view tests/test-removeemptydirs.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

Tests for experimental.removeemptydirs

  $ NO_RM=--config=experimental.removeemptydirs=0
  $ isdir() { if [ -d $1 ]; then echo yes; else echo no; fi }
  $ isfile() { if [ -f $1 ]; then echo yes; else echo no; fi }

`hg rm` of the last file in a directory:
  $ hg init hgrm
  $ cd hgrm
  $ mkdir somedir
  $ echo hi > somedir/foo
  $ hg ci -qAm foo
  $ isdir somedir
  yes
  $ hg rm somedir/foo
  $ isdir somedir
  no
  $ hg revert -qa
  $ isdir somedir
  yes
  $ hg $NO_RM rm somedir/foo
  $ isdir somedir
  yes
  $ ls somedir
  $ cd $TESTTMP

`hg mv` of the last file in a directory:
  $ hg init hgmv
  $ cd hgmv
  $ mkdir somedir
  $ mkdir destdir
  $ echo hi > somedir/foo
  $ hg ci -qAm foo
  $ isdir somedir
  yes
  $ hg mv somedir/foo destdir/foo
  $ isdir somedir
  no
  $ hg revert -qa
(revert doesn't get rid of destdir/foo?)
  $ rm destdir/foo
  $ isdir somedir
  yes
  $ hg $NO_RM mv somedir/foo destdir/foo
  $ isdir somedir
  yes
  $ ls somedir
  $ cd $TESTTMP

Updating to a commit that doesn't have the directory:
  $ hg init hgupdate
  $ cd hgupdate
  $ echo hi > r0
  $ hg ci -qAm r0
  $ mkdir somedir
  $ echo hi > somedir/foo
  $ hg ci -qAm r1
  $ isdir somedir
  yes
  $ hg co -q -r ".^"
  $ isdir somedir
  no
  $ hg co -q tip
  $ isdir somedir
  yes
  $ hg $NO_RM co -q -r ".^"
  $ isdir somedir
  yes
  $ ls somedir
  $ cd $TESTTMP

Rebasing across a commit that doesn't have the directory, from inside the
directory:
  $ hg init hgrebase
  $ cd hgrebase
  $ echo hi > r0
  $ hg ci -qAm r0
  $ mkdir somedir
  $ echo hi > somedir/foo
  $ hg ci -qAm first_rebase_source
  $ hg $NO_RM co -q -r ".^"
  $ echo hi > somedir/bar
  $ hg ci -qAm first_rebase_dest
  $ hg $NO_RM co -q -r ".^"
  $ echo hi > somedir/baz
  $ hg ci -qAm second_rebase_dest
  $ hg co -qr 'desc(first_rebase_source)'
  $ cd $TESTTMP/hgrebase/somedir
  $ hg --config extensions.rebase= rebase -qr . -d 'desc(first_rebase_dest)'
  current directory was removed (rmcwd !)
  (consider changing to repo root: $TESTTMP/hgrebase) (rmcwd !)
  $ cd $TESTTMP/hgrebase/somedir
(The current node is the rebased first_rebase_source on top of
first_rebase_dest)
This should not output anything about current directory being removed:
  $ hg $NO_RM --config extensions.rebase= rebase -qr . -d 'desc(second_rebase_dest)'
  $ cd $TESTTMP

Histediting across a commit that doesn't have the directory, from inside the
directory (reordering nodes):
  $ hg init hghistedit
  $ cd hghistedit
  $ echo hi > r0
  $ hg ci -qAm r0
  $ echo hi > r1
  $ hg ci -qAm r1
  $ echo hi > r2
  $ hg ci -qAm r2
  $ mkdir somedir
  $ echo hi > somedir/foo
  $ hg ci -qAm migrating_revision
  $ cat > histedit_commands <<EOF
  > pick 89079fab8aee 0 r0
  > pick e6d271df3142 1 r1
  > pick 89e25aa83f0f 3 migrating_revision
  > pick b550aa12d873 2 r2
  > EOF
  $ cd $TESTTMP/hghistedit/somedir
  $ hg --config extensions.histedit= histedit -q --commands ../histedit_commands

histedit doesn't output anything when the current diretory is removed. We rely
on the tests being commonly run on machines where the current directory
disappearing from underneath us actually has an observable effect, such as an
error or no files listed
#if linuxormacos
  $ isfile foo
  no
#endif
  $ cd $TESTTMP/hghistedit/somedir
  $ isfile foo
  yes

