Lab041: add session and restart safety

This commit is contained in:
LittleSam129
2026-08-05 14:14:24 +03:00
parent 88addff5b6
commit f26d7d74ef
18 changed files with 3654 additions and 0 deletions

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"""Прикладные сообщения безопасного сеанса Lab041.
Общий заголовок полезной нагрузки имеет формат ``!BBQQII``: версия, тип
сообщения, 64-битные идентификаторы запуска наземной станции и ровера,
32-битный период управления и 32-битный номер сообщения. Порядок байтов
сетевой, неявного выравнивания нет.
Отдельная контрольная сумма намеренно не добавляется: контрольная сумма
общего пакета Lab033 уже защищает заголовок и всю прикладную нагрузку. После
проверки этой суммы всё равно требуется приведённая здесь смысловая проверка.
"""
from __future__ import annotations
from dataclasses import dataclass
from enum import IntEnum
import math
import struct
from typing import Union
MESSAGE_VERSION = 1
COMMON_FORMAT = "!BBQQII"
COMMON_SIZE = struct.calcsize(COMMON_FORMAT)
UINT32_MODULUS = 1 << 32
UINT32_HALF_RANGE = 1 << 31
MAX_CONTROL_SPEED_MPS = 15.0
MAX_ABS_TURN = 1.0
class ControlMessageError(ValueError):
"""Ошибка формата или смысловой проверки прикладного сообщения."""
class MessageType(IntEnum):
SESSION_HELLO = 1
SESSION_STATUS = 2
MOVEMENT_AUTHORIZE_REQUEST = 3
MOVEMENT_AUTHORIZE_ACK = 4
CONTROL_STATE = 5
EMERGENCY_STOP = 6
EMERGENCY_ACK = 7
RESET_REQUEST = 8
RESET_ACK = 9
SESSION_REJECT = 10
class RoverSafetyCode(IntEnum):
ROVER_BOOT_SAFE = 1
ROVER_SESSION_SYNCED_SAFE = 2
ROVER_MOVEMENT_AUTHORIZED = 3
STAGE1_DECELERATION = 4
STAGE2_BRAKING = 5
EMERGENCY_LATCHED = 6
class SessionRejectReason(IntEnum):
ACCEPTED = 0
GROUND_SESSION_ID = 1
ROVER_BOOT_ID = 2
CONTROL_EPOCH = 3
SEQUENCE_NUMBER = 4
EMERGENCY_EVENT_ID = 5
RESET_REQUEST_ID = 6
NOT_SYNCHRONIZED = 7
MOVEMENT_NOT_AUTHORIZED = 8
class SequenceComparison(IntEnum):
NOT_NEWER = 0
NEWER = 1
AMBIGUOUS = 2
@dataclass(frozen=True)
class MessageContext:
ground_session_id: int
rover_boot_id: int
control_epoch: int
sequence_number: int
@dataclass(frozen=True)
class SessionHello:
context: MessageContext
emergency_intent: bool
emergency_event_id: int
@dataclass(frozen=True)
class SessionStatus:
context: MessageContext
safety_state: RoverSafetyCode
emergency_latched: bool
emergency_event_id: int
@dataclass(frozen=True)
class MovementAuthorizeRequest:
context: MessageContext
authorization_id: int
@dataclass(frozen=True)
class MovementAuthorizeAck:
context: MessageContext
authorization_id: int
accepted: bool
@dataclass(frozen=True)
class ControlStateMessage:
context: MessageContext
desired_speed_mps: float
desired_turn: float
braking: bool
movement_permitted: bool
@dataclass(frozen=True)
class EmergencyStop:
context: MessageContext
emergency_event_id: int
@dataclass(frozen=True)
class EmergencyAck:
context: MessageContext
emergency_event_id: int
@dataclass(frozen=True)
class ResetRequest:
context: MessageContext
emergency_event_id: int
reset_request_id: int
requested_speed_mps: float
movement_permitted: bool
@dataclass(frozen=True)
class ResetAck:
context: MessageContext
emergency_event_id: int
reset_request_id: int
accepted: bool
reason: SessionRejectReason
@dataclass(frozen=True)
class SessionReject:
context: MessageContext
rejected_type: MessageType
reason: SessionRejectReason
ControlMessage = Union[
SessionHello,
SessionStatus,
MovementAuthorizeRequest,
MovementAuthorizeAck,
ControlStateMessage,
EmergencyStop,
EmergencyAck,
ResetRequest,
ResetAck,
SessionReject,
]
_TYPE_BY_CLASS = {
SessionHello: MessageType.SESSION_HELLO,
SessionStatus: MessageType.SESSION_STATUS,
MovementAuthorizeRequest: MessageType.MOVEMENT_AUTHORIZE_REQUEST,
MovementAuthorizeAck: MessageType.MOVEMENT_AUTHORIZE_ACK,
ControlStateMessage: MessageType.CONTROL_STATE,
