// NewDHT creates a new DHT object with the given peer as the 'local' host
func NewDHT(p *peer.Peer, net swarm.Network, dstore ds.Datastore) *IpfsDHT {
dht := new(IpfsDHT)
dht.network = net
dht.netChan = net.GetChannel(swarm.PBWrapper_DHT_MESSAGE)
dht.datastore = dstore
dht.self = p
dht.providers = NewProviderManager(p.ID)
dht.shutdown = make(chan struct{})
dht.routingTables = make([]*kb.RoutingTable, 3)
dht.routingTables[0] = kb.NewRoutingTable(20, kb.ConvertPeerID(p.ID), time.Millisecond*30)
dht.routingTables[1] = kb.NewRoutingTable(20, kb.ConvertPeerID(p.ID), time.Millisecond*100)
dht.routingTables[2] = kb.NewRoutingTable(20, kb.ConvertPeerID(p.ID), time.Hour)
dht.listener = swarm.NewMessageListener()
dht.birth = time.Now()
return dht
}
func (dht *IpfsDHT) getDiagnostic(timeout time.Duration) ([]*diagInfo, error) {
u.DOut("Begin Diagnostic")
//Send to N closest peers
targets := dht.routingTables[0].NearestPeers(kb.ConvertPeerID(dht.self.ID), 10)
// TODO: Add timeout to this struct so nodes know when to return
pmes := Message{
Type: PBDHTMessage_DIAGNOSTIC,
ID: swarm.GenerateMessageID(),
}
listenChan := dht.listener.Listen(pmes.ID, len(targets), time.Minute*2)
pbmes := pmes.ToProtobuf()
for _, p := range targets {
mes := swarm.NewMessage(p, pbmes)
dht.netChan.Outgoing <- mes
}
var out []*diagInfo
after := time.After(timeout)
for count := len(targets); count > 0; {
select {
case <-after:
u.DOut("Diagnostic request timed out.")
return out, u.ErrTimeout
case resp := <-listenChan:
pmesOut := new(PBDHTMessage)
err := proto.Unmarshal(resp.Data, pmesOut)
if err != nil {
// NOTE: here and elsewhere, need to audit error handling,
// some errors should be continued on from
return out, err
}
dec := json.NewDecoder(bytes.NewBuffer(pmesOut.GetValue()))
for {
di := new(diagInfo)
err := dec.Decode(di)
if err != nil {
break
}
out = append(out, di)
}
}
}
return nil, nil
}
func (dht *IpfsDHT) findPeerMultiple(id peer.ID, timeout time.Duration) (*peer.Peer, error) {
// Check if were already connected to them
p, _ := dht.Find(id)
if p != nil {
return p, nil
}
routeLevel := 0
peers := dht.routingTables[routeLevel].NearestPeers(kb.ConvertPeerID(id), AlphaValue)
if len(peers) == 0 {
return nil, kb.ErrLookupFailure
}
found := make(chan *peer.Peer)
after := time.After(timeout)
for _, p := range peers {
go func(p *peer.Peer) {
pmes, err := dht.findPeerSingle(p, id, timeout, routeLevel)
if err != nil {
u.DErr("getPeer error: %v\n", err)
return
}
plist := pmes.GetPeers()
if len(plist) == 0 {
routeLevel++
}
for _, fp := range plist {
nxtp, err := dht.peerFromInfo(fp)
if err != nil {
u.DErr("findPeer error: %v\n", err)
continue
}
if nxtp.ID.Equal(dht.self.ID) {
found <- nxtp
return
}
}
}(p)
}
select {
case p := <-found:
return p, nil
case <-after:
return nil, u.ErrTimeout
}
}
// NOTE: not yet finished, low priority
func (dht *IpfsDHT) handleDiagnostic(p *peer.Peer, pmes *PBDHTMessage) {
seq := dht.routingTables[0].NearestPeers(kb.ConvertPeerID(dht.self.ID), 10)
listenChan := dht.listener.Listen(pmes.GetId(), len(seq), time.Second*30)
for _, ps := range seq {
mes := swarm.NewMessage(ps, pmes)
dht.netChan.Outgoing <- mes
}
buf := new(bytes.Buffer)
di := dht.getDiagInfo()
buf.Write(di.Marshal())
// NOTE: this shouldnt be a hardcoded value
after := time.After(time.Second * 20)
count := len(seq)
for count > 0 {
select {
case <-after:
//Timeout, return what we have
goto out
case reqResp := <-listenChan:
pmesOut := new(PBDHTMessage)
err := proto.Unmarshal(reqResp.Data, pmesOut)
if err != nil {
// It broke? eh, whatever, keep going
continue
}
buf.Write(reqResp.Data)
count--
}
}
out:
resp := Message{
Type: PBDHTMessage_DIAGNOSTIC,
ID: pmes.GetId(),
Value: buf.Bytes(),
Response: true,
}
mes := swarm.NewMessage(p, resp.ToProtobuf())
dht.netChan.Outgoing <- mes
}
// FindPeer searches for a peer with given ID.
func (dht *IpfsDHT) FindPeer(id peer.ID, timeout time.Duration) (*peer.Peer, error) {
// Check if were already connected to them
p, _ := dht.Find(id)
if p != nil {
return p, nil
}
routeLevel := 0
p = dht.routingTables[routeLevel].NearestPeer(kb.ConvertPeerID(id))
if p == nil {
return nil, kb.ErrLookupFailure
}
if p.ID.Equal(id) {
return p, nil
}
for routeLevel < len(dht.routingTables) {
pmes, err := dht.findPeerSingle(p, id, timeout, routeLevel)
plist := pmes.GetPeers()
if plist == nil || len(plist) == 0 {
routeLevel++
continue
}
found := plist[0]
addr, err := ma.NewMultiaddr(found.GetAddr())
if err != nil {
return nil, err
}
nxtPeer, err := dht.network.GetConnection(peer.ID(found.GetId()), addr)
if err != nil {
return nil, err
}
if pmes.GetSuccess() {
if !id.Equal(nxtPeer.ID) {
return nil, errors.New("got back invalid peer from 'successful' response")
}
return nxtPeer, nil
}
p = nxtPeer
}
return nil, u.ErrNotFound
}