comparison mercurial/merge.py @ 35171:b85962350bb3 stable

merge: cache unknown dir checks (issue5716)

As mentioned in D1222, the recent pathconflicts change regresses update
performance in large repositories when many files are being updated.

To mitigate this, we introduce two caches of directories that have
already found to be either:

  - unknown directories, but which are not aliased by files and
    so don't need to be checked if they are files again; and

  - missing directores, which cannot cause path conflicts, and
    cannot contain a file that causes a path conflict.

When checking the paths of a file, testing against this caches means we can
skip tests that involve touching the filesystem.

Differential Revision: https://phab.mercurial-scm.org/D1224

35170:c9740b69b9b7

    return (repo.wvfs.audit.check(f)
        and repo.wvfs.isfileorlink(f)
        and repo.dirstate.normalize(f) not in repo.dirstate
        and mctx[f2].cmp(wctx[f]))

def _checkunknowndirs(repo, f):
    """
    Look for any unknown files or directories that may have a path conflict
    with a file.  If any path prefix of the file exists as a file or link,
    then it conflicts.  If the file itself is a directory that contains any
    file that is not tracked, then it conflicts.

    Returns the shortest path at which a conflict occurs, or None if there is
    no conflict.
    """

    # Check for path prefixes that exist as unknown files.
    for p in reversed(list(util.finddirs(f))):
        if (repo.wvfs.audit.check(p)
                and repo.wvfs.isfileorlink(p)
                and repo.dirstate.normalize(p) not in repo.dirstate):
            return p

    # Check if the file conflicts with a directory containing unknown files.
    if repo.wvfs.audit.check(f) and repo.wvfs.isdir(f):
        # Does the directory contain any files that are not in the dirstate?
        for p, dirs, files in repo.wvfs.walk(f):
            for fn in files:
                relf = repo.dirstate.normalize(repo.wvfs.reljoin(p, fn))
                if relf not in repo.dirstate:
                    return f
    return None

def _checkunknownfiles(repo, wctx, mctx, force, actions, mergeforce):
    """
    Considers any actions that care about the presence of conflicting unknown
    files. For some actions, the result is to abort; for others, it is to

            if config == 'abort':
                abortconflicts.update(conflicts)
            elif config == 'warn':
                warnconflicts.update(conflicts)

        for f, (m, args, msg) in actions.iteritems():
            if m in ('c', 'dc'):
                if _checkunknownfile(repo, wctx, mctx, f):
                    fileconflicts.add(f)
                elif pathconfig and f not in wctx:
                    path = _checkunknowndirs(repo, f)
                    if path is not None:
                        pathconflicts.add(path)
            elif m == 'dg':
                if _checkunknownfile(repo, wctx, mctx, f, args[0]):
                    fileconflicts.add(f)

35171:b85962350bb3

    return (repo.wvfs.audit.check(f)
        and repo.wvfs.isfileorlink(f)
        and repo.dirstate.normalize(f) not in repo.dirstate
        and mctx[f2].cmp(wctx[f]))

class _unknowndirschecker(object):
    """
    Look for any unknown files or directories that may have a path conflict
    with a file.  If any path prefix of the file exists as a file or link,
    then it conflicts.  If the file itself is a directory that contains any
    file that is not tracked, then it conflicts.

    Returns the shortest path at which a conflict occurs, or None if there is
    no conflict.
    """
    def __init__(self):
        # A set of paths known to be good.  This prevents repeated checking of
        # dirs.  It will be updated with any new dirs that are checked and found
        # to be safe.
        self._unknowndircache = set()

        # A set of paths that are known to be absent.  This prevents repeated
        # checking of subdirectories that are known not to exist. It will be
        # updated with any new dirs that are checked and found to be absent.
        self._missingdircache = set()

    def __call__(self, repo, f):
        # Check for path prefixes that exist as unknown files.
        for p in reversed(list(util.finddirs(f))):
            if p in self._missingdircache:
                return
            if p in self._unknowndircache:
                continue
            if repo.wvfs.audit.check(p):
                if (repo.wvfs.isfileorlink(p)
                        and repo.dirstate.normalize(p) not in repo.dirstate):
                    return p
                if not repo.wvfs.lexists(p):
                    self._missingdircache.add(p)
                    return
                self._unknowndircache.add(p)

        # Check if the file conflicts with a directory containing unknown files.
        if repo.wvfs.audit.check(f) and repo.wvfs.isdir(f):
            # Does the directory contain any files that are not in the dirstate?
            for p, dirs, files in repo.wvfs.walk(f):
                for fn in files:
                    relf = repo.dirstate.normalize(repo.wvfs.reljoin(p, fn))
                    if relf not in repo.dirstate:
                        return f
        return None

def _checkunknownfiles(repo, wctx, mctx, force, actions, mergeforce):
    """
    Considers any actions that care about the presence of conflicting unknown
    files. For some actions, the result is to abort; for others, it is to

            if config == 'abort':
                abortconflicts.update(conflicts)
            elif config == 'warn':
                warnconflicts.update(conflicts)

        checkunknowndirs = _unknowndirschecker()
        for f, (m, args, msg) in actions.iteritems():
            if m in ('c', 'dc'):
                if _checkunknownfile(repo, wctx, mctx, f):
                    fileconflicts.add(f)
                elif pathconfig and f not in wctx:
                    path = checkunknowndirs(repo, f)
                    if path is not None:
                        pathconflicts.add(path)
            elif m == 'dg':
                if _checkunknownfile(repo, wctx, mctx, f, args[0]):
                    fileconflicts.add(f)