From 3e1ecb0df105205596ac6da31998796422be36cb Mon Sep 17 00:00:00 2001
From: Sam Willcocks <sam@wlcx.cc>
Date: Thu, 19 Jun 2025 00:25:56 +0100
Subject: [PATCH] use Instant over SystemTime

---
 .../src/atem_lib/atem_socket.rs               | 49 +++++++++----------
 1 file changed, 22 insertions(+), 27 deletions(-)

diff --git a/atem-connection-rs/src/atem_lib/atem_socket.rs b/atem-connection-rs/src/atem_lib/atem_socket.rs
index 06b94cb..89cffe3 100644
--- a/atem-connection-rs/src/atem_lib/atem_socket.rs
+++ b/atem-connection-rs/src/atem_lib/atem_socket.rs
@@ -4,7 +4,7 @@ use std::{
     io,
     net::SocketAddr,
     sync::Arc,
-    time::{Duration, SystemTime},
+    time::{Duration, Instant},
 };
 
 use itertools::Itertools;
@@ -25,10 +25,10 @@ use crate::{
 
 use super::atem_packet::PacketFlag;
 
-const IN_FLIGHT_TIMEOUT: u64 = 60;
-const CONNECTION_TIMEOUT: u64 = 5000;
-const CONNECTION_RETRY_INTERVAL: u64 = 1000;
-const RETRANSMIT_CHECK_INTERVAL: u64 = 1000;
+const IN_FLIGHT_TIMEOUT: Duration = Duration::from_millis(60);
+const CONNECTION_TIMEOUT: Duration = Duration::from_millis(5000);
+const CONNECTION_RETRY_INTERVAL: Duration = Duration::from_millis(1000);
+const RETRANSMIT_CHECK_INTERVAL: Duration = Duration::from_millis(1000);
 const MAX_PACKET_RETRIES: u16 = 10;
 const MAX_PACKET_ID: u16 = 1 << 15;
 const MAX_PACKET_PER_ACK: u16 = 16;
@@ -93,8 +93,8 @@ impl AtemSocketCommand {
 
 pub struct AtemSocket {
     connection_state: ConnectionState,
-    reconnect_timer: Option<SystemTime>,
-    retransmit_timer: Option<SystemTime>,
+    reconnect_timer: Option<Instant>,
+    retransmit_timer: Option<Instant>,
 
     next_tracking_id: u64,
 
@@ -106,10 +106,10 @@ pub struct AtemSocket {
 
     protocol_version: ProtocolVersion,
 
-    last_received_at: SystemTime,
+    last_received_at: Instant,
     last_received_packed_id: u16,
     in_flight: Vec<InFlightPacket>,
-    ack_timer: Option<SystemTime>,
+    ack_timer: Option<Instant>,
     received_without_ack: u16,
 
     atem_message_rx: tokio::sync::mpsc::Receiver<AtemSocketMessage>,
@@ -142,7 +142,7 @@ struct InFlightPacket {
     packet_id: u16,
     tracking_id: u64,
     payload: Vec<u8>,
-    pub last_sent: SystemTime,
+    pub last_sent: Instant,
     pub resent: u16,
 }
 
@@ -171,7 +171,7 @@ impl AtemSocket {
 
             protocol_version: ProtocolVersion::V7_2,
 
-            last_received_at: SystemTime::now(),
+            last_received_at: Instant::now(),
             last_received_packed_id: 0,
             in_flight: vec![],
             ack_timer: None,
@@ -321,7 +321,7 @@ impl AtemSocket {
             packet_id,
             tracking_id,
             payload: buffer,
-            last_sent: SystemTime::now(),
+            last_sent: Instant::now(),
             resent: 0,
         })
     }
@@ -339,17 +339,15 @@ impl AtemSocket {
             }
         }
         if let Some(ack_time) = self.ack_timer {
-            if ack_time <= SystemTime::now() {
+            if ack_time <= Instant::now() {
                 self.ack_timer = None;
                 self.received_without_ack = 0;
                 self.send_ack(self.last_received_packed_id).await;
             }
         }
         if let Some(reconnect_time) = self.reconnect_timer {
-            if reconnect_time <= SystemTime::now() {
-                if self.last_received_at + Duration::from_millis(CONNECTION_TIMEOUT)
-                    <= SystemTime::now()
-                {
+            if reconnect_time <= Instant::now() {
+                if self.last_received_at + CONNECTION_TIMEOUT <= Instant::now() {
                     log::debug!("{:?}", self.last_received_at);
                     log::debug!("Connection timed out, restarting");
                     self.restart_connection().await;
@@ -358,7 +356,7 @@ impl AtemSocket {
             }
         }
         if let Some(retransmit_time) = self.retransmit_timer {
-            if retransmit_time <= SystemTime::now() {
+            if retransmit_time <= Instant::now() {
                 self.check_for_retransmit().await;
                 self.start_retransmit_timer();
             }
@@ -397,7 +395,7 @@ impl AtemSocket {
             atem_packet.raw_fields().map(|f| f.r#type).join(",")
         );
 
-        self.last_received_at = SystemTime::now();
+        self.last_received_at = Instant::now();
 
         self.session_id = atem_packet.session_id();
         // TODO: naming seems rather off here
@@ -476,7 +474,7 @@ impl AtemSocket {
             self.ack_timer = None;
             self.send_ack(self.last_received_packed_id).await;
         } else if self.ack_timer.is_none() {
-            self.ack_timer = Some(SystemTime::now() + Duration::from_millis(5));
+            self.ack_timer = Some(Instant::now() + Duration::from_millis(5));
         }
     }
 
@@ -509,7 +507,7 @@ impl AtemSocket {
                 if sent_packet.packet_id == from_id
                     || !self.is_packet_covered_by_ack(from_id, sent_packet.packet_id)
                 {
-                    sent_packet.last_sent = SystemTime::now();
+                    sent_packet.last_sent = Instant::now();
                     sent_packet.resent += 1;
 
                     self.send_packet(&sent_packet.payload).await;
@@ -523,8 +521,7 @@ impl AtemSocket {
 
     async fn check_for_retransmit(&mut self) {
         for sent_packet in self.in_flight.clone() {
-            if sent_packet.last_sent + Duration::from_millis(IN_FLIGHT_TIMEOUT) < SystemTime::now()
-            {
+            if sent_packet.last_sent + IN_FLIGHT_TIMEOUT < Instant::now() {
                 if sent_packet.resent <= MAX_PACKET_RETRIES
                     && self
                         .is_packet_covered_by_ack(self.next_send_packet_id, sent_packet.packet_id)
@@ -580,13 +577,11 @@ impl AtemSocket {
     }
 
     fn start_reconnect_timer(&mut self) {
-        self.reconnect_timer =
-            Some(SystemTime::now() + Duration::from_millis(CONNECTION_RETRY_INTERVAL));
+        self.reconnect_timer = Some(Instant::now() + CONNECTION_RETRY_INTERVAL);
     }
 
     fn start_retransmit_timer(&mut self) {
-        self.retransmit_timer =
-            Some(SystemTime::now() + Duration::from_millis(RETRANSMIT_CHECK_INTERVAL));
+        self.retransmit_timer = Some(Instant::now() + RETRANSMIT_CHECK_INTERVAL);
     }
 
     fn next_packet_tracking_id(&mut self) -> u64 {