comparison mercurial/copies.py @ 40057:25b2868206e2

copies: add a devel debug mode to trace what copy tracing does

Mercurial can spend a lot of time finding renames between two commits. Having
more information about that process help to understand what makes it slow in
an individual instance. (eg: many files vs 1 file, etc...)

40056:324b4b10351e

def _committedforwardcopies(a, b, match):
    """Like _forwardcopies(), but b.rev() cannot be None (working copy)"""
    # files might have to be traced back to the fctx parent of the last
    # one-side-only changeset, but not further back than that
    limit = _findlimit(a._repo, a.rev(), b.rev())
    if limit is None:
        limit = -1
    am = a.manifest()

    # find where new files came from
    # we currently don't try to find where old files went, too expensive
    # this means we can miss a case like 'hg rm b; hg cp a b'

        filesmatcher = scmutil.matchfiles(a._repo, b.files())
        forwardmissingmatch = matchmod.intersectmatchers(match, filesmatcher)
    missing = _computeforwardmissing(a, b, match=forwardmissingmatch)

    ancestrycontext = a._repo.changelog.ancestors([b.rev()], inclusive=True)
    for f in missing:
        fctx = b[f]
        fctx._ancestrycontext = ancestrycontext
        ofctx = _tracefile(fctx, am, limit)
        if ofctx:
            cm[f] = ofctx.path()
    return cm

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

        r[v] = k
    return r

def pathcopies(x, y, match=None):
    """find {dst@y: src@x} copy mapping for directed compare"""
    if x == y or not x or not y:
        return {}
    a = y.ancestor(x)
    if a == x:
        return _forwardcopies(x, y, match=match)
    if a == y:
        return _backwardrenames(x, y)
    return _chain(x, y, _backwardrenames(x, a),
                  _forwardcopies(a, y, match=match))

def _computenonoverlap(repo, c1, c2, addedinm1, addedinm2, baselabel=''):
    """Computes, based on addedinm1 and addedinm2, the files exclusive to c1

40057:25b2868206e2

def _committedforwardcopies(a, b, match):
    """Like _forwardcopies(), but b.rev() cannot be None (working copy)"""
    # files might have to be traced back to the fctx parent of the last
    # one-side-only changeset, but not further back than that
    repo = a._repo
    debug = repo.ui.debugflag and repo.ui.configbool('devel', 'debug.copies')
    dbg = repo.ui.debug
    if debug:
        dbg('debug.copies:    looking into rename from %s to %s\n'
            % (a, b))
    limit = _findlimit(repo, a.rev(), b.rev())
    if limit is None:
        limit = -1
    if debug:
        dbg('debug.copies:      search limit: %d\n' % limit)
    am = a.manifest()

    # find where new files came from
    # we currently don't try to find where old files went, too expensive
    # this means we can miss a case like 'hg rm b; hg cp a b'

        filesmatcher = scmutil.matchfiles(a._repo, b.files())
        forwardmissingmatch = matchmod.intersectmatchers(match, filesmatcher)
    missing = _computeforwardmissing(a, b, match=forwardmissingmatch)

    ancestrycontext = a._repo.changelog.ancestors([b.rev()], inclusive=True)

    if debug:
        dbg('debug.copies:      missing file to search: %d\n' % len(missing))

    for f in missing:
        if debug:
            dbg('debug.copies:        tracing file: %s\n' % f)
        fctx = b[f]
        fctx._ancestrycontext = ancestrycontext

        ofctx = _tracefile(fctx, am, limit)
        if ofctx:
            if debug:
                dbg('debug.copies:          rename of: %s\n' % ofctx._path)
            cm[f] = ofctx.path()
    return cm

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

        r[v] = k
    return r

def pathcopies(x, y, match=None):
    """find {dst@y: src@x} copy mapping for directed compare"""
    repo = x._repo
    debug = repo.ui.debugflag and repo.ui.configbool('devel', 'debug.copies')
    if debug:
        repo.ui.debug('debug.copies: searching copies from %s to %s\n'
                      % (x, y))
    if x == y or not x or not y:
        return {}
    a = y.ancestor(x)
    if a == x:
        if debug:
            repo.ui.debug('debug.copies: search mode: forward\n')
        return _forwardcopies(x, y, match=match)
    if a == y:
        if debug:
            repo.ui.debug('debug.copies: search mode: backward\n')
        return _backwardrenames(x, y)
    if debug:
        repo.ui.debug('debug.copies: search mode: combined\n')
    return _chain(x, y, _backwardrenames(x, a),
                  _forwardcopies(a, y, match=match))

def _computenonoverlap(repo, c1, c2, addedinm1, addedinm2, baselabel=''):
    """Computes, based on addedinm1 and addedinm2, the files exclusive to c1