package swarm import ( "time" manet "github.com/multiformats/go-multiaddr/net" ma "github.com/multiformats/go-multiaddr" ) // ListenAddresses returns a list of addresses at which this swarm listens. func (s *Swarm) ListenAddresses() []ma.Multiaddr { s.listeners.RLock() defer s.listeners.RUnlock() return s.listenAddressesNoLock() } func (s *Swarm) listenAddressesNoLock() []ma.Multiaddr { addrs := make([]ma.Multiaddr, 0, len(s.listeners.m)+10) // A bit extra so we may avoid an extra allocation in the for loop below. for l := range s.listeners.m { addrs = append(addrs, l.Multiaddr()) } return addrs } const ifaceAddrsCacheDuration = 1 * time.Minute // InterfaceListenAddresses returns a list of addresses at which this swarm // listens. It expands "any interface" addresses (/ip4/0.0.0.0, /ip6/::) to // use the known local interfaces. func (s *Swarm) InterfaceListenAddresses() ([]ma.Multiaddr, error) { s.listeners.RLock() // RLock start ifaceListenAddres := s.listeners.ifaceListenAddres isEOL := time.Now().After(s.listeners.cacheEOL) s.listeners.RUnlock() // RLock end if !isEOL { // Cache is valid, clone the slice return append(ifaceListenAddres[:0:0], ifaceListenAddres...), nil } // Cache is not valid // Perfrom double checked locking s.listeners.Lock() // Lock start ifaceListenAddres = s.listeners.ifaceListenAddres isEOL = time.Now().After(s.listeners.cacheEOL) if isEOL { // Cache is still invalid listenAddres := s.listenAddressesNoLock() if len(listenAddres) > 0 { // We're actually listening on addresses. var err error ifaceListenAddres, err = manet.ResolveUnspecifiedAddresses(listenAddres, nil) if err != nil { s.listeners.Unlock() // Lock early exit return nil, err } } else { ifaceListenAddres = nil } s.listeners.ifaceListenAddres = ifaceListenAddres s.listeners.cacheEOL = time.Now().Add(ifaceAddrsCacheDuration) } s.listeners.Unlock() // Lock end return append(ifaceListenAddres[:0:0], ifaceListenAddres...), nil }