82 lines
2.6 KiB
Python
82 lines
2.6 KiB
Python
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import asyncio
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from typing import Optional, cast
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from .tcp_helpers import tcp_nodelay
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class BaseProtocol(asyncio.Protocol):
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__slots__ = ('_loop', '_paused', '_drain_waiter',
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'_connection_lost', '_reading_paused', 'transport')
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def __init__(self, loop: asyncio.AbstractEventLoop) -> None:
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self._loop = loop # type: asyncio.AbstractEventLoop
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self._paused = False
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self._drain_waiter = None # type: Optional[asyncio.Future[None]]
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self._connection_lost = False
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self._reading_paused = False
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self.transport = None # type: Optional[asyncio.Transport]
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def pause_writing(self) -> None:
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assert not self._paused
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self._paused = True
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def resume_writing(self) -> None:
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assert self._paused
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self._paused = False
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waiter = self._drain_waiter
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if waiter is not None:
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self._drain_waiter = None
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if not waiter.done():
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waiter.set_result(None)
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def pause_reading(self) -> None:
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if not self._reading_paused and self.transport is not None:
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try:
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self.transport.pause_reading()
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except (AttributeError, NotImplementedError, RuntimeError):
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pass
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self._reading_paused = True
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def resume_reading(self) -> None:
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if self._reading_paused and self.transport is not None:
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try:
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self.transport.resume_reading()
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except (AttributeError, NotImplementedError, RuntimeError):
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pass
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self._reading_paused = False
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def connection_made(self, transport: asyncio.BaseTransport) -> None:
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tr = cast(asyncio.Transport, transport)
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tcp_nodelay(tr, True)
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self.transport = tr
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def connection_lost(self, exc: Optional[BaseException]) -> None:
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self._connection_lost = True
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# Wake up the writer if currently paused.
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self.transport = None
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if not self._paused:
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return
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waiter = self._drain_waiter
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if waiter is None:
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return
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self._drain_waiter = None
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if waiter.done():
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return
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if exc is None:
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waiter.set_result(None)
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else:
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waiter.set_exception(exc)
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async def _drain_helper(self) -> None:
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if self._connection_lost:
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raise ConnectionResetError('Connection lost')
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if not self._paused:
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return
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waiter = self._drain_waiter
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assert waiter is None or waiter.cancelled()
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waiter = self._loop.create_future()
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self._drain_waiter = waiter
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await waiter
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