: tip
parent: 1:96155394af80
parent: 2:92cc4c306b19
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: merge a/b -> blah
changeset: 3:e16a66a37edd
parent: 2:92cc4c306b19
parent: 1:96155394af80
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: merge b/a -> blah
changeset: 2:92cc4c306b19
parent: 0:5e0375449e74
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: branch b
changeset: 1:96155394af80
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: branch a
changeset: 0:5e0375449e74
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: test
$ hg debugindex --changelog
rev linkrev nodeid p1-nodeid p2-nodeid
0 0 5e0375449e74 000000000000 000000000000
1 1 96155394af80 5e0375449e74 000000000000
2 2 92cc4c306b19 5e0375449e74 000000000000
3 3 e16a66a37edd 92cc4c306b19 96155394af80
4 4 2ee31f665a86 96155394af80 92cc4c306b19
revision 1
$ hg manifest --debug 1
79d7492df40aa0fa093ec4209be78043c181f094 644 a
2ed2a3912a0b24502043eae84ee4b279c18b90dd 644 b
revision 2
$ hg manifest --debug 2
2ed2a3912a0b24502043eae84ee4b279c18b90dd 644 a
79d7492df40aa0fa093ec4209be78043c181f094 644 b
revision 3
$ hg manifest --debug 3
79d7492df40aa0fa093ec4209be78043c181f094 644 a
79d7492df40aa0fa093ec4209be78043c181f094 644 b
revision 4
$ hg manifest --debug 4
79d7492df40aa0fa093ec4209be78043c181f094 644 a
79d7492df40aa0fa093ec4209be78043c181f094 644 b
$ hg debugindex a
rev linkrev nodeid p1-nodeid p2-nodeid
0 0 2ed2a3912a0b 000000000000 000000000000
1 1 79d7492df40a 2ed2a3912a0b 000000000000
$ hg verify -q