// 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.
//!
//! You can also store provider records instead of key value records.
//!
//! 1. Using two terminal windows, start two instances. If you local network
//! allows mDNS, they will automatically connect.
//!
//! 2. Type `PUT_PROVIDER my-key` in terminal one and hit return.
//!
//! 3. Type `GET_PROVIDERS 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::{
AddProviderOk,
Kademlia,
KademliaEvent,
PeerRecord,
PutRecordOk,
QueryResult,
Quorum,
Record,
record::Key,
};
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<dyn Error>> {
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<MemoryStore>,
mdns: Mdns
}
impl NetworkBehaviourEventProcess<MdnsEvent> for MyBehaviour {
// 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<KademliaEvent> for MyBehaviour {
// Called when `kademlia` produces an event.
fn inject_event(&mut self, message: KademliaEvent) {
match message {
KademliaEvent::QueryResult { result, .. } => match result {
QueryResult::GetProviders(Ok(ok)) => {
for peer in ok.providers {
println!(
"Peer {:?} provides key {:?}",
peer,
std::str::from_utf8(ok.key.as_ref()).unwrap()
);
}
}
QueryResult::GetProviders(Err(err)) => {
eprintln!("Failed to get providers: {:?}", err);
}
QueryResult::GetRecord(Ok(ok)) => {
for PeerRecord { record: Record { key, value, .. }, ..} in ok.records {
println!(
"Got record {:?} {:?}",
std::str::from_utf8(key.as_ref()).unwrap(),
std::str::from_utf8(&value).unwrap(),
);
}
}
QueryResult::GetRecord(Err(err)) => {
eprintln!("Failed to get record: {:?}", err);
}
QueryResult::PutRecord(Ok(PutRecordOk { key })) => {
println!(
"Successfully put record {:?}",
std::str::from_utf8(key.as_ref()).unwrap()
);
}
QueryResult::PutRecord(Err(err)) => {
eprintln!("Failed to put record: {:?}", err);
}
QueryResult::StartProviding(Ok(AddProviderOk { key })) => {
println!("Successfully put provider record {:?}",
std::str::from_utf8(key.as_ref()).unwrap()
);
}
QueryResult::StartProviding(Err(err)) => {
eprintln!("Failed to put provider 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<MemoryStore>, line: String) {
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("GET_PROVIDERS") => {
let key = {
match args.next() {
Some(key) => Key::new(&key),
None => {
eprintln!("Expected key");
return
}
}
};
kademlia.get_providers(key);
}
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).expect("Failed to store record locally.");
},
Some("PUT_PROVIDER") => {
let key = {
match args.next() {
Some(key) => Key::new(&key),
None => {
eprintln!("Expected key");
return;
}
}
};
kademlia.start_providing(key).expect("Failed to start providing key");
}
_ => {
eprintln!("expected GET, GET_PROVIDERS, PUT or PUT_PROVIDER");
}
}
}