Move bitswap to its own crate (#12242)

* Introduce `sc-network-bitswap`

Move the bitswap protocol out of `sc-network` to its own crate.

* Improve test coverage

* Remove mention of bitswap from `sc-network`

* Fix documentation

* Fix clippy and remove the void dependency

* Remove unneeded trait bound and bump prost to 0.11

substrate/client/service/src/builder.rs

@@ -37,7 +37,8 @@ use sc_client_db::{Backend, DatabaseSettings};
 use sc_consensus::import_queue::ImportQueue;
 use sc_executor::RuntimeVersionOf;
 use sc_keystore::LocalKeystore;
-use sc_network::{bitswap::Bitswap, config::SyncMode, NetworkService};
+use sc_network::{config::SyncMode, NetworkService};
+use sc_network_bitswap::BitswapRequestHandler;
 use sc_network_common::{
 	service::{NetworkStateInfo, NetworkStatusProvider, NetworkTransaction},
 	sync::warp::WarpSyncProvider,
@@ -746,6 +747,8 @@ where
 		warp_sync,
 	} = params;
 
+	let mut request_response_protocol_configs = Vec::new();
+
 	if warp_sync.is_none() && config.network.sync_mode.is_warp() {
 		return Err("Warp sync enabled, but no warp sync provider configured.".into())
 	}
@@ -835,6 +838,13 @@ where
 		config.network.max_parallel_downloads,
 		warp_sync_provider,
 	)?;
+
+	request_response_protocol_configs.push(config.network.ipfs_server.then(|| {
+		let (handler, protocol_config) = BitswapRequestHandler::new(client.clone());
+		spawn_handle.spawn("bitswap-request-handler", Some("networking"), handler.run());
+		protocol_config
+	}));
+
 	let network_params = sc_network::config::Params {
 		role: config.role.clone(),
 		executor: {
@@ -856,12 +866,15 @@ where
 		fork_id: config.chain_spec.fork_id().map(ToOwned::to_owned),
 		import_queue: Box::new(import_queue),
 		chain_sync: Box::new(chain_sync),
-		bitswap: config.network.ipfs_server.then(|| Bitswap::from_client(client.clone())),
 		metrics_registry: config.prometheus_config.as_ref().map(|config| config.registry.clone()),
 		block_request_protocol_config,
 		state_request_protocol_config,
 		warp_sync_protocol_config,
 		light_client_request_protocol_config,
+		request_response_protocol_configs: request_response_protocol_configs
+			.into_iter()
+			.flatten()
+			.collect::<Vec<_>>(),
 	};
 
 	let has_bootnodes = !network_params.network_config.boot_nodes.is_empty();