/brz/remove-bazaar

# Copyright (C) 2009 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

"""Map from Git sha's to Bazaar objects."""

from dulwich.objects import (

    Blob,

    sha_to_hex,

    )

from dulwich.object_store import (

    BaseObjectStore,

    )

from bzrlib import (

    debug,

    errors,

    trace,

    ui,

    )

from bzrlib.revision import (

    NULL_REVISION,

    )

from bzrlib.plugins.git.mapping import (

    default_mapping,

    directory_to_tree,

    extract_unusual_modes,

    mapping_registry,

    revision_to_commit,

    )

from bzrlib.plugins.git.shamap import (

    SqliteGitShaMap,

    TdbGitShaMap,

    )

def get_object_store(repo, mapping=None):

    git = getattr(repo, "_git", None)

    if git is not None:

        return git.object_store

    return BazaarObjectStore(repo, mapping)

class BazaarObjectStore(BaseObjectStore):

    """A Git-style object store backed onto a Bazaar repository."""

    def __init__(self, repository, mapping=None):

        self.repository = repository

        if mapping is None:

            self.mapping = default_mapping

        else:

            self.mapping = mapping

        try:

            self._idmap = TdbGitShaMap.from_repository(repository)

        except ImportError:

            self._idmap = SqliteGitShaMap.from_repository(repository)

    def _update_sha_map(self, stop_revision=None):

        if stop_revision is None:

            all_revids = self.repository.all_revision_ids()

        else:

            all_revids = self.repository.get_ancestry(stop_revision)

            first = all_revids.pop(0) # Pop leading None

            assert first is None

        graph = self.repository.get_graph()

        present_revids = set(self._idmap.revids())

        missing_revids = [revid for revid in graph.iter_topo_order(all_revids) if revid not in present_revids]

        pb = ui.ui_factory.nested_progress_bar()

        try:

            for i, revid in enumerate(missing_revids):

                pb.update("updating git map", i, len(missing_revids))

                self._update_sha_map_revision(revid)

        finally:

            self._idmap.commit()

            pb.finished()

    def __iter__(self):

        self._update_sha_map()

        return iter(self._idmap.sha1s())

    def _revision_to_commit(self, rev, tree_sha):

        def parent_lookup(revid):

            try:

                return self._lookup_revision_sha1(revid)

            except errors.NoSuchRevision:

                trace.warning("Ignoring ghost parent %s", revid)

                return None

        return revision_to_commit(rev, tree_sha, parent_lookup)

    def _update_sha_map_revision(self, revid):

        inv = self.repository.get_inventory(revid)

        rev = self.repository.get_revision(revid)

        unusual_modes = extract_unusual_modes(rev)

        tree_sha = self._get_ie_sha1(inv.root, inv, unusual_modes)

        commit_obj = self._revision_to_commit(rev, tree_sha)

        try:

            foreign_revid, mapping = mapping_registry.parse_revision_id(revid)

        except errors.InvalidRevisionId:

            pass

        else:

            if foreign_revid != commit_obj.id:

                if not "fix-shamap" in debug.debug_flags:

                    raise AssertionError("recreated git commit had different sha1: expected %s, got %s" % (foreign_revid, commit_obj.id))

        self._idmap.add_entry(commit_obj.id, "commit", (revid, tree_sha))

    def _check_expected_sha(self, expected_sha, object):

        if expected_sha is None:

            return

        if len(expected_sha) == 40:

            if expected_sha != object.sha().hexdigest():

                raise AssertionError("Invalid sha for %r: %s" % (object, expected_sha))

        elif len(expected_sha) == 20:

            if expected_sha != object.sha().digest():

                raise AssertionError("Invalid sha for %r: %s" % (object, sha_to_hex(expected_sha)))

        else:

            raise AssertionError("Unknown length %d for %r" % (len(expected_sha), expected_sha))

    def _get_ie_object(self, entry, inv, unusual_modes):  

        if entry.kind == "directory":

            return self._get_tree(entry.file_id, inv.revision_id, inv, unusual_modes)

        else:

            return self._get_blob(entry.file_id, entry.revision)

    def _get_ie_object_or_sha1(self, entry, inv, unusual_modes):

        if entry.kind == "directory":

            try:

                return self._idmap.lookup_tree(entry.file_id, inv.revision_id), None

            except KeyError:

                ret = self._get_ie_object(entry, inv, unusual_modes)

                if ret is None:

