protected final boolean checkFlushed() {
    // check the var without any lock. Suppose even if we see the old
    // value here still it is ok to continue because we will not be resetting
    // the heap but will continue with the referenced memstore's snapshot. For compactions
    // any way we don't need the updateReaders at all to happen as we still continue with
    // the older files
    if (flushed) {
      // If there is a flush and the current scan is notified on the flush ensure that the
      // scan's heap gets reset and we do a seek on the newly flushed file.
      if (this.closing) {
        return false;
      }
      // reset the flag
      flushed = false;
      return true;
    }
    return false;
  }
Do a reseek in a normal StoreScanner(scan forward)
@return true if scanner has values left, false if end of scanner
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java