feat: calling FindProvidersAsync with a count of zero now completes the query

routing.go

@@ -539,14 +539,22 @@ func (dht *IpfsDHT) FindProviders(ctx context.Context, c cid.Cid) ([]peer.AddrIn
 
 // FindProvidersAsync is the same thing as FindProviders, but returns a channel.
 // Peers will be returned on the channel as soon as they are found, even before
-// the search query completes.
+// the search query completes. If count is zero then the query will run until it
+// completes. Note: not reading from the returned channel may block the query
+// from progressing.
 func (dht *IpfsDHT) FindProvidersAsync(ctx context.Context, key cid.Cid, count int) <-chan peer.AddrInfo {
-	peerOut := make(chan peer.AddrInfo, count)
 	if !dht.enableProviders {
+		peerOut := make(chan peer.AddrInfo)
 		close(peerOut)
 		return peerOut
 	}
 
+	chSize := count
+	if count == 0 {
+		chSize = 1
+	}
+	peerOut := make(chan peer.AddrInfo, chSize)
+
 	keyMH := key.Hash()
 	logger.Event(ctx, "findProviders", multihashLoggableKey(keyMH))
 
@@ -558,7 +566,14 @@ func (dht *IpfsDHT) findProvidersAsyncRoutine(ctx context.Context, key multihash
 	defer logger.EventBegin(ctx, "findProvidersAsync", multihashLoggableKey(key)).Done()
 	defer close(peerOut)
 
-	ps := peer.NewLimitedSet(count)
+	findAll := count == 0
+	var ps *peer.Set
+	if findAll {
+		ps = peer.NewSet()
+	} else {
+		ps = peer.NewLimitedSet(count)
+	}
+
 	provs := dht.ProviderManager.GetProviders(ctx, key)
 	for _, p := range provs {
 		// NOTE: Assuming that this list of peers is unique
@@ -573,7 +588,7 @@ func (dht *IpfsDHT) findProvidersAsyncRoutine(ctx context.Context, key multihash
 
 		// If we have enough peers locally, don't bother with remote RPC
 		// TODO: is this a DOS vector?
-		if ps.Size() >= count {
+		if !findAll && ps.Size() >= count {
 			return
 		}
 	}
@@ -610,7 +625,7 @@ func (dht *IpfsDHT) findProvidersAsyncRoutine(ctx context.Context, key multihash
 						return nil, ctx.Err()
 					}
 				}
-				if ps.Size() >= count {
+				if !findAll && ps.Size() >= count {
 					logger.Debugf("got enough providers (%d/%d)", ps.Size(), count)
 					return nil, nil
 				}
@@ -630,7 +645,7 @@ func (dht *IpfsDHT) findProvidersAsyncRoutine(ctx context.Context, key multihash
 			return peers, nil
 		},
 		func(peerset *kpeerset.SortedPeerset) bool {
-			return ps.Size() >= count
+			return !findAll && ps.Size() >= count
 		},
 	)