EmergencyStop: MessageType.EMERGENCY_STOP,
EmergencyAck: MessageType.EMERGENCY_ACK,
ResetRequest: MessageType.RESET_REQUEST,
ResetAck: MessageType.RESET_ACK,
SessionReject: MessageType.SESSION_REJECT,
}
def _unsigned(value: int, maximum: int, name: str) -> int:
if not isinstance(value, int) or isinstance(value, bool) or not 0 <= value <= maximum:
raise ControlMessageError(f"{name} выходит за допустимый беззнаковый диапазон")
return value
def validate_context(context: MessageContext) -> MessageContext:
if not isinstance(context, MessageContext):
raise TypeError("требуется MessageContext")
_unsigned(context.ground_session_id, 0xFFFFFFFFFFFFFFFF, "ground_session_id")
_unsigned(context.rover_boot_id, 0xFFFFFFFFFFFFFFFF, "rover_boot_id")
_unsigned(context.control_epoch, 0xFFFFFFFF, "control_epoch")
_unsigned(context.sequence_number, 0xFFFFFFFF, "sequence_number")
return context
def compare_sequence(new: int, old: int) -> SequenceComparison:
"""Сравнить 32-битные номера по модулю с неоднозначной серединой."""
_unsigned(new, 0xFFFFFFFF, "new sequence_number")
_unsigned(old, 0xFFFFFFFF, "old sequence_number")
delta = (new - old) % UINT32_MODULUS
if delta == UINT32_HALF_RANGE:
return SequenceComparison.AMBIGUOUS
if 0 < delta < UINT32_HALF_RANGE:
return SequenceComparison.NEWER
return SequenceComparison.NOT_NEWER
def _common(message_type: MessageType, context: MessageContext) -> bytes:
validate_context(context)
return struct.pack(
COMMON_FORMAT,
MESSAGE_VERSION,
int(message_type),
context.ground_session_id,
context.rover_boot_id,
context.control_epoch,
context.sequence_number,
)
def _boolean(value: bool, name: str) -> int:
if not isinstance(value, bool):
raise ControlMessageError(f"{name} должен быть логическим значением")
return int(value)
def _finite(value: float, name: str) -> float:
value = float(value)
if not math.isfinite(value):
raise ControlMessageError(f"{name} должен быть конечным числом")
return value
def encode_message(message: ControlMessage) -> bytes:
"""Проверить и сериализовать одно прикладное сообщение."""
message_type = _TYPE_BY_CLASS.get(type(message))
if message_type is None:
raise TypeError("неподдерживаемый класс прикладного сообщения")
prefix = _common(message_type, message.context)
if isinstance(message, SessionHello):
event = _unsigned(message.emergency_event_id, 0xFFFFFFFFFFFFFFFF, "emergency_event_id")
return prefix + struct.pack("!BQ", _boolean(message.emergency_intent, "emergency_intent"), event)
if isinstance(message, SessionStatus):
try:
state = RoverSafetyCode(message.safety_state)
except ValueError as error:
raise ControlMessageError("неизвестное состояние безопасности ровера") from error
event = _unsigned(message.emergency_event_id, 0xFFFFFFFFFFFFFFFF, "emergency_event_id")
return prefix + struct.pack("!BBQ", int(state), _boolean(message.emergency_latched, "emergency_latched"), event)
if isinstance(message, MovementAuthorizeRequest):
return prefix + struct.pack("!Q", _unsigned(message.authorization_id, 0xFFFFFFFFFFFFFFFF, "authorization_id"))
if isinstance(message, MovementAuthorizeAck):
return prefix + struct.pack(
"!QB",
_unsigned(message.authorization_id, 0xFFFFFFFFFFFFFFFF, "authorization_id"),
_boolean(message.accepted, "accepted"),
)
if isinstance(message, ControlStateMessage):
speed = _finite(message.desired_speed_mps, "desired_speed_mps")
turn = _finite(message.desired_turn, "desired_turn")
if not 0.0 <= speed <= MAX_CONTROL_SPEED_MPS:
raise ControlMessageError("требуемая скорость вне диапазона 0…15 м/с")
if not -MAX_ABS_TURN <= turn <= MAX_ABS_TURN:
raise ControlMessageError("требуемый поворот вне диапазона -1…1")
braking = _boolean(message.braking, "braking")
permitted = _boolean(message.movement_permitted, "movement_permitted")
if (braking or not permitted) and speed != 0.0:
raise ControlMessageError("при торможении или запрете движения скорость должна быть нулевой")
