1# Copyright (C) 2007-2010 Canonical Ltd
2#
3# This program is free software; you can redistribute it and/or modify
4# it under the terms of the GNU General Public License as published by
5# the Free Software Foundation; either version 2 of the License, or
6# (at your option) any later version.
7#
8# This program is distributed in the hope that it will be useful,
9# but WITHOUT ANY WARRANTY; without even the implied warranty of
10# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11# GNU General Public License for more details.
12#
13# You should have received a copy of the GNU General Public License
14# along with this program; if not, write to the Free Software
15# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
16
17import bz2
18from io import (
19    BytesIO,
20    )
21import re
22
23from .... import (
24    bencode,
25    errors,
26    iterablefile,
27    lru_cache,
28    multiparent,
29    osutils,
30    repository as _mod_repository,
31    revision as _mod_revision,
32    trace,
33    ui,
34    )
35from ... import (
36    pack,
37    serializer,
38    versionedfile as _mod_versionedfile,
39    )
40from .. import bundle_data, serializer as bundle_serializer
41from ....i18n import ngettext
42
43
44class _MPDiffInventoryGenerator(_mod_versionedfile._MPDiffGenerator):
45    """Generate Inventory diffs serialized inventories."""
46
47    def __init__(self, repo, inventory_keys):
48        super(_MPDiffInventoryGenerator, self).__init__(repo.inventories,
49                                                        inventory_keys)
50        self.repo = repo
51        self.sha1s = {}
52
53    def iter_diffs(self):
54        """Compute the diffs one at a time."""
55        # This is instead of compute_diffs() since we guarantee our ordering of
56        # inventories, we don't have to do any buffering
57        self._find_needed_keys()
58        # We actually use a slightly different ordering. We grab all of the
59        # parents first, and then grab the ordered requests.
60        needed_ids = [k[-1] for k in self.present_parents]
61        needed_ids.extend([k[-1] for k in self.ordered_keys])
62        inv_to_lines = self.repo._serializer.write_inventory_to_chunks
63        for inv in self.repo.iter_inventories(needed_ids):
64            revision_id = inv.revision_id
65            key = (revision_id,)
66            if key in self.present_parents:
67                # Not a key we will transmit, which is a shame, since because
68                # of that bundles don't work with stacked branches
69                parent_ids = None
70            else:
71                parent_ids = [k[-1] for k in self.parent_map[key]]
72            as_chunks = inv_to_lines(inv)
73            self._process_one_record(key, as_chunks)
74            if parent_ids is None:
75                continue
76            diff = self.diffs.pop(key)
77            sha1 = osutils.sha_strings(as_chunks)
78            yield revision_id, parent_ids, sha1, diff
79
80
81class BundleWriter(object):
82    """Writer for bundle-format files.
83
84    This serves roughly the same purpose as ContainerReader, but acts as a
85    layer on top of it.
86
87    Provides ways of writing the specific record types supported this bundle
88    format.
89    """
90
91    def __init__(self, fileobj):
92        self._container = pack.ContainerWriter(self._write_encoded)
93        self._fileobj = fileobj
94        self._compressor = bz2.BZ2Compressor()
95
96    def _write_encoded(self, bytes):
97        """Write bzip2-encoded bytes to the file"""
98        self._fileobj.write(self._compressor.compress(bytes))
99
100    def begin(self):
101        """Start writing the bundle"""
102        self._fileobj.write(bundle_serializer._get_bundle_header('4'))
103        self._fileobj.write(b'#\n')
104        self._container.begin()
105
106    def end(self):
107        """Finish writing the bundle"""
108        self._container.end()
109        self._fileobj.write(self._compressor.flush())
110
111    def add_multiparent_record(self, mp_bytes, sha1, parents, repo_kind,
112                               revision_id, file_id):
113        """Add a record for a multi-parent diff
114
115        :mp_bytes: A multi-parent diff, as a bytestring
116        :sha1: The sha1 hash of the fulltext
117        :parents: a list of revision-ids of the parents
118        :repo_kind: The kind of object in the repository.  May be 'file' or
119            'inventory'
120        :revision_id: The revision id of the mpdiff being added.
