lbry-sdk/lbry/schema/base.py
2020-01-01 15:57:56 -05:00

125 lines
3.1 KiB
Python

from binascii import hexlify, unhexlify
from typing import List, Iterator, TypeVar, Generic
from google.protobuf.message import DecodeError
from google.protobuf.json_format import MessageToDict
class Signable:
__slots__ = (
'message', 'version', 'signature',
'signature_type', 'unsigned_payload', 'signing_channel_hash'
)
message_class = None
def __init__(self, message=None):
self.message = message or self.message_class()
self.version = 2
self.signature = None
self.signature_type = 'SECP256k1'
self.unsigned_payload = None
self.signing_channel_hash = None
def clear_signature(self):
self.signature = None
self.unsigned_payload = None
self.signing_channel_hash = None
@property
def signing_channel_id(self):
return hexlify(self.signing_channel_hash[::-1]).decode() if self.signing_channel_hash else None
@signing_channel_id.setter
def signing_channel_id(self, channel_id: str):
self.signing_channel_hash = unhexlify(channel_id)[::-1]
@property
def is_signed(self):
return self.signature is not None
def to_dict(self):
return MessageToDict(self.message)
def to_message_bytes(self) -> bytes:
return self.message.SerializeToString()
def to_bytes(self) -> bytes:
pieces = bytearray()
if self.is_signed:
pieces.append(1)
pieces.extend(self.signing_channel_hash)
pieces.extend(self.signature)
else:
pieces.append(0)
pieces.extend(self.to_message_bytes())
return bytes(pieces)
@classmethod
def from_bytes(cls, data: bytes):
signable = cls()
if data[0] == 0:
signable.message.ParseFromString(data[1:])
elif data[0] == 1:
signable.signing_channel_hash = data[1:21]
signable.signature = data[21:85]
signable.message.ParseFromString(data[85:])
else:
raise DecodeError('Could not determine message format version.')
return signable
def __len__(self):
return len(self.to_bytes())
def __bytes__(self):
return self.to_bytes()
class Metadata:
__slots__ = 'message',
def __init__(self, message):
self.message = message
I = TypeVar('I')
class BaseMessageList(Metadata, Generic[I]):
__slots__ = ()
item_class = None
@property
def _message(self):
return self.message
def add(self) -> I:
return self.item_class(self._message.add())
def extend(self, values: List[str]):
for value in values:
self.append(value)
def append(self, value: str):
raise NotImplemented
def __len__(self):
return len(self._message)
def __iter__(self) -> Iterator[I]:
for item in self._message:
yield self.item_class(item)
def __getitem__(self, item) -> I:
return self.item_class(self._message[item])
def __delitem__(self, key):
del self._message[key]
def __eq__(self, other) -> bool:
return self._message == other