if braking and permitted:
raise ControlMessageError("торможение несовместимо с разрешением движения")
return prefix + struct.pack("!ffBB", speed, turn, braking, permitted)
if isinstance(message, (EmergencyStop, EmergencyAck)):
event = _unsigned(message.emergency_event_id, 0xFFFFFFFFFFFFFFFF, "emergency_event_id")
return prefix + struct.pack("!Q", event)
if isinstance(message, ResetRequest):
event = _unsigned(message.emergency_event_id, 0xFFFFFFFFFFFFFFFF, "emergency_event_id")
request = _unsigned(message.reset_request_id, 0xFFFFFFFFFFFFFFFF, "reset_request_id")
speed = _finite(message.requested_speed_mps, "requested_speed_mps")
permitted = _boolean(message.movement_permitted, "movement_permitted")
if speed != 0.0 or permitted:
raise ControlMessageError("безопасный сброс требует нулевой скорости и запрета движения")
return prefix + struct.pack("!QQfB", event, request, speed, permitted)
if isinstance(message, ResetAck):
try:
reason = SessionRejectReason(message.reason)
except ValueError as error:
raise ControlMessageError("неизвестная причина подтверждения сброса") from error
return prefix + struct.pack(
"!QQBB",
_unsigned(message.emergency_event_id, 0xFFFFFFFFFFFFFFFF, "emergency_event_id"),
_unsigned(message.reset_request_id, 0xFFFFFFFFFFFFFFFF, "reset_request_id"),
_boolean(message.accepted, "accepted"),
int(reason),
)
if isinstance(message, SessionReject):
try:
rejected_type = MessageType(message.rejected_type)
reason = SessionRejectReason(message.reason)
except ValueError as error:
raise ControlMessageError("неизвестный код отказа сеанса") from error
return prefix + struct.pack("!BB", int(rejected_type), int(reason))
raise AssertionError("необработанный тип сообщения")
def _decode_bool(value: int, name: str) -> bool:
if value not in (0, 1):
raise ControlMessageError(f"{name} должен быть равен нулю или единице")
return bool(value)
def _unpack_exact(body: bytes, format_string: str) -> tuple[object, ...]:
expected = struct.calcsize(format_string)
if len(body) != expected:
raise ControlMessageError(f"неверная длина тела сообщения: {len(body)}, ожидается {expected}")
return struct.unpack(format_string, body)
def decode_message(payload: bytes) -> ControlMessage:
"""Разобрать сообщение и выполнить полную смысловую проверку."""
if not isinstance(payload, (bytes, bytearray)):
raise TypeError("полезная нагрузка должна быть последовательностью байтов")
payload = bytes(payload)
if len(payload) < COMMON_SIZE:
raise ControlMessageError("сообщение короче общего заголовка")
version, raw_type, ground, rover, epoch, sequence = struct.unpack(COMMON_FORMAT, payload[:COMMON_SIZE])
if version != MESSAGE_VERSION:
raise ControlMessageError("неподдерживаемая версия прикладного сообщения")
try:
message_type = MessageType(raw_type)
except ValueError as error:
raise ControlMessageError("неизвестный тип прикладного сообщения") from error
context = MessageContext(ground, rover, epoch, sequence)
body = payload[COMMON_SIZE:]
if message_type is MessageType.SESSION_HELLO:
intent, event = _unpack_exact(body, "!BQ")
message: ControlMessage = SessionHello(context, _decode_bool(intent, "emergency_intent"), event)
elif message_type is MessageType.SESSION_STATUS:
state, latched, event = _unpack_exact(body, "!BBQ")
try:
safety_state = RoverSafetyCode(state)
except ValueError as error:
raise ControlMessageError("неизвестное состояние безопасности ровера") from error
message = SessionStatus(context, safety_state, _decode_bool(latched, "emergency_latched"), event)
elif message_type is MessageType.MOVEMENT_AUTHORIZE_REQUEST:
(authorization,) = _unpack_exact(body, "!Q")
message = MovementAuthorizeRequest(context, authorization)
elif message_type is MessageType.MOVEMENT_AUTHORIZE_ACK:
authorization, accepted = _unpack_exact(body, "!QB")
