Refactor: get rid of single huge _handle_incoming

This commit is contained in:
mhchia 2019-09-14 14:59:07 +08:00
parent 4a689c7d57
commit 5f064dd329
No known key found for this signature in database
GPG Key ID: 389EFBEA1362589A

View File

@ -181,98 +181,13 @@ class Mplex(IMuxedConn):
while True: while True:
try: try:
channel_id, flag, message = await self._wait_until_shutting_down_or_closed( await self._handle_incoming_message()
self.read_message()
)
except MplexUnavailable as error:
print(f"!@# handle_incoming: read_message: exception={error}")
break
stream_id = StreamID(channel_id=channel_id, is_initiator=bool(flag & 1))
is_stream_id_seen: bool
stream: MplexStream
async with self.streams_lock:
is_stream_id_seen = stream_id in self.streams
if is_stream_id_seen:
stream = self.streams[stream_id]
if flag == HeaderTags.NewStream.value:
if is_stream_id_seen:
# `NewStream` for the same id is received twice...
# TODO: Shutdown
pass
mplex_stream = await self._initialize_stream(
stream_id, message.decode()
)
try:
await self._wait_until_shutting_down_or_closed(
self.new_stream_queue.put(mplex_stream)
)
except MplexUnavailable: except MplexUnavailable:
break break
elif flag in (
HeaderTags.MessageInitiator.value,
HeaderTags.MessageReceiver.value,
):
if not is_stream_id_seen:
# We receive a message of the stream `stream_id` which is not accepted
# before. It is abnormal. Possibly disconnect?
# TODO: Warn and emit logs about this.
continue
async with stream.close_lock:
if stream.event_remote_closed.is_set():
# TODO: Warn "Received data from remote after stream was closed by them. (len = %d)" # noqa: E501
continue
try:
await self._wait_until_shutting_down_or_closed(
stream.incoming_data.put(message)
)
except MplexUnavailable:
break
elif flag in (
HeaderTags.CloseInitiator.value,
HeaderTags.CloseReceiver.value,
):
if not is_stream_id_seen:
continue
# NOTE: If remote is already closed, then return: Technically a bug
# on the other side. We should consider killing the connection.
async with stream.close_lock:
if stream.event_remote_closed.is_set():
continue
is_local_closed: bool
async with stream.close_lock:
stream.event_remote_closed.set()
is_local_closed = stream.event_local_closed.is_set()
# If local is also closed, both sides are closed. Then, we should clean up
# the entry of this stream, to avoid others from accessing it.
if is_local_closed:
async with self.streams_lock:
del self.streams[stream_id]
elif flag in (
HeaderTags.ResetInitiator.value,
HeaderTags.ResetReceiver.value,
):
if not is_stream_id_seen:
# This is *ok*. We forget the stream on reset.
continue
async with stream.close_lock:
if not stream.event_remote_closed.is_set():
stream.event_reset.set()
stream.event_remote_closed.set()
# If local is not closed, we should close it.
if not stream.event_local_closed.is_set():
stream.event_local_closed.set()
async with self.streams_lock:
del self.streams[stream_id]
else:
# TODO: logging
if is_stream_id_seen:
await stream.reset()
# Force context switch # Force context switch
await asyncio.sleep(0) await asyncio.sleep(0)
# If we enter here, it means this connection is shutting down. # If we enter here, it means this connection is shutting down.
# We should clean the things up. # We should clean things up.
await self._cleanup() await self._cleanup()
async def read_message(self) -> Tuple[int, int, bytes]: async def read_message(self) -> Tuple[int, int, bytes]:
@ -303,6 +218,102 @@ class Mplex(IMuxedConn):
return channel_id, flag, message return channel_id, flag, message
async def _handle_incoming_message(self) -> None:
"""
Read and handle a new incoming message.
:raise MplexUnavailable: `Mplex` encounters fatal error or is shutting down.
"""
channel_id, flag, message = await self._wait_until_shutting_down_or_closed(
self.read_message()
)
stream_id = StreamID(channel_id=channel_id, is_initiator=bool(flag & 1))
if flag == HeaderTags.NewStream.value:
await self._handle_new_stream(stream_id, message)
elif flag in (
HeaderTags.MessageInitiator.value,
HeaderTags.MessageReceiver.value,
):
await self._handle_message(stream_id, message)
elif flag in (HeaderTags.CloseInitiator.value, HeaderTags.CloseReceiver.value):
await self._handle_close(stream_id)
elif flag in (HeaderTags.ResetInitiator.value, HeaderTags.ResetReceiver.value):
await self._handle_reset(stream_id)
else:
# Receives messages with an unknown flag
# TODO: logging
async with self.streams_lock:
if stream_id in self.streams:
stream = self.streams[stream_id]
await stream.reset()
async def _handle_new_stream(self, stream_id: StreamID, message: bytes) -> None:
async with self.streams_lock:
if stream_id in self.streams:
# `NewStream` for the same id is received twice...
raise MplexUnavailable(
f"received NewStream message for existing stream: {stream_id}"
)
mplex_stream = await self._initialize_stream(stream_id, message.decode())
await self._wait_until_shutting_down_or_closed(
self.new_stream_queue.put(mplex_stream)
)
async def _handle_message(self, stream_id: StreamID, message: bytes) -> None:
async with self.streams_lock:
if stream_id not in self.streams:
# We receive a message of the stream `stream_id` which is not accepted
# before. It is abnormal. Possibly disconnect?
# TODO: Warn and emit logs about this.
return
stream = self.streams[stream_id]
async with stream.close_lock:
if stream.event_remote_closed.is_set():
# TODO: Warn "Received data from remote after stream was closed by them. (len = %d)" # noqa: E501
return
await self._wait_until_shutting_down_or_closed(
stream.incoming_data.put(message)
)
async def _handle_close(self, stream_id: StreamID) -> None:
async with self.streams_lock:
if stream_id not in self.streams:
# Ignore unmatched messages for now.
return
stream = self.streams[stream_id]
# NOTE: If remote is already closed, then return: Technically a bug
# on the other side. We should consider killing the connection.
async with stream.close_lock:
if stream.event_remote_closed.is_set():
return
is_local_closed: bool
async with stream.close_lock:
stream.event_remote_closed.set()
is_local_closed = stream.event_local_closed.is_set()
# If local is also closed, both sides are closed. Then, we should clean up
# the entry of this stream, to avoid others from accessing it.
if is_local_closed:
async with self.streams_lock:
del self.streams[stream_id]
async def _handle_reset(self, stream_id: StreamID) -> None:
async with self.streams_lock:
if stream_id not in self.streams:
# This is *ok*. We forget the stream on reset.
return
stream = self.streams[stream_id]
async with stream.close_lock:
if not stream.event_remote_closed.is_set():
stream.event_reset.set()
stream.event_remote_closed.set()
# If local is not closed, we should close it.
if not stream.event_local_closed.is_set():
stream.event_local_closed.set()
async with self.streams_lock:
del self.streams[stream_id]
async def _cleanup(self) -> None: async def _cleanup(self) -> None:
if not self.event_shutting_down.is_set(): if not self.event_shutting_down.is_set():
self.event_shutting_down.set() self.event_shutting_down.set()