/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.cache import (

    from_repository as cache_from_repository,

    )

import posixpath

import stat

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:

            tree = self._cache[revid]

        except KeyError:

            tree = self.repository.revision_tree(revid)

            self.add(tree)

        assert tree.get_revision_id() == tree.inventory.revision_id

        return tree

    def iter_revision_trees(self, revids):

        trees = {}

        todo = []

        for revid in revids:

            try:

                tree = self._cache[revid]

            except KeyError:

                todo.append(revid)

            else:

                assert tree.get_revision_id() == revid

                assert tree.inventory.revision_id == revid

                trees[revid] = tree

        for tree in self.repository.revision_trees(todo):

            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 _find_missing_bzr_revids(get_parent_map, want, have):

    """Find the revisions that have to be pushed.

    :param get_parent_map: Function that returns the parents for a sequence

        of revisions.

    :param want: Revisions the target wants

    :param have: Revisions the target already has

    :return: Set of revisions to fetch

    """

    pending = want - have

    processed = set()

    todo = set()

    while pending:

        processed.update(pending)

        next_map = get_parent_map(pending)

        next_pending = set()

        for item in next_map.iteritems():

            if item[0] in have:

                continue

            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)

    return todo

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,

                     dummy_file_name=None):

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

    :param idmap: id map

    :param parent_trees: Parent revision trees

    :param unusual_modes: Unusual file modes dictionary

    :param dummy_file_name: File name to use for dummy files

        in empty directories. None to skip empty directories

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

    """

    new_trees = {}

    new_blobs = []

    shamap = {}

    try:

        base_tree = parent_trees[0]

        other_parent_trees = parent_trees[1:]

    except IndexError:

        base_tree = tree._repository.revision_tree(NULL_REVISION)

        other_parent_trees = []

    def find_unchanged_parent_ie(ie, parent_trees):

        assert ie.kind in ("symlink", "file")

        for ptree in parent_trees:

            try:

                pie = ptree.inventory[ie.file_id]

            except errors.NoSuchId:

                pass

            else:

                if (pie.text_sha1 == ie.text_sha1 and 

                    pie.kind == ie.kind and

                    pie.symlink_target == ie.symlink_target):

                    return pie

        raise KeyError

    # Find all the changed blobs

    for (file_id, path, changed_content, versioned, parent, name, kind,

         executable) in tree.iter_changes(base_tree):

        if kind[1] == "file":

            ie = tree.inventory[file_id]

            if changed_content:

                try:

                    pie = find_unchanged_parent_ie(ie, other_parent_trees)

                except KeyError:

                    pass

                else:

                    try:

                        shamap[ie.file_id] = idmap.lookup_blob_id(

                            pie.file_id, pie.revision)

                    except KeyError:

                        # no-change merge ?

                        blob = Blob()

                        blob.data = tree.get_file_text(ie.file_id)

                        shamap[ie.file_id] = blob.id

            if not file_id in shamap:

                new_blobs.append((path[1], ie))

            new_trees[posixpath.dirname(path[1])] = parent[1]

        elif kind[1] == "symlink":

            ie = tree.inventory[file_id]

            if changed_content:

                blob = symlink_to_blob(ie)

                shamap[file_id] = blob.id

                try:

                    find_unchanged_parent_ie(ie, other_parent_trees)

                except KeyError:

                    yield path[1], blob, ie

            new_trees[posixpath.dirname(path[1])] = parent[1]

        elif kind[1] not in (None, "directory"):

            raise AssertionError(kind[1])

        if path[0] is not None and parent[0] in tree.inventory and tree.inventory[parent[0]].kind == "directory":

            # Removal

            new_trees[posixpath.dirname(path[0])] = parent[0]

    # Fetch contents of the blobs that were changed

    for (path, ie), chunks in tree.iter_files_bytes(

        [(ie.file_id, (path, ie)) for (path, ie) in new_blobs]):

        obj = Blob()

        obj.chunked = chunks

        yield path, obj, ie

        shamap[ie.file_id] = obj.id

    for path in unusual_modes:

        parent_path = posixpath.dirname(path)

        new_trees[parent_path] = tree.path2id(parent_path)

    trees = {}

    while new_trees:

        items = new_trees.items()

        new_trees = {}

        for path, file_id in items:

            parent_id = tree.inventory[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:

            # FIXME: Should be the same as in parent

            if ie.kind in ("file", "symlink"):

                try:

                    return idmap.lookup_blob_id(ie.file_id, ie.revision)

                except KeyError:

                    # no-change merge ?

                    blob = Blob()

                    blob.data = tree.get_file_text(ie.file_id)

                    return blob.id

            elif ie.kind == "directory":

                # Not all cache backends store the tree information, 

                # calculate again from scratch

                ret = directory_to_tree(ie, ie_to_hexsha, unusual_modes,

                    dummy_file_name)

                if ret is None:

                    return ret

                return ret.id

            else:

                raise AssertionError

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

        ie = tree.inventory[trees[path]]

        assert ie.kind == "directory"

        obj = directory_to_tree(ie, ie_to_hexsha, unusual_modes,

            dummy_file_name)

        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 _reconstruct_commit(self, rev, tree_sha, roundtrip):

        def parent_lookup(revid):

            try:

                return self._lookup_revision_sha1(revid)

            except errors.NoSuchRevision:

                return None

        return self.mapping.export_commit(rev, tree_sha, parent_lookup,

            roundtrip)

    def _create_fileid_map_blob(self, inv):

        # FIXME: This can probably be a lot more efficient, 

        # not all files necessarily have to be processed.

        file_ids = {}

        for (path, ie) in inv.iter_entries():

            if self.mapping.generate_file_id(path) != ie.file_id:

                file_ids[path] = ie.file_id

        return self.mapping.export_fileid_map(file_ids)

    def _revision_to_objects(self, rev, tree, roundtrip):

        """Convert a revision to a set of git objects.