message = MovementAuthorizeAck(context, authorization, _decode_bool(accepted, "accepted"))
elif message_type is MessageType.CONTROL_STATE:
speed, turn, braking, permitted = _unpack_exact(body, "!ffBB")
message = ControlStateMessage(
context,
speed,
turn,
_decode_bool(braking, "braking"),
_decode_bool(permitted, "movement_permitted"),
)
elif message_type is MessageType.EMERGENCY_STOP:
(event,) = _unpack_exact(body, "!Q")
message = EmergencyStop(context, event)
elif message_type is MessageType.EMERGENCY_ACK:
(event,) = _unpack_exact(body, "!Q")
message = EmergencyAck(context, event)
elif message_type is MessageType.RESET_REQUEST:
event, request, speed, permitted = _unpack_exact(body, "!QQfB")
message = ResetRequest(context, event, request, speed, _decode_bool(permitted, "movement_permitted"))
elif message_type is MessageType.RESET_ACK:
event, request, accepted, reason = _unpack_exact(body, "!QQBB")
try:
reset_reason = SessionRejectReason(reason)
except ValueError as error:
raise ControlMessageError("неизвестная причина подтверждения сброса") from error
message = ResetAck(context, event, request, _decode_bool(accepted, "accepted"), reset_reason)
else:
rejected_type, reason = _unpack_exact(body, "!BB")
try:
message = SessionReject(context, MessageType(rejected_type), SessionRejectReason(reason))
except ValueError as error:
raise ControlMessageError("неизвестный код отказа сеанса") from error
return decode_validated_message(message)
def decode_validated_message(message: ControlMessage) -> ControlMessage:
"""Повторно применить смысловую проверку к разобранному объекту."""
return decode_without_recursion(encode_message(message))
def decode_without_recursion(payload: bytes) -> ControlMessage:
"""Внутренний разбор уже проверенного представления."""
version, raw_type, ground, rover, epoch, sequence = struct.unpack(COMMON_FORMAT, payload[:COMMON_SIZE])
assert version == MESSAGE_VERSION
message_type = MessageType(raw_type)
context = MessageContext(ground, rover, epoch, sequence)
body = payload[COMMON_SIZE:]
if message_type is MessageType.SESSION_HELLO:
intent, event = struct.unpack("!BQ", body)
return SessionHello(context, bool(intent), event)
if message_type is MessageType.SESSION_STATUS:
state, latched, event = struct.unpack("!BBQ", body)
return SessionStatus(context, RoverSafetyCode(state), bool(latched), event)
if message_type is MessageType.MOVEMENT_AUTHORIZE_REQUEST:
return MovementAuthorizeRequest(context, struct.unpack("!Q", body)[0])
if message_type is MessageType.MOVEMENT_AUTHORIZE_ACK:
authorization, accepted = struct.unpack("!QB", body)
return MovementAuthorizeAck(context, authorization, bool(accepted))
if message_type is MessageType.CONTROL_STATE:
speed, turn, braking, permitted = struct.unpack("!ffBB", body)
return ControlStateMessage(context, speed, turn, bool(braking), bool(permitted))
if message_type is MessageType.EMERGENCY_STOP:
return EmergencyStop(context, struct.unpack("!Q", body)[0])
if message_type is MessageType.EMERGENCY_ACK:
return EmergencyAck(context, struct.unpack("!Q", body)[0])
if message_type is MessageType.RESET_REQUEST:
event, request, speed, permitted = struct.unpack("!QQfB", body)
return ResetRequest(context, event, request, speed, bool(permitted))
if message_type is MessageType.RESET_ACK:
event, request, accepted, reason = struct.unpack("!QQBB", body)
return ResetAck(context, event, request, bool(accepted), SessionRejectReason(reason))
rejected_type, reason = struct.unpack("!BB", body)
return SessionReject(context, MessageType(rejected_type), SessionRejectReason(reason))
assert COMMON_SIZE == 26

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protocol/session_state.py Normal file
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"""Автоматы безопасного сеанса наземной станции и ровера для Lab041."""
