test used.

XXX info is passed in by value.

ForeachObjectStats executes onStats on each object stats until onStats returns false or all object stats have been visited.

caller makes sure the data has column meta fot the given seqnum.

used only in some special cases.

used only in some special cases.

used only in some special cases.

used only in some special cases.

used only in some special cases.

used only in some special cases.

CkpMetaEnd = CkpMetaStart + `MaxIDX`.

uuid[36]+_[1]+filename[5].

reserved 5 column for special committs、committs etc.

BlockReadStats collect blk read related cache statistics, include mem and disk.

ObjectBuffer is the buffer prepared before writing to the object file, all data written to the object needs to be filled in it, and then written to the object file at one time.

Reader is to read data from fileservice.

Writer is to virtualize batches into multiple blocks and write them into filefservice at one time.

Alg | Offset | Length | OriginSize ----|--------|--------|------------ 1 | 4 | 4 | 4 Alg: Specifies the compression algorithm Offset: The offset of the compressed data in the file Length: The length of the compressed data OriginSize: The length of the original data.

Location is a fixed-length unmodifiable byte array.

ObjectName is a fixed-length unmodifiable byte array.

ObjectStats has format: +------------------------------------------------------------------------------------------------+ |object_name(60B)|extent(13B)|row_cnt(4B)|block_cnt(4B)|zone_map(64B)|objectSize|objectOriginSize| +------------------------------------------------------------------------------------------------+.