feat: optimization

internal/dedup/filter.go

@@ -0,0 +1,36 @@
+package dedup
+
+import (
+	"fmt"
+	"sync"
+)
+
+type Filter struct {
+	seen map[string]struct{}
+	mu   sync.RWMutex
+}
+
+func New() *Filter {
+	return &Filter{
+		seen: make(map[string]struct{}),
+	}
+}
+
+// Check returns true if the item is NEW (not seen before)
+func (f *Filter) Seen(address string, port int) bool {
+	key := fmt.Sprintf("%s:%d", address, port)
+	
+	f.mu.RLock()
+	_, exists := f.seen[key]
+	f.mu.RUnlock()
+
+	if exists {
+		return true
+	}
+
+	f.mu.Lock()
+	f.seen[key] = struct{}{}
+	f.mu.Unlock()
+	
+	return false
+}