implement batching for leveldb

flatfs.go

@@ -99,7 +99,7 @@ func (fs *Datastore) makePrefixDirNoSync(dir string) error {
 	return nil
 }
 
-var putMaxRetries = 3
+var putMaxRetries = 6
 
 func (fs *Datastore) Put(key datastore.Key, value interface{}) error {
 	val, ok := value.([]byte)
@@ -111,15 +111,15 @@ func (fs *Datastore) Put(key datastore.Key, value interface{}) error {
 	for i := 0; i < putMaxRetries; i++ {
 		err = fs.doPut(key, val)
 		if err == nil {
-			return nil
+			break
 		}
 
 		if !strings.Contains(err.Error(), "too many open files") {
-			return err
+			break
 		}
 
 		log.Errorf("too many open files, retrying in %dms", 100*i)
-		time.Sleep(time.Millisecond * 100 * time.Duration(i))
+		time.Sleep(time.Millisecond * 100 * time.Duration(i+1))
 	}
 	return err
 }