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.
#testcases tree flat-fncache flat-nofncache
Tests narrow stream clones
$ . "$TESTDIR/narrow-library.sh"
#if tree
$ cat << EOF >> $HGRCPATH
> [experimental]
> treemanifest = 1
> EOF
#endif
#if flat-nofncache
$ cat << EOF >> $HGRCPATH
> [format]
> usefncache = 0
> EOF
#endif
Server setup
$ hg init master
$ cd master
$ mkdir dir
$ mkdir dir/src
$ cd dir/src
$ for x in `$TESTDIR/seq.py 20`; do echo $x > "F$x"; hg add "F$x"; hg commit -m "Commit src $x"; done
$ cd ..
$ mkdir tests
$ cd tests
$ for x in `$TESTDIR/seq.py 20`; do echo $x > "F$x"; hg add "F$x"; hg commit -m "Commit src $x"; done
$ cd ../../..
Trying to stream clone when the server does not support it
$ hg clone --narrow ssh://user@dummy/master narrow --noupdate --include "dir/src/F10" --stream
streaming all changes
remote: abort: server does not support narrow stream clones
abort: pull failed on remote
[100]
Enable stream clone on the server
$ echo "[experimental]" >> master/.hg/hgrc
$ echo "server.stream-narrow-clones=True" >> master/.hg/hgrc
Cloning a specific file when stream clone is supported
$ hg clone --narrow ssh://user@dummy/master narrow --noupdate --include "dir/src/F10" --stream
streaming all changes
* files to transfer, * KB of data (glob)
transferred * KB in * seconds (* */sec) (glob)
$ cd narrow
$ ls -A
.hg
$ hg tracked
I path:dir/src/F10
Making sure we have the correct set of requirements
$ hg debugrequires
dotencode (tree !)
dotencode (flat-fncache !)
dirstate-v2 (dirstate-v2 !)
fncache (tree !)
fncache (flat-fncache !)
generaldelta
narrowhg-experimental
persistent-nodemap (rust !)
revlog-compression-zstd (zstd !)
revlogv1
share-safe
sparserevlog
store
treemanifest (tree !)
Making sure store has the required files
$ ls .hg/store/
00changelog-????????.nd (glob) (rust !)
00changelog.d
00changelog.i
00changelog.n (rust !)
00manifest.i
data
fncache (tree !)
fncache (flat-fncache !)
meta (tree !)
narrowspec
requires
undo
undo.backupfiles
Checking that repository has all the required data and not broken
$ hg verify
checking changesets
checking manifests
checking directory manifests (tree !)
crosschecking files in changesets and manifests
checking files
checking dirstate
checked 40 changesets with 1 changes to 1 files