from __future__ import annotations
from dataclasses import dataclass
from enum import Enum
import hashlib
from protocol.control_messages import (
ControlStateMessage,
EmergencyAck,
EmergencyStop,
MessageContext,
MessageType,
MovementAuthorizeAck,
MovementAuthorizeRequest,
ResetAck,
ResetRequest,
RoverSafetyCode,
SequenceComparison,
SessionHello,
SessionRejectReason,
SessionStatus,
compare_sequence,
)
class GroundSessionState(str, Enum):
GROUND_BOOT = "ground_boot"
GROUND_SYNCING = "ground_syncing"
GROUND_SAFE_SYNCHRONIZED = "ground_safe_synchronized"
GROUND_MOVEMENT_AUTH_REQUESTED = "ground_movement_auth_requested"
GROUND_ACTIVE = "ground_active"
GROUND_EMERGENCY_REQUESTED = "ground_emergency_requested"
GROUND_EMERGENCY_CONFIRMED = "ground_emergency_confirmed"
GROUND_RESET_REQUESTED = "ground_reset_requested"
class RoverSessionState(str, Enum):
ROVER_BOOT_SAFE = "rover_boot_safe"
ROVER_SESSION_SYNCED_SAFE = "rover_session_synced_safe"
ROVER_MOVEMENT_AUTHORIZED = "rover_movement_authorized"
STAGE1_DECELERATION = "stage1_deceleration"
STAGE2_BRAKING = "stage2_braking"
EMERGENCY_LATCHED = "emergency_latched"
class RejectionCause(str, Enum):
GROUND_SESSION_ID = "ground_session_id"
ROVER_BOOT_ID = "rover_boot_id"
CONTROL_EPOCH = "control_epoch"
SEQUENCE_NUMBER = "sequence_number"
EMERGENCY_EVENT_ID = "emergency_event_id"
RESET_REQUEST_ID = "reset_request_id"
NOT_SYNCHRONIZED = "not_synchronized"
MOVEMENT_NOT_AUTHORIZED = "movement_not_authorized"
@dataclass(frozen=True)
class ControlDecision:
accepted: bool
reason: RejectionCause | None
ambiguous_sequence: bool = False
@dataclass(frozen=True)
class ResetDecision:
acknowledgement: ResetAck
performed: bool
duplicate: bool
def deterministic_identifier(seed: int, purpose: str) -> int:
"""Получить воспроизводимый ненулевой 64-битный идентификатор."""
if not isinstance(seed, int):
raise TypeError("начальное значение генератора должно быть целым")
digest = hashlib.blake2b(f"Lab041:{purpose}:{seed}".encode("utf-8"), digest_size=8).digest()
return int.from_bytes(digest, "big") or 1
class GroundSessionController:
"""Наземный автомат без автоматического восстановления движения."""
def __init__(
self,
seed: int,
*,
persisted_emergency_intent: bool = False,
persisted_emergency_event_id: int = 0,
) -> None:
self.ground_session_id = deterministic_identifier(seed, "ground")
self.rover_boot_id = 0
self.control_epoch = 0
self.sequence_number = 0
self.state = GroundSessionState.GROUND_BOOT
self.emergency_intent = bool(persisted_emergency_intent)
self.emergency_event_id = persisted_emergency_event_id if self.emergency_intent else 0
self.authorization_id = 0
self.reset_request_id = 0
self.last_operator_sequence: int | None = None
self.movement_permitted = False
self.current_speed_mps = 0.0
self.zero_commands_after_restart = 0
def _next_sequence(self) -> int:
value = self.sequence_number
self.sequence_number = (self.sequence_number + 1) & 0xFFFFFFFF
return value
def _context(self, *, epoch: int | None = None) -> MessageContext:
return MessageContext(
self.ground_session_id,
self.rover_boot_id,
self.control_epoch if epoch is None else epoch,
self._next_sequence(),
)
def start_synchronization(self) -> SessionHello:
if self.state is not GroundSessionState.GROUND_BOOT:
raise RuntimeError("синхронизацию можно начать только после запуска")
self.state = GroundSessionState.GROUND_SYNCING
self.movement_permitted = False
self.current_speed_mps = 0.0
return SessionHello(self._context(epoch=0), self.emergency_intent, self.emergency_event_id)
def repeat_hello(self) -> SessionHello:
if self.state is not GroundSessionState.GROUND_SYNCING:
raise RuntimeError("повтор приветствия допустим только при синхронизации")
return SessionHello(self._context(epoch=0), self.emergency_intent, self.emergency_event_id)
def receive_status(self, status: SessionStatus) -> bool:
if self.state is not GroundSessionState.GROUND_SYNCING:
return False
if status.context.ground_session_id != self.ground_session_id:
return False
if status.context.rover_boot_id == 0:
return False
self.rover_boot_id = status.context.rover_boot_id
self.control_epoch = 0
self.movement_permitted = False
self.current_speed_mps = 0.0
