Files
g0v0-server/app/signalr/packet.py
2025-07-30 06:01:17 +00:00

274 lines
8.4 KiB
Python

from __future__ import annotations
from dataclasses import dataclass
from enum import IntEnum
import json
from typing import (
Any,
Protocol as TypingProtocol,
)
import msgpack_lazer_api as m
SEP = b"\x1e"
class PacketType(IntEnum):
INVOCATION = 1
STREAM_ITEM = 2
COMPLETION = 3
STREAM_INVOCATION = 4
CANCEL_INVOCATION = 5
PING = 6
CLOSE = 7
@dataclass(kw_only=True)
class Packet:
type: PacketType
header: dict[str, Any] | None = None
@dataclass(kw_only=True)
class InvocationPacket(Packet):
type: PacketType = PacketType.INVOCATION
invocation_id: str | None
target: str
arguments: list[Any] | None = None
stream_ids: list[str] | None = None
@dataclass(kw_only=True)
class CompletionPacket(Packet):
type: PacketType = PacketType.COMPLETION
invocation_id: str
result: Any
error: str | None = None
@dataclass(kw_only=True)
class PingPacket(Packet):
type: PacketType = PacketType.PING
@dataclass(kw_only=True)
class ClosePacket(Packet):
type: PacketType = PacketType.CLOSE
error: str | None = None
allow_reconnect: bool = False
PACKETS = {
PacketType.INVOCATION: InvocationPacket,
PacketType.COMPLETION: CompletionPacket,
PacketType.PING: PingPacket,
PacketType.CLOSE: ClosePacket,
}
class Protocol(TypingProtocol):
@staticmethod
def decode(input: bytes) -> list[Packet]: ...
@staticmethod
def encode(packet: Packet) -> bytes: ...
class MsgpackProtocol:
@staticmethod
def _encode_varint(value: int) -> bytes:
result = []
while value >= 0x80:
result.append((value & 0x7F) | 0x80)
value >>= 7
result.append(value & 0x7F)
return bytes(result)
@staticmethod
def _decode_varint(data: bytes, offset: int = 0) -> tuple[int, int]:
result = 0
shift = 0
pos = offset
while pos < len(data):
byte = data[pos]
result |= (byte & 0x7F) << shift
pos += 1
if (byte & 0x80) == 0:
break
shift += 7
return result, pos
@staticmethod
def decode(input: bytes) -> list[Packet]:
length, offset = MsgpackProtocol._decode_varint(input)
message_data = input[offset : offset + length]
unpacked = m.decode(message_data)
packet_type = PacketType(unpacked[0])
if packet_type not in PACKETS:
raise ValueError(f"Unknown packet type: {packet_type}")
match packet_type:
case PacketType.INVOCATION:
return [
InvocationPacket(
header=unpacked[1],
invocation_id=unpacked[2],
target=unpacked[3],
arguments=unpacked[4] if len(unpacked) > 4 else None,
stream_ids=unpacked[5] if len(unpacked) > 5 else None,
)
]
case PacketType.COMPLETION:
result_kind = unpacked[3]
return [
CompletionPacket(
header=unpacked[1],
invocation_id=unpacked[2],
error=unpacked[4] if result_kind == 1 else None,
result=unpacked[5] if result_kind == 3 else None,
)
]
case PacketType.PING:
return [PingPacket()]
case PacketType.CLOSE:
return [
ClosePacket(
error=unpacked[1],
allow_reconnect=unpacked[2] if len(unpacked) > 2 else False,
)
]
raise ValueError(f"Unsupported packet type: {packet_type}")
@staticmethod
def encode(packet: Packet) -> bytes:
payload = [packet.type.value, packet.header or {}]
if isinstance(packet, InvocationPacket):
payload.extend(
[
packet.invocation_id,
packet.target,
]
)
if packet.arguments is not None:
payload.append(packet.arguments)
if packet.stream_ids is not None:
payload.append(packet.stream_ids)
elif isinstance(packet, CompletionPacket):
result_kind = 2
if packet.error:
result_kind = 1
elif packet.result is None:
result_kind = 3
payload.extend(
[
packet.invocation_id,
result_kind,
packet.error or packet.result or None,
]
)
elif isinstance(packet, ClosePacket):
payload.extend(
[
packet.error or "",
packet.allow_reconnect,
]
)
elif isinstance(packet, PingPacket):
payload.pop(-1)
data = m.encode(payload)
return MsgpackProtocol._encode_varint(len(data)) + data
class JSONProtocol:
@staticmethod
def decode(input: bytes) -> list[Packet]:
packets_raw = input.removesuffix(SEP).split(SEP)
packets = []
if len(packets_raw) > 1:
for packet_raw in packets_raw:
packets.extend(JSONProtocol.decode(packet_raw))
return packets
else:
data = json.loads(packets_raw[0])
packet_type = PacketType(data["type"])
if packet_type not in PACKETS:
raise ValueError(f"Unknown packet type: {packet_type}")
match packet_type:
case PacketType.INVOCATION:
return [
InvocationPacket(
header=data.get("header"),
invocation_id=data.get("invocationId"),
target=data["target"],
arguments=data.get("arguments"),
stream_ids=data.get("streamIds"),
)
]
case PacketType.COMPLETION:
return [
CompletionPacket(
header=data.get("header"),
invocation_id=data["invocationId"],
error=data.get("error"),
result=data.get("result"),
)
]
case PacketType.PING:
return [PingPacket()]
case PacketType.CLOSE:
return [
ClosePacket(
error=data.get("error"),
allow_reconnect=data.get("allowReconnect", False),
)
]
raise ValueError(f"Unsupported packet type: {packet_type}")
@staticmethod
def encode(packet: Packet) -> bytes:
payload: dict[str, Any] = {
"type": packet.type.value,
}
if packet.header:
payload["header"] = packet.header
if isinstance(packet, InvocationPacket):
payload.update(
{
"target": packet.target,
}
)
if packet.invocation_id is not None:
payload["invocationId"] = packet.invocation_id
if packet.arguments is not None:
payload["arguments"] = packet.arguments
if packet.stream_ids is not None:
payload["streamIds"] = packet.stream_ids
elif isinstance(packet, CompletionPacket):
payload.update(
{
"invocationId": packet.invocation_id,
}
)
if packet.error is not None:
payload["error"] = packet.error
if packet.result is not None:
payload["result"] = packet.result
elif isinstance(packet, PingPacket):
pass
elif isinstance(packet, ClosePacket):
payload.update(
{
"allowReconnect": packet.allow_reconnect,
}
)
if packet.error is not None:
payload["error"] = packet.error
return json.dumps(payload).encode("utf-8") + SEP
PROTOCOLS: dict[str, Protocol] = {
"json": JSONProtocol,
"messagepack": MsgpackProtocol,
}