annotate tests/test-impexp-branch.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

  $ echo '[extensions]' >> $HGRCPATH
  $ echo 'strip =' >> $HGRCPATH

  $ cat >findbranch.py <<EOF
  > from __future__ import absolute_import
  > import re
  > import sys
  > 
  > head_re = re.compile('^#(?:(?:\\s+([A-Za-z][A-Za-z0-9_]*)(?:\\s.*)?)|(?:\\s*))$')
  > 
  > for line in sys.stdin:
  >     hmatch = head_re.match(line)
  >     if not hmatch:
  >         sys.exit(1)
  >     if hmatch.group(1) == 'Branch':
  >         sys.exit(0)
  > sys.exit(1)
  > EOF

  $ hg init a
  $ cd a
  $ echo "Rev 1" >rev
  $ hg add rev
  $ hg commit -m "No branch."
  $ hg branch abranch
  marked working directory as branch abranch
  (branches are permanent and global, did you want a bookmark?)
  $ echo "Rev  2" >rev
  $ hg commit -m "With branch."

  $ hg export 0 > ../r0.patch
  $ hg export 1 > ../r1.patch
  $ cd ..

  $ if "$PYTHON" findbranch.py < r0.patch; then
  >     echo "Export of default branch revision has Branch header" 1>&2
  >     exit 1
  > fi

  $ if "$PYTHON" findbranch.py < r1.patch; then
  >     :  # Do nothing
  > else
  >     echo "Export of branch revision is missing Branch header" 1>&2
  >     exit 1
  > fi

Make sure import still works with branch information in patches.

  $ hg init b
  $ cd b
  $ hg import ../r0.patch
  applying ../r0.patch
  $ hg import ../r1.patch
  applying ../r1.patch
  $ cd ..

  $ hg init c
  $ cd c
  $ hg import --exact --no-commit ../r0.patch
  applying ../r0.patch
  warning: can't check exact import with --no-commit
  $ hg st
  A rev
  $ hg revert -a
  forgetting rev
  $ rm rev
  $ hg import --exact ../r0.patch
  applying ../r0.patch
  $ hg import --exact ../r1.patch
  applying ../r1.patch

Test --exact and patch header separators (issue3356)

  $ hg strip --no-backup .
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  >>> import re
  >>> p = open('../r1.patch', 'rb').read()
  >>> p = re.sub(br'Parent\s+', b'Parent ', p)
  >>> open('../r1-ws.patch', 'wb').write(p) and None
  $ hg import --exact ../r1-ws.patch
  applying ../r1-ws.patch

  $ cd ..