125 lines
3.7 KiB
Python
125 lines
3.7 KiB
Python
import asyncio
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from .constants import HEADER_TAGS
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from ..muxed_stream_interface import IMuxedStream
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class MplexStream(IMuxedStream):
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# pylint: disable=too-many-instance-attributes
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"""
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reference: https://github.com/libp2p/go-mplex/blob/master/stream.go
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"""
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def __init__(self, stream_id, initiator, mplex_conn):
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"""
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create new MuxedStream in muxer
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:param stream_id: stream stream id
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:param initiator: boolean if this is an initiator
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:param mplex_conn: muxed connection of this muxed_stream
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"""
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self.stream_id = stream_id
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self.initiator = initiator
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self.mplex_conn = mplex_conn
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self.read_deadline = None
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self.write_deadline = None
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self.local_closed = False
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self.remote_closed = False
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self.stream_lock = asyncio.Lock()
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def get_flag(self, action):
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"""
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get header flag based on action for mplex
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:param action: action type in str
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:return: int flag
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"""
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if self.initiator:
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return HEADER_TAGS[action]
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return HEADER_TAGS[action] - 1
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async def read(self):
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"""
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read messages associated with stream from buffer til end of file
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:return: bytes of input
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"""
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return await self.mplex_conn.read_buffer(self.stream_id)
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async def write(self, data):
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"""
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write to stream
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:return: number of bytes written
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"""
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return await self.mplex_conn.send_message(self.get_flag("MESSAGE"), data, self.stream_id)
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async def close(self):
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"""
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Closing a stream closes it for writing and closes the remote end for reading
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but allows writing in the other direction.
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:return: true if successful
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"""
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# TODO error handling with timeout
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# TODO understand better how mutexes are used from go repo
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await self.mplex_conn.send_message(self.get_flag("CLOSE"), None, self.stream_id)
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remote_lock = ""
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async with self.stream_lock:
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if self.local_closed:
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return True
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self.local_closed = True
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remote_lock = self.remote_closed
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if remote_lock:
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async with self.mplex_conn.conn_lock:
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self.mplex_conn.buffers.pop(self.stream_id)
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return True
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async def reset(self):
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"""
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closes both ends of the stream
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tells this remote side to hang up
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:return: true if successful
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"""
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# TODO understand better how mutexes are used here
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# TODO understand the difference between close and reset
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async with self.stream_lock:
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if self.remote_closed and self.local_closed:
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return True
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if not self.remote_closed:
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await self.mplex_conn.send_message(self.get_flag("RESET"), None, self.stream_id)
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self.local_closed = True
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self.remote_closed = True
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async with self.mplex_conn.conn_lock:
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self.mplex_conn.buffers.pop(self.stream_id, None)
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return True
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# TODO deadline not in use
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def set_deadline(self, ttl):
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"""
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set deadline for muxed stream
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:return: True if successful
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"""
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self.read_deadline = ttl
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self.write_deadline = ttl
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return True
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def set_read_deadline(self, ttl):
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"""
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set read deadline for muxed stream
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:return: True if successful
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"""
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self.read_deadline = ttl
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return True
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def set_write_deadline(self, ttl):
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"""
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set write deadline for muxed stream
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:return: True if successful
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"""
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self.write_deadline = ttl
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return True
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