121        :file_id: The file-id of the file, or None for inventories.
122        """
123        metadata = {b'parents': parents,
124                    b'storage_kind': b'mpdiff',
125                    b'sha1': sha1}
126        self._add_record(mp_bytes, metadata, repo_kind, revision_id, file_id)
127
128    def add_fulltext_record(self, bytes, parents, repo_kind, revision_id):
129        """Add a record for a fulltext
130
131        :bytes: The fulltext, as a bytestring
132        :parents: a list of revision-ids of the parents
133        :repo_kind: The kind of object in the repository.  May be 'revision' or
134            'signature'
135        :revision_id: The revision id of the fulltext being added.
136        """
137        metadata = {b'parents': parents,
138                    b'storage_kind': b'mpdiff'}
139        self._add_record(bytes, {b'parents': parents,
140                                 b'storage_kind': b'fulltext'}, repo_kind, revision_id, None)
141
142    def add_info_record(self, kwargs):
143        """Add an info record to the bundle
144
145        Any parameters may be supplied, except 'self' and 'storage_kind'.
146        Values must be lists, strings, integers, dicts, or a combination.
147        """
148        kwargs[b'storage_kind'] = b'header'
149        self._add_record(None, kwargs, 'info', None, None)
150
151    @staticmethod
152    def encode_name(content_kind, revision_id, file_id=None):
153        """Encode semantic ids as a container name"""
154        if content_kind not in ('revision', 'file', 'inventory', 'signature',
155                                'info'):
156            raise ValueError(content_kind)
157        if content_kind == 'file':
158            if file_id is None:
159                raise AssertionError()
160        else:
161            if file_id is not None:
162                raise AssertionError()
163        if content_kind == 'info':
164            if revision_id is not None:
165                raise AssertionError()
166        elif revision_id is None:
167            raise AssertionError()
168        names = [n.replace(b'/', b'//') for n in
169                 (content_kind.encode('ascii'), revision_id, file_id) if n is not None]
170        return b'/'.join(names)
171
172    def _add_record(self, bytes, metadata, repo_kind, revision_id, file_id):
173        """Add a bundle record to the container.
174
175        Most bundle records are recorded as header/body pairs, with the
176        body being nameless.  Records with storage_kind 'header' have no
177        body.
178        """
179        name = self.encode_name(repo_kind, revision_id, file_id)
180        encoded_metadata = bencode.bencode(metadata)
181        self._container.add_bytes_record([encoded_metadata], len(encoded_metadata), [(name, )])
182        if metadata[b'storage_kind'] != b'header':
183            self._container.add_bytes_record([bytes], len(bytes), [])
184
185
186class BundleReader(object):
187    """Reader for bundle-format files.
188
189    This serves roughly the same purpose as ContainerReader, but acts as a
190    layer on top of it, providing metadata, a semantic name, and a record
191    body
192    """
193
194    def __init__(self, fileobj, stream_input=True):
195        """Constructor
196
197        :param fileobj: a file containing a bzip-encoded container
198        :param stream_input: If True, the BundleReader stream input rather than
199            reading it all into memory at once.  Reading it into memory all at
200            once is (currently) faster.
