2.1.2 Block Format
The first 20 bytes of the block header format is the same for all
types of blocks.
- 0 blk:id
- The ID of this block.
- 4 blk:top-id
- The ID of the root block of this tree.
- 8 blk:nxt-id
- The ID of the next block in the chain (at same level as this one).
- 12 blk:time
- The 32-bit time/date when this block was last modified.
- 16 blk:end
- Two-byte length of data in block, including header.
- 18 blk:level
- Block level; 0 is leaf.
- 19 blk:typ
- Block type, one of:
- dir-typ Directory tree.
- ind-typ Other tree.
- seq-typ Sequential chain (unused).
- frl-typ Free-list chain.
- Start of data for SEQ-TYP blocks. Data spans to blk:end.
- 20 leaf-split-key
- Start of data for other block types. Data spans to blk:end.