package nat import ( "net" "sync" ) type Table struct { mapping sync.Map } func (t *Table) Set(key string, pc net.PacketConn) { t.mapping.Store(key, pc) } func (t *Table) Get(key string) net.PacketConn { item, exist := t.mapping.Load(key) if !exist { return nil } return item.(net.PacketConn) } 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{} }