view tests/test-missing-capability.t @ 44861:065421e12248

files: speed up `hg files` when no flags change display

It's not the first time I see slowness from this command slow down
tools built on top of hg.

The majority of the time is spent merely printing the result before
this change, which is clearly not how it should be (especially since
the computation of the result also looks slow).

Running `hg files` in mozilla-central:

parent revision: 1,260s
this commit: 0,683s
this commit without batching ui.write: 0,931s
this commit replacing the body of the loop with `pass`: 0,566s

This looks like a prime candidate for a rust fast path, but until
then, it seems reasonable to optimize the python.

Differential Revision: https://phab.mercurial-scm.org/D8586

Checking how hg behaves when one side of a pull/push doesn't support
some capability (because it's running an older hg version, usually).

  $ hg init repo1
  $ cd repo1
  $ echo a > a; hg add -q a; hg commit -q -m a
  $ hg bookmark a
  $ hg clone -q . ../repo2
  $ cd ../repo2

  $ touch $TESTTMP/disable-lookup.py
  $ disable_cap() {
  >   rm -f $TESTTMP/disable-lookup.pyc # pyc caching is buggy
  >   cat <<EOF > $TESTTMP/disable-lookup.py
  > from mercurial import extensions, wireprotov1server
  > def wcapabilities(orig, *args, **kwargs):
  >   cap = orig(*args, **kwargs)
  >   cap.remove(b'$1')
  >   return cap
  > extensions.wrapfunction(wireprotov1server, '_capabilities', wcapabilities)
  > EOF
  > }
  $ cat >> ../repo1/.hg/hgrc <<EOF
  > [extensions]
  > disable-lookup = $TESTTMP/disable-lookup.py
  > EOF
  $ cat >> .hg/hgrc <<EOF
  > [ui]
  > ssh = "$PYTHON" "$TESTDIR/dummyssh"
  > EOF

  $ hg pull ssh://user@dummy/repo1 -r tip -B a
  pulling from ssh://user@dummy/repo1
  no changes found

  $ disable_cap lookup
  $ hg pull ssh://user@dummy/repo1 -r tip -B a
  pulling from ssh://user@dummy/repo1
  abort: other repository doesn't support revision lookup, so a rev cannot be specified.
  [255]

  $ disable_cap pushkey
  $ hg pull ssh://user@dummy/repo1 -r tip -B a
  pulling from ssh://user@dummy/repo1
  abort: remote bookmark a not found!
  [255]