branchcache: skip entries that are topological heads in the on disk file
In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.
So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.
test branch selection options
$ hg init branch
$ cd branch
$ hg branch a
marked working directory as branch a
(branches are permanent and global, did you want a bookmark?)
$ echo a > foo
$ hg ci -d '0 0' -Ama
adding foo
$ echo a2 > foo
$ hg ci -d '0 0' -ma2
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch c
marked working directory as branch c
$ echo c > foo
$ hg ci -d '0 0' -mc
$ hg tag -l z
$ cd ..
$ hg clone -r 0 branch branch2
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 5b65ba7c951d
updating to branch a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd branch2
$ hg up 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch b
marked working directory as branch b
$ echo b > foo
$ hg ci -d '0 0' -mb
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg --encoding utf-8 branch æ
marked working directory as branch \xc3\xa6 (esc)
$ echo ae1 > foo
$ hg ci -d '0 0' -mae1
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg --encoding utf-8 branch -f æ
marked working directory as branch \xc3\xa6 (esc)
$ echo ae2 > foo
$ hg ci -d '0 0' -mae2
created new head
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch -f b
marked working directory as branch b
$ echo b2 > foo
$ hg ci -d '0 0' -mb2
created new head
unknown branch and fallback
$ hg in -qbz
abort: unknown branch 'z'
[10]
$ hg in -q ../branch#z
2:f25d57ab0566
$ hg out -qbz
abort: unknown branch 'z'
[10]
in rev c branch a
$ hg in -qr c ../branch#a
1:dd6e60a716c6
2:f25d57ab0566
$ hg in -qr c -b a
1:dd6e60a716c6
2:f25d57ab0566
out branch .
$ hg out -q ../branch#.
1:b84708d77ab7
4:65511d0e2b55
$ hg out -q -b .
1:b84708d77ab7
4:65511d0e2b55
out branch . non-ascii
$ hg --encoding utf-8 up æ
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg --encoding latin1 out -q ../branch#.
2:df5a44224d4e
3:4f4a5125ca10
$ hg --encoding latin1 out -q -b .
2:df5a44224d4e
3:4f4a5125ca10
clone branch b
$ cd ..
$ hg clone branch2#b branch3
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files (+1 heads)
new changesets 5b65ba7c951d:65511d0e2b55
updating to branch b
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg -q -R branch3 heads b
2:65511d0e2b55
1:b84708d77ab7
$ hg -q -R branch3 parents
2:65511d0e2b55
$ rm -rf branch3
clone rev a branch b
$ hg clone -r a branch2#b branch3
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files (+1 heads)
new changesets 5b65ba7c951d:65511d0e2b55
updating to branch a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg -q -R branch3 heads b
2:65511d0e2b55
1:b84708d77ab7
$ hg -q -R branch3 parents
0:5b65ba7c951d
$ rm -rf branch3