/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,

    Tree,

    sha_to_hex,

    )

from dulwich.object_store import (

    BaseObjectStore,

    )

from bzrlib import (

    errors,

    lru_cache,

    trace,

    ui,

    urlutils,

    )

from bzrlib.revision import (

    NULL_REVISION,

    )

from bzrlib.plugins.git.mapping import (

    default_mapping,

    directory_to_tree,

    extract_unusual_modes,

    mapping_registry,

    symlink_to_blob,

    )

from bzrlib.plugins.git.shamap import (

    from_repository as cache_from_repository,

    )

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)

MAX_TREE_CACHE_SIZE = 50 * 1024 * 1024

class LRUTreeCache(object):

    def __init__(self, repository):

        def approx_tree_size(tree):

            # Very rough estimate, 1k per inventory entry

            return len(tree.inventory) * 1024

        self.repository = repository

        self._cache = lru_cache.LRUSizeCache(max_size=MAX_TREE_CACHE_SIZE,

            after_cleanup_size=None, compute_size=approx_tree_size)

    def revision_tree(self, revid):            

        try:

            return self._cache[revid] 

        except KeyError:

            tree = self.repository.revision_tree(revid)

            self.add(tree)

            return tree

    def iter_revision_trees(self, revids):

        trees = dict([(k, self._cache.get(k)) for k in revids]) 

        for tree in self.repository.revision_trees(

                [r for r, v in trees.iteritems() if v is None]):

            trees[tree.get_revision_id()] = tree

            self.add(tree)

        return (trees[r] for r in revids)

    def revision_trees(self, revids):

        return list(self.iter_revision_trees(revids))

    def add(self, tree):

        self._cache.add(tree.get_revision_id(), tree)

def _check_expected_sha(expected_sha, object):

    """Check whether an object matches an expected SHA.

    :param expected_sha: None or expected SHA as either binary or as hex digest

    :param object: Object to verify

    """

    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 _tree_to_objects(tree, parent_trees, idmap,

        unusual_modes, iter_files_bytes, has_ghost_parents):

    """Iterate over the objects that were introduced in a revision.

    :param idmap: id map

    :param unusual_modes: Unusual file modes

    :param iter_files_bytes: Repository.iter_files_bytes-like callback

    :return: Yields (path, object, ie) entries

    """

    inv = tree.inventory

    parent_invs = [t.inventory for t in parent_trees]

    new_trees = {}

    new_blobs = []

    shamap = {}

    for path, ie in inv.entries():

        if ie.kind == "file":

            if ie.revision != inv.revision_id:

                for pinv in parent_invs:

                    try:

                        pie = pinv[ie.file_id]

                    except errors.NoSuchId:

                        pass

                    else:

                        if (pie.text_sha1 == ie.text_sha1 and 

                            pie.kind == ie.kind):

                            shamap[ie.file_id] = idmap.lookup_blob_id(

                                pie.file_id, pie.revision)

                            break

            if not ie.file_id in shamap:

                new_blobs.append((path, ie))

                new_trees[urlutils.dirname(path)] = ie.parent_id

        elif ie.kind == "symlink":

            blob = symlink_to_blob(ie)

            for pinv in parent_invs:

                try:

                    pie = pinv[ie.file_id]

                except errors.NoSuchId:

                    pass

                else:

                    if (ie.kind == pie.kind and

                        ie.symlink_target == pie.symlink_target):

                        break

            else:

                yield path, blob, ie

                new_trees[urlutils.dirname(path)] = ie.parent_id

            shamap[ie.file_id] = blob.id

        elif ie.kind == "directory":

            for pinv in parent_invs:

                try:

                    pie = pinv[ie.file_id]

                except errors.NoSuchId:

                    pass

                else:

                    if (pie.kind == ie.kind and 

                        pie.children.keys() == ie.children.keys()):

                        try:

                            shamap[ie.file_id] = idmap.lookup_tree_id(

                                ie.file_id, inv.revision_id)

                        except (NotImplementedError, KeyError):

                            pass

                        else:

