trie: apply fastNodeEncoder to StackTrie

trie/stacktrie.go

@@ -376,26 +376,26 @@ func (st *StackTrie) hash() {
 
 	switch st.nodeType {
 	case branchNode:
-		var nodes [17]node
+		var n rawFullNode
 		for i, child := range st.children {
 			if child == nil {
-				nodes[i] = nilValueNode
+				n[i] = nilValueNode
 				continue
 			}
 			child.hash()
 			if len(child.val) < 32 {
-				nodes[i] = rawNode(child.val)
+				n[i] = rawNode(child.val)
 			} else {
-				nodes[i] = hashNode(child.val)
+				n[i] = hashNode(child.val)
 			}
 			st.children[i] = nil // Reclaim mem from subtree
 			returnToPool(child)
 		}
-		nodes[16] = nilValueNode
+		n[16] = nilValueNode
 		h = newHasher(false)
 		defer returnHasherToPool(h)
 		h.tmp.Reset()
-		if err := rlp.Encode(&h.tmp, nodes); err != nil {
+		if err := frlp.Encode(&h.tmp, n); err != nil {
 			panic(err)
 		}
 	case extNode:
@@ -409,14 +409,11 @@ func (st *StackTrie) hash() {
 		} else {
 			valuenode = hashNode(st.children[0].val)
 		}
-		n := struct {
-			Key []byte
-			Val node
-		}{
+		n := &rawShortNode{
 			Key: hexToCompact(st.key),
 			Val: valuenode,
 		}
-		if err := rlp.Encode(&h.tmp, n); err != nil {
+		if err := frlp.Encode(&h.tmp, n); err != nil {
 			panic(err)
 		}
 		returnToPool(st.children[0])