view tests/test-subrepo-missing.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

  $ hg init repo
  $ cd repo
  $ hg init subrepo
  $ echo a > subrepo/a
  $ hg -R subrepo ci -Am adda
  adding a
  $ echo 'subrepo = subrepo' > .hgsub
  $ hg ci -Am addsubrepo
  adding .hgsub
  $ echo b > subrepo/b
  $ hg -R subrepo ci -Am addb
  adding b
  $ hg ci -m updatedsub

ignore blanklines in .hgsubstate

  >>> open('.hgsubstate', 'wb').write(b'\n\n   \t \n   \n') and None
  $ hg st --subrepos
  M .hgsubstate
  $ hg revert -qC .hgsubstate

abort more gracefully on .hgsubstate parsing error

  $ cp .hgsubstate .hgsubstate.old
  >>> open('.hgsubstate', 'wb').write(b'\ninvalid') and None
  $ hg st --subrepos --cwd $TESTTMP -R $TESTTMP/repo
  abort: invalid subrepository revision specifier in 'repo/.hgsubstate' line 2
  [255]
  $ mv .hgsubstate.old .hgsubstate

delete .hgsub and revert it

  $ rm .hgsub
  $ hg revert .hgsub
  warning: subrepo spec file '.hgsub' not found
  warning: subrepo spec file '.hgsub' not found

delete .hgsubstate and revert it

  $ rm .hgsubstate
  $ hg revert .hgsubstate

delete .hgsub and update

  $ rm .hgsub
  $ hg up 0 --cwd $TESTTMP -R $TESTTMP/repo
  warning: subrepo spec file 'repo/.hgsub' not found
  warning: subrepo spec file 'repo/.hgsub' not found
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg st
  warning: subrepo spec file '.hgsub' not found
  ! .hgsub
  $ ls subrepo
  a

delete .hgsubstate and update

  $ hg up -C
  warning: subrepo spec file '.hgsub' not found
  warning: subrepo spec file '.hgsub' not found
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm .hgsubstate
  $ hg up 0
  other [destination] changed .hgsubstate which local [working copy] deleted
  use (c)hanged version or leave (d)eleted? c
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg st
  $ ls subrepo
  a

Enable obsolete

  $ cat >> $HGRCPATH << EOF
  > [ui]
  > logtemplate= {rev}:{node|short} {desc|firstline}
  > [phases]
  > publish=False
  > [experimental]
  > evolution.createmarkers=True
  > EOF

check that we can update parent repo with missing (amended) subrepo revision

  $ hg up --repository subrepo -r tip
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg ci -m "updated subrepo to tip"
  created new head
  $ cd subrepo
  $ hg update -r tip
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo foo > a
  $ hg commit --amend -m "addb (amended)"
  $ cd ..
  $ hg update --clean .
  revision 102a90ea7b4a in subrepository "subrepo" is hidden
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

check that --hidden is propagated to the subrepo

  $ hg -R subrepo up tip
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg ci -m 'commit with amended subrepo'
  $ echo bar > subrepo/a
  $ hg -R subrepo ci --amend -m "amend a (again)"
  $ hg --hidden cat subrepo/a
  foo

verify will warn if locked-in subrepo revisions are hidden or missing

  $ hg ci -m "amended subrepo (again)"
  $ hg --config extensions.strip= --hidden strip -R subrepo -qr 'tip' --config devel.strip-obsmarkers=no
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 5 changesets with 5 changes to 2 files
  checking subrepo links
  subrepo 'subrepo' is hidden in revision a66de08943b6
  subrepo 'subrepo' is hidden in revision 674d05939c1e
  subrepo 'subrepo' not found in revision a7d05d9055a4

verifying shouldn't init a new subrepo if the reference doesn't exist

  $ mv subrepo b
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 5 changesets with 5 changes to 2 files
  checking subrepo links
  0: repository $TESTTMP/repo/subrepo not found
  1: repository $TESTTMP/repo/subrepo not found
  3: repository $TESTTMP/repo/subrepo not found
  4: repository $TESTTMP/repo/subrepo not found
  $ ls
  b
  $ mv b subrepo

  $ cd ..