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 interaction of sparse and narrow when both are enabled on the client
side and we do a non-ellipsis clone
#testcases tree flat
$ . "$TESTDIR/narrow-library.sh"
$ cat << EOF >> $HGRCPATH
> [extensions]
> sparse =
> EOF
#if tree
$ cat << EOF >> $HGRCPATH
> [experimental]
> treemanifest = 1
> EOF
#endif
$ hg init master
$ cd master
$ mkdir inside
$ echo 'inside' > inside/f
$ hg add inside/f
$ hg commit -m 'add inside'
$ mkdir widest
$ echo 'widest' > widest/f
$ hg add widest/f
$ hg commit -m 'add widest'
$ mkdir outside
$ echo 'outside' > outside/f
$ hg add outside/f
$ hg commit -m 'add outside'
$ cd ..
narrow clone the inside file
$ hg clone --narrow ssh://user@dummy/master narrow --include inside/f
requesting all changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 1 changes to 1 files
new changesets *:* (glob)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd narrow
$ hg tracked
I path:inside/f
$ hg files
inside/f
XXX: we should have a flag in `hg debugsparse` to list the sparse profile
$ test -f .hg/sparse
[1]
$ hg debugrequires
dotencode
dirstate-v2 (dirstate-v2 !)
fncache
generaldelta
narrowhg-experimental
persistent-nodemap (rust !)
revlog-compression-zstd (zstd !)
revlogv1
share-safe
sparserevlog
store
treemanifest (tree !)
$ hg debugrebuilddirstate
We only make the following assertions for the flat test case since in the
treemanifest test case debugsparse fails with "path ends in directory
separator: outside/" which seems like a bug unrelated to the regression this is
testing for.
#if flat
widening with both sparse and narrow is possible
$ cat >> .hg/hgrc <<EOF
> [extensions]
> sparse =
> narrow =
> EOF
$ hg debugsparse -X outside/f -X widest/f
$ hg tracked -q --addinclude outside/f
$ find . -name .hg -prune -o -type f -print | sort
./inside/f
$ hg debugsparse -d outside/f
$ find . -name .hg -prune -o -type f -print | sort
./inside/f
./outside/f
#endif