private MemStoreSize doDropStoreMemStoreContentsForSeqId(HStore s, long currentSeqId)
    throws IOException {
    MemStoreSize flushableSize = s.getFlushableSize();
    this.decrMemStoreSize(flushableSize);
    StoreFlushContext ctx = s.createFlushContext(currentSeqId, FlushLifeCycleTracker.DUMMY);
    ctx.prepare();
    ctx.abort();
    return flushableSize;
  }
Drops the memstore contents after replaying a flush descriptor or region open event replay if
the memstore edits have seqNums smaller than the given seq id
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java