def Init(self):
"""Initializes the payload object.
This is a prerequisite for any other public API call.
Raises:
PayloadError if object already initialized or fails to initialize
correctly.
"""
if self.is_init:
raise PayloadError('payload object already initialized')
# Initialize hash context.
# pylint: disable=E1101
self.manifest_hasher = hashlib.sha256()
# Read the file header.
self.header = self._ReadHeader()
# Read the manifest.
manifest_raw = self._ReadManifest()
self.manifest = update_metadata_pb2.DeltaArchiveManifest()
self.manifest.ParseFromString(manifest_raw)
# Read the metadata signature (if any).
metadata_signature_raw = self._ReadMetadataSignature()
if metadata_signature_raw:
self.metadata_signature = update_metadata_pb2.Signatures()
self.metadata_signature.ParseFromString(metadata_signature_raw)
self.metadata_size = self.header.size + self.header.manifest_len
self.data_offset = self.metadata_size + self.header.metadata_signature_len
self.is_init = True
def Init(self):
self.header = self._PayloadHeader()
self.header.ReadFromPayload(self.payload_file)
manifest_raw = self._ReadManifest()
self.manifest = update_metadata_pb2.DeltaArchiveManifest()
self.manifest.ParseFromString(manifest_raw)
metadata_signature_raw = self._ReadMetadataSignature()
if metadata_signature_raw:
self.metadata_signature = update_metadata_pb2.Signatures()
self.metadata_signature.ParseFromString(metadata_signature_raw)
self.metadata_size = self.header.size + self.header.manifest_len
self.data_offset = self.metadata_size + self.header.metadata_signature_len
def __init__(self): self.sigs = update_metadata_pb2.Signatures()