fix up FindProvidersAsync

routing/dht/dht.go

@@ -368,8 +368,8 @@ func (dht *IpfsDHT) Update(p *peer.Peer) {
 	// after some deadline of inactivity.
 }
 
-// Find looks for a peer with a given ID connected to this dht and returns the peer and the table it was found in.
-func (dht *IpfsDHT) Find(id peer.ID) (*peer.Peer, *kb.RoutingTable) {
+// FindLocal looks for a peer with a given ID connected to this dht and returns the peer and the table it was found in.
+func (dht *IpfsDHT) FindLocal(id peer.ID) (*peer.Peer, *kb.RoutingTable) {
 	for _, table := range dht.routingTables {
 		p := table.Find(id)
 		if p != nil {
@@ -465,7 +465,7 @@ func (dht *IpfsDHT) peerFromInfo(pbp *Message_Peer) (*peer.Peer, error) {
 
 	p, _ := dht.peerstore.Get(id)
 	if p == nil {
-		p, _ = dht.Find(id)
+		p, _ = dht.FindLocal(id)
 		if p != nil {
 			panic("somehow peer not getting into peerstore")
 		}

routing/dht/dht_test.go

@@ -227,13 +227,16 @@ func TestProvides(t *testing.T) {
 	time.Sleep(time.Millisecond * 60)
 
 	ctxT, _ := context.WithTimeout(context.Background(), time.Second)
-	provs, err := dhts[0].FindProviders(ctxT, u.Key("hello"))
-	if err != nil {
-		t.Fatal(err)
-	}
+	provchan := dhts[0].FindProvidersAsync(ctxT, u.Key("hello"), 1)
 
-	if len(provs) != 1 {
-		t.Fatal("Didnt get back providers")
+	after := time.After(time.Second)
+	select {
+	case prov := <-provchan:
+		if prov == nil {
+			t.Fatal("Got back nil provider")
+		}
+	case <-after:
+		t.Fatal("Did not get a provider back.")
 	}
 }
 

routing/dht/routing.go

@@ -3,6 +3,7 @@ package dht
 import (
 	"bytes"
 	"encoding/json"
+	"sync"
 
 	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
 
@@ -117,26 +118,7 @@ func (dht *IpfsDHT) Provide(ctx context.Context, key u.Key) error {
 	return nil
 }
 
-// NB: not actually async. Used to keep the interface consistent while the
-// actual async method, FindProvidersAsync2 is under construction
 func (dht *IpfsDHT) FindProvidersAsync(ctx context.Context, key u.Key, count int) <-chan *peer.Peer {
-	ch := make(chan *peer.Peer)
-	providers, err := dht.FindProviders(ctx, key)
-	if err != nil {
-		close(ch)
-		return ch
-	}
-	go func() {
-		defer close(ch)
-		for _, p := range providers {
-			ch <- p
-		}
-	}()
-	return ch
-}
-
-// FIXME: there's a bug here!
-func (dht *IpfsDHT) FindProvidersAsync2(ctx context.Context, key u.Key, count int) <-chan *peer.Peer {
 	peerOut := make(chan *peer.Peer, count)
 	go func() {
 		ps := newPeerSet()
@@ -151,9 +133,12 @@ func (dht *IpfsDHT) FindProvidersAsync2(ctx context.Context, key u.Key, count in
 			}
 		}
 
+		wg := new(sync.WaitGroup)
 		peers := dht.routingTables[0].NearestPeers(kb.ConvertKey(key), AlphaValue)
 		for _, pp := range peers {
+			wg.Add(1)
 			go func(p *peer.Peer) {
+				defer wg.Done()
 				pmes, err := dht.findProvidersSingle(ctx, p, key, 0)
 				if err != nil {
 					log.Error("%s", err)
@@ -162,7 +147,8 @@ func (dht *IpfsDHT) FindProvidersAsync2(ctx context.Context, key u.Key, count in
 				dht.addPeerListAsync(key, pmes.GetProviderPeers(), ps, count, peerOut)
 			}(pp)
 		}
-
+		wg.Wait()
+		close(peerOut)
 	}()
 	return peerOut
 }
@@ -186,61 +172,16 @@ func (dht *IpfsDHT) addPeerListAsync(k u.Key, peers []*Message_Peer, ps *peerSet
 	}
 }
 
-// FindProviders searches for peers who can provide the value for given key.
-func (dht *IpfsDHT) FindProviders(ctx context.Context, key u.Key) ([]*peer.Peer, error) {
-	// get closest peer
-	log.Debug("Find providers for: '%s'", key)
-	p := dht.routingTables[0].NearestPeer(kb.ConvertKey(key))
-	if p == nil {
-		log.Warning("Got no nearest peer for find providers: '%s'", key)
-		return nil, nil
-	}
-
-	for level := 0; level < len(dht.routingTables); {
-
-		// attempt retrieving providers
-		pmes, err := dht.findProvidersSingle(ctx, p, key, level)
-		if err != nil {
-			return nil, err
-		}
-
-		// handle providers
-		provs := pmes.GetProviderPeers()
-		if provs != nil {
-			log.Debug("Got providers back from findProviders call!")
-			return dht.addProviders(key, provs), nil
-		}
-
-		log.Debug("Didnt get providers, just closer peers.")
-		closer := pmes.GetCloserPeers()
-		if len(closer) == 0 {
-			level++
-			continue
-		}
-
-		np, err := dht.peerFromInfo(closer[0])
-		if err != nil {
-			log.Debug("no peerFromInfo")
-			level++
-			continue
-		}
-		p = np
-	}
-	return nil, u.ErrNotFound
-}
-
 // Find specific Peer
-
 // FindPeer searches for a peer with given ID.
 func (dht *IpfsDHT) FindPeer(ctx context.Context, id peer.ID) (*peer.Peer, error) {
 
 	// Check if were already connected to them
-	p, _ := dht.Find(id)
+	p, _ := dht.FindLocal(id)
 	if p != nil {
 		return p, nil
 	}
 
-	// @whyrusleeping why is this here? doesn't the dht.Find above cover it?
 	routeLevel := 0
 	p = dht.routingTables[routeLevel].NearestPeer(kb.ConvertPeerID(id))
 	if p == nil {
@@ -277,7 +218,7 @@ func (dht *IpfsDHT) FindPeer(ctx context.Context, id peer.ID) (*peer.Peer, error
 func (dht *IpfsDHT) findPeerMultiple(ctx context.Context, id peer.ID) (*peer.Peer, error) {
 
 	// Check if were already connected to them
-	p, _ := dht.Find(id)
+	p, _ := dht.FindLocal(id)
 	if p != nil {
 		return p, nil
 	}

routing/routing.go

@@ -26,11 +26,7 @@ type IpfsRouting interface {
 	// Announce that this node can provide value for given key
 	Provide(context.Context, u.Key) error
 
-	// FindProviders searches for peers who can provide the value for given key.
-	FindProviders(context.Context, u.Key) ([]*peer.Peer, error)
-
 	// Find specific Peer
-
 	// FindPeer searches for a peer with given ID.
 	FindPeer(context.Context, peer.ID) (*peer.Peer, error)
 }