201        """
202        line = fileobj.readline()
203        if line != '\n':
204            fileobj.readline()
205        self.patch_lines = []
206        if stream_input:
207            source_file = iterablefile.IterableFile(self.iter_decode(fileobj))
208        else:
209            source_file = BytesIO(bz2.decompress(fileobj.read()))
210        self._container_file = source_file
211
212    @staticmethod
213    def iter_decode(fileobj):
214        """Iterate through decoded fragments of the file"""
215        decompressor = bz2.BZ2Decompressor()
216        for line in fileobj:
217            try:
218                yield decompressor.decompress(line)
219            except EOFError:
220                return
221
222    @staticmethod
223    def decode_name(name):
224        """Decode a name from its container form into a semantic form
225
226        :retval: content_kind, revision_id, file_id
227        """
228        segments = re.split(b'(//?)', name)
229        names = [b'']
230        for segment in segments:
231            if segment == b'//':
232                names[-1] += b'/'
233            elif segment == b'/':
234                names.append(b'')
235            else:
236                names[-1] += segment
237        content_kind = names[0]
238        revision_id = None
239        file_id = None
240        if len(names) > 1:
241            revision_id = names[1]
242        if len(names) > 2:
243            file_id = names[2]
244        return content_kind.decode('ascii'), revision_id, file_id
245
246    def iter_records(self):
247        """Iterate through bundle records
248
249        :return: a generator of (bytes, metadata, content_kind, revision_id,
250            file_id)
251        """
252        iterator = pack.iter_records_from_file(self._container_file)
253        for names, bytes in iterator:
254            if len(names) != 1:
255                raise errors.BadBundle('Record has %d names instead of 1'
256                                       % len(names))
257            metadata = bencode.bdecode(bytes)
258            if metadata[b'storage_kind'] == b'header':
259                bytes = None
260            else:
261                _unused, bytes = next(iterator)
262            yield (bytes, metadata) + self.decode_name(names[0][0])
263
264
265class BundleSerializerV4(bundle_serializer.BundleSerializer):
266    """Implement the high-level bundle interface"""
267
268    def write_bundle(self, repository, target, base, fileobj):
269        """Write a bundle to a file object
270
271        :param repository: The repository to retrieve revision data from
272        :param target: The head revision to include ancestors of
273        :param base: The ancestor of the target to stop including acestors
274            at.
275        :param fileobj: The file-like object to write to
276        """
277        write_op = BundleWriteOperation(base, target, repository, fileobj)
278        return write_op.do_write()
279
280    def read(self, file):
281        """return a reader object for a given file"""
282        bundle = BundleInfoV4(file, self)
283        return bundle
284
285    @staticmethod
286    def get_source_serializer(info):
287        """Retrieve the serializer for a given info object"""
288        return serializer.format_registry.get(info[b'serializer'].decode('ascii'))
289
290
291class BundleWriteOperation(object):
292    """Perform the operation of writing revisions to a bundle"""
293
294    def __init__(self, base, target, repository, fileobj, revision_ids=None):
295        self.base = base
296        self.target = target
297        self.repository = repository
298        bundle = BundleWriter(fileobj)
299        self.bundle = bundle
300        if revision_ids is not None:
301            self.revision_ids = revision_ids
302        else:
303            graph = repository.get_graph()
304            revision_ids = graph.find_unique_ancestors(target, [base])
305            # Strip ghosts
306            parents = graph.get_parent_map(revision_ids)
307            self.revision_ids = [r for r in revision_ids if r in parents]
308        self.revision_keys = {(revid,) for revid in self.revision_ids}
309
310    def do_write(self):
311        """Write all data to the bundle"""
312        trace.note(ngettext('Bundling %d revision.', 'Bundling %d revisions.',
313                            len(self.revision_ids)), len(self.revision_ids))
314        with self.repository.lock_read():
315            self.bundle.begin()
316            self.write_info()
317            self.write_files()
318            self.write_revisions()
319            self.bundle.end()
320        return self.revision_ids
321
322    def write_info(self):
323        """Write format info"""
324        serializer_format = self.repository.get_serializer_format()
325        supports_rich_root = {True: 1, False: 0}[
326            self.repository.supports_rich_root()]
327        self.bundle.add_info_record({b'serializer': serializer_format,
328                                     b'supports_rich_root': supports_rich_root})
329
330    def write_files(self):
331        """Write bundle records for all revisions of all files"""
332        text_keys = []
333        altered_fileids = self.repository.fileids_altered_by_revision_ids(
334            self.revision_ids)
335        for file_id, revision_ids in altered_fileids.items():
336            for revision_id in revision_ids:
337                text_keys.append((file_id, revision_id))
338        self._add_mp_records_keys('file', self.repository.texts, text_keys)
339
340    def write_revisions(self):
341        """Write bundle records for all revisions and signatures"""
342        inv_vf = self.repository.inventories
343        topological_order = [key[-1] for key in multiparent.topo_iter_keys(
344            inv_vf, self.revision_keys)]
345        revision_order = topological_order
346        if self.target is not None and self.target in self.revision_ids:
347            # Make sure the target revision is always the last entry
348            revision_order = list(topological_order)
349            revision_order.remove(self.target)
350            revision_order.append(self.target)
351        if self.repository._serializer.support_altered_by_hack:
352            # Repositories that support_altered_by_hack means that
353            # inventories.make_mpdiffs() contains all the data about the tree
354            # shape. Formats without support_altered_by_hack require
355            # chk_bytes/etc, so we use a different code path.
356            self._add_mp_records_keys('inventory', inv_vf,
357                                      [(revid,) for revid in topological_order])
358        else:
359            # Inventories should always be added in pure-topological order, so
360            # that we can apply the mpdiff for the child to the parent texts.
361            self._add_inventory_mpdiffs_from_serializer(topological_order)
362        self._add_revision_texts(revision_order)
363
364    def _add_inventory_mpdiffs_from_serializer(self, revision_order):
365        """Generate mpdiffs by serializing inventories.
366
367        The current repository only has part of the tree shape information in
368        the 'inventories' vf. So we use serializer.write_inventory_to_lines to
369        get a 'full' representation of the tree shape, and then generate
370        mpdiffs on that data stream. This stream can then be reconstructed on
371        the other side.
372        """
373        inventory_key_order = [(r,) for r in revision_order]
374        generator = _MPDiffInventoryGenerator(self.repository,
375                                              inventory_key_order)
376        for revision_id, parent_ids, sha1, diff in generator.iter_diffs():
377            text = b''.join(diff.to_patch())
378            self.bundle.add_multiparent_record(text, sha1, parent_ids,
379                                               'inventory', revision_id, None)
380
381    def _add_revision_texts(self, revision_order):
382        parent_map = self.repository.get_parent_map(revision_order)
383        revision_to_bytes = self.repository._serializer.write_revision_to_string
384        revisions = self.repository.get_revisions(revision_order)
385        for revision in revisions:
386            revision_id = revision.revision_id
387            parents = parent_map.get(revision_id, None)
388            revision_text = revision_to_bytes(revision)
389            self.bundle.add_fulltext_record(revision_text, parents,
390                                            'revision', revision_id)
391            try:
392                self.bundle.add_fulltext_record(
393                    self.repository.get_signature_text(
394                        revision_id), parents, 'signature', revision_id)
395            except errors.NoSuchRevision:
396                pass
397
398    @staticmethod
399    def get_base_target(revision_ids, forced_bases, repository):
400        """Determine the base and target from old-style revision ids"""
401        if len(revision_ids) == 0:
402            return None, None
403        target = revision_ids[0]
404        base = forced_bases.get(target)
405        if base is None:
406            parents = repository.get_revision(target).parent_ids
407            if len(parents) == 0:
408                base = _mod_revision.NULL_REVISION
409            else:
410                base = parents[0]
411        return base, target
412
413    def _add_mp_records_keys(self, repo_kind, vf, keys):
414        """Add multi-parent diff records to a bundle"""
415        ordered_keys = list(multiparent.topo_iter_keys(vf, keys))
416        mpdiffs = vf.make_mpdiffs(ordered_keys)
417        sha1s = vf.get_sha1s(ordered_keys)
418        parent_map = vf.get_parent_map(ordered_keys)
419        for mpdiff, item_key, in zip(mpdiffs, ordered_keys):
420            sha1 = sha1s[item_key]
421            parents = [key[-1] for key in parent_map[item_key]]
422            text = b''.join(mpdiff.to_patch())
423            # Infer file id records as appropriate.
