comparison mercurial/copies.py @ 43786:421ea5772039

copies: split the combination of the copies mapping in its own function

In some case, this part take up to 95% of the copy tracing that take about a
hundred second. This poor performance comes from the fact we keep duplciating
and merging dictionary that are mostly similar.

I want to experiment with smarter native code to do this, so I need to isolate
the function first.

43785:3b039e43a1e6

    iterrevs = set(from_head)
    iterrevs &= mrset
    iterrevs.update(roots)
    iterrevs.remove(b.rev())
    all_copies = {}
    alwaysmatch = match.always()
    for r in sorted(iterrevs):
        copies = all_copies.pop(r, None)
        if copies is None:
            # this is a root
            copies = {}
        for i, c in enumerate(children[r]):

                if parent == 1:
                    othercopies.update(newcopies)
                else:
                    newcopies.update(othercopies)
                    all_copies[c] = newcopies
    return all_copies[b.rev()]


def _forwardcopies(a, b, base=None, match=None):
    """find {dst@b: src@a} copy mapping where a is an ancestor of b"""

43786:421ea5772039

    iterrevs = set(from_head)
    iterrevs &= mrset
    iterrevs.update(roots)
    iterrevs.remove(b.rev())
    revs = sorted(iterrevs)
    return _combinechangesetcopies(revs, children, b.rev(), revinfo, match)


def _combinechangesetcopies(revs, children, targetrev, revinfo, match):
    """combine the copies information for each item of iterrevs

    revs: sorted iterable of revision to visit
    children: a {parent: [children]} mapping.
    targetrev: the final copies destination revision (not in iterrevs)
    revinfo(rev): a function that return (p1, p2, p1copies, p2copies, removed)
    match: a matcher

    It returns the aggregated copies information for `targetrev`.
    """
    all_copies = {}
    alwaysmatch = match.always()
    for r in revs:
        copies = all_copies.pop(r, None)
        if copies is None:
            # this is a root
            copies = {}
        for i, c in enumerate(children[r]):

                if parent == 1:
                    othercopies.update(newcopies)
                else:
                    newcopies.update(othercopies)
                    all_copies[c] = newcopies
    return all_copies[targetrev]


def _forwardcopies(a, b, base=None, match=None):
    """find {dst@b: src@a} copy mapping where a is an ancestor of b"""