downloader: reset the queue if a peer response with an empty hash set

eth/downloader/downloader.go

@@ -17,8 +17,9 @@ import (
 )
 
 const (
-	maxBlockFetch       = 256 // Amount of max blocks to be fetched per chunk
+	maxBlockFetch       = 256              // Amount of max blocks to be fetched per chunk
-	minDesiredPeerCount = 3   // Amount of peers desired to start syncing
+	minDesiredPeerCount = 3                // Amount of peers desired to start syncing
+	blockTtl            = 15 * time.Second // The amount of time it takes for a request to time out
 )
 
 var (
@@ -96,7 +97,7 @@ func (d *Downloader) RegisterPeer(id string, td *big.Int, hash common.Hash, getH
 	// add peer to our peer set
 	d.peers[id] = peer
 	// broadcast new peer
-	//d.newPeerCh <- peer
+	d.newPeerCh <- peer
 
 	return nil
 }
@@ -265,6 +266,9 @@ out:
 
 // XXX Make synchronous
 func (d *Downloader) startFetchingHashes(p *peer, hash common.Hash, ignoreInitial bool) error {
+	atomic.StoreInt32(&d.fetchingHashes, 1)
+	defer atomic.StoreInt32(&d.fetchingHashes, 0)
+
 	glog.V(logger.Debug).Infof("Downloading hashes (%x) from %s", hash.Bytes()[:4], p.id)
 
 	start := time.Now()
@@ -275,10 +279,8 @@ func (d *Downloader) startFetchingHashes(p *peer, hash common.Hash, ignoreInitia
 		// Add the hash to the queue first
 		d.queue.hashPool.Add(hash)
 	}
-
 	// Get the first batch of hashes
 	p.getHashes(hash)
-	atomic.StoreInt32(&d.fetchingHashes, 1)
 
 out:
 	for {
@@ -299,14 +301,16 @@ out:
 			d.queue.put(hashSet)
 
 			// Add hashes to the chunk set
-			// Check if we're done fetching
+			if len(hashes) == 0 { // Make sure the peer actually gave you something valid
-			if !done && len(hashes) > 0 {
+				glog.V(logger.Debug).Infof("Peer (%s) responded with empty hash set\n", p.id)
+				d.queue.reset()
+
+				break out
+			} else if !done { // Check if we're done fetching
 				//fmt.Println("re-fetch. current =", d.queue.hashPool.Size())
 				// Get the next set of hashes
 				p.getHashes(hashes[len(hashes)-1])
-				atomic.StoreInt32(&d.fetchingHashes, 1)
+			} else { // we're done
-			} else {
-				atomic.StoreInt32(&d.fetchingHashes, 0)
 				break out
 			}
 		}
@@ -319,6 +323,7 @@ out:
 func (d *Downloader) startFetchingBlocks(p *peer) error {
 	glog.V(logger.Detail).Infoln("Downloading", d.queue.hashPool.Size(), "blocks")
 	atomic.StoreInt32(&d.downloadingBlocks, 1)
+	defer atomic.StoreInt32(&d.downloadingBlocks, 0)
 
 	start := time.Now()
 
@@ -364,8 +369,6 @@ out:
 				// When there are no more queue and no more `fetching`. We can
 				// safely assume we're done. Another part of the process will  check
 				// for parent errors and will re-request anything that's missing
-				atomic.StoreInt32(&d.downloadingBlocks, 0)
-				// Break out so that we can process with processing blocks
 				break out
 			} else {
 				// Check for bad peers. Bad peers may indicate a peer not responding
@@ -376,7 +379,7 @@ out:
 				d.queue.mu.Lock()
 				var badPeers []string
 				for pid, chunk := range d.queue.fetching {
-					if time.Since(chunk.itime) > 5*time.Second {
+					if time.Since(chunk.itime) > blockTtl {
 						badPeers = append(badPeers, pid)
 						// remove peer as good peer from peer list
 						d.UnregisterPeer(pid)
@@ -466,8 +469,11 @@ func (d *Downloader) process() error {
 	// to a seperate goroutine where it periodically checks for linked pieces.
 	types.BlockBy(types.Number).Sort(d.queue.blocks)
 	blocks := d.queue.blocks
+	if len(blocks) == 0 {
+		return nil
+	}
 
-	glog.V(logger.Debug).Infoln("Inserting chain with", len(blocks), "blocks")
+	glog.V(logger.Debug).Infof("Inserting chain with %d blocks (#%v - #%v)\n", len(blocks), blocks[0].Number(), blocks[len(blocks)-1].Number())
 
 	var err error
 	// Loop untill we're out of blocks
@@ -491,6 +497,11 @@ func (d *Downloader) process() error {
 				}
 			}
 			break
+		} else if err != nil {
+			// Reset chain completely. This needs much, much improvement.
+			// instead: check all blocks leading down to this block false block and remove it
+			blocks = nil
+			break
 		}
 		blocks = blocks[max:]
 	}

eth/downloader/queue.go

@@ -31,6 +31,17 @@ func newqueue() *queue {
 	}
 }
 
+func (c *queue) reset() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.hashPool.Clear()
+	c.fetchPool.Clear()
+	c.blockHashes.Clear()
+	c.blocks = nil
+	c.fetching = make(map[string]*chunk)
+}
+
 // reserve a `max` set of hashes for `p` peer.
 func (c *queue) get(p *peer, max int) *chunk {
 	c.mu.Lock()

eth/handler.go

@@ -95,7 +95,7 @@ func NewProtocolManager(protocolVersion, networkId int, txpool txPool, chainman
 		Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
 			peer := manager.newPeer(protocolVersion, networkId, p, rw)
 			err := manager.handle(peer)
-			glog.V(logger.Detail).Infof("[%s]: %v\n", peer.id, err)
+			//glog.V(logger.Detail).Infof("[%s]: %v\n", peer.id, err)
 
 			return err
 		},