comparison mercurial/copies.py @ 43199:069cbbb53cdf

copies: drop the findlimit logic

We don't use the limit anymore so we should stop computing that limit.

I did not bother measuring the potential performance gain. I am assuming that
not running any code will be faster that doing some computation and not using
the result.

43198:c16fe77e340a

)

from .revlogutils import sidedata as sidedatamod

from .utils import stringutil


def _findlimit(repo, ctxa, ctxb):
    """
    Find the last revision that needs to be checked to ensure that a full
    transitive closure for file copies can be properly calculated.
    Generally, this means finding the earliest revision number that's an
    ancestor of a or b but not both, except when a or b is a direct descendent
    of the other, in which case we can return the minimum revnum of a and b.
    """

    # basic idea:
    # - mark a and b with different sides
    # - if a parent's children are all on the same side, the parent is
    #   on that side, otherwise it is on no side
    # - walk the graph in topological order with the help of a heap;
    #   - add unseen parents to side map
    #   - clear side of any parent that has children on different sides
    #   - track number of interesting revs that might still be on a side
    #   - track the lowest interesting rev seen
    #   - quit when interesting revs is zero

    cl = repo.changelog
    wdirparents = None
    a = ctxa.rev()
    b = ctxb.rev()
    if a is None:
        wdirparents = (ctxa.p1(), ctxa.p2())
        a = node.wdirrev
    if b is None:
        assert not wdirparents
        wdirparents = (ctxb.p1(), ctxb.p2())
        b = node.wdirrev

    side = {a: -1, b: 1}
    visit = [-a, -b]
    heapq.heapify(visit)
    interesting = len(visit)
    limit = node.wdirrev

    while interesting:
        r = -(heapq.heappop(visit))
        if r == node.wdirrev:
            parents = [pctx.rev() for pctx in wdirparents]
        else:
            parents = cl.parentrevs(r)
        if parents[1] == node.nullrev:
            parents = parents[:1]
        for p in parents:
            if p not in side:
                # first time we see p; add it to visit
                side[p] = side[r]
                if side[p]:
                    interesting += 1
                heapq.heappush(visit, -p)
            elif side[p] and side[p] != side[r]:
                # p was interesting but now we know better
                side[p] = 0
                interesting -= 1
        if side[r]:
            limit = r  # lowest rev visited
            interesting -= 1

    # Consider the following flow (see test-commit-amend.t under issue4405):
    # 1/ File 'a0' committed
    # 2/ File renamed from 'a0' to 'a1' in a new commit (call it 'a1')
    # 3/ Move back to first commit
    # 4/ Create a new commit via revert to contents of 'a1' (call it 'a1-amend')
    # 5/ Rename file from 'a1' to 'a2' and commit --amend 'a1-msg'
    #
    # During the amend in step five, we will be in this state:
    #
    # @  3 temporary amend commit for a1-amend
    # |
    # o  2 a1-amend
    # |
    # | o  1 a1
    # |/
    # o  0 a0
    #
    # When _findlimit is called, a and b are revs 3 and 0, so limit will be 2,
    # yet the filelog has the copy information in rev 1 and we will not look
    # back far enough unless we also look at the a and b as candidates.
    # This only occurs when a is a descendent of b or visa-versa.
    return min(limit, a, b)


def _filter(src, dst, t):
    """filters out invalid copies after chaining"""

        else:
            t[k] = v
    return t


def _tracefile(fctx, am, basemf, limit):
    """return file context that is the ancestor of fctx present in ancestor
    manifest am

    Note: we used to try and stop after a given limit, however checking if that
    limit is reached turned out to be very expensive. we are better off

    debug = repo.ui.debugflag and repo.ui.configbool(b'devel', b'debug.copies')
    dbg = repo.ui.debug
    if debug:
        dbg(b'debug.copies:    looking into rename from %s to %s\n' % (a, b))
    limit = _findlimit(repo, a, b)
    if debug:
        dbg(b'debug.copies:      search limit: %d\n' % limit)
    am = a.manifest()
    basemf = None if base is None else base.manifest()

    # find where new files came from
    # we currently don't try to find where old files went, too expensive

        fctx = b[f]
        fctx._ancestrycontext = ancestrycontext

        if debug:
            start = util.timer()
        opath = _tracefile(fctx, am, basemf, limit)
        if opath:
            if debug:
                dbg(b'debug.copies:          rename of: %s\n' % opath)
            cm[f] = opath
        if debug:

43199:069cbbb53cdf

)

from .revlogutils import sidedata as sidedatamod

from .utils import stringutil


def _filter(src, dst, t):
    """filters out invalid copies after chaining"""

        else:
            t[k] = v
    return t


def _tracefile(fctx, am, basemf):
    """return file context that is the ancestor of fctx present in ancestor
    manifest am

    Note: we used to try and stop after a given limit, however checking if that
    limit is reached turned out to be very expensive. we are better off

    debug = repo.ui.debugflag and repo.ui.configbool(b'devel', b'debug.copies')
    dbg = repo.ui.debug
    if debug:
        dbg(b'debug.copies:    looking into rename from %s to %s\n' % (a, b))
    am = a.manifest()
    basemf = None if base is None else base.manifest()

    # find where new files came from
    # we currently don't try to find where old files went, too expensive

        fctx = b[f]
        fctx._ancestrycontext = ancestrycontext

        if debug:
            start = util.timer()
        opath = _tracefile(fctx, am, basemf)
        if opath:
            if debug:
                dbg(b'debug.copies:          rename of: %s\n' % opath)
            cm[f] = opath
        if debug: