Reusable/util Swarm

[rvalle]

Projects depending on subp2p explorer will need to build a swarm too.

It would be beneficial to move the swarm building code to utility including the typical sets of behaviors used, while still allowing for a custom set of behaviors.

This would also facilitate managing the later #3 migration.

[rvalle]

@lexnv I am looking into it.
This seems not obvious, by the way behaviors are created and initialized after/become swarm is created.

I currently need the behavior PeerId+Discovery and you use also the PeerId+Discovery+Notification, are you planning on putting together other sets?

Perhaps we could provide utility swarm creation for the typical ones.

[lexnv]

One way to approach this would be to make the default-behavior exposed by the subp2p explorer have an optional notifications::behavior::Notifications. This way users can enable it or disable it depending on their workflow.

In the meanwhile, I think you could use the following approach:

subp2p-explorer/cli/src/utils.rs

Lines 107 to 128 in da19e6d

	let mut swarm: Swarm<Behaviour> = {
	let transport = TransportBuilder::new()
	.yamux_maximum_buffer_size(256 * MIB)
	.build(local_key.clone());
	let discovery = DiscoveryBuilder::new()
	.record_ttl(Some(Duration::from_secs(0)))
	.provider_ttl(Some(Duration::from_secs(0)))
	.query_timeout(Duration::from_secs(5 * 60))
	.build(local_peer_id, genesis);
	let peer_info = PeerBehaviour::new(local_key.public());
	let notifications = Notifications::new(protocol_data);
	let behavior = Behaviour {
	notifications,
	peer_info,
	discovery,
	};
	SwarmBuilder::with_tokio_executor(transport, behavior, local_peer_id).build()
	};

And define your own custom Behavior protocol, similar to:

subp2p-explorer/subp2p-explorer/src/lib.rs

Lines 15 to 22 in da19e6d

	pub struct Behaviour {
	/// Notification protocols.
	pub notifications: notifications::behavior::Notifications,
	/// Implements Ping and Identity and stores peer information in a cache.
	pub peer_info: peer_behavior::PeerBehaviour,
	/// Discovers nodes of the network.
	pub discovery: discovery::Discovery,
	}

[rvalle]

Having an optional notifications, or a behavior with optional sub-behaviors sounds ideal. I will investigate.

Yes, perhaps we can start by the default behaviour.