73     def __init__(self):  argument
74       self.version = None
75       self.manifest_len = None
76       self.metadata_signature_len = None
77       self.size = None
79     def ReadFromPayload(self, payload_file, hasher=None):  argument
97       magic = common.Read(payload_file, len(self._MAGIC), hasher=hasher)
98       if magic != self._MAGIC:
101       self.version = _ReadInt(payload_file, self._VERSION_SIZE, True,
103       self.manifest_len = _ReadInt(payload_file, self._MANIFEST_LEN_SIZE, True,
105       self.size = (len(self._MAGIC) + self._VERSION_SIZE +
106                    self._MANIFEST_LEN_SIZE)
107       self.metadata_signature_len = 0
109       if self.version == common.BRILLO_MAJOR_PAYLOAD_VERSION:
110         self.size += self._METADATA_SIGNATURE_LEN_SIZE
111         self.metadata_signature_len = _ReadInt(
112             payload_file, self._METADATA_SIGNATURE_LEN_SIZE, True,
115   def __init__(self, payload_file, payload_file_offset=0):  argument
122     self.payload_file = payload_file
123     self.payload_file_offset = payload_file_offset
124     self.manifest_hasher = None
125     self.is_init = False
126     self.header = None
127     self.manifest = None
128     self.data_offset = None
129     self.metadata_signature = None
130     self.metadata_size = None
132   def _ReadHeader(self):  argument
141     header = self._PayloadHeader()
142     header.ReadFromPayload(self.payload_file, self.manifest_hasher)
145   def _ReadManifest(self):  argument
154     if not self.header:
157     return common.Read(self.payload_file, self.header.manifest_len,
158                        hasher=self.manifest_hasher)
160   def _ReadMetadataSignature(self):  argument
170     if not self.header:
174         self.payload_file, self.header.metadata_signature_len,
175         offset=self.payload_file_offset + self.header.size +
176         self.header.manifest_len)
178   def ReadDataBlob(self, offset, length):  argument
191     return common.Read(self.payload_file, length,
192                        offset=self.payload_file_offset + self.data_offset +
195   def Init(self):  argument
204     if self.is_init:
207     self.manifest_hasher = hashlib.sha256()
210     self.payload_file.seek(self.payload_file_offset)
211     self.header = self._ReadHeader()
214     manifest_raw = self._ReadManifest()
215     self.manifest = update_metadata_pb2.DeltaArchiveManifest()
216     self.manifest.ParseFromString(manifest_raw)
219     metadata_signature_raw = self._ReadMetadataSignature()
221       self.metadata_signature = update_metadata_pb2.Signatures()
222       self.metadata_signature.ParseFromString(metadata_signature_raw)
224     self.metadata_size = self.header.size + self.header.manifest_len
225     self.data_offset = self.metadata_size + self.header.metadata_signature_len
227     self.is_init = True
229   def Describe(self):  argument
248     if self.manifest.HasField('old_image_info'):
249       _DescribeImageInfo('Old Image', self.manifest.old_image_info)
251     if self.manifest.HasField('new_image_info'):
252       _DescribeImageInfo('New Image', self.manifest.new_image_info)
254   def _AssertInit(self):  argument
256     if not self.is_init:
259   def ResetFile(self):  argument
261     self.payload_file.seek(self.payload_file_offset + self.data_offset)
263   def IsDelta(self):  argument
265     self._AssertInit()
267                 for partition in self.manifest.partitions))
269   def IsFull(self):  argument
271     return not self.IsDelta()
273   def Check(self, pubkey_file_name=None, metadata_sig_file=None,  argument
293     self._AssertInit()
297         self, assert_type=assert_type, block_size=block_size,
305   def Apply(self, new_parts, old_parts=None, bsdiff_in_place=True,  argument
323     self._AssertInit()
327         self, bsdiff_in_place=bsdiff_in_place, bspatch_path=bspatch_path,