func (dht *IpfsDHT) handleFindPeer(p peer.Peer, pmes *pb.Message) (*pb.Message, error) {
resp := pb.NewMessage(pmes.GetType(), "", pmes.GetClusterLevel())
var closest []peer.Peer
// if looking for self... special case where we send it on CloserPeers.
if peer.ID(pmes.GetKey()).Equal(dht.self.ID()) {
closest = []peer.Peer{dht.self}
} else {
closest = dht.betterPeersToQuery(pmes, CloserPeerCount)
}
if closest == nil {
log.Errorf("handleFindPeer: could not find anything.")
return resp, nil
}
var withAddresses []peer.Peer
for _, p := range closest {
if len(p.Addresses()) > 0 {
withAddresses = append(withAddresses, p)
}
}
for _, p := range withAddresses {
log.Debugf("handleFindPeer: sending back '%s'", p)
}
resp.CloserPeers = pb.PeersToPBPeers(withAddresses)
return resp, nil
}
func (dht *IpfsDHT) handleGetProviders(p peer.Peer, pmes *pb.Message) (*pb.Message, error) {
resp := pb.NewMessage(pmes.GetType(), pmes.GetKey(), pmes.GetClusterLevel())
// check if we have this value, to add ourselves as provider.
log.Debugf("handling GetProviders: '%s'", u.Key(pmes.GetKey()))
dsk := u.Key(pmes.GetKey()).DsKey()
has, err := dht.datastore.Has(dsk)
if err != nil && err != ds.ErrNotFound {
log.Errorf("unexpected datastore error: %v\n", err)
has = false
}
// setup providers
providers := dht.providers.GetProviders(u.Key(pmes.GetKey()))
if has {
providers = append(providers, dht.self)
}
// if we've got providers, send thos those.
if providers != nil && len(providers) > 0 {
resp.ProviderPeers = pb.PeersToPBPeers(providers)
}
// Also send closer peers.
closer := dht.betterPeersToQuery(pmes, CloserPeerCount)
if closer != nil {
resp.CloserPeers = pb.PeersToPBPeers(closer)
}
return resp, nil
}
// nearestPeersToQuery returns the routing tables closest peers.
func (dht *IpfsDHT) nearestPeersToQuery(pmes *pb.Message, count int) []peer.Peer {
level := pmes.GetClusterLevel()
cluster := dht.routingTables[level]
key := u.Key(pmes.GetKey())
closer := cluster.NearestPeers(kb.ConvertKey(key), count)
return closer
}
func (dht *IpfsDHT) handleGetValue(p peer.Peer, pmes *pb.Message) (*pb.Message, error) {
log.Debugf("%s handleGetValue for key: %s\n", dht.self, pmes.GetKey())
// setup response
resp := pb.NewMessage(pmes.GetType(), pmes.GetKey(), pmes.GetClusterLevel())
// first, is the key even a key?
key := pmes.GetKey()
if key == "" {
return nil, errors.New("handleGetValue but no key was provided")
}
// let's first check if we have the value locally.
log.Debugf("%s handleGetValue looking into ds", dht.self)
dskey := u.Key(pmes.GetKey()).DsKey()
iVal, err := dht.datastore.Get(dskey)
log.Debugf("%s handleGetValue looking into ds GOT %v", dht.self, iVal)
// if we got an unexpected error, bail.
if err != nil && err != ds.ErrNotFound {
return nil, err
}
// Note: changed the behavior here to return _as much_ info as possible
// (potentially all of {value, closer peers, provider})
// if we have the value, send it back
if err == nil {
log.Debugf("%s handleGetValue success!", dht.self)
byts, ok := iVal.([]byte)
if !ok {
return nil, fmt.Errorf("datastore had non byte-slice value for %v", dskey)
}
rec := new(pb.Record)
err := proto.Unmarshal(byts, rec)
if err != nil {
log.Error("Failed to unmarshal dht record from datastore")
return nil, err
}
resp.Record = rec
}
// if we know any providers for the requested value, return those.
provs := dht.providers.GetProviders(u.Key(pmes.GetKey()))
if len(provs) > 0 {
log.Debugf("handleGetValue returning %d provider[s]", len(provs))
resp.ProviderPeers = pb.PeersToPBPeers(provs)
}
// Find closest peer on given cluster to desired key and reply with that info
closer := dht.betterPeersToQuery(pmes, CloserPeerCount)
if closer != nil {
for _, p := range closer {
log.Debugf("handleGetValue returning closer peer: '%s'", p)
if len(p.Addresses()) < 1 {
log.Critical("no addresses on peer being sent!")
}
}
resp.CloserPeers = pb.PeersToPBPeers(closer)
}
return resp, nil
}