if self.emergency_intent:
self.state = GroundSessionState.GROUND_EMERGENCY_REQUESTED
else:
self.state = GroundSessionState.GROUND_SAFE_SYNCHRONIZED
return True
def request_movement_authorization(self, authorization_id: int) -> MovementAuthorizeRequest:
if self.state is not GroundSessionState.GROUND_SAFE_SYNCHRONIZED:
raise RuntimeError("разрешение движения требует безопасного согласованного сеанса")
if self.emergency_intent:
raise RuntimeError("при аварийном намерении движение запрещено")
if not 0 <= authorization_id <= 0xFFFFFFFFFFFFFFFF:
raise ValueError("authorization_id вне диапазона uint64")
self.authorization_id = authorization_id
self.state = GroundSessionState.GROUND_MOVEMENT_AUTH_REQUESTED
return MovementAuthorizeRequest(self._context(epoch=0), authorization_id)
def receive_movement_authorize_ack(self, acknowledgement: MovementAuthorizeAck) -> bool:
if self.state is not GroundSessionState.GROUND_MOVEMENT_AUTH_REQUESTED:
return False
context = acknowledgement.context
if (
context.ground_session_id != self.ground_session_id
or context.rover_boot_id != self.rover_boot_id
or acknowledgement.authorization_id != self.authorization_id
or not acknowledgement.accepted
or context.control_epoch == 0
):
return False
self.control_epoch = context.control_epoch
self.state = GroundSessionState.GROUND_ACTIVE
self.movement_permitted = False
self.current_speed_mps = 0.0
self.last_operator_sequence = None
return True
def new_operator_control(self, speed_mps: float, turn: float = 0.0) -> ControlStateMessage:
if self.state is not GroundSessionState.GROUND_ACTIVE:
raise RuntimeError("новая команда движения возможна только в активном сеансе")
if speed_mps <= 0.0:
raise ValueError("скорость новой команды должна быть положительной")
context = self._context()
self.last_operator_sequence = context.sequence_number
self.movement_permitted = True
self.current_speed_mps = speed_mps
return ControlStateMessage(context, speed_mps, turn, False, True)
def safe_zero_control(self) -> ControlStateMessage:
self.zero_commands_after_restart += 1
return ControlStateMessage(self._context(), 0.0, 0.0, True, False)
def request_emergency(self, emergency_event_id: int) -> EmergencyStop:
if not 0 < emergency_event_id <= 0xFFFFFFFFFFFFFFFF:
raise ValueError("emergency_event_id должен быть ненулевым uint64")
self.emergency_intent = True
self.emergency_event_id = emergency_event_id
self.movement_permitted = False
self.current_speed_mps = 0.0
self.state = GroundSessionState.GROUND_EMERGENCY_REQUESTED
return EmergencyStop(self._context(), emergency_event_id)
def receive_emergency_ack(self, acknowledgement: EmergencyAck) -> bool:
if acknowledgement.context.ground_session_id != self.ground_session_id:
return False
if acknowledgement.emergency_event_id != self.emergency_event_id:
return False
if self.state is GroundSessionState.GROUND_EMERGENCY_REQUESTED:
self.state = GroundSessionState.GROUND_EMERGENCY_CONFIRMED
return True
def request_reset(self, reset_request_id: int) -> ResetRequest:
if not self.emergency_intent:
raise RuntimeError("сброс требует аварийного намерения")
if not 0 < reset_request_id <= 0xFFFFFFFFFFFFFFFF:
raise ValueError("reset_request_id должен быть ненулевым uint64")
self.reset_request_id = reset_request_id
self.state = GroundSessionState.GROUND_RESET_REQUESTED
return ResetRequest(self._context(), self.emergency_event_id, reset_request_id, 0.0, False)
def receive_reset_ack(self, acknowledgement: ResetAck) -> bool:
if self.state is not GroundSessionState.GROUND_RESET_REQUESTED:
return False
if (
acknowledgement.context.ground_session_id != self.ground_session_id
or acknowledgement.context.rover_boot_id != self.rover_boot_id
or acknowledgement.emergency_event_id != self.emergency_event_id
or acknowledgement.reset_request_id != self.reset_request_id
or not acknowledgement.accepted
):
return False
self.emergency_intent = False
self.emergency_event_id = 0
self.movement_permitted = False
self.current_speed_mps = 0.0
self.control_epoch = 0
self.state = GroundSessionState.GROUND_SAFE_SYNCHRONIZED
return True
class RoverSessionController:
"""Ровер, который после каждого запуска начинает с безопасного запрета."""
