all: remove LenIter, use Go 1.22 range-over-int instead

Updates tailscale#11058
Updates golang/go#65685

Change-Id: Ibb216b346e511d486271ab3d84e4546c521e4e22
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/tsconnect/wasm/wasm_js.go

@@ -264,7 +264,7 @@ func (i *jsIPN) run(jsCallbacks js.Value) {
 						name = p.Hostinfo().Hostname()
 					}
 					addrs := make([]string, p.Addresses().Len())
-					for i := range p.Addresses().LenIter() {
+					for i := range p.Addresses().Len() {
 						addrs[i] = p.Addresses().At(i).Addr().String()
 					}
 					return jsNetMapPeerNode{
@@ -582,7 +582,7 @@ func mapSlice[T any, M any](a []T, f func(T) M) []M {
 
 func mapSliceView[T any, M any](a views.Slice[T], f func(T) M) []M {
 	n := make([]M, a.Len())
-	for i := range a.LenIter() {
+	for i := range a.Len() {
 		n[i] = f(a.At(i))
 	}
 	return n

control/controlclient/map.go

@@ -728,7 +728,7 @@ func peerChangeDiff(was tailcfg.NodeView, n *tailcfg.Node) (_ *tailcfg.PeerChang
 				return nil, false
 			}
 
-			for i := range va.LenIter() {
+			for i := range va.Len() {
 				if !va.At(i).Equal(vb.At(i)) {
 					return nil, false
 				}

ipn/ipnlocal/local.go

@@ -792,7 +792,7 @@ func (b *LocalBackend) UpdateStatus(sb *ipnstate.StatusBuilder) {
 	var tailscaleIPs []netip.Addr
 	if b.netMap != nil {
 		addrs := b.netMap.GetAddresses()
-		for i := range addrs.LenIter() {
+		for i := range addrs.Len() {
 			if addr := addrs.At(i); addr.IsSingleIP() {
 				sb.AddTailscaleIP(addr.Addr())
 				tailscaleIPs = append(tailscaleIPs, addr.Addr())
@@ -856,7 +856,7 @@ func (b *LocalBackend) populatePeerStatusLocked(sb *ipnstate.StatusBuilder) {
 			lastSeen = *p.LastSeen()
 		}
 		tailscaleIPs := make([]netip.Addr, 0, p.Addresses().Len())
-		for i := range p.Addresses().LenIter() {
+		for i := range p.Addresses().Len() {
 			addr := p.Addresses().At(i)
 			if addr.IsSingleIP() && tsaddr.IsTailscaleIP(addr.Addr()) {
 				tailscaleIPs = append(tailscaleIPs, addr.Addr())
@@ -977,7 +977,7 @@ func (b *LocalBackend) peerCapsLocked(src netip.Addr) tailcfg.PeerCapMap {
 		return nil
 	}
 	addrs := b.netMap.GetAddresses()
-	for i := range addrs.LenIter() {
+	for i := range addrs.Len() {
 		a := addrs.At(i)
 		if !a.IsSingleIP() {
 			continue
@@ -1433,7 +1433,7 @@ func setExitNodeID(prefs *ipn.Prefs, nm *netmap.NetworkMap) (prefsChanged bool)
 	}
 
 	for _, peer := range nm.Peers {
-		for i := range peer.Addresses().LenIter() {
+		for i := range peer.Addresses().Len() {
 			addr := peer.Addresses().At(i)
 			if !addr.IsSingleIP() || addr.Addr() != prefs.ExitNodeIP {
 				continue
@@ -1877,7 +1877,7 @@ func (b *LocalBackend) updateFilterLocked(netMap *netmap.NetworkMap, prefs ipn.P
 	logNetsB.RemovePrefix(tsaddr.ChromeOSVMRange())
 	if haveNetmap {
 		addrs = netMap.GetAddresses()
-		for i := range addrs.LenIter() {
+		for i := range addrs.Len() {
 			localNetsB.AddPrefix(addrs.At(i))
 		}
 		packetFilter = netMap.PacketFilter
@@ -1987,7 +1987,7 @@ func packetFilterPermitsUnlockedNodes(peers map[tailcfg.NodeID]tailcfg.NodeView,
 			continue
 		}
 		numUnlocked++
-		for i := range p.AllowedIPs().LenIter() { // not only addresses!
+		for i := range p.AllowedIPs().Len() { // not only addresses!
 			b.AddPrefix(p.AllowedIPs().At(i))
 		}
 	}
@@ -3640,14 +3640,14 @@ func dnsConfigForNetmap(nm *netmap.NetworkMap, peers map[tailcfg.NodeID]tailcfg.
 			return // TODO: propagate error?
 		}
 		var have4 bool
-		for i := range addrs.LenIter() {
+		for i := range addrs.Len() {
 			if addrs.At(i).Addr().Is4() {
 				have4 = true
 				break
 			}
 		}
 		var ips []netip.Addr
-		for i := range addrs.LenIter() {
+		for i := range addrs.Len() {
 			addr := addrs.At(i)
 			if selfV6Only {
 				if addr.Addr().Is6() {
@@ -3936,7 +3936,7 @@ func (b *LocalBackend) initPeerAPIListener() {
 	b.peerAPIServer = ps
 
