In memory statedb

core/state/database.go

@@ -83,6 +83,15 @@ func NewDatabase(db ethdb.Database) Database {
 	}
 }
 
+// NewDatabaseWithTrieDB creates a backing store for state from a previously created trie database.
+func NewDatabaseWithTrieDB(db *trie.Database) Database {
+	csc, _ := lru.New(codeSizeCacheSize)
+	return &cachingDB{
+		db:            db,
+		codeSizeCache: csc,
+	}
+}
+
 type cachingDB struct {
 	db            *trie.Database
 	mu            sync.Mutex