Add post-consensus processing of blockchain (add new block to blockchain)

benchmark_main.go

@@ -76,7 +76,9 @@ func main() {
 	consensus := consensus.NewConsensus(*ip, *port, shardId, peers, leader)
 
 	node := node.NewNode(&consensus)
-	consensus.BlockVerifier = node.VerifyNewBlock // Assign block verifier to the consensus
+	// Assign closure functions to the consensus object
+	consensus.BlockVerifier = node.VerifyNewBlock
+	consensus.OnConsensusDone = node.AddNewBlockToBlockchain
 
 	// Temporary testing code, to be removed.
 	node.AddMoreFakeTransactions()
@@ -90,6 +92,11 @@ func main() {
 		go func() {
 			node.WaitForConsensusReady(consensus.ReadySignal)
 		}()
+	} else {
+		// Node waiting to add new block to the blockchain
+		go func() {
+			node.WaitForConsensusReady(consensus.ReadySignal)
+		}()
 	}
 
 	node.StartServer(*port)

consensus/consensus.go

@@ -41,7 +41,11 @@ type Consensus struct {
 
 	// Signal channel for starting a new consensus process
 	ReadySignal chan int
+	// The verifier func passed from Node object
 	BlockVerifier func(*blockchain.Block)bool
+	// The post-consensus processing func passed from Node object
+	// Called when consensus on a new block is done
+	OnConsensusDone func(*blockchain.Block)
 
 	//// Network related fields
 	msgCategory byte

consensus/consensus_leader.go

@@ -287,6 +287,16 @@ func (consensus *Consensus) processResponseMessage(payload []byte) {
 			consensus.Log.Debug("HOORAY!!! CONSENSUS REACHED!!!", "numOfNodes", len(consensus.validators))
 
 			consensus.ResetState()
+
+			// TODO: reconstruct the whole block from header and transactions
+			// For now, we used the stored whole block in consensus.blockHeader
+			txDecoder := gob.NewDecoder(bytes.NewReader(consensus.blockHeader))
+			var blockHeaderObj blockchain.Block
+			err := txDecoder.Decode(&blockHeaderObj)
+			if err != nil {
+				consensus.Log.Debug("failed to construct the new block after consensus")
+			}
+			consensus.OnConsensusDone(&blockHeaderObj)
 			consensus.consensusId++
 
 			// Send signal to Node so the new block can be added and new round of consensus can be triggered

consensus/consensus_validator.go

@@ -94,13 +94,13 @@ func (consensus *Consensus) processAnnounceMessage(payload []byte) {
 
 	// check block header is valid
 	txDecoder := gob.NewDecoder(bytes.NewReader(blockHeader))
-
-	var blockHeaderObj blockchain.Block // TODO: separate header from block
+	var blockHeaderObj blockchain.Block // TODO: separate header from block. Right now, this blockHeader data is actually the whole block
 	err := txDecoder.Decode(&blockHeaderObj)
 	if err != nil {
 		consensus.Log.Debug("[ERROR] Unparseable block header data")
 		return
 	}
+	consensus.blockHeader = blockHeader
 
 	// check block hash
 	if bytes.Compare(blockHash[:], blockHeaderObj.HashTransactions()[:]) != 0 || bytes.Compare(blockHeaderObj.Hash[:], blockHeaderObj.HashTransactions()[:]) != 0 {
@@ -230,6 +230,20 @@ func (consensus *Consensus) processChallengeMessage(payload []byte) {
 	// Set state to RESPONSE_DONE
 	consensus.state = RESPONSE_DONE
 	consensus.consensusId++
+
+
+	// TODO: think about when validators know about the consensus is reached.
+	// For now, the blockchain is updated right here.
+
+	// TODO: reconstruct the whole block from header and transactions
+	// For now, we used the stored whole block in consensus.blockHeader
+	txDecoder := gob.NewDecoder(bytes.NewReader(consensus.blockHeader))
+	var blockHeaderObj blockchain.Block
+	err := txDecoder.Decode(&blockHeaderObj)
+	if err != nil {
+		consensus.Log.Debug("failed to construct the new block after consensus")
+	}
+	consensus.OnConsensusDone(&blockHeaderObj)
 }
 
 // Construct the response message to send to leader (assumption the consensus data is already verified)

node/node_handler.go

@@ -116,14 +116,6 @@ func (node *Node) WaitForConsensusReady(readySignal chan int) {
 	for { // keep waiting for consensus ready
 		<-readySignal
 		//node.log.Debug("Adding new block", "currentChainSize", len(node.blockchain.Blocks), "numTxs", len(node.blockchain.GetLatestBlock().Transactions), "PrevHash", node.blockchain.GetLatestBlock().PrevBlockHash, "Hash", node.blockchain.GetLatestBlock().Hash)
-		if newBlock != nil {
-			// Consensus is done on the newBlock (in the previous round of consensus), add it to blockchain
-			node.blockchain.Blocks = append(node.blockchain.Blocks, newBlock)
-			// Update UTXO pool
-			node.UtxoPool.Update(node.transactionInConsensus)
-			// Clear transaction-in-consensus list
-			node.transactionInConsensus = []*blockchain.Transaction{}
-		}
 		for {
 			// Once we have more than 10 transactions pending we will try creating a new block
 			if len(node.pendingTransactions) >= 10 {
@@ -149,6 +141,15 @@ func (node *Node) WaitForConsensusReady(readySignal chan int) {
 	}
 }
 
-func (node *Node) VerifyNewBlock(block *blockchain.Block) bool {
-	return node.UtxoPool.VerifyTransactions(block.Transactions)
+func (node *Node) VerifyNewBlock(newBlock *blockchain.Block) bool {
+	return node.UtxoPool.VerifyTransactions(newBlock.Transactions)
+}
+
+func (node *Node) AddNewBlockToBlockchain(newBlock *blockchain.Block) {
+	// Add it to blockchain
+	node.blockchain.Blocks = append(node.blockchain.Blocks, newBlock)
+	// Update UTXO pool
+	node.UtxoPool.Update(newBlock.Transactions)
+	// Clear transaction-in-consensus list
+	node.transactionInConsensus = []*blockchain.Transaction{}
 }