view tests/test-mq-qfold.t @ 42743:8c9a6adec67a

rust-discovery: using the children cache in add_missing

The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.

The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.

This is a case where staying on the same side of the interface
between the two languages has clear benefits.

On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.

For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:

Rust version with simple iteration
  addcommons: 57.287us
  first undecided computation: 184.278334ms
  first children cache computation: 131.056us
  addmissings iteration: 42.766us
  first addinfo total: 185.24 ms

Python + C version
  first addcommons: 0.29 ms
  addcommons 0.21 ms
  first undecided computation 191.35 ms
  addmissings 45.75 ms
  first addinfo total: 237.77 ms

On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:

Rust version:
  first undecided computation: 293.842629ms
  first children cache computation: 407.911297ms
  addmissings iteration: 34.312869ms
  first addinfo total: 776.02 ms
  taking initial sample
  query 2: sampling time: 1318.38 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings: 143.062us

Python + C version:
  first undecided computation 298.13 ms
  addmissings 80.13 ms
  first addinfo total: 399.62 ms
  taking initial sample
  query 2: sampling time: 3957.23 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings 52.88 ms

Differential Revision: https://phab.mercurial-scm.org/D6428

  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > mq =
  > [mq]
  > git = keep
  > [diff]
  > nodates = 1
  > EOF

init:

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg ci -Am adda
  adding a
  $ echo a >> a
  $ hg qnew -f p1
  $ echo b >> a
  $ hg qnew -f p2
  $ echo c >> a
  $ hg qnew -f p3

Fold in the middle of the queue:
(this tests also that editor is not invoked if '--edit' is not
specified)

  $ hg qpop p1
  popping p3
  popping p2
  now at: p1

  $ hg qdiff
  diff -r 07f494440405 a
  --- a/a
  +++ b/a
  @@ -1,1 +1,2 @@
   a
  +a

  $ HGEDITOR=cat hg qfold p2
  $ grep git .hg/patches/p1 && echo 'git patch found!'
  [1]

  $ hg qser
  p1
  p3

  $ hg qdiff
  diff -r 07f494440405 a
  --- a/a
  +++ b/a
  @@ -1,1 +1,3 @@
   a
  +a
  +b

Fold with local changes:

  $ echo d >> a
  $ hg qfold p3
  abort: local changes found, qrefresh first
  [255]

  $ hg diff -c .
  diff -r 07f494440405 -r ???????????? a (glob)
  --- a/a
  +++ b/a
  @@ -1,1 +1,3 @@
   a
  +a
  +b

  $ hg revert -a --no-backup
  reverting a

Fold git patch into a regular patch, expect git patch:

  $ echo a >> a
  $ hg qnew -f regular
  $ hg cp a aa
  $ hg qnew --git -f git

  $ hg qpop
  popping git
  now at: regular

  $ hg qfold git

  $ cat .hg/patches/regular
  # HG changeset patch
  # Parent  ???????????????????????????????????????? (glob)
  
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,3 +1,4 @@
   a
   a
   b
  +a
  diff --git a/a b/aa
  copy from a
  copy to aa
  --- a/a
  +++ b/aa
  @@ -1,3 +1,4 @@
   a
   a
   b
  +a

  $ hg qpop
  popping regular
  now at: p1

  $ hg qdel regular

Fold regular patch into a git patch, expect git patch:

  $ hg cp a aa
  $ hg qnew --git -f git
  $ echo b >> aa
  $ hg qnew -f regular

  $ hg qpop
  popping regular
  now at: git

  $ hg qfold regular

  $ cat .hg/patches/git
  # HG changeset patch
  # Parent  ???????????????????????????????????????? (glob)
  
  diff --git a/a b/aa
  copy from a
  copy to aa
  --- a/a
  +++ b/aa
  @@ -1,3 +1,4 @@
   a
   a
   b
  +b

Test saving last-message.txt:

  $ hg qrefresh -m "original message"

  $ cat > $TESTTMP/commitfailure.py <<EOF
  > from mercurial import error
  > def reposetup(ui, repo):
  >     class commitfailure(repo.__class__):
  >         def commit(self, *args, **kwargs):
  >             raise error.Abort('emulating unexpected abort')
  >     repo.__class__ = commitfailure
  > EOF

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > # this failure occurs before editor invocation
  > commitfailure = $TESTTMP/commitfailure.py
  > EOF

  $ cat > $TESTTMP/editor.sh << EOF
  > echo "==== before editing"
  > cat \$1
  > echo "===="
  > (echo; echo "test saving last-message.txt") >> \$1
  > EOF

  $ hg qapplied
  p1
  git
  $ hg tip --template "{files}\n"
  aa

(test that editor is not invoked before transaction starting,
and that combination of '--edit' and '--message' doesn't abort execution)

  $ rm -f .hg/last-message.txt
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg qfold -e -m MESSAGE p3
  qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
  abort: emulating unexpected abort
  [255]
  $ test -f .hg/last-message.txt
  [1]

(reset applied patches and directory status)

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > # this failure occurs after editor invocation
  > commitfailure = !
  > EOF

  $ hg qapplied
  p1
  $ hg status -A aa
  ? aa
  $ rm aa
  $ hg status -m
  M a
  $ hg revert --no-backup -q a
  $ hg qpush -q git
  now at: git

(test that editor is invoked and commit message is saved into
"last-message.txt")

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > # this failure occurs after editor invocation
  > pretxncommit.unexpectedabort = false
  > EOF

  $ rm -f .hg/last-message.txt
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg qfold -e p3
  ==== before editing
  original message
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to use default message.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: added aa
  HG: changed a
  ====
  note: commit message saved in .hg/last-message.txt
  transaction abort!
  rollback completed
  qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
  abort: pretxncommit.unexpectedabort hook exited with status 1
  [255]
  $ cat .hg/last-message.txt
  original message
  
  
  
  test saving last-message.txt

(confirm whether files listed up in the commit message editing are correct)

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > pretxncommit.unexpectedabort =
  > EOF
  $ hg status -u | while read f; do rm ${f}; done
  $ hg revert --no-backup -q --all
  $ hg qpush -q git
  now at: git
  $ hg qpush -q --move p3
  now at: p3

  $ hg status --rev "git^1" --rev . -arm
  M a
  A aa

  $ cd ..