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.
Previously, the `DummyConnectionHandler` offered a "keep alive" functionality,
i.e. it allowed users to set the value of what is returned from
`ConnectionHandler::keep_alive`. This handler is primarily used in tests or
`NetworkBehaviour`s that don't open any connections (like mDNS). In all of these
cases, it is statically known whether we want to keep connections alive. As
such, this functionality is better represented by a static
`KeepAliveConnectionHandler` that always returns `KeepAlive::Yes` and a
`DummyConnectionHandler` that always returns `KeepAlive::No`.
To follow the naming conventions described in
https://github.com/libp2p/rust-libp2p/issues/2217, we introduce a top-level
`keep_alive` and `dummy` behaviour in `libp2p-swarm` that contains both the
`NetworkBehaviour` and `ConnectionHandler` implementation for either case.
Remove default features. You need to enable required features
explicitly now. As a quick workaround, you may want to use the
new `full` feature which activates all features.
Instead of having a mix of `poll_event`, `poll_outbound` and `poll_close`, we
flatten the entire interface of `StreamMuxer` into 4 individual functions:
- `poll_inbound`
- `poll_outbound`
- `poll_address_change`
- `poll_close`
This design is closer to the design of other async traits like `AsyncRead` and
`AsyncWrite`. It also allows us to delete the `StreamMuxerEvent`.
* misc/metrics: Explicitly delegate event recording to each recorder
This allows delegating a single event to multiple `Recorder`s. That enables e.g. the
`identify::Metrics` `Recorder` to act both on `IdentifyEvent` and `SwarmEvent`. The latter enables
it to garbage collect per peer data on disconnects.
* protocols/dcutr: Expose PROTOCOL_NAME
* protocols/identify: Expose PROTOCOL_NAME and PUSH_PROTOCOL_NAME
* protocols/ping: Expose PROTOCOL_NAME
* protocols/relay: Expose HOP_PROTOCOL_NAME and STOP_PROTOCOL_NAME
* misc/metrics: Track # connected nodes supporting specific protocol
An example metric exposed with this patch:
```
libp2p_identify_protocols{protocol="/ipfs/ping/1.0.0"} 10
```
This implies that 10 of the currently connected nodes support the ping protocol.
Previously `libp2p-swarm` required a `Transport` to be `Clone`. Methods
on `Transport`, e.g. `Transport::dial` would take ownership, requiring
e.g. a `Clone::clone` before calling `Transport::dial`.
The requirement of `Transport` to be `Clone` is no longer needed in
`libp2p-swarm`. E.g. concurrent dialing can be done without a clone per
dial.
This commit removes the requirement of `Clone` for `Transport` in
`libp2p-swarm`. As a follow-up methods on `Transport` no longer take
ownership, but instead a mutable reference (`&mut self`).
On the one hand this simplifies `libp2p-swarm`, on the other it
simplifies implementations of `Transport`.
* *: Import `libp2p` with `default-features = false`
While not a win in most cases, it reduces compile time for tests of
individual crates.
* Cargo.toml: Set features for examples
Metrics example server based on hyper replaces a component based on Tide
framework. This removes dependency on Tide which triggered audit warnings.
Co-authored-by: Max Inden <mail@max-inden.de>
This commit removes the `Network` abstraction, thus managing `Listeners`
and the connection `Pool` in `Swarm` directly. This is done under the
assumption that noone uses the `Network` abstraction directly, but
instead everyone always uses it through `Swarm`. Both `Listeners` and
`Pool` are moved from `libp2p-core` into `libp2p-swarm`. Given that they
are no longer exposed via `Network`, they can be treated as an
implementation detail of `libp2p-swarm` and `Swarm`.
This change does not include any behavioural changes.
This change has the followin benefits:
- Removal of `NetworkEvent`, which was mostly an isomorphism of
`SwarmEvent`.
- Removal of the never-directly-used `Network` abstraction.
- Removal of now obsolete verbose `Peer` (`core/src/network/peer.rs`)
construct.
- Removal of `libp2p-core` `DialOpts`, which is a direct mapping of
`libp2p-swarm` `DialOpts`.
- Allowing breaking changes to the connection handling and `Swarm` API
interface without a breaking change in `libp2p-core` and thus a
without a breaking change in `/transport` protocols.
This change enables the following potential future changes:
- Removal of `NodeHandler` and `ConnectionHandler`. Thus allowing to
rename `ProtocolsHandler` into `ConnectionHandler`.
- Moving `NetworkBehaviour` and `ProtocolsHandler` into `libp2p-core`,
having `libp2p-xxx` protocol crates only depend on `libp2p-core` and
thus allowing general breaking changes to `Swarm` without breaking all
`libp2p-xxx` crates.
