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mirror of https://github.com/trezor/trezor-firmware.git synced 2024-11-26 01:18:28 +00:00
trezor-firmware/python/src/trezorlib/mapping.py
matejcik a5aa515631 style(python): upgrade to pyright 1.1.361
had to add a typestub for PIL due to
https://github.com/microsoft/pyright/issues/7832

We should remove it if that is either fixed or, if I fail to convince
Eric, after the relevant type information is added to Pillow

[no changelog]
2024-05-07 11:57:10 +02:00

104 lines
3.5 KiB
Python

# This file is part of the Trezor project.
#
# Copyright (C) 2012-2022 SatoshiLabs and contributors
#
# This library is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3
# as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the License along with this library.
# If not, see <https://www.gnu.org/licenses/lgpl-3.0.html>.
from __future__ import annotations
import io
from types import ModuleType
from typing import Dict, Optional, Tuple, Type, TypeVar
from typing_extensions import Self
from . import messages, protobuf
T = TypeVar("T")
class ProtobufMapping:
"""Mapping of protobuf classes to Python classes"""
def __init__(self) -> None:
self.type_to_class: Dict[int, Type[protobuf.MessageType]] = {}
self.class_to_type_override: Dict[Type[protobuf.MessageType], int] = {}
def register(
self,
msg_class: Type[protobuf.MessageType],
msg_wire_type: Optional[int] = None,
) -> None:
"""Register a Python class as a protobuf type.
If `msg_wire_type` is specified, it is used instead of the internal value in
`msg_class`.
Any existing registrations are overwritten.
"""
if msg_wire_type is not None:
self.class_to_type_override[msg_class] = msg_wire_type
elif msg_class.MESSAGE_WIRE_TYPE is None:
raise ValueError("Cannot register class without wire type")
else:
msg_wire_type = msg_class.MESSAGE_WIRE_TYPE
self.type_to_class[msg_wire_type] = msg_class
def encode(self, msg: protobuf.MessageType) -> Tuple[int, bytes]:
"""Serialize a Python protobuf class.
Returns the message wire type and a byte representation of the protobuf message.
"""
wire_type = self.class_to_type_override.get(type(msg), msg.MESSAGE_WIRE_TYPE)
if wire_type is None:
raise ValueError("Cannot encode class without wire type")
buf = io.BytesIO()
protobuf.dump_message(buf, msg)
return wire_type, buf.getvalue()
def decode(self, msg_wire_type: int, msg_bytes: bytes) -> protobuf.MessageType:
"""Deserialize a protobuf message into a Python class."""
cls = self.type_to_class[msg_wire_type]
buf = io.BytesIO(msg_bytes)
return protobuf.load_message(buf, cls)
@classmethod
def from_module(cls, module: ModuleType) -> Self:
"""Generate a mapping from a module.
The module must have a `MessageType` enum that specifies individual wire types.
"""
mapping = cls()
message_types = getattr(module, "MessageType")
for entry in message_types:
msg_class = getattr(module, entry.name, None)
if msg_class is None:
raise ValueError(
f"Implementation of protobuf message '{entry.name}' is missing"
)
if msg_class.MESSAGE_WIRE_TYPE != entry.value:
raise ValueError(
f"Inconsistent wire type and MessageType record for '{entry.name}'"
)
mapping.register(msg_class)
return mapping
DEFAULT_MAPPING = ProtobufMapping.from_module(messages)