trie: enable batch updates

core/state/database.go

@@ -69,7 +69,8 @@ type Trie interface {
 	// by the caller while they are stored in the trie. If a node was not found in the
 	// database, a trie.MissingNodeError is returned.
 	TryUpdate(key, value []byte) error
-
+	BatchStart()
+	BatchEnd()
 	// TryDelete removes any existing value for key from the trie. If a node was not
 	// found in the database, a trie.MissingNodeError is returned.
 	TryDelete(key []byte) error

core/state/statedb.go

@@ -688,7 +688,7 @@ func (s *StateDB) Finalise(deleteEmptyObjects bool) {
 func (s *StateDB) IntermediateRoot(deleteEmptyObjects bool) common.Hash {
 	// Finalise all the dirty storage states and write them into the tries
 	s.Finalise(deleteEmptyObjects)
-
+	s.trie.BatchStart()
 	for addr := range s.stateObjectsPending {
 		obj := s.stateObjects[addr]
 		if obj.deleted {
@@ -698,6 +698,7 @@ func (s *StateDB) IntermediateRoot(deleteEmptyObjects bool) common.Hash {
 			s.updateStateObject(obj)
 		}
 	}
+	s.trie.BatchEnd()
 	if len(s.stateObjectsPending) > 0 {
 		s.stateObjectsPending = make(map[common.Address]struct{})
 	}

light/trie.go

@@ -112,6 +112,9 @@ func (t *odrTrie) TryUpdate(key, value []byte) error {
 	})
 }
 
+func (t *odrTrie) BatchStart() {}
+func (t *odrTrie) BatchEnd()   {}
+
 func (t *odrTrie) TryDelete(key []byte) error {
 	key = crypto.Keccak256(key)
 	return t.do(key, func() error {

trie/secure_trie.go

@@ -109,6 +109,13 @@ func (t *SecureTrie) TryUpdate(key, value []byte) error {
 	return nil
 }
 
+func (t *SecureTrie) BatchStart(){
+	t.trie.batchStart()
+}
+func (t *SecureTrie) BatchEnd(){
+	t.trie.batchEnd()
+}
+
 // Delete removes any existing value for key from the trie.
 func (t *SecureTrie) Delete(key []byte) {
 	if err := t.TryDelete(key); err != nil {

trie/trie.go

@@ -52,6 +52,7 @@ type Trie struct {
 	dirtyCount int
 	// And leafs to hash
 	unhashedCount int
+	batchMode bool
 }
 
 // newFlag returns the cache flag value for a newly created node.
@@ -186,6 +187,13 @@ func (t *Trie) TryUpdate(key, value []byte) error {
 	return nil
 }
 
+func (t *Trie) batchStart(){
+	t.batchMode = true
+}
+func (t *Trie) batchEnd(){
+	t.batchMode = false
+}
+
 func (t *Trie) insert(n node, prefix, key []byte, value node) (bool, node, error) {
 	if len(key) == 0 {
 		if v, ok := n.(valueNode); ok {
@@ -228,7 +236,20 @@ func (t *Trie) insert(n node, prefix, key []byte, value node) (bool, node, error
 		if !dirty || err != nil {
 			return false, n, err
 		}
-		n = n.copy()
+		// If we're in batch-mode, we don't keep 'ephemeral' changes.
+		// When we modify a node, we only copy it in case it is an old committed
+		// node.
+		// If the node is "new", we just update in place.
+		if t.batchMode{
+			if h, dirty := n.cache(); !dirty || h != nil{
+				// This node is either not dirty, or already hashed. We copy it
+				n = n.copy()
+			}else{
+				// No copy
+			}
+		}else{
+			n = n.copy()
+		}
 		n.flags = t.newFlag()
 		n.Children[key[0]] = nn
 		return true, n, nil