Initial Art-Net protocol library

poller.go

@@ -0,0 +1,104 @@
+package artnet
+
+import (
+	"net"
+	"time"
+)
+
+type Poller struct {
+	sender   *Sender
+	targets  []*net.UDPAddr
+	interval time.Duration
+	done     chan struct{}
+}
+
+func NewPoller(sender *Sender, targets []*net.UDPAddr, interval time.Duration) *Poller {
+	return &Poller{
+		sender:   sender,
+		targets:  targets,
+		interval: interval,
+		done:     make(chan struct{}),
+	}
+}
+
+func NewBroadcastPoller(sender *Sender, interval time.Duration) *Poller {
+	return &Poller{
+		sender:   sender,
+		targets:  []*net.UDPAddr{{IP: net.IPv4bcast, Port: Port}},
+		interval: interval,
+		done:     make(chan struct{}),
+	}
+}
+
+func (p *Poller) Start() {
+	go p.loop()
+}
+
+func (p *Poller) Stop() {
+	close(p.done)
+}
+
+func (p *Poller) Poll() {
+	for _, target := range p.targets {
+		p.sender.SendPoll(target)
+	}
+}
+
+func (p *Poller) loop() {
+	p.Poll()
+
+	ticker := time.NewTicker(p.interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-p.done:
+			return
+		case <-ticker.C:
+			p.Poll()
+		}
+	}
+}
+
+func (p *Poller) SetTargets(targets []*net.UDPAddr) {
+	p.targets = targets
+}
+
+func (p *Poller) AddTarget(target *net.UDPAddr) {
+	p.targets = append(p.targets, target)
+}
+
+func BroadcastAddr() *net.UDPAddr {
+	return &net.UDPAddr{IP: net.IPv4bcast, Port: Port}
+}
+
+func UnicastAddr(ip net.IP) *net.UDPAddr {
+	return &net.UDPAddr{IP: ip, Port: Port}
+}
+
+func InterfaceBroadcast(iface net.Interface) *net.UDPAddr {
+	addrs, err := iface.Addrs()
+	if err != nil {
+		return BroadcastAddr()
+	}
+
+	for _, addr := range addrs {
+		ipnet, ok := addr.(*net.IPNet)
+		if !ok {
+			continue
+		}
+
+		ip4 := ipnet.IP.To4()
+		if ip4 == nil {
+			continue
+		}
+
+		bcast := make(net.IP, 4)
+		for i := 0; i < 4; i++ {
+			bcast[i] = ip4[i] | ^ipnet.Mask[i]
+		}
+		return &net.UDPAddr{IP: bcast, Port: Port}
+	}
+
+	return BroadcastAddr()
+}