1	field: u64 timestamp;	offset:0;	size:8;	signed:0;
2	field: local_t commit;	offset:8;	size:8;	signed:1;
3	field: int overwrite;	offset:8;	size:1;	signed:1;
4	field: char data;	offset:16;	size:4080;	signed:0;
5