def __init__(self, seed: int) -> None:
self.rover_boot_id = deterministic_identifier(seed, "rover")
self.ground_session_id = 0
self.control_epoch = 0
self.state = RoverSessionState.ROVER_BOOT_SAFE
self.speed_mps = 0.0
self.movement_permitted = False
self.emergency_event_id = 0
self.last_sequences: dict[tuple[int, int, int, int], int] = {}
self.accepted_reset_keys: set[tuple[int, int, int, int]] = set()
self.duplicate_hellos = 0
self.duplicate_resets = 0
@property
def safe(self) -> bool:
return self.speed_mps == 0.0 and not self.movement_permitted
def _status_context(self, sequence_number: int = 0) -> MessageContext:
return MessageContext(self.ground_session_id, self.rover_boot_id, self.control_epoch, sequence_number)
def receive_hello(self, hello: SessionHello) -> SessionStatus:
if hello.context.ground_session_id == 0:
raise ValueError("ground_session_id должен быть ненулевым")
if hello.context.ground_session_id == self.ground_session_id:
self.duplicate_hellos += 1
else:
self.ground_session_id = hello.context.ground_session_id
self.control_epoch = 0
self.last_sequences.clear()
self.movement_permitted = False
self.speed_mps = 0.0
self.state = RoverSessionState.ROVER_SESSION_SYNCED_SAFE
if hello.emergency_intent:
self.emergency_event_id = hello.emergency_event_id
self.state = RoverSessionState.EMERGENCY_LATCHED
code = {
RoverSessionState.ROVER_BOOT_SAFE: RoverSafetyCode.ROVER_BOOT_SAFE,
RoverSessionState.ROVER_SESSION_SYNCED_SAFE: RoverSafetyCode.ROVER_SESSION_SYNCED_SAFE,
RoverSessionState.ROVER_MOVEMENT_AUTHORIZED: RoverSafetyCode.ROVER_MOVEMENT_AUTHORIZED,
RoverSessionState.STAGE1_DECELERATION: RoverSafetyCode.STAGE1_DECELERATION,
RoverSessionState.STAGE2_BRAKING: RoverSafetyCode.STAGE2_BRAKING,
RoverSessionState.EMERGENCY_LATCHED: RoverSafetyCode.EMERGENCY_LATCHED,
}[self.state]
return SessionStatus(
self._status_context(hello.context.sequence_number),
code,
self.state is RoverSessionState.EMERGENCY_LATCHED,
self.emergency_event_id,
)
def authorize_movement(self, request: MovementAuthorizeRequest) -> MovementAuthorizeAck:
accepted = (
self.state is RoverSessionState.ROVER_SESSION_SYNCED_SAFE
and request.context.ground_session_id == self.ground_session_id
and request.context.rover_boot_id == self.rover_boot_id
and self.emergency_event_id == 0
)
if accepted:
self.control_epoch = (self.control_epoch + 1) & 0xFFFFFFFF
if self.control_epoch == 0:
self.control_epoch = 1
self.state = RoverSessionState.ROVER_MOVEMENT_AUTHORIZED
self.speed_mps = 0.0
self.movement_permitted = False
return MovementAuthorizeAck(
MessageContext(self.ground_session_id, self.rover_boot_id, self.control_epoch, request.context.sequence_number),
request.authorization_id,
accepted,
)
def receive_control(self, message: ControlStateMessage, stream_id: int) -> ControlDecision:
context = message.context
if context.ground_session_id != self.ground_session_id:
return ControlDecision(False, RejectionCause.GROUND_SESSION_ID)
if context.rover_boot_id != self.rover_boot_id:
return ControlDecision(False, RejectionCause.ROVER_BOOT_ID)
if context.control_epoch != self.control_epoch:
return ControlDecision(False, RejectionCause.CONTROL_EPOCH)
if self.state is RoverSessionState.EMERGENCY_LATCHED:
return ControlDecision(False, RejectionCause.MOVEMENT_NOT_AUTHORIZED)
if self.state is not RoverSessionState.ROVER_MOVEMENT_AUTHORIZED:
return ControlDecision(False, RejectionCause.MOVEMENT_NOT_AUTHORIZED)
key = (context.ground_session_id, context.rover_boot_id, context.control_epoch, stream_id)
old = self.last_sequences.get(key)
if old is not None:
comparison = compare_sequence(context.sequence_number, old)
if comparison is SequenceComparison.AMBIGUOUS:
return ControlDecision(False, RejectionCause.SEQUENCE_NUMBER, True)
