269   librados::bufferlist _buffer;      // write buffer  member in ROCKSDB_NAMESPACE::LibradosWritableFile
280     int r = _io_ctx->append(_fid, _buffer, _buffer_size);  in _SyncLocked()
285       _buffer.clear();  in _SyncLocked()
302         _buffer(),  in LibradosWritableFile()
333     _buffer.append(data.data(), data.size());  in Append()
371         _buffer.clear();  in Truncate()
376       _buffer.clear();  in Truncate()
380       tmp.claim(_buffer);  in Truncate()
381       _buffer.substr_of(tmp, 0, size - _file_size);  in Truncate()
410     r = _io_ctx->aio_append(_fid, write_completion, _buffer, _buffer_size);  in Flush()
414       _buffer.clear();  in Flush()