  $ cd $TESTTMP/hghistedit
  $ cat > histedit_commands <<EOF
  > pick 89079fab8aee 0 r0
  > pick 7c7a22c6009f 3 migrating_revision
  > pick e6d271df3142 1 r1
  > pick 40a53c2d4276 2 r2
  > EOF
  $ cd $TESTTMP/hghistedit/somedir
  $ hg $NO_RM --config extensions.histedit= histedit -q --commands ../histedit_commands
Regardless of system, we should always get a 'yes' here.
  $ isfile foo
  yes
  $ cd $TESTTMP

This is essentially the exact test from issue5826, just cleaned up a little:

  $ hg init issue5826_withrm
  $ cd issue5826_withrm

Let's only turn this on for this repo so that we don't contaminate later tests.
  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > histedit =
  > EOF
Commit three revisions that each create a directory:

  $ mkdir foo
  $ touch foo/bar
  $ hg commit -qAm "add foo"

  $ mkdir bar
  $ touch bar/bar
  $ hg commit -qAm "add bar"

  $ mkdir baz
  $ touch baz/bar
  $ hg commit -qAm "add baz"

Enter the first directory:

  $ cd foo

Histedit doing 'pick, pick, fold':

#if rmcwd

  $ hg histedit --commands - <<EOF
  > pick 6274c77c93c3 1 add bar
  > pick ff70a87b588f 0 add foo
  > fold 9992bb0ac0db 2 add baz
  > EOF
  abort: $ENOENT$
  [255]

Go back to the repo root after losing it as part of that operation:
  $ cd $TESTTMP/issue5826_withrm

Note the lack of a non-zero exit code from this function - it exits
successfully, but doesn't really do anything.
  $ hg histedit --continue
  9992bb0ac0db: cannot fold - working copy is not a descendant of previous commit 5c806432464a
  saved backup bundle to $TESTTMP/issue5826_withrm/.hg/strip-backup/ff70a87b588f-e94f9789-histedit.hg

  $ hg log -T '{rev}:{node|short} {desc}\n'
  2:94e3f9fae1d6 fold-temp-revision 9992bb0ac0db
  1:5c806432464a add foo
  0:d17db4b0303a add bar

#else

  $ cd $TESTTMP/issue5826_withrm

  $ hg histedit --commands - <<EOF
  > pick 6274c77c93c3 1 add bar
  > pick ff70a87b588f 0 add foo
  > fold 9992bb0ac0db 2 add baz
  > EOF
  saved backup bundle to $TESTTMP/issue5826_withrm/.hg/strip-backup/5c806432464a-cd4c8d86-histedit.hg

  $ hg log -T '{rev}:{node|short} {desc}\n'
  1:b9eddaa97cbc add foo
  ***
  add baz
  0:d17db4b0303a add bar

#endif

Now test that again with experimental.removeemptydirs=false:
  $ hg init issue5826_norm
  $ cd issue5826_norm

Let's only turn this on for this repo so that we don't contaminate later tests.
  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > histedit =
  > [experimental]
  > removeemptydirs = false
  > EOF
Commit three revisions that each create a directory:

  $ mkdir foo
  $ touch foo/bar
  $ hg commit -qAm "add foo"

  $ mkdir bar
  $ touch bar/bar
  $ hg commit -qAm "add bar"

  $ mkdir baz
  $ touch baz/bar
  $ hg commit -qAm "add baz"

Enter the first directory:

  $ cd foo

Histedit doing 'pick, pick, fold':

  $ hg histedit --commands - <<EOF
  > pick 6274c77c93c3 1 add bar
  > pick ff70a87b588f 0 add foo
  > fold 9992bb0ac0db 2 add baz
  > EOF
  saved backup bundle to $TESTTMP/issue5826_withrm/issue5826_norm/.hg/strip-backup/5c806432464a-cd4c8d86-histedit.hg

Note the lack of a 'cd' being necessary here, and we don't need to 'histedit
--continue'

  $ hg log -T '{rev}:{node|short} {desc}\n'
  1:b9eddaa97cbc add foo
  ***
  add baz
  0:d17db4b0303a add bar

  $ cd $TESTTMP