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.
=========================================
Testing single head enforcement: Case A-4
=========================================
A repository is set to only accept a single head per name (typically named
branch). However, obsolete changesets can make this enforcement more
complicated, because they can be kept visible by other changeset on other
branch.
This case is part of a series of tests checking this behavior.
Category A: Involving obsolescence
TestCase 4: Partial rewrite of a branch to deinterleave it
.. old-state:
..
.. * 2 changesets on branch default
.. * 2 changesets on branch Z interleaved with the other one
..
.. new-state:
..
.. * 2 changesets on branch Z at the same location
.. * 1 changeset on default untouched (the lower one)
.. * 1 changeset on default moved on the other one
..
.. expected-result:
..
.. * only one head detected
..
.. graph-summary:
..
.. D ● (branch Z)
.. |
.. C ø⇠◔ C'
.. | |
.. B ● | (branch Z)
.. |/
.. A ●
.. |
.. ●
$ . $TESTDIR/testlib/push-checkheads-util.sh
$ cat >> $HGRCPATH << EOF
> [command-templates]
> log = "{node|short} [{branch}] ({phase}): {desc}\n"
> EOF
Test setup
----------
$ mkdir A4
$ cd A4
$ setuprepos single-head
creating basic server and client repo
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd client
$ hg branch Z
marked working directory as branch Z
(branches are permanent and global, did you want a bookmark?)
$ mkcommit B0
$ hg branch default --force
marked working directory as branch default
$ mkcommit C0
created new head
$ hg branch Z --force
marked working directory as branch Z
$ mkcommit D0
created new head
$ hg push --new-branch
pushing to $TESTTMP/A4/server
searching for changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 3 files
$ hg up 'desc("A0")'
0 files updated, 0 files merged, 3 files removed, 0 files unresolved
$ mkcommit C1
created new head
$ hg debugobsolete `getid "desc(C0)"` `getid "desc(C1)"`
1 new obsolescence markers
obsoleted 1 changesets
1 new orphan changesets
$ hg heads
cfe9ed94fa4a [default] (draft): C1
78578c4306ce [Z] (draft): D0
$ hg log -G --hidden
@ cfe9ed94fa4a [default] (draft): C1
|
| * 78578c4306ce [Z] (draft): D0
| |
| x afc55ba2ce61 [default] (draft): C0
| |
| o 93e5c1321ece [Z] (draft): B0
|/
o 8aaa48160adc [default] (draft): A0
|
o 1e4be0697311 [default] (public): root
Actual testing
--------------
(force push to make sure we get the changeset on the remote)
$ hg push -r 'desc("C1")' --force
pushing to $TESTTMP/A4/server
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
1 new obsolescence markers
obsoleted 1 changesets
1 new orphan changesets