/brz/remove-bazaar

# Copyright (C) 2009-2018 Jelmer Vernooij <jelmer@jelmer.uk>

# Copyright (C) 2012 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

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

from __future__ import absolute_import

from dulwich.objects import (

    Blob,

    Commit,

    Tree,

    sha_to_hex,

    ZERO_SHA,

    )

from dulwich.object_store import (

    BaseObjectStore,

    )

from dulwich.pack import (

    pack_objects_to_data,

    PackData,

    Pack,

    )

from .. import (

    errors,

    lru_cache,

    trace,

    osutils,

    ui,

    )

from ..tree import find_previous_path

from ..lock import LogicalLockResult

from ..revision import (

    NULL_REVISION,

    )

from ..sixish import viewitems

from ..bzr.testament import (

    StrictTestament3,

    )

from .cache import (

    from_repository as cache_from_repository,

    )

from .mapping import (

    default_mapping,

    entry_mode,

    extract_unusual_modes,

    mapping_registry,

    symlink_to_blob,

    )

from .unpeel_map import (

    UnpeelMap,

    )

import posixpath

import stat

BANNED_FILENAMES = ['.git']

def get_object_store(repo, mapping=None):

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

    if git is not None:

        git.object_store.unlock = lambda: None

        git.object_store.lock_read = lambda: LogicalLockResult(lambda: None)

        git.object_store.lock_write = lambda: LogicalLockResult(lambda: 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, 250 per inventory entry

            try:

                inv = tree.root_inventory

            except AttributeError:

                inv = tree.inventory

            return len(inv) * 250

        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)

        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:

                if tree.get_revision_id() != revid:

                    raise AssertionError(

                        "revision id did not match: %s != %s" % (

                            tree.get_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[tree.get_revision_id()] = tree

def _find_missing_bzr_revids(graph, 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

    """

    handled = set(have)

    todo = set()

    for rev in want:

        extra_todo = graph.find_unique_ancestors(rev, handled)

        todo.update(extra_todo)

        handled.update(extra_todo)

    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().encode('ascii'):

            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 directory_to_tree(path, children, lookup_ie_sha1, unusual_modes,

                      empty_file_name, allow_empty=False):

    """Create a Git Tree object from a Bazaar directory.

    :param path: directory path

    :param children: Children inventory entries

    :param lookup_ie_sha1: Lookup the Git SHA1 for a inventory entry

    :param unusual_modes: Dictionary with unusual file modes by file ids

    :param empty_file_name: Name to use for dummy files in empty directories,

        None to ignore empty directories.

    """

    tree = Tree()

    for value in children:

        if value.name in BANNED_FILENAMES:

            continue

        child_path = osutils.pathjoin(path, value.name)

        try:

            mode = unusual_modes[child_path]

        except KeyError:

            mode = entry_mode(value)

        hexsha = lookup_ie_sha1(child_path, value)

        if hexsha is not None:

            tree.add(value.name.encode("utf-8"), mode, hexsha)

    if not allow_empty and len(tree) == 0:

        # Only the root can be an empty tree

        if empty_file_name is not None:

            tree.add(empty_file_name, stat.S_IFREG | 0o644, Blob().id)

        else:

            return None

    return tree

def _tree_to_objects(tree, parent_trees, idmap, unusual_modes,

                     dummy_file_name=None, add_cache_entry=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

    """

    dirty_dirs = set()

    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(path, kind, other, parent_trees):

        for ptree in parent_trees:

            ppath = find_previous_path(tree, ptree, path)

            if ppath is not None:

                pkind = ptree.kind(ppath)

                if kind == "file":

                    if (pkind == "file" and

                            ptree.get_file_sha1(ppath) == other):

                        return (

                            ptree.path2id(ppath), ptree.get_file_revision(ppath))

                if kind == "symlink":

                    if (pkind == "symlink" and

                            ptree.get_symlink_target(ppath) == other):