 	isNetstack := b.sys.IsNetstack()
-	for i := range addrs.LenIter() {
+	for i := range addrs.Len() {
 		a := addrs.At(i)
 		var ln net.Listener
 		var err error
@@ -4250,7 +4250,7 @@ func (b *LocalBackend) enterStateLockedOnEntry(newState ipn.State) {
 	case ipn.Running:
 		var addrStrs []string
 		addrs := netMap.GetAddresses()
-		for i := range addrs.LenIter() {
+		for i := range addrs.Len() {
 			addrStrs = append(addrStrs, addrs.At(i).Addr().String())
 		}
 		systemd.Status("Connected; %s; %s", activeLogin, strings.Join(addrStrs, " "))
@@ -4626,7 +4626,7 @@ func (b *LocalBackend) setNetMapLocked(nm *netmap.NetworkMap) {
 		b.nodeByAddr[k] = 0
 	}
 	addNode := func(n tailcfg.NodeView) {
-		for i := range n.Addresses().LenIter() {
+		for i := range n.Addresses().Len() {
 			if ipp := n.Addresses().At(i); ipp.IsSingleIP() {
 				b.nodeByAddr[ipp.Addr()] = n.ID()
 			}
@@ -5062,7 +5062,7 @@ func (b *LocalBackend) SetDNS(ctx context.Context, name, value string) error {
 
 func peerAPIPorts(peer tailcfg.NodeView) (p4, p6 uint16) {
 	svcs := peer.Hostinfo().Services()
-	for i := range svcs.LenIter() {
+	for i := range svcs.Len() {
 		s := svcs.At(i)
 		switch s.Proto {
 		case tailcfg.PeerAPI4:
@@ -5095,7 +5095,7 @@ func peerAPIBase(nm *netmap.NetworkMap, peer tailcfg.NodeView) string {
 
 	var have4, have6 bool
 	addrs := nm.GetAddresses()
-	for i := range addrs.LenIter() {
+	for i := range addrs.Len() {
 		a := addrs.At(i)
 		if !a.IsSingleIP() {
 			continue
@@ -5118,7 +5118,7 @@ func peerAPIBase(nm *netmap.NetworkMap, peer tailcfg.NodeView) string {
 }
 
 func nodeIP(n tailcfg.NodeView, pred func(netip.Addr) bool) netip.Addr {
-	for i := range n.Addresses().LenIter() {
+	for i := range n.Addresses().Len() {
 		a := n.Addresses().At(i)
 		if a.IsSingleIP() && pred(a.Addr()) {
 			return a.Addr()
@@ -5296,7 +5296,7 @@ func wireguardExitNodeDNSResolvers(nm *netmap.NetworkMap, peers map[tailcfg.Node
 				resolvers := p.ExitNodeDNSResolvers()
 				if !resolvers.IsNil() && resolvers.Len() > 0 {
 					copies := make([]*dnstype.Resolver, resolvers.Len())
-					for i := range resolvers.LenIter() {
+					for i := range resolvers.Len() {
 						copies[i] = resolvers.At(i).AsStruct()
 					}
 					return copies, true
@@ -5319,7 +5319,7 @@ func peerCanProxyDNS(p tailcfg.NodeView) bool {
 	// If p.Cap is not populated (e.g. older control server), then do the old
 	// thing of searching through services.
 	services := p.Hostinfo().Services()
-	for i := range services.LenIter() {
+	for i := range services.Len() {
 		if s := services.At(i); s.Proto == tailcfg.PeerAPIDNS && s.Port >= 1 {
 			return true
 		}
@@ -5495,7 +5495,7 @@ func (b *LocalBackend) handleQuad100Port80Conn(w http.ResponseWriter, r *http.Re
 		return
 	}
 	io.WriteString(w, "<p>Local addresses:</p><ul>\n")
-	for i := range addrs.LenIter() {
+	for i := range addrs.Len() {
 		fmt.Fprintf(w, "<li>%v</li>\n", addrs.At(i).Addr())
 	}
 	io.WriteString(w, "</ul>\n")

