Prefixing a variable with an underscore (`_`) in Rust indicates that it is not used. Through refactorings, it can sometimes happen that we do end up using such a variable. In this case, the underscore should be removed.
Clippy can help us with this.
Pull-Request: #3484.
Previously, a `ConnectionHandler` was immediately requested from the `NetworkBehaviour` as soon as a new dial was initiated or a new incoming connection accepted.
With this patch, we delay the creation of the handler until the connection is actually established and fully upgraded, i.e authenticated and multiplexed.
As a consequence, `NetworkBehaviour::new_handler` is now deprecated in favor of a new set of callbacks:
- `NetworkBehaviour::handle_pending_inbound_connection`
- `NetworkBehaviour::handle_pending_outbound_connection`
- `NetworkBehaviour::handle_established_inbound_connection`
- `NetworkBehaviour::handle_established_outbound_connection`
All callbacks are fallible, allowing the `NetworkBehaviour` to abort the connection either immediately or after it is fully established. All callbacks also receive a `ConnectionId` parameter which uniquely identifies the connection. For example, in case a `NetworkBehaviour` issues a dial via `NetworkBehaviourAction::Dial`, it can unambiguously detect this dial in these lifecycle callbacks via the `ConnectionId`.
Finally, `NetworkBehaviour::handle_pending_outbound_connection` also replaces `NetworkBehaviour::addresses_of_peer` by allowing the behaviour to return more addresses to be used for the dial.
Resolves#2824.
Pull-Request: #3254.
We create the `ConnectionId` for the new connection as part of `DialOpts`. This allows `NetworkBehaviour`s to accurately track state regarding their own dial attempts.
This patch is the main enabler of https://github.com/libp2p/rust-libp2p/pull/3254. Removing the `handler` field will allow us to deprecate the `NetworkBehaviour::new_handler` function in favor of four new ones that give more control over the connection lifecycle.
This PR isolates the bugfix for the `NetworkBehaviour` derive implementation for structures with generic fields. When `out_event` was not provided, the generated enum was missing the `NetworkBehaviour` impl constraint for the generic variants whilst using the generics for `<Generic>::OutEvent`.
Meanwhile I also found that the generated `poll` function `loop`s the sub behaviours and either `return`'s when `Poll::Ready` or `break`'s when `Poll::Pending`. This is a relict from when we still had `NetworkBehaviourEventProcess` which had added a branch within this loop that did not `return` but consume the event and `continue`. This trait was removed a while ago meaning this `loop` is no longer needed.
Previously, we used the full reference to the `OutEvent` of the `ConnectionHandler` in all implementations of `NetworkBehaviour`. Not only is this very verbose, it is also more brittle to changes. With the current implementation plan for #2824, we will be removing the `IntoConnectionHandler` abstraction. Using a type-alias to refer to the `OutEvent` makes the migration much easier.
Currently, our `NetworkBehaviour` derive macro depends on the `libp2p` crate to be in scope. This prevents standalone usage which forces us to depend on `libp2p` in all our tests where we want to derive a `NetworkBehaviour`.
This PR introduces a `prelude` option that - by default - points to `libp2p::swarm::derive_prelude`, a new module added to `libp2p_swarm`. With this config option, users of `libp2p_swarm` can now refer to the macro without depending on `libp2p`, breaking the circular dependency in our workspace. For consistency with the ecosystem, the macro is now also re-exported by `libp2p_swarm` instead of `libp2p` at the same position as the trait that it implements.
Lastly, we introduce an off-by-default `macros` feature flag that shrinks the dependency tree for users that don't need the derive macro.
* Rename Transport::RawConn to Output
* Remove AsyncRead + AsyncWrite bound on Transport::Output
* UpgradedNode now always implements Transport
* Add and tweak modifiers for Transport and ConnectionUpgrade
* Secio upgrade now returns the pubkey in its output
* Add upgrade::apply
* Add Transport::and_then
* Rework the swarm
* Rustfmt
* Fix concerns
Currently, connection substreams are added to
`connection_reuse::Shared::active_connections`, but never removed. This
is not least because the `StreamMuxer` trait defines its inbound and
outbound substream futures to always yield a substream and contains no
provision to signal that no more substreams can be created, which would
allow client code (e.g. `ConnectionReuse`) to detect this and purge its
caches.
This PR defines the `StreamMuxer` trait to optionally yield
inbound/outbound substreams and changes `libp2p-mplex` to handle
stream EOFs by marking the underlying resource as closed.
`ConnectionReuse` will remove stream muxers from its active connections
cache if a `None` substream is returned.
