path: root/whisper/peer.go

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()
    self.peer.Infoln("whisper started")
}

func (self *peer) stop() {
    self.peer.Infoln("whisper stopped")

    close(self.quit)
}

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++
        }
    }

    if i > 0 {
        msg := p2p.NewMsg(envelopesMsg, envs[:i]...)
        if err := self.ws.WriteMsg(msg); err != nil {
            return err
        }
        self.peer.Infoln("broadcasted", i, "message(s)")
    }

    return nil
}

func (self *peer) addKnown(envelope *Envelope) {
    self.known.Add(envelope.Hash())
}

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)
}