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|
use std::{future::Future, sync::Arc};
use log::{error, trace, warn};
use karyon_core::{
async_util::{Backoff, Executor, TaskGroup, TaskResult},
crypto::KeyPair,
};
use karyon_net::{tcp, tls, Conn, Endpoint, NetError};
use crate::{
monitor::{ConnEvent, Monitor},
slots::ConnectionSlots,
tls_config::tls_client_config,
Error, PeerID, Result,
};
static DNS_NAME: &str = "karyontech.net";
/// Responsible for creating outbound connections with other peers.
pub struct Connector {
/// Identity Key pair
key_pair: KeyPair,
/// Managing spawned tasks.
task_group: TaskGroup<'static>,
/// Manages available outbound slots.
connection_slots: Arc<ConnectionSlots>,
/// The maximum number of retries allowed before successfully
/// establishing a connection.
max_retries: usize,
/// Enables secure connection.
enable_tls: bool,
/// Responsible for network and system monitoring.
monitor: Arc<Monitor>,
}
impl Connector {
/// Creates a new Connector
pub fn new(
key_pair: &KeyPair,
max_retries: usize,
connection_slots: Arc<ConnectionSlots>,
enable_tls: bool,
monitor: Arc<Monitor>,
ex: Executor<'static>,
) -> Arc<Self> {
Arc::new(Self {
key_pair: key_pair.clone(),
max_retries,
task_group: TaskGroup::with_executor(ex),
monitor,
connection_slots,
enable_tls,
})
}
/// Shuts down the connector
pub async fn shutdown(&self) {
self.task_group.cancel().await;
}
/// Establish a connection to the specified `endpoint`. If the connection
/// attempt fails, it performs a backoff and retries until the maximum allowed
/// number of retries is exceeded. On a successful connection, it returns a
/// `Conn` instance.
///
/// This method will block until it finds an available slot.
pub async fn connect(&self, endpoint: &Endpoint, peer_id: &Option<PeerID>) -> Result<Conn> {
self.connection_slots.wait_for_slot().await;
self.connection_slots.add();
let mut retry = 0;
let backoff = Backoff::new(500, 2000);
while retry < self.max_retries {
match self.dial(endpoint, peer_id).await {
Ok(conn) => {
self.monitor
.notify(&ConnEvent::Connected(endpoint.clone()).into())
.await;
return Ok(conn);
}
Err(err) => {
error!("Failed to establish a connection to {endpoint}: {err}");
}
}
self.monitor
.notify(&ConnEvent::ConnectRetried(endpoint.clone()).into())
.await;
backoff.sleep().await;
warn!("try to reconnect {endpoint}");
retry += 1;
}
self.monitor
.notify(&ConnEvent::ConnectFailed(endpoint.clone()).into())
.await;
self.connection_slots.remove().await;
Err(NetError::Timeout.into())
}
/// Establish a connection to the given `endpoint`. For each new connection,
/// it invokes the provided `callback`, and pass the connection to the callback.
pub async fn connect_with_cback<Fut>(
self: &Arc<Self>,
endpoint: &Endpoint,
peer_id: &Option<PeerID>,
callback: impl FnOnce(Conn) -> Fut + Send + 'static,
) -> Result<()>
where
Fut: Future<Output = Result<()>> + Send + 'static,
{
let conn = self.connect(endpoint, peer_id).await?;
let selfc = self.clone();
let endpoint = endpoint.clone();
let on_disconnect = |res| async move {
if let TaskResult::Completed(Err(err)) = res {
trace!("Outbound connection dropped: {err}");
}
selfc
.monitor
.notify(&ConnEvent::Disconnected(endpoint.clone()).into())
.await;
selfc.connection_slots.remove().await;
};
self.task_group.spawn(callback(conn), on_disconnect);
Ok(())
}
async fn dial(&self, endpoint: &Endpoint, peer_id: &Option<PeerID>) -> Result<Conn> {
if self.enable_tls {
let tls_config = tls_client_config(&self.key_pair, peer_id.clone())?;
tls::dial(endpoint, tls_config, DNS_NAME)
.await
.map(|l| Box::new(l) as Conn)
} else {
tcp::dial(endpoint).await.map(|l| Box::new(l) as Conn)
}
.map_err(Error::KaryonNet)
}
}
|