        :param rev: Bazaar revision object

        :param tree: Bazaar revision tree

        :param roundtrip: Whether to roundtrip all Bazaar revision data

        """

        unusual_modes = extract_unusual_modes(rev)

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

        parent_trees = self.tree_cache.revision_trees(

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

        root_tree = None

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

                self._cache.idmap, unusual_modes, self.mapping.BZR_DUMMY_FILE):

            if path == "":

                root_tree = obj

                root_ie = ie

                # Don't yield just yet

            else:

                yield path, obj, ie

        if root_tree is None:

            # Pointless commit - get the tree sha elsewhere

            if not rev.parent_ids:

                root_tree = Tree()

            else:

                base_sha1 = self._lookup_revision_sha1(rev.parent_ids[0])

                root_tree = self[self[base_sha1].tree]

            root_ie = tree.inventory.root

        if roundtrip and self.mapping.BZR_FILE_IDS_FILE is not None:

            b = self._create_fileid_map_blob(tree.inventory)

            if b is not None:

                root_tree[self.mapping.BZR_FILE_IDS_FILE] = ((stat.S_IFREG | 0644), b.id)

                yield self.mapping.BZR_FILE_IDS_FILE, b, None

        yield "", root_tree, root_ie

        commit_obj = self._reconstruct_commit(rev, root_tree.id,

            roundtrip=roundtrip)

        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,

            roundtrip=True):

            updater.add_object(obj, ie, path)

        commit_obj = updater.finish()

        return commit_obj.id

    def _reconstruct_blobs(self, keys):

        """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

        """

        stream = self.repository.iter_files_bytes(

            ((key[0], key[1], key) for key in keys))

        for (fileid, revision, expected_sha), chunks in stream:

            blob = Blob()

            blob.chunked = chunks

            if blob.id != expected_sha and blob.data == "":

                # Perhaps it's a symlink ?

                tree = self.tree_cache.revision_tree(revision)

                entry = tree.inventory[fileid]

                if entry.kind == 'symlink':

                    blob = symlink_to_blob(entry)

            _check_expected_sha(expected_sha, blob)

            yield blob

    def _reconstruct_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,

                        revid)

                except (NotImplementedError, KeyError):

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

                        unusual_modes)

                    if obj is None:

                        return None

                    else:

                        return obj.id

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

                try:

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

                        entry.revision)

                except KeyError:

                    # no-change merge?

                    return self._reconstruct_blobs(

                        [(entry.file_id, entry.revision, None)]).next().id

            else:

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

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

            self.mapping.BZR_DUMMY_FILE)

        if (inv.root.file_id == fileid and

            self.mapping.BZR_FILE_IDS_FILE is not None):

            b = self._create_fileid_map_blob(inv)

            # If this is the root tree, add the file ids

            tree[self.mapping.BZR_FILE_IDS_FILE] = ((stat.S_IFREG | 0644), b.id)

        _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."""

        from dulwich.protocol import ZERO_SHA

        if revid == NULL_REVISION:

            return ZERO_SHA

        try:

            return self._cache.idmap.lookup_commit(revid)

        except KeyError:

            try:

                return mapping_registry.parse_revision_id(revid)[0]

            except errors.InvalidRevisionId:

                self.repository.lock_read()

                try:

                    self._update_sha_map(revid)

                finally:

                    self.repository.unlock()

                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_key(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_shas(self, shas, update_map=True):

        from dulwich.protocol import ZERO_SHA

        ret = {}

        for sha in shas:

            if sha == ZERO_SHA:

                ret[sha] = ("commit", (NULL_REVISION, None))

                continue

            try:

                ret[sha] = self._cache.idmap.lookup_git_sha(sha)

            except KeyError:

                if update_map:

                    # 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()

                    update_map = False

                    try:

                        ret[sha] = self._cache.idmap.lookup_git_sha(sha)

                    except KeyError:

                        pass

        return ret

    def lookup_git_sha(self, sha, update_map=True):

        return self.lookup_git_shas([sha], update_map=update_map)[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._reconstruct_commit(rev, tree_sha, roundtrip=True)

            _check_expected_sha(sha, commit)

            return commit

        elif type == "blob":

            (fileid, revision) = type_data

            return self._reconstruct_blobs([(fileid, revision, sha)]).next()

        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._reconstruct_tree(fileid, revid, tree.inventory,

                    unusual_modes, expected_sha=sha)

            except errors.NoSuchRevision:

                raise KeyError(sha)

        else:

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