                            break

            else:

                new_trees[path] = ie.file_id

        else:

            raise AssertionError(ie.kind)

    for (path, ie), chunks in iter_files_bytes(

        [(ie.file_id, ie.revision, (path, ie))

            for (path, ie) in new_blobs]):

        obj = Blob()

        obj.chunked = chunks

        yield path, obj, ie

        shamap[ie.file_id] = obj.id

    for fid in unusual_modes:

        new_trees[inv.id2path(fid)] = inv[fid].parent_id

    trees = {}

    while new_trees:

        items = new_trees.items()

        new_trees = {}

        for path, file_id in items:

            parent_id = inv[file_id].parent_id

            if parent_id is not None:

                parent_path = urlutils.dirname(path)

                new_trees[parent_path] = parent_id

            trees[path] = file_id

    def ie_to_hexsha(ie):

        try:

            return shamap[ie.file_id]

        except KeyError:

            # Not all cache backends store the tree information, 

            # calculate again from scratch

            ret = directory_to_tree(ie, ie_to_hexsha, unusual_modes)

            if ret is None:

                return ret

            return ret.id

    for path in sorted(trees.keys(), reverse=True):

        ie = inv[trees[path]]

        assert ie.kind == "directory"

        obj = directory_to_tree(ie, ie_to_hexsha, unusual_modes)

        if obj is not None:

            yield path, obj, ie

            shamap[ie.file_id] = obj.id

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

        self._cache = cache_from_repository(repository)

        self._content_cache_types = ("tree")

        self.start_write_group = self._cache.idmap.start_write_group

        self.abort_write_group = self._cache.idmap.abort_write_group

        self.commit_write_group = self._cache.idmap.commit_write_group

        self.tree_cache = LRUTreeCache(self.repository)

    def _update_sha_map(self, stop_revision=None):

        graph = self.repository.get_graph()

        if stop_revision is None:

            heads = graph.heads(self.repository.all_revision_ids())

        else:

            heads = set([stop_revision])

        missing_revids = self._cache.idmap.missing_revisions(heads)

        while heads:

            parents = graph.get_parent_map(heads)

            todo = set()

            for p in parents.values():

                todo.update([x for x in p if x not in missing_revids])

            heads = self._cache.idmap.missing_revisions(todo)

            missing_revids.update(heads)

        if NULL_REVISION in missing_revids:

            missing_revids.remove(NULL_REVISION)

        missing_revids = self.repository.has_revisions(missing_revids)

        if not missing_revids:

            return

        self.start_write_group()

        try:

            pb = ui.ui_factory.nested_progress_bar()

            try:

                for i, revid in enumerate(graph.iter_topo_order(missing_revids)):

                    trace.mutter('processing %r', revid)

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

                    self._update_sha_map_revision(revid)

            finally:

                pb.finished()

        except:

            self.abort_write_group()

            raise

        else:

            self.commit_write_group()

    def __iter__(self):

        self._update_sha_map()

        return iter(self._cache.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 self.mapping.export_commit(rev, tree_sha, parent_lookup)

    def _revision_to_objects(self, rev, tree):

        unusual_modes = extract_unusual_modes(rev)

        present_parents = self.repository.has_revisions(rev.parent_ids)

        has_ghost_parents = (len(rev.parent_ids) < len(present_parents))

        parent_trees = self.tree_cache.revision_trees(

            [p for p in rev.parent_ids if p in present_parents])

        tree_sha = None

        for path, obj, ie in _tree_to_objects(tree, parent_trees,

                self._cache.idmap, unusual_modes,

                self.repository.iter_files_bytes, has_ghost_parents):

            yield path, obj, ie

            if path == "":

                tree_sha = obj.id

        if tree_sha is None:

            if not rev.parent_ids:

                tree_sha = Tree().id

            else:

                raise AssertionError

        commit_obj = self._revision_to_commit(rev, tree_sha)

        try:

            foreign_revid, mapping = mapping_registry.parse_revision_id(

                rev.revision_id)

        except errors.InvalidRevisionId:

            pass

        else:

            _check_expected_sha(foreign_revid, commit_obj)

        yield None, commit_obj, None

    def _get_updater(self, rev):

        return self._cache.get_updater(rev)

    def _update_sha_map_revision(self, revid):

        rev = self.repository.get_revision(revid)

        tree = self.tree_cache.revision_tree(rev.revision_id)

        updater = self._get_updater(rev)

        for path, obj, ie in self._revision_to_objects(rev, tree):

            updater.add_object(obj, ie)

        commit_obj = updater.finish()

        return commit_obj.id

    def _get_blob(self, fileid, revision, expected_sha):

        """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

        """

        blob = Blob()

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

        blob.chunked = chunks

        if blob.id != expected_sha:

            # Perhaps it's a symlink ?

            tree = self.tree_cache.revision_tree(revision)

            entry = tree.inventory[fileid]

            assert entry.kind == 'symlink'

            blob = symlink_to_blob(entry)

        _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.

