| import asyncio
|
| from typing import Optional, cast
|
|
|
| from .client_exceptions import ClientConnectionResetError
|
| from .helpers import set_exception
|
| from .tcp_helpers import tcp_nodelay
|
|
|
|
|
| class BaseProtocol(asyncio.Protocol):
|
| __slots__ = (
|
| "_loop",
|
| "_paused",
|
| "_drain_waiter",
|
| "_connection_lost",
|
| "_reading_paused",
|
| "transport",
|
| )
|
|
|
| def __init__(self, loop: asyncio.AbstractEventLoop) -> None:
|
| self._loop: asyncio.AbstractEventLoop = loop
|
| self._paused = False
|
| self._drain_waiter: Optional[asyncio.Future[None]] = None
|
| self._reading_paused = False
|
|
|
| self.transport: Optional[asyncio.Transport] = None
|
|
|
| @property
|
| def connected(self) -> bool:
|
| """Return True if the connection is open."""
|
| return self.transport is not None
|
|
|
| @property
|
| def writing_paused(self) -> bool:
|
| return self._paused
|
|
|
| def pause_writing(self) -> None:
|
| assert not self._paused
|
| self._paused = True
|
|
|
| def resume_writing(self) -> None:
|
| assert self._paused
|
| self._paused = False
|
|
|
| waiter = self._drain_waiter
|
| if waiter is not None:
|
| self._drain_waiter = None
|
| if not waiter.done():
|
| waiter.set_result(None)
|
|
|
| def pause_reading(self) -> None:
|
| if not self._reading_paused and self.transport is not None:
|
| try:
|
| self.transport.pause_reading()
|
| except (AttributeError, NotImplementedError, RuntimeError):
|
| pass
|
| self._reading_paused = True
|
|
|
| def resume_reading(self) -> None:
|
| if self._reading_paused and self.transport is not None:
|
| try:
|
| self.transport.resume_reading()
|
| except (AttributeError, NotImplementedError, RuntimeError):
|
| pass
|
| self._reading_paused = False
|
|
|
| def connection_made(self, transport: asyncio.BaseTransport) -> None:
|
| tr = cast(asyncio.Transport, transport)
|
| tcp_nodelay(tr, True)
|
| self.transport = tr
|
|
|
| def connection_lost(self, exc: Optional[BaseException]) -> None:
|
|
|
| self.transport = None
|
| if not self._paused:
|
| return
|
| waiter = self._drain_waiter
|
| if waiter is None:
|
| return
|
| self._drain_waiter = None
|
| if waiter.done():
|
| return
|
| if exc is None:
|
| waiter.set_result(None)
|
| else:
|
| set_exception(
|
| waiter,
|
| ConnectionError("Connection lost"),
|
| exc,
|
| )
|
|
|
| async def _drain_helper(self) -> None:
|
| if self.transport is None:
|
| raise ClientConnectionResetError("Connection lost")
|
| if not self._paused:
|
| return
|
| waiter = self._drain_waiter
|
| if waiter is None:
|
| waiter = self._loop.create_future()
|
| self._drain_waiter = waiter
|
| await asyncio.shield(waiter)
|
|
|
