pub const META_PAGE_B: u32 = 1;Expand description
2f: the second commit slot. Generation g lives in page g % 2, so writing generation g+1 only ever overwrites the slot of g-1 – the newest published root is never touched by the write that supersedes it, and a torn slot write fails its page checksum and loses to the other slot. (LMDB’s dual meta page; its pick is by txnid, ours by generation, and unlike LMDB every slot is protected by the ordinary page checksum.)