if comparison is not SequenceComparison.NEWER:
return ControlDecision(False, RejectionCause.SEQUENCE_NUMBER)
self.last_sequences[key] = context.sequence_number
self.speed_mps = message.desired_speed_mps
self.movement_permitted = message.movement_permitted
return ControlDecision(True, None)
def receive_emergency(self, message: EmergencyStop) -> EmergencyAck | None:
if (
message.context.ground_session_id != self.ground_session_id
or message.context.rover_boot_id != self.rover_boot_id
):
return None
self.emergency_event_id = message.emergency_event_id
self.state = RoverSessionState.EMERGENCY_LATCHED
self.speed_mps = 0.0
self.movement_permitted = False
return EmergencyAck(
MessageContext(self.ground_session_id, self.rover_boot_id, self.control_epoch, message.context.sequence_number),
message.emergency_event_id,
)
def receive_reset(self, request: ResetRequest) -> ResetDecision:
context = request.context
reason = SessionRejectReason.NOT_SYNCHRONIZED
if context.ground_session_id != self.ground_session_id:
reason = SessionRejectReason.GROUND_SESSION_ID
elif context.rover_boot_id != self.rover_boot_id:
reason = SessionRejectReason.ROVER_BOOT_ID
elif request.emergency_event_id != self.emergency_event_id:
reason = SessionRejectReason.EMERGENCY_EVENT_ID
elif self.speed_mps != 0.0:
reason = SessionRejectReason.MOVEMENT_NOT_AUTHORIZED
else:
reason = SessionRejectReason.RESET_REQUEST_ID
key = (
context.ground_session_id,
context.rover_boot_id,
request.emergency_event_id,
request.reset_request_id,
)
if key in self.accepted_reset_keys:
self.duplicate_resets += 1
acknowledgement = ResetAck(context, request.emergency_event_id, request.reset_request_id, True, SessionRejectReason.ACCEPTED)
return ResetDecision(acknowledgement, False, True)
accepted = (
context.ground_session_id == self.ground_session_id
and context.rover_boot_id == self.rover_boot_id
and self.state is RoverSessionState.EMERGENCY_LATCHED
and request.emergency_event_id == self.emergency_event_id
and request.requested_speed_mps == 0.0
and not request.movement_permitted
and self.speed_mps == 0.0
)
if accepted:
self.accepted_reset_keys.add(key)
self.emergency_event_id = 0
self.state = RoverSessionState.ROVER_SESSION_SYNCED_SAFE
self.speed_mps = 0.0
self.movement_permitted = False
reason = SessionRejectReason.ACCEPTED
acknowledgement = ResetAck(context, request.emergency_event_id, request.reset_request_id, accepted, reason)
return ResetDecision(acknowledgement, accepted, False)
def enter_watchdog_stage1(self) -> None:
if self.state is RoverSessionState.ROVER_MOVEMENT_AUTHORIZED:
self.state = RoverSessionState.STAGE1_DECELERATION
self.movement_permitted = False
def enter_watchdog_stage2(self) -> None:
if self.state in (RoverSessionState.ROVER_MOVEMENT_AUTHORIZED, RoverSessionState.STAGE1_DECELERATION):
self.state = RoverSessionState.STAGE2_BRAKING
self.movement_permitted = False
def rejection_reason_for_message(reason: RejectionCause) -> SessionRejectReason:
return {
RejectionCause.GROUND_SESSION_ID: SessionRejectReason.GROUND_SESSION_ID,
RejectionCause.ROVER_BOOT_ID: SessionRejectReason.ROVER_BOOT_ID,
RejectionCause.CONTROL_EPOCH: SessionRejectReason.CONTROL_EPOCH,
RejectionCause.SEQUENCE_NUMBER: SessionRejectReason.SEQUENCE_NUMBER,
RejectionCause.EMERGENCY_EVENT_ID: SessionRejectReason.EMERGENCY_EVENT_ID,
RejectionCause.RESET_REQUEST_ID: SessionRejectReason.RESET_REQUEST_ID,
RejectionCause.NOT_SYNCHRONIZED: SessionRejectReason.NOT_SYNCHRONIZED,
RejectionCause.MOVEMENT_NOT_AUTHORIZED: SessionRejectReason.MOVEMENT_NOT_AUTHORIZED,
}[reason]
assert len({state.value for state in GroundSessionState}) == len(GroundSessionState)
assert len({state.value for state in RoverSessionState}) == len(RoverSessionState)