LSNdisk_lsn;// The LSN as of the most recent version on disk.
LSNlog_lsn;// The LSN as of the most recent log write.
intlayout_version;// What version of the data structure?
BRTNODEparent_brtnode;/* Invariant: The parent of an in-memory node must be in main memory. This is so we can find and update the down pointer when we change the diskoff of a node. */
intheight;/* height is always >= 0. 0 for leaf, >0 for nonleaf. */
u_int32_trand4fingerprint;
u_int32_tlocal_fingerprint;/* For leaves this is everything in the buffer. For nonleaves, this is everything in the hash tables, but does not include child subtree fingerprints. */