def _assert_pack_file(self, pack, version, size): assert pack.version() == 2 assert pack.size() == size assert len(pack.checksum()) == 20 num_obj = 0 for obj in pack.stream_iter(): num_obj += 1 info = pack.info(obj.pack_offset) stream = pack.stream(obj.pack_offset) assert info.pack_offset == stream.pack_offset assert info.type_id == stream.type_id assert hasattr(stream, 'read') # it should be possible to read from both streams assert obj.read() == stream.read() streams = pack.collect_streams(obj.pack_offset) assert streams # read the stream try: dstream = DeltaApplyReader.new(streams) except ValueError: # ignore these, old git versions use only ref deltas, # which we havent resolved ( as we are without an index ) # Also ignore non-delta streams continue # END get deltastream # read all data = dstream.read() assert len(data) == dstream.size # test seek dstream.seek(0) assert dstream.read() == data # read chunks # NOTE: the current implementation is safe, it basically transfers # all calls to the underlying memory map # END for each object assert num_obj == size
def _object(self, sha, as_stream, index=-1): """:return: OInfo or OStream object providing information about the given sha :param index: if not -1, its assumed to be the sha's index in the IndexFile""" # its a little bit redundant here, but it needs to be efficient if index < 0: index = self._sha_to_index(sha) if sha is None: sha = self._index.sha(index) # END assure sha is present ( in output ) offset = self._index.offset(index) type_id, uncomp_size, data_rela_offset = pack_object_header_info( self._pack._cursor.use_region(offset).buffer()) if as_stream: if type_id not in delta_types: packstream = self._pack.stream(offset) return OStream(sha, packstream.type, packstream.size, packstream.stream) # END handle non-deltas # produce a delta stream containing all info # To prevent it from applying the deltas when querying the size, # we extract it from the delta stream ourselves streams = self.collect_streams_at_offset(offset) dstream = DeltaApplyReader.new(streams) return ODeltaStream(sha, dstream.type, None, dstream) else: if type_id not in delta_types: return OInfo(sha, type_id_to_type_map[type_id], uncomp_size) # END handle non-deltas # deltas are a little tougher - unpack the first bytes to obtain # the actual target size, as opposed to the size of the delta data streams = self.collect_streams_at_offset(offset) buf = streams[0].read(512) offset, src_size = msb_size(buf) offset, target_size = msb_size(buf, offset) # collect the streams to obtain the actual object type if streams[-1].type_id in delta_types: raise BadObject(sha, "Could not resolve delta object") return OInfo(sha, streams[-1].type, target_size)
def _object(self, sha, as_stream, index=-1): """:return: OInfo or OStream object providing information about the given sha :param index: if not -1, its assumed to be the sha's index in the IndexFile""" # its a little bit redundant here, but it needs to be efficient if index < 0: index = self._sha_to_index(sha) if sha is None: sha = self._index.sha(index) # END assure sha is present ( in output ) offset = self._index.offset(index) type_id, uncomp_size, data_rela_offset = pack_object_header_info(self._pack._cursor.use_region(offset).buffer()) if as_stream: if type_id not in delta_types: packstream = self._pack.stream(offset) return OStream(sha, packstream.type, packstream.size, packstream.stream) # END handle non-deltas # produce a delta stream containing all info # To prevent it from applying the deltas when querying the size, # we extract it from the delta stream ourselves streams = self.collect_streams_at_offset(offset) dstream = DeltaApplyReader.new(streams) return ODeltaStream(sha, dstream.type, None, dstream) else: if type_id not in delta_types: return OInfo(sha, type_id_to_type_map[type_id], uncomp_size) # END handle non-deltas # deltas are a little tougher - unpack the first bytes to obtain # the actual target size, as opposed to the size of the delta data streams = self.collect_streams_at_offset(offset) buf = streams[0].read(512) offset, src_size = msb_size(buf) offset, target_size = msb_size(buf, offset) # collect the streams to obtain the actual object type if streams[-1].type_id in delta_types: raise BadObject(sha, "Could not resolve delta object") return OInfo(sha, streams[-1].type, target_size)