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.
test sparse
$ cat >> $HGRCPATH << EOF
> [ui]
> username = nobody <no.reply@fb.com>
> [extensions]
> sparse=
> purge=
> strip=
> rebase=
> EOF
$ hg init myrepo
$ cd myrepo
$ echo a > index.html
$ echo x > data.py
$ echo z > readme.txt
$ cat > webpage.sparse <<EOF
> [include]
> *.html
> EOF
$ cat > backend.sparse <<EOF
> [include]
> *.py
> EOF
$ hg ci -Aqm 'initial'
$ cd ..
Verify local clone with a sparse profile works
$ hg clone --enable-profile webpage.sparse myrepo clone1
updating to branch default
warning: sparse profile 'webpage.sparse' not found in rev 000000000000 - ignoring it
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd clone1
$ ls -A
.hg
index.html
$ cd ..
Verify local clone with include works
$ hg clone --include *.sparse myrepo clone2
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd clone2
$ ls -A
.hg
backend.sparse
webpage.sparse
$ cd ..
Verify local clone with exclude works
$ hg clone --exclude data.py myrepo clone3
updating to branch default
4 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd clone3
$ ls -A
.hg
backend.sparse
index.html
readme.txt
webpage.sparse
$ cd ..
Verify sparse clone profile over ssh works
$ hg clone -q --enable-profile webpage.sparse ssh://user@dummy/myrepo clone4
warning: sparse profile 'webpage.sparse' not found in rev 000000000000 - ignoring it
$ cd clone4
$ ls -A
.hg
index.html
$ cd ..