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
}
}
// TODO: Im not certain on this implementation, we get a list of peers/providers
// from someone what do we do with it? Connect to each of them? randomly pick
// one to get the value from? Or just connect to one at a time until we get a
// successful connection and request the value from it?
func (dht *IpfsDHT) getFromPeerList(key u.Key, timeout time.Duration,
peerlist []*PBDHTMessage_PBPeer, level int) ([]byte, error) {
for _, pinfo := range peerlist {
p, _ := dht.Find(peer.ID(pinfo.GetId()))
if p == nil {
maddr, err := ma.NewMultiaddr(pinfo.GetAddr())
if err != nil {
u.PErr("getValue error: %s\n", err)
continue
}
p, err = dht.network.GetConnection(peer.ID(pinfo.GetId()), maddr)
if err != nil {
u.PErr("getValue error: %s\n", err)
continue
}
}
pmes, err := dht.getValueSingle(p, key, timeout, level)
if err != nil {
u.DErr("getFromPeers error: %s\n", err)
continue
}
dht.providers.AddProvider(key, p)
// Make sure it was a successful get
if pmes.GetSuccess() && pmes.Value != nil {
return pmes.GetValue(), nil
}
}
return nil, u.ErrNotFound
}
// GetValue searches for the value corresponding to given Key.
// If the search does not succeed, a multiaddr string of a closer peer is
// returned along with util.ErrSearchIncomplete
func (dht *IpfsDHT) GetValue(key u.Key, timeout time.Duration) ([]byte, error) {
ll := startNewRPC("GET")
defer func() {
ll.EndLog()
ll.Print()
}()
// If we have it local, dont bother doing an RPC!
// NOTE: this might not be what we want to do...
val, err := dht.getLocal(key)
if err == nil {
ll.Success = true
u.DOut("Found local, returning.\n")
return val, nil
}
routeLevel := 0
closest := dht.routingTables[routeLevel].NearestPeers(kb.ConvertKey(key), PoolSize)
if closest == nil || len(closest) == 0 {
return nil, kb.ErrLookupFailure
}
valChan := make(chan []byte)
npeerChan := make(chan *peer.Peer, 30)
procPeer := make(chan *peer.Peer, 30)
errChan := make(chan error)
after := time.After(timeout)
pset := newPeerSet()
for _, p := range closest {
pset.Add(p)
npeerChan <- p
}
c := counter{}
count := 0
go func() {
defer close(procPeer)
for {
select {
case p, ok := <-npeerChan:
if !ok {
return
}
count++
if count >= KValue {
errChan <- u.ErrNotFound
return
}
c.Increment()
procPeer <- p
default:
if c.Size() <= 0 {
select {
case errChan <- u.ErrNotFound:
default:
}
return
}
}
}
}()
process := func() {
defer c.Decrement()
for p := range procPeer {
if p == nil {
return
}
val, peers, err := dht.getValueOrPeers(p, key, timeout/4, routeLevel)
if err != nil {
u.DErr("%v\n", err.Error())
continue
}
if val != nil {
select {
case valChan <- val:
default:
u.DOut("Wasnt the first to return the value!")
}
return
}
for _, np := range peers {
// TODO: filter out peers that arent closer
if !pset.Contains(np) && pset.Size() < KValue {
pset.Add(np) //This is racey... make a single function to do operation
npeerChan <- np
}
}
c.Decrement()
}
}
for i := 0; i < AlphaValue; i++ {
go process()
}
select {
case val := <-valChan:
return val, nil
case err := <-errChan:
return nil, err
case <-after:
return nil, u.ErrTimeout
}
}
