# Source code for scrapy.signalmanager

    from __future__ import annotations

    import warnings
    from typing import Any

    from pydispatch import dispatcher
    from twisted.internet.defer import Deferred

    from scrapy.exceptions import ScrapyDeprecationWarning
    from scrapy.utils import signal as _signal
    from scrapy.utils.defer import maybe_deferred_to_future

    class SignalManager:
        def __init__(self, sender: Any = dispatcher.Anonymous):
            self.sender: Any = sender

        def connect(self, receiver: Any, signal: Any, **kwargs: Any) -> None:
            """
            Connect a receiver function to a signal.

            The signal can be any object, although Scrapy comes with some
            predefined signals that are documented in the :ref:`topics-signals`
            section.

            :param receiver: the function to be connected
            :type receiver: collections.abc.Callable

            :param signal: the signal to connect to
            :type signal: object
            """
            kwargs.setdefault("sender", self.sender)
            dispatcher.connect(receiver, signal, **kwargs)

        def disconnect(self, receiver: Any, signal: Any, **kwargs: Any) -> None:
            """
            Disconnect a receiver function from a signal. This has the
            opposite effect of the :meth:`connect` method, and the arguments
            are the same.
            """
            kwargs.setdefault("sender", self.sender)
            dispatcher.disconnect(receiver, signal, **kwargs)

        def send_catch_log(self, signal: Any, **kwargs: Any) -> list[tuple[Any, Any]]:
            """
            Send a signal, catch exceptions and log them.

            The keyword arguments are passed to the signal handlers (connected
            through the :meth:`connect` method).
            """
            kwargs.setdefault("sender", self.sender)
            return _signal.send_catch_log(signal, **kwargs)

        def send_catch_log_deferred(
            self, signal: Any, **kwargs: Any
        ) -> Deferred[list[tuple[Any, Any]]]:  # pragma: no cover
            """
            Like :meth:`send_catch_log` but supports :ref:`asynchronous signal
            handlers <signal-deferred>`.

            Returns a Deferred that gets fired once all signal handlers
            have finished. Send a signal, catch exceptions and log them.

            The keyword arguments are passed to the signal handlers (connected
            through the :meth:`connect` method).
            """
            kwargs.setdefault("sender", self.sender)
            warnings.warn(
                "send_catch_log_deferred() is deprecated, use send_catch_log_async() instead",
                ScrapyDeprecationWarning,
                stacklevel=2,
            )
            return _signal._send_catch_log_deferred(signal, **kwargs)

        async def send_catch_log_async(
            self, signal: Any, **kwargs: Any
        ) -> list[tuple[Any, Any]]:
            """
            Like :meth:`send_catch_log` but supports :ref:`asynchronous signal
            handlers <signal-deferred>`.

            Returns a coroutine that completes once all signal handlers
            have finished. Send a signal, catch exceptions and log them.

            The keyword arguments are passed to the signal handlers (connected
            through the :meth:`connect` method).

            .. versionadded:: 2.14
            """
            # note that this returns exceptions instead of Failures in the second tuple member
            kwargs.setdefault("sender", self.sender)
            return await _signal.send_catch_log_async(signal, **kwargs)

        def disconnect_all(self, signal: Any, **kwargs: Any) -> None:
            """
            Disconnect all receivers from the given signal.

            :param signal: the signal to disconnect from
            :type signal: object
            """
            kwargs.setdefault("sender", self.sender)
            _signal.disconnect_all(signal, **kwargs)

        async def wait_for(self, signal):
            """Await the next *signal*.

            See :ref:`start-requests-lazy` for an example.
            """
            d = Deferred()

            def handle():
                self.disconnect(handle, signal)
                d.callback(None)

            self.connect(handle, signal)
            await maybe_deferred_to_future(d)