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.
This test file aims at test topological iteration and the various configuration it can has.
$ cat >> $HGRCPATH << EOF
> [command-templates]
> log={rev}\n
> EOF
On this simple example, all topological branch are displayed in turn until we
can finally display 0. this implies skipping from 8 to 3 and coming back to 7
later.
$ hg init test01
$ cd test01
$ hg unbundle $TESTDIR/bundles/remote.hg
adding changesets
adding manifests
adding file changes
added 9 changesets with 7 changes to 4 files (+1 heads)
new changesets bfaf4b5cbf01:916f1afdef90 (9 drafts)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg log -G
o 8
|
| o 7
| |
| o 6
| |
| o 5
| |
| o 4
| |
o | 3
| |
o | 2
| |
o | 1
|/
o 0
(display all nodes)
$ hg log -G -r 'sort(all(), topo)'
o 8
|
o 3
|
o 2
|
o 1
|
| o 7
| |
| o 6
| |
| o 5
| |
| o 4
|/
o 0
(display nodes filtered by log options)
$ hg log -G -r 'sort(all(), topo)' -k '.3'
o 8
|
o 3
|
~
o 7
|
o 6
|
~
(revset skipping nodes)
$ hg log -G --rev 'sort(not (2+6), topo)'
o 8
|
o 3
:
o 1
|
| o 7
| :
| o 5
| |
| o 4
|/
o 0
(begin) from the other branch
$ hg log -G -r 'sort(all(), topo, topo.firstbranch=5)'
o 7
|
o 6
|
o 5
|
o 4
|
| o 8
| |
| o 3
| |
| o 2
| |
| o 1
|/
o 0
Topological sort can be turned on via config
$ cat >> $HGRCPATH << EOF
> [experimental]
> log.topo=true
> EOF
$ hg log -G
o 8
|
o 3
|
o 2
|
o 1
|
| o 7
| |
| o 6
| |
| o 5
| |
| o 4
|/
o 0
Does not affect non-graph log
$ hg log -T '{rev}\n'
8
7
6
5
4
3
2
1
0