Fix: some UDP issues (#265)

component/nat/table.go

@@ -0,0 +1,46 @@
+package nat
+
+import (
+	"net"
+	"sync"
+)
+
+type Table struct {
+	mapping sync.Map
+}
+
+type element struct {
+	RemoteAddr net.Addr
+	RemoteConn net.PacketConn
+}
+
+func (t *Table) Set(key string, pc net.PacketConn, addr net.Addr) {
+	// set conn read timeout
+	t.mapping.Store(key, &element{
+		RemoteConn: pc,
+		RemoteAddr: addr,
+	})
+}
+
+func (t *Table) Get(key string) (net.PacketConn, net.Addr) {
+	item, exist := t.mapping.Load(key)
+	if !exist {
+		return nil, nil
+	}
+	elm := item.(*element)
+	return elm.RemoteConn, elm.RemoteAddr
+}
+
+func (t *Table) GetOrCreateLock(key string) (*sync.WaitGroup, bool) {
+	item, loaded := t.mapping.LoadOrStore(key, &sync.WaitGroup{})
+	return item.(*sync.WaitGroup), loaded
+}
+
+func (t *Table) Delete(key string) {
+	t.mapping.Delete(key)
+}
+
+// New return *Cache
+func New() *Table {
+	return &Table{}
+}