feat: add min_speed option to speed measurement for filtering results

src/main.rs

@@ -118,7 +118,11 @@ struct SpeedArgs {
     #[arg(long, default_value_t = 10_000_000)]
     bytes: u64,
 
-    /// Keep only the best N nodes. 0 means keep all.
+    /// Reject IPs slower than this (Mbps). 0 = keep all.
+    #[arg(long = "min", default_value_t = 0.0)]
+    min_speed: f64,
+
+    /// Keep only the best N results. 0 means keep all.
     #[arg(short = 'p', long, default_value_t = 0)]
     top: usize,
 
@@ -394,6 +398,7 @@ async fn run_speed(args: SpeedArgs) -> Result<()> {
         args.concurrency.max(1),
         Duration::from_secs_f64(args.timeout),
         args.bytes,
+        args.min_speed,
         |p| {
             bar.set_position(p.done as u64);
             match p.speed_mbps {

src/speed.rs

@@ -37,14 +37,16 @@ pub fn bucket(speed_mbps: f64) -> i64 {
     speed_mbps.floor() as i64
 }
 
-/// Speed-test every input IP, carrying its latency through, and return
-/// successes ranked best-first (speed bucket desc, then latency asc).
+/// Speed-test every input IP, carrying its latency through. Keeps results at
+/// or above `min_speed` Mbps (zero = disabled), ranked best-first (speed
+/// bucket desc, then latency asc).
 pub async fn run(
     node: &VlessNode,
     inputs: &[(IpAddr, Duration)],
     concurrency: usize,
     timeout: Duration,
     limit_bytes: u64,
+    min_speed: f64,
     mut on_progress: impl FnMut(Probed),
 ) -> Vec<SpeedResult> {
     let total = inputs.len();
@@ -58,11 +60,15 @@ pub async fn run(
 
     while let Some((ip, latency, outcome)) = stream.next().await {
         done += 1;
-        let speed = outcome.ok();
-        if let Some(mbps) = speed {
-            results.push(SpeedResult { ip, latency, speed_mbps: mbps });
-        }
-        on_progress(Probed { ip, speed_mbps: speed, done, total });
+        // Kept only if it succeeded and meets the optional min-speed floor.
+        let kept = match outcome {
+            Ok(mbps) if min_speed <= 0.0 || mbps >= min_speed => {
+                results.push(SpeedResult { ip, latency, speed_mbps: mbps });
+                Some(mbps)
+            }
+            _ => None,
+        };
+        on_progress(Probed { ip, speed_mbps: kept, done, total });
     }
 
     results.sort_by(|a, b| {