comparison mercurial/revset.py @ 34065:c6c8a52e28c9

revset: optimize "draft() & ::x" pattern

The `draft() & ::x` type query could be common for selecting one or more
draft feature branches being worked on.

Before this patch, `::x` may travel through the changelog DAG for a long
distance until it gets a smaller revision number than `min(draft())`. It
could be very slow on long changelog with distant (in terms of revision
numbers) drafts.

This patch adds a fast path for this situation, and will stop traveling the
changelog DAG once `::x` hits a non-draft revision.

The fast path also works for `secret()` and `not public()`.

To measure the performance difference, I used drawdag to create a repo that
emulates distant drafts:

          DRAFT4
           |
          DRAFT3 # draft
          /
  PUBLIC9999 # public
      |
  PUBLIC9998
      |
      .   DRAFT2
      .    |
      .   DRAFT1 # draft
      |   /
  PUBLIC0001 # public

And measured the performance using the repo:

  (BEFORE)
  $ hg perfrevset 'draft() & ::(DRAFT2+DRAFT4)'
  ! wall 0.017132 comb 0.010000 user 0.010000 sys 0.000000 (best of 156)
  $ hg perfrevset 'draft() & ::(all())'
  ! wall 0.024221 comb 0.030000 user 0.030000 sys 0.000000 (best of 113)
  (AFTER)
  $ hg perfrevset 'draft() & ::(DRAFT2+DRAFT4)'
  ! wall 0.000243 comb 0.000000 user 0.000000 sys 0.000000 (best of 9303)
  $ hg perfrevset 'draft() & ::(all())'
  ! wall 0.004319 comb 0.000000 user 0.000000 sys 0.000000 (best of 655)

Differential Revision: https://phab.mercurial-scm.org/D441

34064:8b659b7388c0

@predicate('_notpublic', safe=True)
def _notpublic(repo, subset, x):
    getargs(x, 0, 0, "_notpublic takes no arguments")
    return _phase(repo, subset, phases.draft, phases.secret)

@predicate('public()', safe=True)
def public(repo, subset, x):
    """Changeset in public phase."""
    # i18n: "public" is a keyword
    getargs(x, 0, 0, _("public takes no arguments"))

34065:c6c8a52e28c9

@predicate('_notpublic', safe=True)
def _notpublic(repo, subset, x):
    getargs(x, 0, 0, "_notpublic takes no arguments")
    return _phase(repo, subset, phases.draft, phases.secret)

# for internal use
@predicate('_phaseandancestors(phasename, set)', safe=True)
def _phaseandancestors(repo, subset, x):
    # equivalent to (phasename() & ancestors(set)) but more efficient
    # phasename could be one of 'draft', 'secret', or '_notpublic'
    args = getargs(x, 2, 2, "_phaseandancestors requires two arguments")
    phasename = getsymbol(args[0])
    s = getset(repo, fullreposet(repo), args[1])

    draft = phases.draft
    secret = phases.secret
    phasenamemap = {
        '_notpublic': draft,
        'draft': draft, # follow secret's ancestors
        'secret': secret,
    }
    if phasename not in phasenamemap:
        raise error.ParseError('%r is not a valid phasename' % phasename)

    minimalphase = phasenamemap[phasename]
    getphase = repo._phasecache.phase

    def cutfunc(rev):
        return getphase(repo, rev) < minimalphase

    revs = dagop.revancestors(repo, s, cutfunc=cutfunc)

    if phasename == 'draft': # need to remove secret changesets
        revs = revs.filter(lambda r: getphase(repo, r) == draft)
    return subset & revs

@predicate('public()', safe=True)
def public(repo, subset, x):
    """Changeset in public phase."""
    # i18n: "public" is a keyword
    getargs(x, 0, 0, _("public takes no arguments"))