# censor code related to censoring revision

#

# Copyright 2021 Pierre-Yves David <pierre-yves.david@octobus.net>

# Copyright 2015 Google, Inc <martinvonz@google.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

from ..node import (

    nullrev,

)

from ..i18n import _

from .. import (

    error,

)

from ..utils import (

    storageutil,

)

from . import constants

def v1_censor(rl, tr, censornode, tombstone=b''):

    """censors a revision in a "version 1" revlog"""

    assert rl._format_version == constants.REVLOGV1, rl._format_version

    # avoid cycle

    from .. import revlog

    censorrev = rl.rev(censornode)

    tombstone = storageutil.packmeta({b'censored': tombstone}, b'')

    # Rewriting the revlog in place is hard. Our strategy for censoring is

    # to create a new revlog, copy all revisions to it, then replace the

    # revlogs on transaction close.

    #

    # This is a bit dangerous. We could easily have a mismatch of state.

    newrl = revlog.revlog(

        rl.opener,

        target=rl.target,

        radix=rl.radix,

        postfix=b'tmpcensored',

        censorable=True,

    )

    newrl._format_version = rl._format_version

    newrl._format_flags = rl._format_flags

    newrl._generaldelta = rl._generaldelta

    newrl._parse_index = rl._parse_index

    for rev in rl.revs():

        node = rl.node(rev)

        p1, p2 = rl.parents(node)

        if rev == censorrev:

            newrl.addrawrevision(

                tombstone,

                tr,

                rl.linkrev(censorrev),

                p1,

                p2,

                censornode,

                constants.REVIDX_ISCENSORED,

            )

            if newrl.deltaparent(rev) != nullrev:

                m = _(b'censored revision stored as delta; cannot censor')

                h = _(

                    b'censoring of revlogs is not fully implemented;'

                    b' please report this bug'

                )

                raise error.Abort(m, hint=h)

            continue

        if rl.iscensored(rev):

            if rl.deltaparent(rev) != nullrev:

                m = _(

                    b'cannot censor due to censored '

                    b'revision having delta stored'

                )

                raise error.Abort(m)

            rawtext = rl._chunk(rev)

        else:

            rawtext = rl.rawdata(rev)

        newrl.addrawrevision(

            rawtext, tr, rl.linkrev(rev), p1, p2, node, rl.flags(rev)

        )

    tr.addbackup(rl._indexfile, location=b'store')

    if not rl._inline:

        tr.addbackup(rl._datafile, location=b'store')

    rl.opener.rename(newrl._indexfile, rl._indexfile)

    if not rl._inline:

        rl.opener.rename(newrl._datafile, rl._datafile)

    rl.clearcaches()

    rl._loadindex()