Merge pull request #1188 from karalabe/newblockhashes-proposal

eth: implement the NewBlockHashes protocol proposal

1 files changed, 126 insertions, 6 deletions

diff --git a/eth/sync.go b/eth/sync.go
index 56084f2f0..dd7414da8 100644
--- a/eth/sync.go
+++ b/eth/sync.go
@@ -5,15 +5,135 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 )
 
-// update periodically tries to synchronise with the network, both downloading
-// hashes and blocks as well as retrieving cached ones.
-func (pm *ProtocolManager) update() {
+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 {
+	hash common.Hash
+	peer *peer
+	time time.Time
+}
+
+// fetcher is responsible for collecting hash notifications, and periodically
+// checking all unknown ones and individually fetching them.
+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
+	for {
+		select {
+		case notifications := <-pm.newHashCh:
+			// A batch of hashes the notified, schedule them for retrieval
+			glog.V(logger.Debug).Infof("Scheduling %d hash announcements from %s", len(notifications), notifications[0].peer.id)
+			for _, announce := range notifications {
+				announces[announce.hash] = announce
+			}
+
+		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)
+				}
+			}
+			if len(request) == 0 {
+				break
+			}
+			// Send out all block requests
+			for peer, hashes := range request {
+				glog.V(logger.Debug).Infof("Explicitly fetching %d blocks from %s", len(hashes), peer.id)
+				peer.requestBlocks(hashes)
+			}
+			request = make(map[*peer][]common.Hash)
+
+		case filter := <-pm.newBlockCh:
+			// Blocks arrived, extract any explicit fetches, return all else
+			var blocks types.Blocks
+			select {
+			case blocks = <-filter:
+			case <-pm.quitSync:
+				return
+			}
+
+			explicit, download := []*types.Block{}, []*types.Block{}
+			for _, block := range blocks {
+				hash := block.Hash()
+
+				// Filter explicitly requested blocks from hash announcements
+				if _, ok := pending[hash]; ok {
+					// Discard if already imported by other means
+					if !pm.chainman.HasBlock(hash) {
+						explicit = append(explicit, block)
+					} else {
+						delete(pending, hash)
+					}
+				} else {
+					download = append(download, block)
+				}
+			}
+
+			select {
+			case filter <- download:
+			case <-pm.quitSync:
+				return
+			}
+			// If any explicit fetches were replied to, import them
+			if count := len(explicit); count > 0 {
+				glog.V(logger.Debug).Infof("Importing %d explicitly fetched blocks", count)
+				go func() {
+					for _, block := range explicit {
+						hash := block.Hash()
+
+						// Make sure there's still something pending to import
+						if announce := pending[hash]; announce != nil {
+							delete(pending, hash)
+							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
+		}
+	}
+}
+
+// syncer is responsible for periodically synchronising with the network, both
+// downloading hashes and blocks as well as retrieving cached ones.
+func (pm *ProtocolManager) syncer() {
 	forceSync := time.Tick(forceSyncCycle)
 	blockProc := time.Tick(blockProcCycle)
 	blockProcPend := int32(0)
@@ -99,15 +219,15 @@ func (pm *ProtocolManager) synchronise(peer *peer) {
 		return
 	}
 	// Get the hashes from the peer (synchronously)
-	glog.V(logger.Debug).Infof("Attempting synchronisation: %v, 0x%x", peer.id, peer.recentHash)
+	glog.V(logger.Detail).Infof("Attempting synchronisation: %v, 0x%x", peer.id, peer.recentHash)
 
 	err := pm.downloader.Synchronise(peer.id, peer.recentHash)
 	switch err {
 	case nil:
-		glog.V(logger.Debug).Infof("Synchronisation completed")
+		glog.V(logger.Detail).Infof("Synchronisation completed")
 
 	case downloader.ErrBusy:
-		glog.V(logger.Debug).Infof("Synchronisation already in progress")
+		glog.V(logger.Detail).Infof("Synchronisation already in progress")
 
 	case downloader.ErrTimeout, downloader.ErrBadPeer, downloader.ErrEmptyHashSet, downloader.ErrInvalidChain, downloader.ErrCrossCheckFailed:
 		glog.V(logger.Debug).Infof("Removing peer %v: %v", peer.id, err)