Enable advanced dialing requests both on `Swarm` and via
`NetworkBehaviourAction`. Users can now trigger a dial with a specific
set of addresses, optionally extended via
`NetworkBehaviour::addresses_of_peer`. In addition the whole process is
now modelled in a type safe way via the builder pattern.
Example of a `NetworkBehaviour` requesting a dial to a specific peer
with a set of addresses additionally extended through
`NetworkBehaviour::addresses_of_peer`:
```rust
NetworkBehaviourAction::Dial {
opts: DialOpts::peer_id(peer_id)
.condition(PeerCondition::Always)
.addresses(addresses)
.extend_addresses_through_behaviour()
.build(),
handler,
}
```
Example of a user requesting a dial to an unknown peer with a single
address via `Swarm`:
```rust
swarm1.dial(
DialOpts::unknown_peer_id()
.address(addr2.clone())
.build()
)
```
Change `Stream` implementation of `ExpandedSwarm` to return all
`SwarmEvents` instead of only the `NetworkBehaviour`'s events.
Remove `ExpandedSwarm::next_event`. Users can use `<ExpandedSwarm as
StreamExt>::next` instead.
Remove `ExpandedSwarm::next`. Users can use `<ExpandedSwarm as
StreamExt>::filter_map` instead.
This commit extends the ping example in `src/tutorial.rs, by walking a
newcomer through the implementation of a simple ping node step-by-step,
introducing all the core libp2p concepts along the way.
With the ping tutorial in place, there is no need for the lengthy libp2p
crate level introduction, which is thus removed with this commit.
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
