eth, eth/fetcher: move propagated block import into fetcher

eth/fetcher/fetcher.go

@@ -29,12 +29,18 @@ type hashCheckFn func(common.Hash) bool
 // blockRequesterFn is a callback type for sending a block retrieval request.
 type blockRequesterFn func([]common.Hash) error
 
-// blockImporterFn is a callback type for trying to inject a block into the local chain.
-type blockImporterFn func(peer string, block *types.Block) error
+// blockBroadcasterFn is a callback type for broadcasting a block to connected peers.
+type blockBroadcasterFn func(block *types.Block)
 
 // chainHeightFn is a callback type to retrieve the current chain height.
 type chainHeightFn func() uint64
 
+// chainInsertFn is a callback type to insert a batch of blocks into the local chain.
+type chainInsertFn func(types.Blocks) (int, error)
+
+// peerDropFn is a callback type for dropping a peer detected as malicious.
+type peerDropFn func(id string)
+
 // announce is the hash notification of the availability of a new block in the
 // network.
 type announce struct {
@@ -70,26 +76,30 @@ type Fetcher struct {
 	queued map[common.Hash]struct{} // Presence set of already queued blocks (to dedup imports)
 
 	// Callbacks
-	hasBlock    hashCheckFn     // Checks if a block is present in the chain
-	importBlock blockImporterFn // Injects a block from an origin peer into the chain
-	chainHeight chainHeightFn   // Retrieves the current chain's height
+	hasBlock       hashCheckFn        // Checks if a block is present in the chain
+	broadcastBlock blockBroadcasterFn // Broadcasts a block to connected peers
+	chainHeight    chainHeightFn      // Retrieves the current chain's height
+	insertChain    chainInsertFn      // Injects a batch of blocks into the chain
+	dropPeer       peerDropFn         // Drops a peer for misbehaving
 }
 
 // New creates a block fetcher to retrieve blocks based on hash announcements.
-func New(hasBlock hashCheckFn, importBlock blockImporterFn, chainHeight chainHeightFn) *Fetcher {
+func New(hasBlock hashCheckFn, broadcastBlock blockBroadcasterFn, chainHeight chainHeightFn, insertChain chainInsertFn, dropPeer peerDropFn) *Fetcher {
 	return &Fetcher{
-		notify:      make(chan *announce),
-		inject:      make(chan *inject),
-		filter:      make(chan chan []*types.Block),
-		done:        make(chan common.Hash),
-		quit:        make(chan struct{}),
-		announced:   make(map[common.Hash][]*announce),
-		fetching:    make(map[common.Hash]*announce),
-		queue:       prque.New(),
-		queued:      make(map[common.Hash]struct{}),
-		hasBlock:    hasBlock,
-		importBlock: importBlock,
-		chainHeight: chainHeight,
+		notify:         make(chan *announce),
+		inject:         make(chan *inject),
+		filter:         make(chan chan []*types.Block),
+		done:           make(chan common.Hash),
+		quit:           make(chan struct{}),
+		announced:      make(map[common.Hash][]*announce),
+		fetching:       make(map[common.Hash]*announce),
+		queue:          prque.New(),
+		queued:         make(map[common.Hash]struct{}),
+		hasBlock:       hasBlock,
+		broadcastBlock: broadcastBlock,
+		chainHeight:    chainHeight,
+		insertChain:    insertChain,
+		dropPeer:       dropPeer,
 	}
 }
 
@@ -328,10 +338,17 @@ func (f *Fetcher) insert(peer string, block *types.Block) {
 	go func() {
 		defer func() { f.done <- hash }()
 
-		// Run the actual import and log any issues
-		if err := f.importBlock(peer, block); err != nil {
-			glog.V(logger.Detail).Infof("Peer %s: block #%d [%x] import failed: %v", peer, block.NumberU64(), hash[:4], err)
+		// If the parent's unknown, abort insertion
+		if !f.hasBlock(block.ParentHash()) {
 			return
 		}
+		// Run the actual import and log any issues
+		if _, err := f.insertChain(types.Blocks{block}); err != nil {
+			glog.V(logger.Detail).Infof("Peer %s: block #%d [%x] import failed: %v", peer, block.NumberU64(), hash[:4], err)
+			f.dropPeer(peer)
+			return
+		}
+		// If import succeeded, broadcast the block
+		go f.broadcastBlock(block)
 	}()
 }