190 lines
6.7 KiB
Python
190 lines
6.7 KiB
Python
"""
|
|
wsproto/connection
|
|
~~~~~~~~~~~~~~~~~~
|
|
|
|
An implementation of a WebSocket connection.
|
|
"""
|
|
|
|
from collections import deque
|
|
from enum import Enum
|
|
from typing import Deque, Generator, List, Optional
|
|
|
|
from .events import (
|
|
BytesMessage,
|
|
CloseConnection,
|
|
Event,
|
|
Message,
|
|
Ping,
|
|
Pong,
|
|
TextMessage,
|
|
)
|
|
from .extensions import Extension
|
|
from .frame_protocol import CloseReason, FrameProtocol, Opcode, ParseFailed
|
|
from .utilities import LocalProtocolError
|
|
|
|
|
|
class ConnectionState(Enum):
|
|
"""
|
|
RFC 6455, Section 4 - Opening Handshake
|
|
"""
|
|
|
|
#: The opening handshake is in progress.
|
|
CONNECTING = 0
|
|
#: The opening handshake is complete.
|
|
OPEN = 1
|
|
#: The remote WebSocket has initiated a connection close.
|
|
REMOTE_CLOSING = 2
|
|
#: The local WebSocket (i.e. this instance) has initiated a connection close.
|
|
LOCAL_CLOSING = 3
|
|
#: The closing handshake has completed.
|
|
CLOSED = 4
|
|
#: The connection was rejected during the opening handshake.
|
|
REJECTING = 5
|
|
|
|
|
|
class ConnectionType(Enum):
|
|
"""An enumeration of connection types."""
|
|
|
|
#: This connection will act as client and talk to a remote server
|
|
CLIENT = 1
|
|
|
|
#: This connection will as as server and waits for client connections
|
|
SERVER = 2
|
|
|
|
|
|
CLIENT = ConnectionType.CLIENT
|
|
SERVER = ConnectionType.SERVER
|
|
|
|
|
|
class Connection:
|
|
"""
|
|
A low-level WebSocket connection object.
|
|
|
|
This wraps two other protocol objects, an HTTP/1.1 protocol object used
|
|
to do the initial HTTP upgrade handshake and a WebSocket frame protocol
|
|
object used to exchange messages and other control frames.
|
|
|
|
:param conn_type: Whether this object is on the client- or server-side of
|
|
a connection. To initialise as a client pass ``CLIENT`` otherwise
|
|
pass ``SERVER``.
|
|
:type conn_type: ``ConnectionType``
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
connection_type: ConnectionType,
|
|
extensions: Optional[List[Extension]] = None,
|
|
trailing_data: bytes = b"",
|
|
) -> None:
|
|
self.client = connection_type is ConnectionType.CLIENT
|
|
self._events: Deque[Event] = deque()
|
|
self._proto = FrameProtocol(self.client, extensions or [])
|
|
self._state = ConnectionState.OPEN
|
|
self.receive_data(trailing_data)
|
|
|
|
@property
|
|
def state(self) -> ConnectionState:
|
|
return self._state
|
|
|
|
def send(self, event: Event) -> bytes:
|
|
data = b""
|
|
if isinstance(event, Message) and self.state == ConnectionState.OPEN:
|
|
data += self._proto.send_data(event.data, event.message_finished)
|
|
elif isinstance(event, Ping) and self.state == ConnectionState.OPEN:
|
|
data += self._proto.ping(event.payload)
|
|
elif isinstance(event, Pong) and self.state == ConnectionState.OPEN:
|
|
data += self._proto.pong(event.payload)
|
|
elif isinstance(event, CloseConnection) and self.state in {
|
|
ConnectionState.OPEN,
|
|
ConnectionState.REMOTE_CLOSING,
|
|
}:
|
|
data += self._proto.close(event.code, event.reason)
|
|
if self.state == ConnectionState.REMOTE_CLOSING:
|
|
self._state = ConnectionState.CLOSED
|
|
else:
|
|
self._state = ConnectionState.LOCAL_CLOSING
|
|
else:
|
|
raise LocalProtocolError(
|
|
f"Event {event} cannot be sent in state {self.state}."
|
|
)
|
|
return data
|
|
|
|
def receive_data(self, data: Optional[bytes]) -> None:
|
|
"""
|
|
Pass some received data to the connection for handling.
|
|
|
|
A list of events that the remote peer triggered by sending this data can
|
|
be retrieved with :meth:`~wsproto.connection.Connection.events`.
|
|
|
|
:param data: The data received from the remote peer on the network.
|
|
:type data: ``bytes``
|
|
"""
|
|
|
|
if data is None:
|
|
# "If _The WebSocket Connection is Closed_ and no Close control
|
|
# frame was received by the endpoint (such as could occur if the
|
|
# underlying transport connection is lost), _The WebSocket
|
|
# Connection Close Code_ is considered to be 1006."
|
|
self._events.append(CloseConnection(code=CloseReason.ABNORMAL_CLOSURE))
|
|
self._state = ConnectionState.CLOSED
|
|
return
|
|
|
|
if self.state in (ConnectionState.OPEN, ConnectionState.LOCAL_CLOSING):
|
|
self._proto.receive_bytes(data)
|
|
elif self.state is ConnectionState.CLOSED:
|
|
raise LocalProtocolError("Connection already closed.")
|
|
else:
|
|
pass # pragma: no cover
|
|
|
|
def events(self) -> Generator[Event, None, None]:
|
|
"""
|
|
Return a generator that provides any events that have been generated
|
|
by protocol activity.
|
|
|
|
:returns: generator of :class:`Event <wsproto.events.Event>` subclasses
|
|
"""
|
|
while self._events:
|
|
yield self._events.popleft()
|
|
|
|
try:
|
|
for frame in self._proto.received_frames():
|
|
if frame.opcode is Opcode.PING:
|
|
assert frame.frame_finished and frame.message_finished
|
|
assert isinstance(frame.payload, (bytes, bytearray))
|
|
yield Ping(payload=frame.payload)
|
|
|
|
elif frame.opcode is Opcode.PONG:
|
|
assert frame.frame_finished and frame.message_finished
|
|
assert isinstance(frame.payload, (bytes, bytearray))
|
|
yield Pong(payload=frame.payload)
|
|
|
|
elif frame.opcode is Opcode.CLOSE:
|
|
assert isinstance(frame.payload, tuple)
|
|
code, reason = frame.payload
|
|
if self.state is ConnectionState.LOCAL_CLOSING:
|
|
self._state = ConnectionState.CLOSED
|
|
else:
|
|
self._state = ConnectionState.REMOTE_CLOSING
|
|
yield CloseConnection(code=code, reason=reason)
|
|
|
|
elif frame.opcode is Opcode.TEXT:
|
|
assert isinstance(frame.payload, str)
|
|
yield TextMessage(
|
|
data=frame.payload,
|
|
frame_finished=frame.frame_finished,
|
|
message_finished=frame.message_finished,
|
|
)
|
|
|
|
elif frame.opcode is Opcode.BINARY:
|
|
assert isinstance(frame.payload, (bytes, bytearray))
|
|
yield BytesMessage(
|
|
data=frame.payload,
|
|
frame_finished=frame.frame_finished,
|
|
message_finished=frame.message_finished,
|
|
)
|
|
|
|
else:
|
|
pass # pragma: no cover
|
|
except ParseFailed as exc:
|
|
yield CloseConnection(code=exc.code, reason=str(exc))
|