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-2
=========================================
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 2: A branch is split in two, effectively creating two heads
.. old-state:
..
.. * 2 changesets on branch default
.. * 2 changesets on branch Z on top of them
..
.. new-state:
..
.. * 2 changesets on branch Z at the same location
.. * 1 changeset on branch default unchanged
.. * 1 changeset on branch default superseding the other ones
..
.. expected-result:
..
.. * two heads detected
..
.. graph-summary:
..
.. D ● (branch Z)
.. |
.. C ● (branch Z)
.. |
.. B ø⇠◔ B'
.. | |
.. A ● |
.. |/
.. ●
$ . $TESTDIR/testlib/push-checkheads-util.sh
$ cat >> $HGRCPATH << EOF
> [command-templates]
> log = "{node|short} [{branch}] ({phase}): {desc}\n"
> EOF
Test setup
----------
$ mkdir A2
$ cd A2
$ 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
$ mkcommit B0
$ hg branch Z
marked working directory as branch Z
(branches are permanent and global, did you want a bookmark?)
$ mkcommit C0
$ mkcommit D0
$ hg push --new-branch
pushing to $TESTTMP/A2/server
searching for changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 3 files
$ hg up 0
0 files updated, 0 files merged, 4 files removed, 0 files unresolved
$ mkcommit B1
created new head
$ hg debugobsolete `getid "desc(B0)"` `getid "desc(B1)"`
1 new obsolescence markers
obsoleted 1 changesets
2 new orphan changesets
$ hg heads
25c56d33e4c4 [default] (draft): B1
cdf1dbb37a67 [Z] (draft): D0
8aaa48160adc [default] (draft): A0
$ hg log -G --hidden
@ 25c56d33e4c4 [default] (draft): B1
|
| * cdf1dbb37a67 [Z] (draft): D0
| |
| * 3213e3e16c67 [Z] (draft): C0
| |
| x d73caddc5533 [default] (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("B1")' --force
pushing to $TESTTMP/A2/server
searching for changes
adding changesets
adding manifests
adding file changes
transaction abort!
rollback completed
abort: rejecting multiple heads on branch "default"
(2 heads: 8aaa48160adc 25c56d33e4c4)
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