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.
Make a narrow clone then archive it
$ . "$TESTDIR/narrow-library.sh"
$ hg init master
$ cd master
$ for x in `$TESTDIR/seq.py 3`; do
> echo $x > "f$x"
> hg add "f$x"
> hg commit -m "Add $x"
> done
$ hg serve -a localhost -p $HGPORT1 -d --pid-file=hg.pid
$ cat hg.pid >> "$DAEMON_PIDS"
$ cd ..
$ hg clone --narrow --include f1 --include f2 http://localhost:$HGPORT1/ narrowclone1
requesting all changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 2 changes to 2 files
new changesets * (glob)
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
The tar should only contain f1 and f2
$ cd narrowclone1
$ hg archive -t tgz repo.tgz
$ tar tfz repo.tgz
repo/f1
repo/f2