contrib/dirstatenonnormalcheck.py

dirstate: add a function to update tracking status while "moving" parents

The `scmutil.dirstateparent` is moving the dirstate parent without touching the
working copy. It is used by history-rewriting operations like amending of
folding.

The function was directly doing the "low level" computation and dirstate
change.  All that logic belong to the dirstate and should be moved there.

For this purpose we introduce a new function that does just that and use it.

Differential Revision: https://phab.mercurial-scm.org/D11012

# dirstatenonnormalcheck.py - extension to check the consistency of the
# dirstate's non-normal map
#
# For most operations on dirstate, this extensions checks that the nonnormalset
# contains the right entries.
# It compares the nonnormal file to a nonnormalset built from the map of all
# the files in the dirstate to check that they contain the same files.

from __future__ import absolute_import

from mercurial import (
    dirstate,
    extensions,
    pycompat,
)


def nonnormalentries(dmap):
    """Compute nonnormal entries from dirstate's dmap"""
    res = set()
    for f, e in dmap.iteritems():
        if e.state != b'n' or e.mtime == -1:
            res.add(f)
    return res


def checkconsistency(ui, orig, dmap, _nonnormalset, label):
    """Compute nonnormalset from dmap, check that it matches _nonnormalset"""
    nonnormalcomputedmap = nonnormalentries(dmap)
    if _nonnormalset != nonnormalcomputedmap:
        b_orig = pycompat.sysbytes(repr(orig))
        ui.develwarn(b"%s call to %s\n" % (label, b_orig), config=b'dirstate')
        ui.develwarn(b"inconsistency in nonnormalset\n", config=b'dirstate')
        b_nonnormal = pycompat.sysbytes(repr(_nonnormalset))
        ui.develwarn(b"[nonnormalset] %s\n" % b_nonnormal, config=b'dirstate')
        b_nonnormalcomputed = pycompat.sysbytes(repr(nonnormalcomputedmap))
        ui.develwarn(b"[map] %s\n" % b_nonnormalcomputed, config=b'dirstate')


def _checkdirstate(orig, self, arg):
    """Check nonnormal set consistency before and after the call to orig"""
    checkconsistency(
        self._ui, orig, self._map, self._map.nonnormalset, b"before"
    )
    r = orig(self, arg)
    checkconsistency(
        self._ui, orig, self._map, self._map.nonnormalset, b"after"
    )
    return r


def extsetup(ui):
    """Wrap functions modifying dirstate to check nonnormalset consistency"""
    dirstatecl = dirstate.dirstate
    devel = ui.configbool(b'devel', b'all-warnings')
    paranoid = ui.configbool(b'experimental', b'nonnormalparanoidcheck')
    if devel:
        extensions.wrapfunction(dirstatecl, '_writedirstate', _checkdirstate)
        if paranoid:
            # We don't do all these checks when paranoid is disable as it would
            # make the extension run very slowly on large repos
            extensions.wrapfunction(dirstatecl, 'normallookup', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'otherparent', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'normal', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'write', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'add', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'remove', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'merge', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'drop', _checkdirstate)