integrate snapshot feature with statedb and add cache to states

core/blockchain_impl.go

@@ -262,7 +262,6 @@ func newBlockChainWithOptions(
 	if stateCache == nil {
 		stateCache = state.NewDatabaseWithNodeDB(db, triedb)
 	}
-
 	bodyCache, _ := lru.New(bodyCacheLimit)
 	bodyRLPCache, _ := lru.New(bodyCacheLimit)
 	receiptsCache, _ := lru.New(receiptsCacheLimit)

core/state/snapshot/snapshot.go

@@ -206,7 +206,6 @@ func New(config Config, diskdb ethdb.KeyValueStore, triedb *trie.Database, root
 		utils.Logger().Warn().Err(err).Msg("Snapshot maintenance disabled (syncing)")
 		return snap, nil
 	}
-
 	// Create the building waiter if the background generation is allowed
 	if !config.NoBuild && !config.AsyncBuild {
 		defer snap.waitBuild()