                        return (

                            ptree.path2id(ppath), ptree.get_file_revision(ppath))

        raise KeyError

    # Find all the changed blobs

    for change in tree.iter_changes(base_tree):

        if change.name[1] in BANNED_FILENAMES:

            continue

        if change.kind[1] == "file":

            sha1 = tree.get_file_sha1(change.path[1])

            blob_id = None

            try:

                (pfile_id, prevision) = find_unchanged_parent_ie(

                    change.path[1], change.kind[1], sha1, other_parent_trees)

            except KeyError:

                pass

            else:

                # It existed in one of the parents, with the same contents.

                # So no need to yield any new git objects.

                try:

                    blob_id = idmap.lookup_blob_id(

                        pfile_id, prevision)

                except KeyError:

                    if not changed_content:

                        # no-change merge ?

                        blob = Blob()

                        blob.data = tree.get_file_text(change.path[1])

                        blob_id = blob.id

            if blob_id is None:

                new_blobs.append((change.path[1], change.file_id))

            else:

                # TODO(jelmer): This code path does not have any test coverage.

                shamap[change.path[1]] = blob_id

                if add_cache_entry is not None:

                    add_cache_entry(

                        ("blob", blob_id),

                        (change.file_id, tree.get_file_revision(change.path[1])), change.path[1])

        elif change.kind[1] == "symlink":

            target = tree.get_symlink_target(change.path[1])

            blob = symlink_to_blob(target)

            shamap[change.path[1]] = blob.id

            if add_cache_entry is not None:

                add_cache_entry(

                    blob, (change.file_id, tree.get_file_revision(change.path[1])), change.path[1])

            try:

                find_unchanged_parent_ie(

                    change.path[1], change.kind[1], target, other_parent_trees)

            except KeyError:

                if change.changed_content:

                    yield (change.path[1], blob,

                           (change.file_id, tree.get_file_revision(change.path[1])))

        elif change.kind[1] is None:

            shamap[change.path[1]] = None

        elif change.kind[1] != 'directory':

            raise AssertionError(change.kind[1])

        for p in change.path:

            if p is None:

                continue

            dirty_dirs.add(osutils.dirname(p))

    # Fetch contents of the blobs that were changed

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

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

        obj = Blob()

        obj.chunked = chunks

        if add_cache_entry is not None:

            add_cache_entry(obj, (file_id, tree.get_file_revision(path)), path)

        yield path, obj, (file_id, tree.get_file_revision(path))

        shamap[path] = obj.id

    for path in unusual_modes:

        dirty_dirs.add(posixpath.dirname(path))

    for dir in list(dirty_dirs):

        for parent in osutils.parent_directories(dir):

            if parent in dirty_dirs:

                break

            dirty_dirs.add(parent)

    if dirty_dirs:

        dirty_dirs.add('')

    def ie_to_hexsha(path, ie):

        try:

            return shamap[path]

        except KeyError:

            pass

        # FIXME: Should be the same as in parent

        if ie.kind == "file":

            try:

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

            except KeyError:

                # no-change merge ?

                blob = Blob()

                blob.data = tree.get_file_text(path)

                if add_cache_entry is not None:

                    add_cache_entry(blob, (ie.file_id, ie.revision), path)

                return blob.id

        elif ie.kind == "symlink":

            try:

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

            except KeyError:

                # no-change merge ?

                target = tree.get_symlink_target(path)

                blob = symlink_to_blob(target)

                if add_cache_entry is not None:

                    add_cache_entry(blob, (ie.file_id, ie.revision), path)

                return blob.id

        elif ie.kind == "directory":

            # Not all cache backends store the tree information,

            # calculate again from scratch

            ret = directory_to_tree(

                path, ie.children.values(), ie_to_hexsha, unusual_modes,

                dummy_file_name, ie.parent_id is None)

            if ret is None:

                return ret

            return ret.id

        else:

            raise AssertionError

    for path in sorted(dirty_dirs, reverse=True):

        if not tree.has_filename(path):

            continue

        if tree.kind(path) != 'directory':

            continue

        obj = directory_to_tree(

            path, tree.iter_child_entries(path), ie_to_hexsha, unusual_modes,

            dummy_file_name, path == '')

        if obj is not None:

            file_id = tree.path2id(path)

            if add_cache_entry is not None:

                add_cache_entry(obj, (file_id, tree.get_revision_id()), path)

            yield path, obj, (file_id, tree.get_revision_id())

            shamap[path] = obj.id

class PackTupleIterable(object):

    def __init__(self, store):

        self.store = store

        self.store.lock_read()

        self.objects = {}

    def __del__(self):

        self.store.unlock()

    def add(self, sha, path):

        self.objects[sha] = path

    def __len__(self):

        return len(self.objects)

    def __iter__(self):

        return ((self.store[object_id], path) for (object_id, path) in

                viewitems(self.objects))

class BazaarObjectStore(BaseObjectStore):

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

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

        self.repository = repository

        self._map_updated = False

        self._locked = None

        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)

        self.unpeel_map = UnpeelMap.from_repository(self.repository)

    def _missing_revisions(self, revisions):

        return self._cache.idmap.missing_revisions(revisions)

    def _update_sha_map(self, stop_revision=None):

        if not self.is_locked():

            raise errors.LockNotHeld(self)

        if self._map_updated:

            return

        if (stop_revision is not None and

                not self._missing_revisions([stop_revision])):

            return

        graph = self.repository.get_graph()

        if stop_revision is None:

            all_revids = self.repository.all_revision_ids()

            missing_revids = self._missing_revisions(all_revids)

        else:

            heads = set([stop_revision])

            missing_revids = self._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._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:

            if stop_revision is None:

                self._map_updated = True

            return

        self.start_write_group()

        try:

            with ui.ui_factory.nested_progress_bar() as pb:

                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)

            if stop_revision is None:

                self._map_updated = True

        except BaseException:

            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, lossy, verifiers):

        """Reconstruct a Commit object.

        :param rev: Revision object

        :param tree_sha: SHA1 of the root tree object

        :param lossy: Whether or not to roundtrip bzr metadata

        :param verifiers: Verifiers for the commits

        :return: Commit object

        """

        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,

                                          lossy, verifiers)

    def _create_fileid_map_blob(self, tree):

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

        # not all files necessarily have to be processed.

        file_ids = {}

        for (path, ie) in tree.iter_entries_by_dir():

            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, lossy, add_cache_entry=None):

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

        :param rev: Bazaar revision object

        :param tree: Bazaar revision tree

        :param lossy: Whether to not 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, bzr_key_data in _tree_to_objects(

                tree, parent_trees, self._cache.idmap, unusual_modes,

                self.mapping.BZR_DUMMY_FILE, add_cache_entry):

            if path == "":

                root_tree = obj

                root_key_data = bzr_key_data

                # Don't yield just yet

            else:

                yield path, obj

        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_key_data = (tree.get_root_id(), tree.get_revision_id())

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

            b = self._create_fileid_map_blob(tree)

            if b is not None:

                root_tree[self.mapping.BZR_FILE_IDS_FILE] = (

                    (stat.S_IFREG | 0o644), b.id)

                yield self.mapping.BZR_FILE_IDS_FILE, b

        if add_cache_entry is not None:

            add_cache_entry(root_tree, root_key_data, "")

        yield "", root_tree

        if not lossy:

            testament3 = StrictTestament3(rev, tree)

            verifiers = {"testament3-sha1": testament3.as_sha1()}

        else:

            verifiers = {}

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

                                              lossy=lossy, verifiers=verifiers)

        try:

            foreign_revid, mapping = mapping_registry.parse_revision_id(

                rev.revision_id)

        except errors.InvalidRevisionId:

            pass

        else:

            _check_expected_sha(foreign_revid, commit_obj)

        if add_cache_entry is not None:

            add_cache_entry(commit_obj, verifiers, None)

        yield None, commit_obj

    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)

        # FIXME JRV 2011-12-15: Shouldn't we try both values for lossy ?

        for path, obj in self._revision_to_objects(

                rev, tree, lossy=(not self.mapping.roundtripping),

                add_cache_entry=updater.add_object):

            if isinstance(obj, Commit):

                commit_obj = obj

        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.