        """

        def get_ie_sha1(entry):

            if entry.kind == "directory":

                try:

                    return self._cache.idmap.lookup_tree_id(entry.file_id)

                except (NotImplementedError, KeyError):

                    obj = self._get_tree(entry.file_id, revid, inv,

                        unusual_modes)

                    if obj is None:

                        return None

                    else:

                        return obj.id

            elif entry.kind in ("file", "symlink"):

                return self._cache.idmap.lookup_blob_id(entry.file_id, entry.revision)

            else:

                raise AssertionError("unknown entry kind '%s'" % entry.kind)

        tree = directory_to_tree(inv[fileid], get_ie_sha1, unusual_modes)

        _check_expected_sha(expected_sha, tree)

        return tree

    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._cache.idmap.lookup_commit(revid)

        except KeyError:

            try:

                return mapping_registry.parse_revision_id(revid)[0]

            except errors.InvalidRevisionId:

                self._update_sha_map(revid)

                return self._cache.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

    def _lookup_git_sha(self, sha):

        # See if sha is in map

        try:

            return self._cache.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._cache.idmap.lookup_git_sha(sha)

    def __getitem__(self, sha):

        if self._cache.content_cache is not None:

            try:

                return self._cache.content_cache[sha]

            except KeyError:

                pass

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

        # convert object to git object

        if type == "commit":

            (revid, tree_sha) = type_data

            try:

                rev = self.repository.get_revision(revid)

            except errors.NoSuchRevision:

                trace.mutter('entry for %s %s in shamap: %r, but not found in '

                             'repository', type, sha, type_data)

                raise KeyError(sha)

            commit = self._revision_to_commit(rev, tree_sha)

            _check_expected_sha(sha, commit)

            return commit

        elif type == "blob":

            (fileid, revision) = type_data

            return self._get_blob(fileid, revision, expected_sha=sha)

        elif type == "tree":

            (fileid, revid) = type_data

            try:

                tree = self.tree_cache.revision_tree(revid)

                rev = self.repository.get_revision(revid)

            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(fileid, revid, tree.inventory,

                    unusual_modes, expected_sha=sha)

            except errors.NoSuchRevision:

                raise KeyError(sha)

        else:

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

    def generate_pack_contents(self, have, want):

        """Iterate over the contents of a pack file.

        :param have: List of SHA1s of objects that should not be sent

        :param want: List of SHA1s of objects that should be sent

        """

        processed = set()

        for commit_sha in have:

            try:

                (type, (revid, tree_sha)) = self._lookup_git_sha(commit_sha)

            except KeyError:

                pass

            else:

                assert type == "commit"

                processed.add(revid)

        pending = set()

        for commit_sha in want:

            if commit_sha in have:

                continue

            (type, (revid, tree_sha)) = self._lookup_git_sha(commit_sha)

            assert type == "commit"

            pending.add(revid)

        todo = set()

        while pending:

            processed.update(pending)

            next_map = self.repository.get_parent_map(pending)

            next_pending = set()

            for item in next_map.iteritems():

                todo.add(item[0])

                next_pending.update(p for p in item[1] if p not in processed)

            pending = next_pending

        if NULL_REVISION in todo:

            todo.remove(NULL_REVISION)

        trace.mutter('sending revisions %r', todo)

        ret = []

        pb = ui.ui_factory.nested_progress_bar()

        try:

            for i, revid in enumerate(todo):

                pb.update("generating git objects", i, len(todo))

                rev = self.repository.get_revision(revid)

                tree = self.tree_cache.revision_tree(revid)

                for path, obj, ie in self._revision_to_objects(rev, tree):

                    ret.append((obj, path))

        finally:

            pb.finished()

        return ret