py-libp2p/libp2p/network/connection/swarm_connection.py
mhchia eef241e70e
Make Mplex and SwarmConn not Service
After second thoughts, they seem not a good candidate of `Service`.
The shutdown logic becomes simpler by making them not `Service`.
2020-01-07 21:50:03 +08:00

104 lines
3.4 KiB
Python

from typing import TYPE_CHECKING, Set, Tuple
import trio
from libp2p.network.connection.net_connection_interface import INetConn
from libp2p.network.stream.net_stream import NetStream
from libp2p.stream_muxer.abc import IMuxedConn, IMuxedStream
from libp2p.stream_muxer.exceptions import MuxedConnUnavailable
if TYPE_CHECKING:
from libp2p.network.swarm import Swarm # noqa: F401
"""
Reference: https://github.com/libp2p/go-libp2p-swarm/blob/04c86bbdafd390651cb2ee14e334f7caeedad722/swarm_conn.go # noqa: E501
"""
class SwarmConn(INetConn):
muxed_conn: IMuxedConn
swarm: "Swarm"
streams: Set[NetStream]
event_started: trio.Event
event_closed: trio.Event
def __init__(self, muxed_conn: IMuxedConn, swarm: "Swarm") -> None:
self.muxed_conn = muxed_conn
self.swarm = swarm
self.streams = set()
self.event_closed = trio.Event()
self.event_started = trio.Event()
@property
def is_closed(self) -> bool:
return self.event_closed.is_set()
async def close(self) -> None:
if self.event_closed.is_set():
return
self.event_closed.set()
await self._cleanup()
async def _cleanup(self) -> None:
self.swarm.remove_conn(self)
await self.muxed_conn.close()
# This is just for cleaning up state. The connection has already been closed.
# We *could* optimize this but it really isn't worth it.
for stream in self.streams:
await stream.reset()
# Force context switch for stream handlers to process the stream reset event we just emit
# before we cancel the stream handler tasks.
await trio.sleep(0.1)
self._notify_disconnected()
async def _handle_new_streams(self) -> None:
self.event_started.set()
while True:
try:
stream = await self.muxed_conn.accept_stream()
# Asynchronously handle the accepted stream, to avoid blocking the next stream.
except MuxedConnUnavailable:
break
self.swarm.manager.run_task(self._handle_muxed_stream, stream)
await self.close()
async def _handle_muxed_stream(self, muxed_stream: IMuxedStream) -> None:
net_stream = self._add_stream(muxed_stream)
if self.swarm.common_stream_handler is not None:
try:
await self.swarm.common_stream_handler(net_stream)
# TODO: More exact exceptions
except Exception:
# TODO: Emit logs.
# TODO: Clean up and remove the stream from SwarmConn if there is anything wrong.
self.remove_stream(net_stream)
def _add_stream(self, muxed_stream: IMuxedStream) -> NetStream:
net_stream = NetStream(muxed_stream)
self.streams.add(net_stream)
self.swarm.notify_opened_stream(net_stream)
return net_stream
def _notify_disconnected(self) -> None:
self.swarm.notify_disconnected(self)
async def start(self) -> None:
await self._handle_new_streams()
async def new_stream(self) -> NetStream:
muxed_stream = await self.muxed_conn.open_stream()
return self._add_stream(muxed_stream)
def get_streams(self) -> Tuple[NetStream, ...]:
return tuple(self.streams)
def remove_stream(self, stream: NetStream) -> None:
if stream not in self.streams:
return
self.streams.remove(stream)