py-libp2p/libp2p/stream_muxer/mplex/mplex_stream.py
2019-08-05 11:17:38 +08:00

138 lines
4.3 KiB
Python

import asyncio
from libp2p.stream_muxer.abc import IMuxedStream, IMuxedConn
from .constants import HeaderTags
class MplexStream(IMuxedStream):
"""
reference: https://github.com/libp2p/go-mplex/blob/master/stream.go
"""
stream_id: int
initiator: bool
mplex_conn: IMuxedConn
read_deadline: float
write_deadline: float
local_closed: bool
remote_closed: bool
stream_lock: asyncio.Lock
def __init__(self, stream_id: int, initiator: bool, mplex_conn: IMuxedConn) -> None:
"""
create new MuxedStream in muxer
:param stream_id: stream stream id
:param initiator: boolean if this is an initiator
:param mplex_conn: muxed connection of this muxed_stream
"""
self.stream_id = stream_id
self.initiator = initiator
self.mplex_conn = mplex_conn
self.read_deadline = None
self.write_deadline = None
self.local_closed = False
self.remote_closed = False
self.stream_lock = asyncio.Lock()
async def read(self) -> bytes:
"""
read messages associated with stream from buffer til end of file
:return: bytes of input
"""
return await self.mplex_conn.read_buffer(self.stream_id)
async def write(self, data: bytes) -> int:
"""
write to stream
:return: number of bytes written
"""
flag = (
HeaderTags.MessageInitiator
if self.initiator
else HeaderTags.MessageReceiver
)
return await self.mplex_conn.send_message(flag, data, self.stream_id)
async def close(self) -> bool:
"""
Closing a stream closes it for writing and closes the remote end for reading
but allows writing in the other direction.
:return: true if successful
"""
# TODO error handling with timeout
# TODO understand better how mutexes are used from go repo
flag = HeaderTags.CloseInitiator if self.initiator else HeaderTags.CloseReceiver
await self.mplex_conn.send_message(flag, None, self.stream_id)
remote_lock = False
async with self.stream_lock:
if self.local_closed:
return True
self.local_closed = True
remote_lock = self.remote_closed
if remote_lock:
# FIXME: mplex_conn has no conn_lock!
async with self.mplex_conn.conn_lock: # type: ignore
# FIXME: Don't access to buffers directly
self.mplex_conn.buffers.pop(self.stream_id) # type: ignore
return True
async def reset(self) -> bool:
"""
closes both ends of the stream
tells this remote side to hang up
:return: true if successful
"""
# TODO understand better how mutexes are used here
# TODO understand the difference between close and reset
async with self.stream_lock:
if self.remote_closed and self.local_closed:
return True
if not self.remote_closed:
flag = (
HeaderTags.ResetInitiator
if self.initiator
else HeaderTags.ResetInitiator
)
await self.mplex_conn.send_message(flag, None, self.stream_id)
self.local_closed = True
self.remote_closed = True
# FIXME: mplex_conn has no conn_lock!
async with self.mplex_conn.conn_lock: # type: ignore
# FIXME: Don't access to buffers directly
self.mplex_conn.buffers.pop(self.stream_id, None) # type: ignore
return True
# TODO deadline not in use
def set_deadline(self, ttl: float) -> bool:
"""
set deadline for muxed stream
:return: True if successful
"""
self.read_deadline = ttl
self.write_deadline = ttl
return True
def set_read_deadline(self, ttl: float) -> bool:
"""
set read deadline for muxed stream
:return: True if successful
"""
self.read_deadline = ttl
return True
def set_write_deadline(self, ttl: float) -> bool:
"""
set write deadline for muxed stream
:return: True if successful
"""
self.write_deadline = ttl
return True