branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
>
> [phases]
> publish=False
>
> [alias]
> tglog = log -G --template "{rev}: {node|short} '{desc}' {branches}\n"
> EOF
$ hg init a
$ cd a
$ echo c1 > c1
$ hg ci -Am c1
adding c1
$ echo c2 > c2
$ hg ci -Am c2
adding c2
$ echo l1 > l1
$ hg ci -Am l1
adding l1
$ hg up -q -C 1
$ echo r1 > r1
$ hg ci -Am r1
adding r1
created new head
$ echo r2 > r2
$ hg ci -Am r2
adding r2
$ hg tglog
@ 4: 225af64d03e6 'r2'
|
o 3: 8d0a8c99b309 'r1'
|
| o 2: 87c180a611f2 'l1'
|/
o 1: 56daeba07f4b 'c2'
|
o 0: e8faad3d03ff 'c1'
Rebase with no arguments - single revision in source branch:
$ hg up -q -C 2
$ hg rebase
rebasing 2:87c180a611f2 "l1"
saved backup bundle to $TESTTMP/a/.hg/strip-backup/87c180a611f2-a5be192d-rebase.hg
$ hg tglog
@ 4: b1152cc99655 'l1'
|
o 3: 225af64d03e6 'r2'
|
o 2: 8d0a8c99b309 'r1'
|
o 1: 56daeba07f4b 'c2'
|
o 0: e8faad3d03ff 'c1'
$ cd ..
$ hg init b
$ cd b
$ echo c1 > c1
$ hg ci -Am c1
adding c1
$ echo c2 > c2
$ hg ci -Am c2
adding c2
$ echo l1 > l1
$ hg ci -Am l1
adding l1
$ echo l2 > l2
$ hg ci -Am l2
adding l2
$ hg up -q -C 1
$ echo r1 > r1
$ hg ci -Am r1
adding r1
created new head
$ hg tglog
@ 4: 8d0a8c99b309 'r1'
|
| o 3: 1ac923b736ef 'l2'
| |
| o 2: 87c180a611f2 'l1'
|/
o 1: 56daeba07f4b 'c2'
|
o 0: e8faad3d03ff 'c1'
Rebase with no arguments - single revision in target branch:
$ hg up -q -C 3
$ hg rebase
rebasing 2:87c180a611f2 "l1"
rebasing 3:1ac923b736ef "l2"
saved backup bundle to $TESTTMP/b/.hg/strip-backup/87c180a611f2-b980535c-rebase.hg
$ hg tglog
@ 4: 023181307ed0 'l2'
|
o 3: 913ab52b43b4 'l1'
|
o 2: 8d0a8c99b309 'r1'
|
o 1: 56daeba07f4b 'c2'
|
o 0: e8faad3d03ff 'c1'
$ cd ..