Add route update metrics tracking to PrefixHandler

- Add RecordIPv4Update and RecordIPv6Update to metrics package
- Add SetMetricsTracker method to PrefixHandler
- Track IPv4/IPv6 route updates when processing announcements
- Add GetMetricsTracker method to Streamer to expose metrics

internal/metrics/metrics.go

@@ -21,6 +21,10 @@ type Tracker struct {
 	byteCounter    metrics.Counter
 	messageRate    metrics.Meter
 	byteRate       metrics.Meter
+
+	// Route update metrics
+	ipv4UpdateRate metrics.Meter
+	ipv6UpdateRate metrics.Meter
 }
 
 // New creates a new metrics tracker
@@ -33,6 +37,8 @@ func New() *Tracker {
 		byteCounter:    metrics.NewCounter(),
 		messageRate:    metrics.NewMeter(),
 		byteRate:       metrics.NewMeter(),
+		ipv4UpdateRate: metrics.NewMeter(),
+		ipv6UpdateRate: metrics.NewMeter(),
 	}
 }
 
@@ -89,6 +95,24 @@ func (t *Tracker) GetStreamMetrics() StreamMetrics {
 	}
 }
 
+// RecordIPv4Update records an IPv4 route update
+func (t *Tracker) RecordIPv4Update() {
+	t.ipv4UpdateRate.Mark(1)
+}
+
+// RecordIPv6Update records an IPv6 route update
+func (t *Tracker) RecordIPv6Update() {
+	t.ipv6UpdateRate.Mark(1)
+}
+
+// GetRouteMetrics returns current route update metrics
+func (t *Tracker) GetRouteMetrics() RouteMetrics {
+	return RouteMetrics{
+		IPv4UpdatesPerSec: t.ipv4UpdateRate.Rate1(),
+		IPv6UpdatesPerSec: t.ipv6UpdateRate.Rate1(),
+	}
+}
+
 // StreamMetrics contains streaming statistics
 type StreamMetrics struct {
 	TotalMessages  uint64
@@ -98,3 +122,9 @@ type StreamMetrics struct {
 	MessagesPerSec float64
 	BitsPerSec     float64
 }
+
+// RouteMetrics contains route update statistics
+type RouteMetrics struct {
+	IPv4UpdatesPerSec float64
+	IPv6UpdatesPerSec float64
+}