view tests/test-remotefilelog-pull-noshallow.t @ 47120:7109a38830c9

dirstate-tree: Fold "tracked descendants" counter update in main walk

For the purpose of implementing `has_tracked_dir` (which means "has tracked
descendants) without an expensive sub-tree traversal, we maintaing a counter
of tracked descendants on each "directory" node of the tree-shaped dirstate.

Before this changeset, mutating or inserting a node at a given path would
involve:

* Walking the tree from root through ancestors to find the node or the spot
  where to insert it
* Looking at the previous node if any to decide what counter update is needed
* Performing any node mutation
* Walking the tree *again* to update counters in ancestor nodes

When profiling `hg status` on a large repo, this second walk takes times
while loading a the dirstate from disk.

It turns out we have enough information to decide before he first tree walk
what counter update is needed. This changeset merges the two walks, gaining
~10% of the total time for `hg update` (in the same hyperfine benchmark as
the previous changeset).

---

Profiling was done by compiling with this `.cargo/config`:

    [profile.release]
    debug = true

then running with:

    py-spy record -r 500 -n -o /tmp/hg.json --format speedscope -- \
    ./hg status -R $REPO --config experimental.dirstate-tree.in-memory=1

then visualizing the recorded JSON file in https://www.speedscope.app/

Differential Revision: https://phab.mercurial-scm.org/D10554

#require no-windows

  $ . "$TESTDIR/remotefilelog-library.sh"

Set up an extension to make sure remotefilelog clientsetup() runs
unconditionally even if we have never used a local shallow repo.
This mimics behavior when using remotefilelog with chg.  clientsetup() can be
triggered due to a shallow repo, and then the code can later interact with
non-shallow repositories.

  $ cat > setupremotefilelog.py << EOF
  > from mercurial import extensions
  > def extsetup(ui):
  >     remotefilelog = extensions.find(b'remotefilelog')
  >     remotefilelog.onetimeclientsetup(ui)
  > EOF

Set up the master repository to pull from.

  $ hg init master
  $ cd master
  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > server=True
  > EOF
  $ echo x > x
  $ hg commit -qAm x

  $ cd ..

  $ hg clone ssh://user@dummy/master child -q

We should see the remotefilelog capability here, which advertises that
the server supports our custom getfiles method.

  $ cd master
  $ echo 'hello' | hg -R . serve --stdio | grep capa | identifyrflcaps
  exp-remotefilelog-ssh-getfiles-1
  x_rfl_getfile
  x_rfl_getflogheads
  $ echo 'capabilities' | hg -R . serve --stdio | identifyrflcaps ; echo
  exp-remotefilelog-ssh-getfiles-1
  x_rfl_getfile
  x_rfl_getflogheads
  

Pull to the child repository.  Use our custom setupremotefilelog extension
to ensure that remotefilelog.onetimeclientsetup() gets triggered.  (Without
using chg it normally would not be run in this case since the local repository
is not shallow.)

  $ echo y > y
  $ hg commit -qAm y

  $ cd ../child
  $ hg pull --config extensions.setuprfl=$TESTTMP/setupremotefilelog.py
  pulling from ssh://user@dummy/master
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets d34c38483be9
  (run 'hg update' to get a working copy)

  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cat y
  y

Test that bundle works in a non-remotefilelog repo w/ remotefilelog loaded

  $ echo y >> y
  $ hg commit -qAm "modify y"
  $ hg bundle --base ".^" --rev . mybundle.hg --config extensions.setuprfl=$TESTTMP/setupremotefilelog.py
  1 changesets found

  $ cd ..