feat: 立体声 client 构建

apps/hello/src/sync.rs

@@ -0,0 +1,34 @@
+use std::time::{SystemTime, UNIX_EPOCH};
+
+pub fn now_us() -> u128 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .expect("Time went backwards")
+        .as_micros()
+}
+
+pub struct ClockSync {
+    pub offset: i128, // server_time - client_time
+}
+
+impl ClockSync {
+    pub fn new() -> Self {
+        Self { offset: 0 }
+    }
+
+    pub fn update(&mut self, client_send_ts: u128, server_ts: u128, client_recv_ts: u128) {
+        let rtt = (client_recv_ts - client_send_ts) as i128;
+        // Estimated server time when client_recv_ts occurred: server_ts + rtt/2
+        let estimated_server_now = server_ts as i128 + rtt / 2;
+        self.offset = estimated_server_now - client_recv_ts as i128;
+    }
+
+    pub fn to_server_time(&self, client_time: u128) -> u128 {
+        (client_time as i128 + self.offset) as u128
+    }
+
+    pub fn to_client_time(&self, server_time: u128) -> u128 {
+        (server_time as i128 - self.offset) as u128
+    }
+}
+