fix timing intervals

fixes #3

config.toml.sample

@@ -3,4 +3,3 @@ listener = "[::]:9898"
 [hosts]
 "1.1.1.1" = 500
 "1.0.0.1" = 500
-

src/ping.rs

@@ -22,8 +22,9 @@ use futures_util::stream::StreamExt;
 use lazy_static::lazy_static;
 use log::{error, info, trace};
 use prometheus::*;
+use std::net::IpAddr;
 use std::time::Duration;
-use tokio::time::delay_for;
+use tokio_ping::Pinger;
 
 lazy_static! {
     static ref PING_HISTOGRAM: HistogramVec = register_histogram_vec!(
@@ -42,7 +43,7 @@ lazy_static! {
 pub(crate) async fn start_pinging_hosts(
     config: Config,
 ) -> std::result::Result<(), tokio_ping::Error> {
-    let pinger = match tokio_ping::Pinger::new().await {
+    let pinger = match Pinger::new().await {
         Ok(pinger) => pinger,
         Err(error) => {
             error!("Couldn't create pinger: {}", error);
@@ -51,27 +52,44 @@ pub(crate) async fn start_pinging_hosts(
     };
     for (host, interval) in config.hosts.clone() {
         info!("Spawn ping task for {}", host);
-        let pingchain = pinger.chain(host).timeout(Duration::from_secs(3));
-        let host = host.to_string();
-        tokio::spawn(pingchain.stream().for_each(move |ping_result| {
-            match ping_result {
-                Ok(time) => match time {
-                    Some(time) => {
-                        let ms = time.as_millis();
-                        trace!("Received pong from {} after {} ms", &host, &ms);
-                        PING_HISTOGRAM
-                            .with_label_values(&[&host])
-                            .observe(ms as f64);
-                    }
-                    None => {
-                        trace!("Received no response from {} within timeout", &host);
-                        PING_HISTOGRAM.with_label_values(&[&host]).observe(3000.0);
-                    }
-                },
-                Err(error) => error!("Couldn't ping {}: {}", &host, error),
-            }
-            delay_for(Duration::from_millis(interval))
-        }));
+        tokio::spawn(ping_host(pinger.clone(), host, interval));
     }
     Ok(())
 }
+
+async fn ping_host(pinger: Pinger, host: IpAddr, interval: u64) {
+    let pingchain = pinger.chain(host).timeout(Duration::from_secs(3));
+    let host = host.to_string();
+    let mut stream = pingchain.stream();
+    let mut interval = tokio::time::interval(Duration::from_millis(interval));
+    loop {
+        interval.tick().await;
+        handle_ping_result(stream.next().await.unwrap(), &host).await;
+    }
+}
+
+async fn handle_ping_result(
+    result: std::result::Result<Option<Duration>, tokio_ping::Error>,
+    host: &str,
+) {
+    let pong = match result {
+        Ok(pong) => pong,
+        Err(error) => {
+            error!("Couldn't ping {}: {}", &host, error);
+            return;
+        }
+    };
+    match pong {
+        Some(time) => {
+            let ms = time.as_millis();
+            trace!("Received pong from {} after {} ms", &host, &ms);
+            PING_HISTOGRAM
+                .with_label_values(&[&host])
+                .observe(ms as f64);
+        }
+        None => {
+            trace!("Received no response from {} within timeout", &host);
+            PING_HISTOGRAM.with_label_values(&[&host]).observe(3000.0);
+        }
+    };
+}