424            if len(item_key) == 2:
425                file_id = item_key[0]
426            else:
427                file_id = None
428            self.bundle.add_multiparent_record(text, sha1, parents, repo_kind,
429                                               item_key[-1], file_id)
430
431
432class BundleInfoV4(object):
433
434    """Provide (most of) the BundleInfo interface"""
435
436    def __init__(self, fileobj, serializer):
437        self._fileobj = fileobj
438        self._serializer = serializer
439        self.__real_revisions = None
440        self.__revisions = None
441
442    def install(self, repository):
443        return self.install_revisions(repository)
444
445    def install_revisions(self, repository, stream_input=True):
446        """Install this bundle's revisions into the specified repository
447
448        :param target_repo: The repository to install into
449        :param stream_input: If True, will stream input rather than reading it
450            all into memory at once.  Reading it into memory all at once is
451            (currently) faster.
452        """
453        with repository.lock_write():
454            ri = RevisionInstaller(self.get_bundle_reader(stream_input),
455                                   self._serializer, repository)
456            return ri.install()
457
458    def get_merge_request(self, target_repo):
459        """Provide data for performing a merge
460
461        Returns suggested base, suggested target, and patch verification status
462        """
463        return None, self.target, 'inapplicable'
464
465    def get_bundle_reader(self, stream_input=True):
466        """Return a new BundleReader for the associated bundle
467
468        :param stream_input: If True, the BundleReader stream input rather than
469            reading it all into memory at once.  Reading it into memory all at
470            once is (currently) faster.
471        """
472        self._fileobj.seek(0)
473        return BundleReader(self._fileobj, stream_input)
474
475    def _get_real_revisions(self):
476        if self.__real_revisions is None:
477            self.__real_revisions = []
478            bundle_reader = self.get_bundle_reader()
479            for bytes, metadata, repo_kind, revision_id, file_id in \
480                    bundle_reader.iter_records():
481                if repo_kind == 'info':
482                    serializer =\
483                        self._serializer.get_source_serializer(metadata)
484                if repo_kind == 'revision':
485                    rev = serializer.read_revision_from_string(bytes)
486                    self.__real_revisions.append(rev)
487        return self.__real_revisions
488    real_revisions = property(_get_real_revisions)
489
490    def _get_revisions(self):
491        if self.__revisions is None:
492            self.__revisions = []
493            for revision in self.real_revisions:
494                self.__revisions.append(
495                    bundle_data.RevisionInfo.from_revision(revision))
496        return self.__revisions
497
498    revisions = property(_get_revisions)
499
500    def _get_target(self):
501        return self.revisions[-1].revision_id
502
503    target = property(_get_target)
504
505
506class RevisionInstaller(object):
507    """Installs revisions into a repository"""
508
509    def __init__(self, container, serializer, repository):
510        self._container = container
511        self._serializer = serializer
512        self._repository = repository
513        self._info = None
514
515    def install(self):
516        """Perform the installation.
517
518        Must be called with the Repository locked.
519        """
520        with _mod_repository.WriteGroup(self._repository):
521            return self._install_in_write_group()
522
523    def _install_in_write_group(self):
524        current_file = None
525        current_versionedfile = None
526        pending_file_records = []
527        inventory_vf = None
528        pending_inventory_records = []
529        added_inv = set()
530        target_revision = None
531        for bytes, metadata, repo_kind, revision_id, file_id in\
532                self._container.iter_records():
533            if repo_kind == 'info':
534                if self._info is not None:
535                    raise AssertionError()
536                self._handle_info(metadata)
537            if (pending_file_records and
538                    (repo_kind, file_id) != ('file', current_file)):
539                # Flush the data for a single file - prevents memory
540                # spiking due to buffering all files in memory.
