/brz/remove-bazaar

# Copyright (C) 2011 Canonical Ltd

#

# 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

"""File graph access."""

from dulwich.errors import (

    NotTreeError,

    )

from dulwich.object_store import (

    tree_lookup_path,

    )

from bzrlib.revision import (

    NULL_REVISION,

    )

class GitFileLastChangeScanner(object):

    def __init__(self, repository):

        self.repository = repository

        self.store = self.repository._git.object_store

    def find_last_change_revision(self, path, commit_id):

        commit = self.store[commit_id]

        target_mode, target_sha = tree_lookup_path(self.store.__getitem__,

            commit.tree, path)

        while True:

            parent_commits = [self.store[c] for c in commit.parents]

            for parent_commit in parent_commits:

                try:

                    mode, sha = tree_lookup_path(self.store.__getitem__,

                        parent_commit.tree, path)

                except (NotTreeError, KeyError):

                    continue

                if mode != target_mode or sha != target_sha:

                    return (path, commit.id)

            if parent_commits == []:

                break

            commit = parent_commits[0]

        return (path, commit.id)

class GitFileParentProvider(object):

    def __init__(self, change_scanner):

        self.change_scanner = change_scanner

        self.store = self.change_scanner.repository._git.object_store

    def _get_parents(self, file_id, text_revision):

        commit_id, mapping = self.change_scanner.repository.lookup_bzr_revision_id(

            text_revision)

        path = mapping.parse_file_id(file_id)

        text_parents = []

        for commit_parent in self.store[commit_id].parents:

            (_, text_parent) = self.change_scanner.find_last_change_revision(path, commit_parent)

            if text_parent not in text_parents:

                text_parents.append(text_parent)

        return [(file_id,

            self.change_scanner.repository.lookup_foreign_revision_id(p)) for p

            in text_parents]

    def get_parent_map(self, keys):

        ret = {}

        for key in keys:

            (file_id, text_revision) = key

            if text_revision == NULL_REVISION:

                continue

            try:

                ret[key] = self._get_parents(file_id, text_revision)

            except KeyError:

                pass

        return ret