// Copyright 20l9 Parity Technologies (UK) Ltd. // // Permission is hereby granted, free of charge, to any person obtaining a // copy of this software and associated documentation files (the "Software"), // to deal in the Software without restriction, including without limitation // the rights to use, copy, modify, merge, publish, distribute, sublicense, // and/or sell copies of the Software, and to permit persons to whom the // Software is furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER // DEALINGS IN THE SOFTWARE. //! A basic key value store demonstrating libp2p and the mDNS and Kademlia protocols. //! //! 1. Using two terminal windows, start two instances. If you local network //! allows mDNS, they will automatically connect. //! //! 2. Type `PUT my-key my-value` in terminal one and hit return. //! //! 3. Type `GET my-key` in terminal two and hit return. //! //! 4. Close with Ctrl-c. use async_std::{io, task}; use futures::prelude::*; use libp2p::kad::record::store::MemoryStore; use libp2p::kad::{record::Key, Kademlia, KademliaEvent, PutRecordOk, Quorum, Record}; use libp2p::{ NetworkBehaviour, PeerId, Swarm, build_development_transport, identity, mdns::{Mdns, MdnsEvent}, swarm::NetworkBehaviourEventProcess }; use std::{error::Error, task::{Context, Poll}}; fn main() -> Result<(), Box> { env_logger::init(); // Create a random key for ourselves. let local_key = identity::Keypair::generate_ed25519(); let local_peer_id = PeerId::from(local_key.public()); // Set up a an encrypted DNS-enabled TCP Transport over the Mplex protocol. let transport = build_development_transport(local_key)?; // We create a custom network behaviour that combines Kademlia and mDNS. #[derive(NetworkBehaviour)] struct MyBehaviour { kademlia: Kademlia, mdns: Mdns } impl NetworkBehaviourEventProcess for MyBehaviour where T: AsyncRead + AsyncWrite { // Called when `mdns` produces an event. fn inject_event(&mut self, event: MdnsEvent) { if let MdnsEvent::Discovered(list) = event { for (peer_id, multiaddr) in list { self.kademlia.add_address(&peer_id, multiaddr); } } } } impl NetworkBehaviourEventProcess for MyBehaviour where T: AsyncRead + AsyncWrite { // Called when `kademlia` produces an event. fn inject_event(&mut self, message: KademliaEvent) { match message { KademliaEvent::GetRecordResult(Ok(result)) => { for Record { key, value, .. } in result.records { println!( "Got record {:?} {:?}", std::str::from_utf8(key.as_ref()).unwrap(), std::str::from_utf8(&value).unwrap(), ); } } KademliaEvent::GetRecordResult(Err(err)) => { eprintln!("Failed to get record: {:?}", err); } KademliaEvent::PutRecordResult(Ok(PutRecordOk { key })) => { println!( "Successfully put record {:?}", std::str::from_utf8(key.as_ref()).unwrap() ); } KademliaEvent::PutRecordResult(Err(err)) => { eprintln!("Failed to put record: {:?}", err); } _ => {} } } } // Create a swarm to manage peers and events. let mut swarm = { // Create a Kademlia behaviour. let store = MemoryStore::new(local_peer_id.clone()); let kademlia = Kademlia::new(local_peer_id.clone(), store); let mdns = task::block_on(Mdns::new())?; let behaviour = MyBehaviour { kademlia, mdns }; Swarm::new(transport, behaviour, local_peer_id) }; // Read full lines from stdin let mut stdin = io::BufReader::new(io::stdin()).lines(); // Listen on all interfaces and whatever port the OS assigns. Swarm::listen_on(&mut swarm, "/ip4/0.0.0.0/tcp/0".parse()?)?; // Kick it off. let mut listening = false; task::block_on(future::poll_fn(move |cx: &mut Context| { loop { match stdin.try_poll_next_unpin(cx)? { Poll::Ready(Some(line)) => handle_input_line(&mut swarm.kademlia, line), Poll::Ready(None) => panic!("Stdin closed"), Poll::Pending => break } } loop { match swarm.poll_next_unpin(cx) { Poll::Ready(Some(event)) => println!("{:?}", event), Poll::Ready(None) => return Poll::Ready(Ok(())), Poll::Pending => { if !listening { if let Some(a) = Swarm::listeners(&swarm).next() { println!("Listening on {:?}", a); listening = true; } } break } } } Poll::Pending })) } fn handle_input_line(kademlia: &mut Kademlia, line: String) where T: AsyncRead + AsyncWrite { let mut args = line.split(" "); match args.next() { Some("GET") => { let key = { match args.next() { Some(key) => Key::new(&key), None => { eprintln!("Expected key"); return; } } }; kademlia.get_record(&key, Quorum::One); } Some("PUT") => { let key = { match args.next() { Some(key) => Key::new(&key), None => { eprintln!("Expected key"); return; } } }; let value = { match args.next() { Some(value) => value.as_bytes().to_vec(), None => { eprintln!("Expected value"); return; } } }; let record = Record { key, value, publisher: None, expires: None, }; kademlia.put_record(record, Quorum::One); } _ => { eprintln!("expected GET or PUT"); } } }