541                self._install_mp_records_keys(self._repository.texts,
542                                              pending_file_records)
543                current_file = None
544                del pending_file_records[:]
545            if len(pending_inventory_records) > 0 and repo_kind != 'inventory':
546                self._install_inventory_records(pending_inventory_records)
547                pending_inventory_records = []
548            if repo_kind == 'inventory':
549                pending_inventory_records.append(
550                    ((revision_id,), metadata, bytes))
551            if repo_kind == 'revision':
552                target_revision = revision_id
553                self._install_revision(revision_id, metadata, bytes)
554            if repo_kind == 'signature':
555                self._install_signature(revision_id, metadata, bytes)
556            if repo_kind == 'file':
557                current_file = file_id
558                pending_file_records.append(
559                    ((file_id, revision_id), metadata, bytes))
560        self._install_mp_records_keys(
561            self._repository.texts, pending_file_records)
562        return target_revision
563
564    def _handle_info(self, info):
565        """Extract data from an info record"""
566        self._info = info
567        self._source_serializer = self._serializer.get_source_serializer(info)
568        if (info[b'supports_rich_root'] == 0 and
569                self._repository.supports_rich_root()):
570            self.update_root = True
571        else:
572            self.update_root = False
573
574    def _install_mp_records(self, versionedfile, records):
575        if len(records) == 0:
576            return
577        d_func = multiparent.MultiParent.from_patch
578        vf_records = [(r, m['parents'], m['sha1'], d_func(t)) for r, m, t in
579                      records if r not in versionedfile]
580        versionedfile.add_mpdiffs(vf_records)
581
582    def _install_mp_records_keys(self, versionedfile, records):
583        d_func = multiparent.MultiParent.from_patch
584        vf_records = []
585        for key, meta, text in records:
586            # Adapt to tuple interface: A length two key is a file_id,
587            # revision_id pair, a length 1 key is a
588            # revision/signature/inventory. We need to do this because
589            # the metadata extraction from the bundle has not yet been updated
590            # to use the consistent tuple interface itself.
591            if len(key) == 2:
592                prefix = key[:1]
593            else:
594                prefix = ()
595            parents = [prefix + (parent,) for parent in meta[b'parents']]
596            vf_records.append((key, parents, meta[b'sha1'], d_func(text)))
597        versionedfile.add_mpdiffs(vf_records)
598
599    def _get_parent_inventory_texts(self, inventory_text_cache,
600                                    inventory_cache, parent_ids):
601        cached_parent_texts = {}
602        remaining_parent_ids = []
603        for parent_id in parent_ids:
604            p_text = inventory_text_cache.get(parent_id, None)
605            if p_text is None:
606                remaining_parent_ids.append(parent_id)
607            else:
608                cached_parent_texts[parent_id] = p_text
609        ghosts = ()
610        # TODO: Use inventory_cache to grab inventories we already have in
611        #       memory
612        if remaining_parent_ids:
613            # first determine what keys are actually present in the local
614            # inventories object (don't use revisions as they haven't been
615            # installed yet.)
