eth: split and handle explicitly vs. download requested blocks

2 files changed, 81 insertions, 23 deletions

diff --git a/eth/handler.go b/eth/handler.go
index 7e9ec593a..acc16812a 100644
--- a/eth/handler.go
+++ b/eth/handler.go
@@ -18,15 +18,6 @@ import (
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
-const (
-	forceSyncCycle      = 10 * time.Second       // Time interval to force syncs, even if few peers are available
-	blockProcCycle      = 500 * time.Millisecond // Time interval to check for new blocks to process
-	notifyCheckCycle    = 100 * time.Millisecond // Time interval to allow hash notifies to fulfill before hard fetching
-	notifyArriveTimeout = 500 * time.Millisecond // Time allowance before an announced block is explicitly requested
-	minDesiredPeerCount = 5                      // Amount of peers desired to start syncing
-	blockProcAmount     = 256
-)
-
 func errResp(code errCode, format string, v ...interface{}) error {
 	return fmt.Errorf("%v - %v", code, fmt.Sprintf(format, v...))
 }
@@ -57,9 +48,11 @@ type ProtocolManager struct {
 	txSub         event.Subscription
 	minedBlockSub event.Subscription
 
-	newPeerCh chan *peer
-	newHashCh chan []*blockAnnounce
-	quitSync  chan struct{}
+	newPeerCh  chan *peer
+	newHashCh  chan []*blockAnnounce
+	newBlockCh chan chan []*types.Block
+	quitSync   chan struct{}
+
 	// wait group is used for graceful shutdowns during downloading
 	// and processing
 	wg   sync.WaitGroup
@@ -77,6 +70,7 @@ func NewProtocolManager(protocolVersion, networkId int, mux *event.TypeMux, txpo
 		peers:      newPeerSet(),
 		newPeerCh:  make(chan *peer, 1),
 		newHashCh:  make(chan []*blockAnnounce, 1),
+		newBlockCh: make(chan chan []*types.Block),
 		quitSync:   make(chan struct{}),
 	}
 
@@ -274,21 +268,26 @@ func (self *ProtocolManager) handleMsg(p *peer) error {
 		return p.sendBlocks(blocks)
 
 	case BlocksMsg:
-		var blocks []*types.Block
-
+		// Decode the arrived block message
 		msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
+
+		var blocks []*types.Block
 		if err := msgStream.Decode(&blocks); err != nil {
 			glog.V(logger.Detail).Infoln("Decode error", err)
 			blocks = nil
 		}
-
-		// Either deliver to the downloader or the importer
-		if self.downloader.Synchronising() {
-			self.downloader.DeliverBlocks(p.id, blocks)
-		} else {
-			for _, block := range blocks {
-				if err := self.importBlock(p, block, nil); err != nil {
-					return err
+		// Filter out any explicitly requested blocks (cascading select to get blocking back to peer)
+		filter := make(chan []*types.Block)
+		select {
+		case <-self.quitSync:
+		case self.newBlockCh <- filter:
+			select {
+			case <-self.quitSync:
+			case filter <- blocks:
+				select {
+				case <-self.quitSync:
+				case blocks := <-filter:
+					self.downloader.DeliverBlocks(p.id, blocks)
 				}
 			}
 		}
@@ -322,7 +321,10 @@ func (self *ProtocolManager) handleMsg(p *peer) error {
 			}
 		}
 		if len(announces) > 0 {
-			self.newHashCh <- announces
+			select {
+			case self.newHashCh <- announces:
+			case <-self.quitSync:
+			}
 		}
 
 	case NewBlockMsg:
diff --git a/eth/sync.go b/eth/sync.go
index 1a1cbdb47..f761f3cd1 100644
--- a/eth/sync.go
+++ b/eth/sync.go
@@ -12,6 +12,16 @@ import (
 	"github.com/ethereum/go-ethereum/logger/glog"
 )
 
+const (
+	forceSyncCycle      = 10 * time.Second       // Time interval to force syncs, even if few peers are available
+	blockProcCycle      = 500 * time.Millisecond // Time interval to check for new blocks to process
+	notifyCheckCycle    = 100 * time.Millisecond // Time interval to allow hash notifies to fulfill before hard fetching
+	notifyArriveTimeout = 500 * time.Millisecond // Time allowance before an announced block is explicitly requested
+	notifyFetchTimeout  = 5 * time.Second        // Maximum alloted time to return an explicitly requested block
+	minDesiredPeerCount = 5                      // Amount of peers desired to start syncing
+	blockProcAmount     = 256
+)
+
 // blockAnnounce is the hash notification of the availability of a new block in
 // the network.
 type blockAnnounce struct {
@@ -25,6 +35,7 @@ type blockAnnounce struct {
 func (pm *ProtocolManager) fetcher() {
 	announces := make(map[common.Hash]*blockAnnounce)
 	request := make(map[*peer][]common.Hash)
+	pending := make(map[common.Hash]*blockAnnounce)
 	cycle := time.Tick(notifyCheckCycle)
 
 	// Iterate the block fetching until a quit is requested
@@ -38,11 +49,18 @@ func (pm *ProtocolManager) fetcher() {
 			}
 
 		case <-cycle:
+			// Clean up any expired block fetches
+			for hash, announce := range pending {
+				if time.Since(announce.time) > notifyFetchTimeout {
+					delete(pending, hash)
+				}
+			}
 			// Check if any notified blocks failed to arrive
 			for hash, announce := range announces {
 				if time.Since(announce.time) > notifyArriveTimeout {
 					if !pm.chainman.HasBlock(hash) {
 						request[announce.peer] = append(request[announce.peer], hash)
+						pending[hash] = announce
 					}
 					delete(announces, hash)
 				}
@@ -57,6 +75,44 @@ func (pm *ProtocolManager) fetcher() {
 			}
 			request = make(map[*peer][]common.Hash)
 
+		case filter := <-pm.newBlockCh:
+			// Blocks arrived, extract any explicit requests, return all else
+			var blocks types.Blocks
+			select {
+			case blocks = <-filter:
+			case <-pm.quitSync:
+				return
+			}
+
+			fetch, sync := []*types.Block{}, []*types.Block{}
+			for _, block := range blocks {
+				hash := block.Hash()
+				if _, ok := pending[hash]; ok {
+					fetch = append(fetch, block)
+				} else {
+					sync = append(sync, block)
+				}
+			}
+
+			select {
+			case filter <- sync:
+			case <-pm.quitSync:
+				return
+			}
+			// If any explicit fetches were replied to, import them
+			if len(fetch) > 0 {
+				go func() {
+					for _, block := range fetch {
+						if announce := pending[block.Hash()]; announce != nil {
+							if err := pm.importBlock(announce.peer, block, nil); err != nil {
+								glog.V(logger.Detail).Infof("Failed to import explicitly fetched block: %v", err)
+								return
+							}
+						}
+					}
+				}()
+			}
+
 		case <-pm.quitSync:
 			return
 		}