First draft of Whisper messages relaying

whisper/peer.go

@@ -0,0 +1,114 @@
+package whisper
+
+import (
+	"fmt"
+	"io/ioutil"
+	"time"
+
+	"github.com/ethereum/go-ethereum/p2p"
+	"gopkg.in/fatih/set.v0"
+)
+
+const (
+	protocolVersion = 0x02
+)
+
+type peer struct {
+	host *Whisper
+	peer *p2p.Peer
+	ws   p2p.MsgReadWriter
+
+	// XXX Eventually this is going to reach exceptional large space. We need an expiry here
+	known *set.Set
+
+	quit chan struct{}
+}
+
+func NewPeer(host *Whisper, p *p2p.Peer, ws p2p.MsgReadWriter) *peer {
+	return &peer{host, p, ws, set.New(), make(chan struct{})}
+}
+
+func (self *peer) init() error {
+	if err := self.handleStatus(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (self *peer) start() {
+	go self.update()
+}
+
+func (self *peer) update() {
+	relay := time.NewTicker(300 * time.Millisecond)
+out:
+	for {
+		select {
+		case <-relay.C:
+			err := self.broadcast(self.host.envelopes())
+			if err != nil {
+				self.peer.Infoln(err)
+				break out
+			}
+
+		case <-self.quit:
+			break out
+		}
+	}
+}
+
+func (self *peer) broadcast(envelopes []*Envelope) error {
+	envs := make([]interface{}, len(envelopes))
+	i := 0
+	for _, envelope := range envelopes {
+		if !self.known.Has(envelope.Hash()) {
+			envs[i] = envelope
+			self.known.Add(envelope.Hash())
+			i++
+		}
+	}
+
+	msg := p2p.NewMsg(envelopesMsg, envs[:i]...)
+	if err := self.ws.WriteMsg(msg); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (self *peer) handleStatus() error {
+	ws := self.ws
+
+	if err := ws.WriteMsg(self.statusMsg()); err != nil {
+		return err
+	}
+
+	msg, err := ws.ReadMsg()
+	if err != nil {
+		return err
+	}
+
+	if msg.Code != statusMsg {
+		return fmt.Errorf("peer send %x before status msg", msg.Code)
+	}
+
+	data, err := ioutil.ReadAll(msg.Payload)
+	if err != nil {
+		return err
+	}
+
+	if len(data) == 0 {
+		return fmt.Errorf("malformed status. data len = 0")
+	}
+
+	if pv := data[0]; pv != protocolVersion {
+		return fmt.Errorf("protocol version mismatch %d != %d", pv, protocolVersion)
+	}
+
+	return nil
+}
+
+func (self *peer) statusMsg() p2p.Msg {
+	return p2p.NewMsg(statusMsg, protocolVersion)
+}