Jiayu Wu

@yiwu-arbug I think we can use output data size to get discardable_size of flushed blob file: 0. If discardable_size == 0, then discardable_size = file_size - output_size 1. if discardable_size...

@yiwu-arbug Yes,. And we can do it in OnFlushCompleted without distinguishing gc rewritten blob file and flushed blob file, since outpu_size of flushed blob file always equals to file_size.