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.
$ . "$TESTDIR/histedit-helpers.sh"
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ hg init r
$ cd r
$ for x in a b c d e f ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
$ hg book -r 1 will-move-backwards
$ hg book -r 2 two
$ hg book -r 2 also-two
$ hg book -r 3 three
$ hg book -r 4 four
$ hg book -r tip five
$ hg log --graph
@ changeset: 5:652413bf663e
| bookmark: five
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:e860deea161a
| bookmark: four
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:055a42cdd887
| bookmark: three
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:177f92b77385
| bookmark: also-two
| bookmark: two
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| bookmark: will-move-backwards
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
$ HGEDITOR=cat hg histedit 1
pick d2ae7f538514 1 b
pick 177f92b77385 2 c
pick 055a42cdd887 3 d
pick e860deea161a 4 e
pick 652413bf663e 5 f
# Edit history between d2ae7f538514 and 652413bf663e
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but allow edits before making new commit
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
$ hg histedit 1 --commands - --verbose << EOF | grep histedit
> pick 177f92b77385 2 c
> drop d2ae7f538514 1 b
> pick 055a42cdd887 3 d
> fold e860deea161a 4 e
> pick 652413bf663e 5 f
> EOF
saved backup bundle to $TESTTMP/r/.hg/strip-backup/96e494a2d553-45c027ab-histedit.hg
$ hg log --graph
@ changeset: 3:cacdfd884a93
| bookmark: five
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 2:59d9f330561f
| bookmark: four
| bookmark: three
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 1:b346ab9a313d
| bookmark: also-two
| bookmark: two
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 0:cb9a9f314b8b
bookmark: will-move-backwards
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
$ HGEDITOR=cat hg histedit 1
pick b346ab9a313d 1 c
pick 59d9f330561f 2 d
pick cacdfd884a93 3 f
# Edit history between b346ab9a313d and cacdfd884a93
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but allow edits before making new commit
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
$ hg histedit 1 --commands - --verbose << EOF | grep histedit
> pick b346ab9a313d 1 c
> pick cacdfd884a93 3 f
> pick 59d9f330561f 2 d
> EOF
saved backup bundle to $TESTTMP/r/.hg/strip-backup/59d9f330561f-073008af-histedit.hg
We expect 'five' to stay at tip, since the tipmost bookmark is most
likely the useful signal.
$ hg log --graph
@ changeset: 3:c04e50810e4b
| bookmark: five
| bookmark: four
| bookmark: three
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:c13eb81022ca
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 1:b346ab9a313d
| bookmark: also-two
| bookmark: two
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 0:cb9a9f314b8b
bookmark: will-move-backwards
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a