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.
#require svn13
$ cat <<EOF >> $HGRCPATH
> [extensions]
> mq =
> [diff]
> nodates = 1
> [subrepos]
> allowed = true
> svn:allowed = true
> EOF
fn to create new repository, and cd into it
$ mkrepo() {
> hg init $1
> cd $1
> hg qinit
> }
handle svn subrepos safely
$ svnadmin create svn-repo-2499
$ SVNREPOPATH=`pwd`/svn-repo-2499/project
$ SVNREPOURL="`"$PYTHON" $TESTDIR/svnurlof.py \"$SVNREPOPATH\"`"
$ mkdir -p svn-project-2499/trunk
$ svn import -qm 'init project' svn-project-2499 "$SVNREPOURL"
qnew on repo w/svn subrepo
$ mkrepo repo-2499-svn-subrepo
$ svn co "$SVNREPOURL"/trunk sub
Checked out revision 1.
$ echo 'sub = [svn]sub' >> .hgsub
$ hg add .hgsub
$ hg status -S -X '**/format'
A .hgsub
$ hg qnew -m0 0.diff
$ cd sub
$ echo foo > a
$ svn add a
A a
$ svn st
A* a (glob)
$ cd ..
$ hg status -S # doesn't show status for svn subrepos (yet)
$ hg qnew -m1 1.diff
abort: uncommitted changes in subrepository "sub"
[255]
$ cd ..