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 >> $HGRCPATH<<EOF
> [extensions]
> rebase=
> drawdag=$TESTDIR/drawdag.py
> EOF
$ hg init non-merge
$ cd non-merge
$ hg debugdrawdag<<'EOS'
> F
> |
> E
> |
> D
> |
> B C
> |/
> A
> EOS
$ for i in C D E F; do
> hg bookmark -r $i -i BOOK-$i
> done
$ hg debugdrawdag<<'EOS'
> E
> |
> D
> |
> B
> EOS
$ hg log -G -T '{rev} {desc} {bookmarks}'
o 7 E
|
o 6 D
|
| o 5 F BOOK-F
| |
| o 4 E BOOK-E
| |
| o 3 D BOOK-D
| |
| o 2 C BOOK-C
| |
o | 1 B
|/
o 0 A
With --keep, bookmark should move
$ hg rebase -r 3+4 -d E --keep
rebasing 3:e7b3f00ed42e BOOK-D "D"
note: not rebasing 3:e7b3f00ed42e BOOK-D "D", its destination already has all its changes
rebasing 4:69a34c08022a BOOK-E "E"
note: not rebasing 4:69a34c08022a BOOK-E "E", its destination already has all its changes
$ hg log -G -T '{rev} {desc} {bookmarks}'
o 7 E BOOK-D BOOK-E
|
o 6 D
|
| o 5 F BOOK-F
| |
| o 4 E
| |
| o 3 D
| |
| o 2 C BOOK-C
| |
o | 1 B
|/
o 0 A
Move D and E back for the next test
$ hg bookmark BOOK-D -fqir 3
$ hg bookmark BOOK-E -fqir 4
Bookmark is usually an indication of a head. For changes that are introduced by
an ancestor of bookmark B, after moving B to B-NEW, the changes are ideally
still introduced by an ancestor of changeset on B-NEW. In the below case,
"BOOK-D", and "BOOK-E" include changes introduced by "C".
$ hg rebase -s 2 -d E
rebasing 2:dc0947a82db8 BOOK-C C "C"
rebasing 3:e7b3f00ed42e BOOK-D "D"
note: not rebasing 3:e7b3f00ed42e BOOK-D "D", its destination already has all its changes
rebasing 4:69a34c08022a BOOK-E "E"
note: not rebasing 4:69a34c08022a BOOK-E "E", its destination already has all its changes
rebasing 5:6b2aeab91270 BOOK-F F "F"
saved backup bundle to $TESTTMP/non-merge/.hg/strip-backup/dc0947a82db8-52bb4973-rebase.hg
$ hg log -G -T '{rev} {desc} {bookmarks}'
o 5 F BOOK-F
|
o 4 C BOOK-C BOOK-D BOOK-E
|
o 3 E
|
o 2 D
|
o 1 B
|
o 0 A
Merge and its ancestors all become empty
$ hg init $TESTTMP/merge1
$ cd $TESTTMP/merge1
$ hg debugdrawdag<<'EOS'
> E
> /|
> B C D
> \|/
> A
> EOS
$ for i in C D E; do
> hg bookmark -r $i -i BOOK-$i
> done
$ hg debugdrawdag<<'EOS'
> H
> |
> D
> |
> C
> |
> B
> EOS
Previously, there was a bug where the empty commit check compared the parent
branch name with the wdir branch name instead of the actual branch name (which
should stay unchanged if --keepbranches is passed), and erroneously assumed
that an otherwise empty changeset should be created because of the incorrectly
assumed branch name change.
$ hg update H -q
$ hg branch foo -q
$ hg rebase -r '(A::)-(B::)-A' -d H --keepbranches
rebasing 2:dc0947a82db8 BOOK-C "C"
note: not rebasing 2:dc0947a82db8 BOOK-C "C", its destination already has all its changes
rebasing 3:b18e25de2cf5 BOOK-D "D"
note: not rebasing 3:b18e25de2cf5 BOOK-D "D", its destination already has all its changes
rebasing 4:86a1f6686812 BOOK-E E "E"
note: not rebasing 4:86a1f6686812 BOOK-E E "E", its destination already has all its changes
saved backup bundle to $TESTTMP/merge1/.hg/strip-backup/b18e25de2cf5-1fd0a4ba-rebase.hg
$ hg update null -q
$ hg log -G -T '{rev} {desc} {bookmarks}'
o 4 H BOOK-C BOOK-D BOOK-E
|
o 3 D
|
o 2 C
|
o 1 B
|
o 0 A
Part of ancestors of a merge become empty
$ hg init $TESTTMP/merge2
$ cd $TESTTMP/merge2
$ hg debugdrawdag<<'EOS'
> G
> /|
> E F
> | |
> B C D
> \|/
> A
> EOS
$ for i in C D E F G; do
> hg bookmark -r $i -i BOOK-$i
> done
$ hg debugdrawdag<<'EOS'
> H
> |
> F
> |
> C
> |
> B
> EOS
$ hg rebase -r '(A::)-(B::)-A' -d H
rebasing 2:dc0947a82db8 BOOK-C "C"
note: not rebasing 2:dc0947a82db8 BOOK-C "C", its destination already has all its changes
rebasing 3:b18e25de2cf5 BOOK-D D "D"
rebasing 4:03ca77807e91 BOOK-E E "E"
rebasing 5:ad6717a6a58e BOOK-F "F"
note: not rebasing 5:ad6717a6a58e BOOK-F "F", its destination already has all its changes
rebasing 6:c58e8bdac1f4 BOOK-G G "G"
saved backup bundle to $TESTTMP/merge2/.hg/strip-backup/b18e25de2cf5-2d487005-rebase.hg
$ hg log -G -T '{rev} {desc} {bookmarks}'
o 7 G BOOK-G
|\
| o 6 E BOOK-E
| |
o | 5 D BOOK-D BOOK-F
|/
o 4 H BOOK-C
|
o 3 F
|
o 2 C
|
o 1 B
|
o 0 A