ipn/ipnlocal/network-lock.go

@@ -100,7 +100,7 @@ func (b *LocalBackend) tkaFilterNetmapLocked(nm *netmap.NetworkMap) {
 					TailscaleIPs: make([]netip.Addr, p.Addresses().Len()),
 					NodeKey:      p.Key(),
 				}
-				for i := range p.Addresses().LenIter() {
+				for i := range p.Addresses().Len() {
 					addr := p.Addresses().At(i)
 					if addr.IsSingleIP() && tsaddr.IsTailscaleIP(addr.Addr()) {
 						fp.TailscaleIPs[i] = addr.Addr()

ipn/ipnlocal/serve.go

@@ -222,7 +222,7 @@ func (b *LocalBackend) updateServeTCPPortNetMapAddrListenersLocked(ports []uint1
 	}
 
 	addrs := nm.GetAddresses()
-	for i := range addrs.LenIter() {
+	for i := range addrs.Len() {
 		a := addrs.At(i)
 		for _, p := range ports {
 			addrPort := netip.AddrPortFrom(a.Addr(), p)

ipn/ipnlocal/web_client.go

@@ -121,7 +121,7 @@ func (b *LocalBackend) updateWebClientListenersLocked() {
 	}
 
 	addrs := b.netMap.GetAddresses()
-	for i := range addrs.LenIter() {
+	for i := range addrs.Len() {
 		addrPort := netip.AddrPortFrom(addrs.At(i).Addr(), webClientPort)
 		if _, ok := b.webClientListeners[addrPort]; ok {
 			continue // already listening

net/tsaddr/tsaddr.go

@@ -203,7 +203,7 @@ func NewContainsIPFunc(addrs views.Slice[netip.Prefix]) func(ip netip.Addr) bool
 	}
 	// General case:
 	m := map[netip.Addr]bool{}
-	for i := range addrs.LenIter() {
+	for i := range addrs.Len() {
 		m[addrs.At(i).Addr()] = true
 	}
 	return func(ip netip.Addr) bool { return m[ip] }
@@ -229,7 +229,7 @@ func PrefixIs6(p netip.Prefix) bool { return p.Addr().Is6() }
 // IPv6 /0 route.
 func ContainsExitRoutes(rr views.Slice[netip.Prefix]) bool {
 	var v4, v6 bool
-	for i := range rr.LenIter() {
+	for i := range rr.Len() {
 		r := rr.At(i)
 		if r == allIPv4 {
 			v4 = true
@@ -243,7 +243,7 @@ func ContainsExitRoutes(rr views.Slice[netip.Prefix]) bool {
 // ContainsNonExitSubnetRoutes reports whether v contains Subnet
 // Routes other than ExitNode Routes.
 func ContainsNonExitSubnetRoutes(rr views.Slice[netip.Prefix]) bool {
-	for i := range rr.LenIter() {
+	for i := range rr.Len() {
 		if rr.At(i).Bits() != 0 {
 			return true
 		}
@@ -274,7 +274,7 @@ func SortPrefixes(p []netip.Prefix) {
 // in that match f.
 func FilterPrefixesCopy(in views.Slice[netip.Prefix], f func(netip.Prefix) bool) []netip.Prefix {
 	var out []netip.Prefix
-	for i := range in.LenIter() {
+	for i := range in.Len() {
 		if v := in.At(i); f(v) {
 			out = append(out, v)
 		}

net/tsdial/dnsmap.go

@@ -42,7 +42,7 @@ func dnsMapFromNetworkMap(nm *netmap.NetworkMap) dnsMap {
 		if dnsname.HasSuffix(nm.Name, suffix) {
 			ret[canonMapKey(dnsname.TrimSuffix(nm.Name, suffix))] = ip
 		}
-		for i := range addrs.LenIter() {
+		for i := range addrs.Len() {
 			if addrs.At(i).Addr().Is4() {
 				have4 = true
 			}
@@ -52,7 +52,7 @@ func dnsMapFromNetworkMap(nm *netmap.NetworkMap) dnsMap {
 		if p.Name() == "" {
 			continue
 		}
-		for i := range p.Addresses().LenIter() {
+		for i := range p.Addresses().Len() {
 			a := p.Addresses().At(i)
 			ip := a.Addr()
 			if ip.Is4() && !have4 {

tsnet/tsnet.go

@@ -428,7 +428,7 @@ func (s *Server) TailscaleIPs() (ip4, ip6 netip.Addr) {
 		return
 	}
 	addrs := nm.GetAddresses()
-	for i := range addrs.LenIter() {
+	for i := range addrs.Len() {
 		addr := addrs.At(i)
 		ip := addr.Addr()
 		if ip.Is6() {

types/views/views.go

@@ -77,11 +77,6 @@ func (v ByteSlice[T]) AppendTo(dst T) T {
 	return append(dst, v.ж...)
 }
 
