refactor(examples): change ipfs-kad from async-std to tokio

Related: #4449.

Pull-Request: #4590.

examples/ipfs-kad/Cargo.toml

@@ -6,8 +6,8 @@ publish = false
 license = "MIT"
 
 [dependencies]
-async-std = { version = "1.12", features = ["attributes"] }
+tokio = { version = "1.12", features = ["rt-multi-thread", "macros"] }
 async-trait = "0.1"
 env_logger = "0.10"
 futures = "0.3.28"
-libp2p = { path = "../../libp2p", features = ["async-std", "dns", "kad", "noise", "tcp", "websocket", "yamux", "rsa"] }
+libp2p = { path = "../../libp2p", features = ["tokio", "dns", "kad", "noise", "tcp", "websocket", "yamux", "rsa"] }

examples/ipfs-kad/src/main.rs

@@ -24,9 +24,9 @@ use futures::StreamExt;
 use libp2p::kad;
 use libp2p::kad::record::store::MemoryStore;
 use libp2p::{
-    development_transport, identity,
+    identity,
     swarm::{SwarmBuilder, SwarmEvent},
-    PeerId,
+    tokio_development_transport, PeerId,
 };
 use std::{env, error::Error, time::Duration};
 
@@ -37,7 +37,7 @@ const BOOTNODES: [&str; 4] = [
     "QmcZf59bWwK5XFi76CZX8cbJ4BhTzzA3gU1ZjYZcYW3dwt",
 ];
 
-#[async_std::main]
+#[tokio::main]
 async fn main() -> Result<(), Box<dyn Error>> {
     env_logger::init();
 
@@ -46,7 +46,7 @@ async fn main() -> Result<(), Box<dyn Error>> {
     let local_peer_id = PeerId::from(local_key.public());
 
     // Set up a an encrypted DNS-enabled TCP Transport over the yamux protocol
-    let transport = development_transport(local_key).await?;
+    let transport = tokio_development_transport(local_key)?;
 
     // Create a swarm to manage peers and events.
     let mut swarm = {
@@ -63,7 +63,7 @@ async fn main() -> Result<(), Box<dyn Error>> {
             behaviour.add_address(&peer.parse()?, "/dnsaddr/bootstrap.libp2p.io".parse()?);
         }
 
-        SwarmBuilder::with_async_std_executor(transport, behaviour, local_peer_id).build()
+        SwarmBuilder::with_tokio_executor(transport, behaviour, local_peer_id).build()
     };
 
     // Order Kademlia to search for a peer.