                    hexsha = None

                else:

                    hexsha = ret.id

                self._idmap.add_entry(hexsha, "tree", (entry.file_id, inv.revision_id))

                return hexsha, ret

        else:

            try:

                return self._idmap.lookup_blob(entry.file_id, entry.revision), None

            except KeyError:

                ret = self._get_ie_object(entry, inv, unusual_modes)

                self._idmap.add_entry(ret.id, "blob", (entry.file_id, entry.revision))

                return ret.id, ret

    def _get_ie_sha1(self, entry, inv, unusual_modes):

        return self._get_ie_object_or_sha1(entry, inv, unusual_modes)[0]

    def _get_blob(self, fileid, revision, expected_sha=None):

        """Return a Git Blob object from a fileid and revision stored in bzr.

        :param fileid: File id of the text

        :param revision: Revision of the text

        """

        chunks = self.repository.iter_files_bytes([(fileid, revision, None)]).next()[1]

        blob = Blob()

        blob._text = "".join(chunks)

        self._check_expected_sha(expected_sha, blob)

        return blob

    def _get_tree(self, fileid, revid, inv, unusual_modes, expected_sha=None):

        """Return a Git Tree object from a file id and a revision stored in bzr.

        :param fileid: fileid in the tree.

        :param revision: Revision of the tree.

        """

        tree = directory_to_tree(inv[fileid], 

            lambda ie: self._get_ie_sha1(ie, inv, unusual_modes),

            unusual_modes)

        self._check_expected_sha(expected_sha, tree)

        return tree

    def _get_commit(self, rev, tree_sha, expected_sha=None):

        commit = self._revision_to_commit(rev, tree_sha)

        self._check_expected_sha(expected_sha, commit)

        return commit

    def get_parents(self, sha):

        """Retrieve the parents of a Git commit by SHA1.

        :param sha: SHA1 of the commit

        :raises: KeyError, NotCommitError

        """

        return self[sha].parents

    def _lookup_revision_sha1(self, revid):

        """Return the SHA1 matching a Bazaar revision."""

        if revid == NULL_REVISION:

            return "0" * 40

        try:

            return self._idmap.lookup_commit(revid)

        except KeyError:

            self._update_sha_map(revid)

            return self._idmap.lookup_commit(revid)

    def get_raw(self, sha):

        """Get the raw representation of a Git object by SHA1.

        :param sha: SHA1 of the git object

        """

        obj = self[sha]

        return (obj.type, obj.as_raw_string())

    def __contains__(self, sha):

        # See if sha is in map

        try:

            (type, type_data) = self._lookup_git_sha(sha)

            if type == "commit":

                return self.repository.has_revision(type_data[0])

            elif type == "blob":

                return self.repository.texts.has_version(type_data)

            elif type == "tree":

                return self.repository.has_revision(type_data[1])

            else:

                raise AssertionError("Unknown object type '%s'" % type)

        except KeyError:

            return False

        else:

            return True

    def _lookup_git_sha(self, sha):

        # See if sha is in map

        try:

            return self._idmap.lookup_git_sha(sha)

        except KeyError:

            # if not, see if there are any unconverted revisions and add them 

            # to the map, search for sha in map again

            self._update_sha_map()

            return self._idmap.lookup_git_sha(sha)

    def __getitem__(self, sha):

        (type, type_data) = self._lookup_git_sha(sha)

        # convert object to git object

        if type == "commit":

            try:

                rev = self.repository.get_revision(type_data[0])

            except errors.NoSuchRevision:

                trace.mutter('entry for %s %s in shamap: %r, but not found in repository', type, sha, type_data)

                raise KeyError(sha)

            return self._get_commit(rev, type_data[1], expected_sha=sha)

        elif type == "blob":

            return self._get_blob(type_data[0], type_data[1], expected_sha=sha)

        elif type == "tree":

            try:

                inv = self.repository.get_inventory(type_data[1])

                rev = self.repository.get_revision(type_data[1])

            except errors.NoSuchRevision:

                trace.mutter('entry for %s %s in shamap: %r, but not found in repository', type, sha, type_data)

                raise KeyError(sha)

            unusual_modes = extract_unusual_modes(rev)

            try:

                return self._get_tree(type_data[0], type_data[1], inv, unusual_modes,

                                      expected_sha=sha)

            except errors.NoSuchRevision:

                raise KeyError(sha)

        else:

            raise AssertionError("Unknown object type '%s'" % type)