Golang Channel.WritePacket Examples

Example #1

File: chord.go Project: utamaro/gogotelehash

func (t *transport) handlePing(ch *e3x.Channel) {
	var (
		err   error
		pkt   *lob.Packet
		id    string
		alive bool
	)

	defer ch.Close()

	pkt, err = ch.ReadPacket()
	if err != nil {
		// log error
		// tracef("error: %s", err)
		return
	}

	id, _ = pkt.Header().GetString("vn")
	rpc := t.lookupRPC(id)
	if rpc == nil {
		alive = false
	} else {
		alive = true
	}

	pkt = &lob.Packet{}
	pkt.Header().SetBool("alive", alive)
	err = ch.WritePacket(pkt)
	if err != nil {
		// log error
		// tracef("error: %s", err)
		return
	}
}

Example #2

File: chord.go Project: utamaro/gogotelehash

// Gets a list of the vnodes on the box
func (t *transport) ListVnodes(hn string) ([]*chord.Vnode, error) {
	var (
		addr *e3x.Addr
		ch   *e3x.Channel
		res  []*completeVnode
		err  error
	)

	addr = t.lookupAddr(hashname.H(hn))
	if addr == nil {
		return nil, e3x.ErrNoAddress
	}

	ch, err = t.e.Open(addr, "chord.list", true)
	if err != nil {
		return nil, err
	}

	defer ch.Close()

	// ch.SetReadDeadline(time.Now().Add(30*time.Second))
	// ch.SetWriteDeadline(time.Now().Add(30*time.Second))

	err = ch.WritePacket(&lob.Packet{})
	if err != nil {
		return nil, err
	}

	err = json.NewDecoder(newStream(ch)).Decode(&res)
	if err != nil {
		return nil, err
	}

	return t.internalVnodes(res), nil
}

Example #3

File: chord.go Project: utamaro/gogotelehash

// Request a nodes predecessor
func (t *transport) GetPredecessor(vn *chord.Vnode) (*chord.Vnode, error) {
	var (
		addr *e3x.Addr
		ch   *e3x.Channel
		pkt  *lob.Packet
		res  *completeVnode
		err  error
	)

	addr = t.lookupAddr(hashname.H(vn.Host))
	if addr == nil {
		return nil, e3x.ErrNoAddress
	}

	ch, err = t.e.Open(addr, "chord.predecessor.get", true)
	if err != nil {
		return nil, err
	}

	defer ch.Close()

	// ch.SetReadDeadline(time.Now().Add(30*time.Second))
	// ch.SetWriteDeadline(time.Now().Add(30*time.Second))

	pkt = &lob.Packet{}
	pkt.Header().SetString("vn", vn.String())
	err = ch.WritePacket(pkt)
	if err != nil {
		return nil, err
	}

	err = json.NewDecoder(newStream(ch)).Decode(&res)
	if err != nil {
		return nil, err
	}

	if res != nil {
		// tracef("GetPredecessor(Vnode(%q)) => Vnode(%q)", vn.String(), res.Id)
	}
	return t.internalVnode(res), nil
}

Example #4

File: chord.go Project: utamaro/gogotelehash

// Ping a Vnode, check for liveness
func (t *transport) Ping(vn *chord.Vnode) (bool, error) {
	var (
		addr  *e3x.Addr
		ch    *e3x.Channel
		pkt   *lob.Packet
		alive bool
		err   error
	)

	addr = t.lookupAddr(hashname.H(vn.Host))
	if addr == nil {
		return false, e3x.ErrNoAddress
	}

	ch, err = t.e.Open(addr, "chord.ping", true)
	if err != nil {
		return false, err
	}

	defer ch.Close()

	// ch.SetReadDeadline(time.Now().Add(30*time.Second))
	// ch.SetWriteDeadline(time.Now().Add(30*time.Second))

	pkt = &lob.Packet{}
	pkt.Header().SetString("vn", vn.String())
	err = ch.WritePacket(pkt)
	if err != nil {
		return false, err
	}

	pkt, err = ch.ReadPacket()
	if err != nil {
		return false, err
	}
	alive, _ = pkt.Header().GetBool("alive")
	// tracef("Ping(Vnode(%q)) => %v", vn.String(), alive)
	return alive, nil
}

Example #5

File: kademlia.go Project: utamaro/gogotelehash

func (d *dht) handle_see(c *e3x.Channel) {
	defer c.Close()

	pkt, err := c.ReadPacket()
	if err != nil {
		return
	}

	key, ok := pkt.Header().GetString("key")
	if !ok {
		return
	}

	h := d.localLookup(key)

	pkt = &lob.Packet{}
	pkt.Header().Set("see", h)
	pkt.Header().SetBool("end", true)
	err = c.WritePacket(pkt)
	if err != nil {
		return
	}
}