-// LenIter returns a slice the same length as the v.Len().
-// The caller can then range over it to get the valid indexes.
-// It does not allocate.
-func (v ByteSlice[T]) LenIter() []struct{} { return make([]struct{}, len(v.ж)) }
-
 // At returns the byte at index `i` of the slice.
 func (v ByteSlice[T]) At(i int) byte { return v.ж[i] }
 
@@ -154,11 +149,6 @@ func (v SliceView[T, V]) IsNil() bool { return v.ж == nil }
 // Len returns the length of the slice.
 func (v SliceView[T, V]) Len() int { return len(v.ж) }
 
-// LenIter returns a slice the same length as the v.Len().
-// The caller can then range over it to get the valid indexes.
-// It does not allocate.
-func (v SliceView[T, V]) LenIter() []struct{} { return make([]struct{}, len(v.ж)) }
-
 // At returns a View of the element at index `i` of the slice.
 func (v SliceView[T, V]) At(i int) V { return v.ж[i].View() }
 
@@ -245,11 +235,6 @@ func (v Slice[T]) IsNil() bool { return v.ж == nil }
 // Len returns the length of the slice.
 func (v Slice[T]) Len() int { return len(v.ж) }
 
-// LenIter returns a slice the same length as the v.Len().
-// The caller can then range over it to get the valid indexes.
-// It does not allocate.
-func (v Slice[T]) LenIter() []struct{} { return make([]struct{}, len(v.ж)) }
-
 // At returns the element at index `i` of the slice.
 func (v Slice[T]) At(i int) T { return v.ж[i] }
 

types/views/views_test.go

@@ -141,27 +141,6 @@ func TestViewUtils(t *testing.T) {
 		qt.Equals, true)
 }
 
-func TestLenIter(t *testing.T) {
-	orig := []string{"foo", "bar"}
-	var got []string
-	v := SliceOf(orig)
-	for i := range v.LenIter() {
-		got = append(got, v.At(i))
-	}
-	if !reflect.DeepEqual(orig, got) {
-		t.Errorf("got %q; want %q", got, orig)
-	}
-	x := 0
-	n := testing.AllocsPerRun(10000, func() {
-		for range v.LenIter() {
-			x++
-		}
-	})
-	if n > 0 {
-		t.Errorf("allocs = %v; want 0", n)
-	}
-}
-
 func TestSliceEqual(t *testing.T) {
 	a := SliceOf([]string{"foo", "bar"})
 	b := SliceOf([]string{"foo", "bar"})

wgengine/magicsock/debughttp.go

@@ -102,7 +102,7 @@ func (c *Conn) ServeHTTPDebug(w http.ResponseWriter, r *http.Request) {
 		sort.Slice(ent, func(i, j int) bool { return ent[i].pub.Less(ent[j].pub) })
 
 		peers := map[key.NodePublic]tailcfg.NodeView{}
-		for i := range c.peers.LenIter() {
+		for i := range c.peers.Len() {
 			p := c.peers.At(i)
 			peers[p.Key()] = p
 		}

wgengine/magicsock/endpoint.go

@@ -1366,15 +1366,15 @@ func (de *endpoint) updateFromNode(n tailcfg.NodeView, heartbeatDisabled bool, p
 }
 
 func (de *endpoint) setEndpointsLocked(eps interface {
-	LenIter() []struct{}
+	Len() int
 	At(i int) netip.AddrPort
 }) {
 	for _, st := range de.endpointState {
 		st.index = indexSentinelDeleted // assume deleted until updated in next loop
 	}
 
 	var newIpps []netip.AddrPort
-	for i := range eps.LenIter() {
+	for i := range eps.Len() {
 		if i > math.MaxInt16 {
 			// Seems unlikely.
 			break

wgengine/magicsock/magicsock.go

@@ -1793,7 +1793,7 @@ func nodesEqual(x, y views.Slice[tailcfg.NodeView]) bool {
 	if x.Len() != y.Len() {
 		return false
 	}
-	for i := range x.LenIter() {
+	for i := range x.Len() {
 		if !x.At(i).Equal(y.At(i)) {
 			return false
 		}
@@ -2056,15 +2056,15 @@ func (c *Conn) logEndpointCreated(n tailcfg.NodeView) {
 			fmt.Fprintf(w, "derp=%v%s ", regionID, code)
 		}
 
-		for i := range n.AllowedIPs().LenIter() {
+		for i := range n.AllowedIPs().Len() {
 			a := n.AllowedIPs().At(i)
 			if a.IsSingleIP() {
 				fmt.Fprintf(w, "aip=%v ", a.Addr())
 			} else {
 				fmt.Fprintf(w, "aip=%v ", a)
 			}
 		}
-		for i := range n.Endpoints().LenIter() {
+		for i := range n.Endpoints().Len() {
 			ep := n.Endpoints().At(i)
 			fmt.Fprintf(w, "ep=%v ", ep)
 		}