trie: move dirty data to clean cache on flush

trie/database.go

@@ -723,14 +723,25 @@ func (db *Database) commit(hash common.Hash, batch ethdb.Batch) error {
 	if !ok {
 		return nil
 	}
+	// Commit all the children and then the current node too
 	for _, child := range node.childs() {
 		if err := db.commit(child, batch); err != nil {
 			return err
 		}
 	}
-	if err := batch.Put(hash[:], node.rlp()); err != nil {
+	blob := node.rlp()
+	if err := batch.Put(hash[:], blob); err != nil {
 		return err
 	}
+	// Move the flushed node into the clean cache to prevent insta-reloads. This
+	// move should really be done **after** flushing the batch. The issue is that
+	// the RLP of the data is lost at that point, requiring reencoding everything.
+	// By doing the move here we open a window of opportunity for failure **if**
+	// writing the data errors out, but at that point we might have bigger issues
+	// anyway.
+	if db.cleans != nil {
+		db.cleans.Set(string(hash[:]), blob)
+	}
 	// If we've reached an optimal batch size, commit and start over
 	if batch.ValueSize() >= ethdb.IdealBatchSize {
 		if err := batch.Write(); err != nil {