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.
$ heads()
> {
> hg heads --template '{rev}: {desc|firstline|strip} ({branches})\n' "$@"
> }
$ hg init a
$ cd a
$ echo 'root' >root
$ hg add root
$ hg commit -m "Adding root node"
$ heads
0: Adding root node ()
-------
$ heads .
0: Adding root node ()
=======
$ echo 'a' >a
$ hg add a
$ hg branch a
marked working directory as branch a
(branches are permanent and global, did you want a bookmark?)
$ hg commit -m "Adding a branch"
$ heads
1: Adding a branch (a)
0: Adding root node ()
-------
$ heads .
1: Adding a branch (a)
=======
$ hg update -C 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo 'b' >b
$ hg add b
$ hg branch b
marked working directory as branch b
$ hg commit -m "Adding b branch"
$ heads
2: Adding b branch (b)
1: Adding a branch (a)
0: Adding root node ()
-------
$ heads .
2: Adding b branch (b)
=======
$ echo 'bh1' >bh1
$ hg add bh1
$ hg commit -m "Adding b branch head 1"
$ heads
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
$ heads .
3: Adding b branch head 1 (b)
=======
$ hg update -C 2
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo 'bh2' >bh2
$ hg add bh2
$ hg commit -m "Adding b branch head 2"
created new head
$ heads
4: Adding b branch head 2 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
$ heads .
4: Adding b branch head 2 (b)
3: Adding b branch head 1 (b)
=======
$ hg update -C 2
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo 'bh3' >bh3
$ hg add bh3
$ hg commit -m "Adding b branch head 3"
created new head
$ heads
5: Adding b branch head 3 (b)
4: Adding b branch head 2 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
$ heads .
5: Adding b branch head 3 (b)
4: Adding b branch head 2 (b)
3: Adding b branch head 1 (b)
=======
$ hg merge 4
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg commit -m "Merging b branch head 2 and b branch head 3"
$ heads
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
$ heads .
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
=======
$ echo 'c' >c
$ hg add c
$ hg branch c
marked working directory as branch c
$ hg commit -m "Adding c branch"
$ heads
7: Adding c branch (c)
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
$ heads .
7: Adding c branch (c)
=======
$ heads -r 3 .
no open branch heads found on branches c (started at 3)
[1]
$ heads -r 2 .
7: Adding c branch (c)
-------
$ hg update -C 4
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
-------
$ heads -r 3 .
3: Adding b branch head 1 (b)
-------
$ heads -r 2 .
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
-------
$ heads -r 7 .
no open branch heads found on branches b (started at 7)
[1]
=======
$ for i in 0 1 2 3 4 5 6 7; do
> hg update -C "$i"
> heads
> echo '-------'
> heads .
> echo '-------'
> done
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
7: Adding c branch (c)
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
0: Adding root node ()
-------
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
7: Adding c branch (c)
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
1: Adding a branch (a)
-------
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
7: Adding c branch (c)
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
-------
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
7: Adding c branch (c)
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
-------
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
7: Adding c branch (c)
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
-------
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
7: Adding c branch (c)
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
-------
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
7: Adding c branch (c)
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
-------
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
7: Adding c branch (c)
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
-------
7: Adding c branch (c)
-------
=======
$ for i in a b c z; do
> heads "$i"
> echo '-------'
> done
1: Adding a branch (a)
-------
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
-------
7: Adding c branch (c)
-------
abort: unknown revision 'z'
-------
=======
$ heads 0 1 2 3 4 5 6 7
7: Adding c branch (c)
6: Merging b branch head 2 and b branch head 3 (b)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
0: Adding root node ()
Topological heads:
$ heads -t
7: Adding c branch (c)
3: Adding b branch head 1 (b)
1: Adding a branch (a)
$ cd ..
______________
"created new head" message tests
$ hg init newheadmsg
$ cd newheadmsg
Init: no msg
$ echo 1 > a
$ hg ci -Am "a0: Initial root"
adding a
$ echo 2 >> a
$ hg ci -m "a1 (HN)"
$ hg branch b
marked working directory as branch b
(branches are permanent and global, did you want a bookmark?)
$ echo 1 > b
$ hg ci -Am "b2: Initial root for branch b"
adding b
$ echo 2 >> b
$ hg ci -m "b3 (HN)"
Case NN: msg
$ hg up -q null
$ hg branch -f b
marked working directory as branch b
$ echo 1 > bb
$ hg ci -Am "b4 (NN): new topo root for branch b"
adding bb
created new head
Case HN: no msg
$ echo 2 >> bb
$ hg ci -m "b5 (HN)"
Case BN: msg
$ hg branch -f default
marked working directory as branch default
$ echo 1 > aa
$ hg ci -Am "a6 (BN): new branch root"
adding aa
created new head
Case CN: msg
$ hg up -q 4
$ echo 3 >> bbb
$ hg ci -Am "b7 (CN): regular new head"
adding bbb
created new head
Case BB: msg
$ hg up -q 4
$ hg merge -q 3
$ hg branch -f default
marked working directory as branch default
$ hg ci -m "a8 (BB): weird new branch root"
created new head
Case CB: msg
$ hg up -q 4
$ hg merge -q 1
$ hg ci -m "b9 (CB): new head from branch merge"
created new head
Case HB: no msg
$ hg up -q 7
$ hg merge -q 6
$ hg ci -m "b10 (HB): continuing head from branch merge"
Case CC: msg
$ hg up -q 4
$ hg merge -q 2
$ hg ci -m "b11 (CC): new head from merge"
created new head
Case CH: no msg
$ hg up -q 2
$ hg merge -q 10
$ hg ci -m "b12 (CH): continuing head from merge"
Case HH: no msg
$ hg merge -q 3
$ hg ci -m "b12 (HH): merging two heads"
$ cd ..