/brz/remove-bazaar

# Copyright (C) 2011 Jelmer Vernooij <jelmer@samba.org>

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""Unpeel map storage."""

from __future__ import absolute_import

from collections import defaultdict

from cStringIO import StringIO

from bzrlib import (

    errors,

    trace,

    )

class UnpeelMap(object):

    """Unpeel map.

    Keeps track of the unpeeled object id of tags.

    """

    def __init__(self):

        self._map = defaultdict(set)

        self._re_map = {}

    def update(self, m):

        for k, v in m.iteritems():

            self._map[k].update(v)

            for i in v:

                self._re_map[i] = k

    def load(self, f):

        firstline = f.readline()

        if firstline != "unpeel map version 1\n":

            raise AssertionError("invalid format for unpeel map: %r" % firstline)

        for l in f.readlines():

            (k, v) = l.split(":", 1)

            k = k.strip()

            v = v.strip()

            self._map[k].add(v)

            self._re_map[v] = k

    def save(self, f):

        f.write("unpeel map version 1\n")

        for k, vs in self._map.iteritems():

            for v in vs:

                f.write("%s: %s\n" % (k, v))

    def save_in_repository(self, repository):

        f = StringIO()

        try:

            self.save(f)

            f.seek(0)

            repository.control_transport.put_file("git-unpeel-map", f)

        finally:

            f.close()

    def peel_tag(self, git_sha, default=None):

        """Peel a tag."""

        return self._re_map.get(git_sha, default)

    def re_unpeel_tag(self, new_git_sha, old_git_sha):

        """Re-unpeel a tag.

        Bazaar can't store unpeeled refs so in order to prevent peeling

        existing tags when pushing they are "unpeeled" here.

        """

        if old_git_sha is not None and old_git_sha in self._map[new_git_sha]:

            trace.mutter("re-unpeeling %r to %r", new_git_sha, old_git_sha)

            return old_git_sha

        return new_git_sha

    @classmethod

    def from_repository(cls, repository):

        """Load the unpeel map for a repository.

        """

        m = UnpeelMap()

        try:

            m.load(repository.control_transport.get("git-unpeel-map"))

        except errors.NoSuchFile:

            pass

        return m