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 no-windows
$ . "$TESTDIR/remotefilelog-library.sh"
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> server=True
> EOF
$ echo x > foo
$ echo y > bar
$ hg commit -qAm one
$ cd ..
# partial shallow clone
$ hg clone --shallow ssh://user@dummy/master shallow --noupdate --config remotefilelog.includepattern=foo
streaming all changes
4 files to transfer, 336 bytes of data (no-zstd !)
transferred 336 bytes in * seconds (* */sec) (glob) (no-zstd !)
4 files to transfer, 338 bytes of data (zstd no-rust !)
transferred 338 bytes in * seconds (* */sec) (glob) (zstd no-rust !)
6 files to transfer, 464 bytes of data (zstd rust !)
transferred 464 bytes in * seconds (*/sec) (glob) (zstd rust !)
searching for changes
no changes found
$ cat >> shallow/.hg/hgrc <<EOF
> [remotefilelog]
> cachepath=$PWD/hgcache
> debug=True
> includepattern=foo
> reponame = master
> [extensions]
> remotefilelog=
> EOF
$ ls shallow/.hg/store/data
bar.i
# update partial clone
$ cd shallow
$ hg update
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ cat foo
x
$ cat bar
y
$ cd ..
# pull partial clone
$ cd master
$ echo a >> foo
$ echo b >> bar
$ hg commit -qm two
$ cd ../shallow
$ hg pull
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files
new changesets a9688f18cb91
(run 'hg update' to get a working copy)
$ hg update
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ cat foo
x
a
$ cat bar
y
b
$ cd ..