616            parent_keys = [(r,) for r in remaining_parent_ids]
617            present_parent_map = self._repository.inventories.get_parent_map(
618                parent_keys)
619            present_parent_ids = []
620            ghosts = set()
621            for p_id in remaining_parent_ids:
622                if (p_id,) in present_parent_map:
623                    present_parent_ids.append(p_id)
624                else:
625                    ghosts.add(p_id)
626            to_lines = self._source_serializer.write_inventory_to_chunks
627            for parent_inv in self._repository.iter_inventories(
628                    present_parent_ids):
629                p_text = b''.join(to_lines(parent_inv))
630                inventory_cache[parent_inv.revision_id] = parent_inv
631                cached_parent_texts[parent_inv.revision_id] = p_text
632                inventory_text_cache[parent_inv.revision_id] = p_text
633
634        parent_texts = [cached_parent_texts[parent_id]
635                        for parent_id in parent_ids
636                        if parent_id not in ghosts]
637        return parent_texts
638
639    def _install_inventory_records(self, records):
640        if (self._info[b'serializer'] == self._repository._serializer.format_num
641                and self._repository._serializer.support_altered_by_hack):
642            return self._install_mp_records_keys(self._repository.inventories,
643                                                 records)
644        # Use a 10MB text cache, since these are string xml inventories. Note
645        # that 10MB is fairly small for large projects (a single inventory can
646        # be >5MB). Another possibility is to cache 10-20 inventory texts
647        # instead
648        inventory_text_cache = lru_cache.LRUSizeCache(10 * 1024 * 1024)
649        # Also cache the in-memory representation. This allows us to create
650        # inventory deltas to apply rather than calling add_inventory from
651        # scratch each time.
652        inventory_cache = lru_cache.LRUCache(10)
653        with ui.ui_factory.nested_progress_bar() as pb:
654            num_records = len(records)
655            for idx, (key, metadata, bytes) in enumerate(records):
656                pb.update('installing inventory', idx, num_records)
657                revision_id = key[-1]
658                parent_ids = metadata[b'parents']
659                # Note: This assumes the local ghosts are identical to the
660                #       ghosts in the source, as the Bundle serialization
661                #       format doesn't record ghosts.
662                p_texts = self._get_parent_inventory_texts(inventory_text_cache,
663                                                           inventory_cache,
664                                                           parent_ids)
665                # Why does to_lines() take strings as the source, it seems that
666                # it would have to cast to a list of lines, which we get back
667                # as lines and then cast back to a string.
668                target_lines = multiparent.MultiParent.from_patch(bytes
669                                                                  ).to_lines(p_texts)
670                sha1 = osutils.sha_strings(target_lines)
671                if sha1 != metadata[b'sha1']:
672                    raise errors.BadBundle("Can't convert to target format")
673                # Add this to the cache so we don't have to extract it again.
674                inventory_text_cache[revision_id] = b''.join(target_lines)
675                target_inv = self._source_serializer.read_inventory_from_lines(
676                    target_lines)
677                del target_lines
678                self._handle_root(target_inv, parent_ids)
679                parent_inv = None
680                if parent_ids:
681                    parent_inv = inventory_cache.get(parent_ids[0], None)
682                try:
683                    if parent_inv is None:
684                        self._repository.add_inventory(revision_id, target_inv,
685                                                       parent_ids)
686                    else:
687                        delta = target_inv._make_delta(parent_inv)
688                        self._repository.add_inventory_by_delta(parent_ids[0],
689                                                                delta, revision_id, parent_ids)
690                except serializer.UnsupportedInventoryKind:
691                    raise errors.IncompatibleRevision(repr(self._repository))
692                inventory_cache[revision_id] = target_inv
693
694    def _handle_root(self, target_inv, parent_ids):
695        revision_id = target_inv.revision_id
696        if self.update_root:
697            text_key = (target_inv.root.file_id, revision_id)
698            parent_keys = [(target_inv.root.file_id, parent) for
699                           parent in parent_ids]
700            self._repository.texts.add_lines(text_key, parent_keys, [])
701        elif not self._repository.supports_rich_root():
702            if target_inv.root.revision != revision_id:
703                raise errors.IncompatibleRevision(repr(self._repository))
704
705    def _install_revision(self, revision_id, metadata, text):
706        if self._repository.has_revision(revision_id):
707            return
708        revision = self._source_serializer.read_revision_from_string(text)
709        self._repository.add_revision(revision.revision_id, revision)
710
711    def _install_signature(self, revision_id, metadata, text):
712        transaction = self._repository.get_transaction()
713        if self._repository.has_signature_for_revision_id(revision_id):
714            return
715        self._repository.add_signature_text(revision_id, text)
716