tracking down a bug dhthell found, added asserts and better logging.

blockservice/blockservice.go

@@ -101,7 +101,6 @@ func (s *BlockService) GetBlock(ctx context.Context, k u.Key) (*blocks.Block, er
 func (s *BlockService) GetBlocks(ctx context.Context, ks []u.Key) <-chan *blocks.Block {
 	out := make(chan *blocks.Block, 32)
 	go func() {
-		defer close(out)
 		var toFetch []u.Key
 		for _, k := range ks {
 			block, err := s.Blockstore.Get(k)
@@ -121,6 +120,7 @@ func (s *BlockService) GetBlocks(ctx context.Context, ks []u.Key) <-chan *blocks
 		for blk := range nblocks {
 			out <- blk
 		}
+		close(out)
 	}()
 	return out
 }

exchange/bitswap/bitswap.go

@@ -197,13 +197,19 @@ func (bs *bitswap) loop(parent context.Context) {
 				}
 			}
 		case ks := <-bs.batchRequests:
+			// TODO: implement batching on len(ks) > X for some X
+			if len(ks) == 0 {
+				log.Warning("Received batch request for zero blocks")
+				continue
+			}
 			for _, k := range ks {
 				bs.wantlist.Add(k)
-				providers := bs.routing.FindProvidersAsync(ctx, k, maxProvidersPerRequest)
-				err := bs.sendWantListTo(ctx, providers)
-				if err != nil {
-					log.Errorf("error sending wantlist: %s", err)
-				}
+			}
+			providers := bs.routing.FindProvidersAsync(ctx, ks[0], maxProvidersPerRequest)
+
+			err := bs.sendWantListTo(ctx, providers)
+			if err != nil {
+				log.Errorf("error sending wantlist: %s", err)
 			}
 		case <-parent.Done():
 			return

net/swarm/conn.go

@@ -182,7 +182,7 @@ func (s *Swarm) fanOut() {
 				return
 			}
 			if len(msg.Data()) >= conn.MaxMessageSize {
-				log.Critical("Attempted to send message bigger than max size.")
+				log.Criticalf("Attempted to send message bigger than max size. (%d)", len(msg.Data()))
 			}
 
 			s.connsLock.RLock()

unixfs/io/dagreader.go

@@ -68,6 +68,7 @@ func (dr *DagReader) precalcNextBuf() error {
 		// TODO: this logic is hard to follow, do it better.
 		// NOTE: the only time this code is used, is during the
 		//			importer tests, consider just changing those tests
+		log.Warning("Running DAGReader with nil DAGService!")
 		if dr.linkPosition >= len(dr.node.Links) {
 			return io.EOF
 		}
@@ -78,6 +79,9 @@ func (dr *DagReader) precalcNextBuf() error {
 		dr.linkPosition++
 
 	} else {
+		if dr.fetchChan == nil {
+			panic("this is wrong.")
+		}
 		select {
 		case nxt, ok = <-dr.fetchChan:
 			if !ok {