view tests/test-convert-svn-tags.t @ 41247:a89b20a49c13

rust-cpython: using MissingAncestors from Python code

As precedently done with LazyAncestors on cpython.rs, we test for the
presence of the 'rustext' module.

incrementalmissingrevs() has two callers within the Mercurial core:
`setdiscovery.partialdiscovery` and the `only()` revset.

This move shows a significant discovery performance improvement
in cases where the baseline is slow: using perfdiscovery on the PyPy
repos, prepared with `contrib/discovery-helper <repo> 50 100`, we
get averaged medians of 403ms with the Rust version vs 742ms without
(about 45% better).

But there are still indications that performance can be worse in cases
the baseline is fast, possibly due to the conversion from Python to
Rust and back becoming the bottleneck. We could measure this on
mozilla-central in cases were the delta is just a few changesets.
This requires confirmation, but if that's the reason, then an
upcoming `partialdiscovery` fully in Rust should solve the problem.

Differential Revision: https://phab.mercurial-scm.org/D5551

#require svn svn-bindings

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > convert =
  > EOF

  $ svnadmin create svn-repo
  $ svnadmin load -q svn-repo < "$TESTDIR/svn/tags.svndump"

Convert
  $ hg convert --datesort svn-repo A-hg
  initializing destination A-hg repository
  scanning source...
  sorting...
  converting...
  5 init projA
  4 adda
  3 changea
  2 changea2
  1 changea3
  0 changea
  updating tags

  $ cd A-hg
  $ hg log -G --template '{rev} {desc|firstline} tags: {tags}\n'
  o  6 update tags tags: tip
  |
  o  5 changea tags: trunk.goodtag
  |
  o  4 changea3 tags:
  |
  o  3 changea2 tags: trunk.v1
  |
  o  2 changea tags:
  |
  o  1 adda tags:
  |
  o  0 init projA tags:
  

  $ hg tags -q
  tip
  trunk.goodtag
  trunk.v1

  $ cd ..

Convert without tags

  $ hg convert --datesort --config convert.svn.tags= svn-repo A-notags-hg
  initializing destination A-notags-hg repository
  scanning source...
  sorting...
  converting...
  5 init projA
  4 adda
  3 changea
  2 changea2
  1 changea3
  0 changea

  $ hg -R A-notags-hg tags -q
  tip