Previously, a connection would be shut down immediately as soon as its `ConnectionHandler` reports `KeepAlive::No`. As we have gained experience with libp2p, it turned out that this isn't ideal.
For one, tests often need to keep connections alive longer than the configured protocols require. Plus, some usecases require connections to be kept alive in general.
Both of these needs are currently served by the `keep_alive::Behaviour`. That one does essentially nothing other than statically returning `KeepAlive::Yes` from its `ConnectionHandler`.
It makes much more sense to deprecate `keep_alive::Behaviour` and instead allow users to globally configure an `idle_conncetion_timeout` on the `Swarm`. This timeout comes into effect once a `ConnectionHandler` reports `KeepAlive::No`. To start with, this timeout is 0. Together with https://github.com/libp2p/rust-libp2p/issues/3844, this will allow us to move towards a much more aggressive closing of idle connections, together with a more ergonomic way of opting out of this behaviour.
Fixes#4121.
Pull-Request: #4161.
Mark constructors `Swarm::with_X_executor` as deprecated.
Move the deprecated functionality to `SwarmBuilder::with_X_executor`
Use `SwarmBuilder` throughout.
Resolves#3186.
Resolves#3107.
Pull-Request: #3588.
As I do frequently, I corrected for the latest clippy warnings. This will make sure the CI won't complain in the future. We could automate this btw and maybe run the nightly version of clippy.
Previously, the executor for connection tasks silently defaulted to a `futures::executor::ThreadPool`. This causes issues such as https://github.com/libp2p/rust-libp2p/issues/2230.
With this patch, we force the user to choose, which executor they want to run the connection tasks on which results in overall simpler API with less footguns.
Closes#3068.
