[Blockchain/IBFT] Update snapshot after processBlock ends (#482)

* implement ProcessHeaders as interface method

* move ProcessHeaders out of VerifyHeaders

blockchain/blockchain.go

@@ -57,6 +57,7 @@ type gasPriceAverage struct {
 
 type Verifier interface {
 	VerifyHeader(parent, header *types.Header) error
+	ProcessHeaders(headers []*types.Header) error
 	GetBlockCreator(header *types.Header) (types.Address, error)
 	PreStateCommit(header *types.Header, txn *state.Transition) error
 }
@@ -700,6 +701,11 @@ func (b *Blockchain) WriteBlock(block *types.Block) error {
 		return err
 	}
 
+	//	update snapshot
+	if err := b.consensus.ProcessHeaders([]*types.Header{header}); err != nil {
+		return err
+	}
+
 	b.dispatchEvent(evnt)
 
 	// Update the average gas price

blockchain/testing.go

@@ -197,6 +197,10 @@ func (m *MockVerifier) VerifyHeader(parent, header *types.Header) error {
 	return nil
 }
 
+func (m *MockVerifier) ProcessHeaders(headers []*types.Header) error {
+	return nil
+}
+
 func (m *MockVerifier) GetBlockCreator(header *types.Header) (types.Address, error) {
 	return header.Miner, nil
 }

consensus/consensus.go

@@ -22,6 +22,9 @@ type Consensus interface {
 	// VerifyHeader verifies the header is correct
 	VerifyHeader(parent, header *types.Header) error
 
+	// ProcessHeaders updates the snapshot based on the verified headers
+	ProcessHeaders(headers []*types.Header) error
+
 	// GetBlockCreator retrieves the block creator (or signer) given the block header
 	GetBlockCreator(header *types.Header) (types.Address, error)
 

consensus/dev/dev.go

@@ -211,6 +211,10 @@ func (d *Dev) VerifyHeader(parent *types.Header, header *types.Header) error {
 	return nil
 }
 
+func (d *Dev) ProcessHeaders(headers []*types.Header) error {
+	return nil
+}
+
 func (d *Dev) GetBlockCreator(header *types.Header) (types.Address, error) {
 	return header.Miner, nil
 }

consensus/dummy/dummy.go

@@ -52,6 +52,10 @@ func (d *Dummy) VerifyHeader(parent *types.Header, header *types.Header) error {
 	return nil
 }
 
+func (d *Dummy) ProcessHeaders(headers []*types.Header) error {
+	return nil
+}
+
 func (d *Dummy) GetBlockCreator(header *types.Header) (types.Address, error) {
 	return header.Miner, nil
 }

consensus/ibft/ibft.go

@@ -1255,14 +1255,14 @@ func (i *Ibft) VerifyHeader(parent, header *types.Header) error {
 		return err
 	}
 
-	// process the new block in order to update the snapshot
-	if err := i.processHeaders([]*types.Header{header}); err != nil {
-		return err
-	}
-
 	return nil
 }
 
+// ProcessHeaders updates the snapshot based on previously verified headers
+func (i *Ibft) ProcessHeaders(headers []*types.Header) error {
+	return i.processHeaders(headers)
+}
+
 // GetBlockCreator retrieves the block signer from the extra data field
 func (i *Ibft) GetBlockCreator(header *types.Header) (types.Address, error) {
 	return ecrecoverFromHeader(header)