Optimize latency checks for significantly faster performance

- Reduced ping interval from 1s to 200ms (5x faster per relay)
- Reduced ping count from 5 to 3 (still reliable, but faster)
- Increased latency workers from 30 to 100 (3.3x more parallelism)
- Increased liveness workers from 20 to 50 (2.5x more parallelism)
- Reduced timeouts: liveness from 3s to 1s, latency from 10s to 3s
- Expected speedup: ~10x faster overall execution time

cmd/mullvadclosest/main.go

@@ -91,8 +91,8 @@ func CollectRelayLatencies(relays []Relay) []RelayLatency {
 	livenessResults := make(chan RelayLatency, len(relays))
 	bar := progressbar.Default(int64(len(relays)), "Checking liveness")
 
-	// Start 20 workers for liveness checks
-	numLivenessWorkers := 20
+	// Start 50 workers for liveness checks (increased from 20)
+	numLivenessWorkers := 50
 	for w := 0; w < numLivenessWorkers; w++ {
 		wg.Add(1)
 		go livenessWorker(w, livenessJobs, livenessResults, &wg, bar)
@@ -123,8 +123,8 @@ func CollectRelayLatencies(relays []Relay) []RelayLatency {
 	latencyResults := make(chan RelayLatency, len(liveRelays))
 	bar = progressbar.Default(int64(len(liveRelays)), "Measuring latency")
 
-	// Start 30 workers for latency checks
-	numLatencyWorkers := 30
+	// Start 100 workers for latency checks (increased from 30)
+	numLatencyWorkers := 100
 	for w := 0; w < numLatencyWorkers; w++ {
 		wg.Add(1)
 		go latencyWorker(w, latencyJobs, latencyResults, &wg, bar)

cmd/mullvadclosest/relays.go

@@ -43,7 +43,7 @@ func (r Relay) CheckLiveness() (bool, time.Duration, error) {
 		return false, 0, err
 	}
 	pinger.Count = 1
-	pinger.Timeout = 3 * time.Second // Increased timeout for the single ping
+	pinger.Timeout = 1 * time.Second // Reduced from 3 seconds for faster checks
 	pinger.SetPrivileged(true)
 	if err := pinger.Run(); err != nil {
 		return false, 0, err
@@ -63,15 +63,15 @@ func (r Relay) CheckLiveness() (bool, time.Duration, error) {
 	return true, stats.AvgRtt, nil
 }
 
-// MeasureLatency measures the minimum latency of the relay over 5 pings
+// MeasureLatency measures the minimum latency of the relay over 3 pings
 func (r Relay) MeasureLatency() (time.Duration, error) {
 	pinger, err := ping.NewPinger(r.Ipv4AddrIn)
 	if err != nil {
 		return 0, err
 	}
-	pinger.Count = 5
-	pinger.Interval = 1 * time.Second // Adding interval between pings
-	pinger.Timeout = 10 * time.Second // Increased overall timeout
+	pinger.Count = 3                         // Reduced from 5 to 3 for faster measurements
+	pinger.Interval = 200 * time.Millisecond // Reduced from 1 second to 200ms
+	pinger.Timeout = 3 * time.Second         // Adjusted timeout for 3 pings
 	pinger.SetPrivileged(true)
 	if err := pinger.Run(); err != nil {
 		return 0, err