branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
Test wire protocol unbundle with hashed heads (capability: unbundlehash)
$ cat << EOF >> $HGRCPATH
> [devel]
> # This tests is intended for bundle1 only.
> # bundle2 carries the head information inside the bundle itself and
> # always uses 'force' as the heads value.
> legacy.exchange = bundle1
> EOF
Create a remote repository.
$ hg init remote
$ hg serve -R remote --config web.push_ssl=False --config web.allow_push=* -p $HGPORT -d --pid-file=hg1.pid -E error.log -A access.log
$ cat hg1.pid >> $DAEMON_PIDS
Clone the repository and push a change.
$ hg clone http://localhost:$HGPORT/ local
no changes found
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ touch local/README
$ hg ci -R local -A -m hoge
adding README
$ hg push -R local
pushing to http://localhost:$HGPORT/
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files
Ensure hashed heads format is used.
The hash here is always the same since the remote repository only has the null head.
$ cat access.log | grep unbundle
* - - [*] "POST /?cmd=unbundle HTTP/1.1" 200 - x-hgarg-1:heads=686173686564+6768033e216468247bd031a0a2d9876d79818f8f* (glob)
Explicitly kill daemons to let the test exit on Windows
$ killdaemons.py