BLOCKHEAD
INFO->tree_depth = BLOCKHEAD (ROOT)->blk_level;
if (BLOCKHEAD (cache)->blk_level != depth)
if (ih == &ITEMHEAD[BLOCKHEAD (LEAF)->blk_nr_item])
ih = (struct item_head *) &BLOCKHEAD (LEAF)->blk_right_delim_key;
int nr_item = BLOCKHEAD (cache)->blk_nr_item;
nr_item = BLOCKHEAD (cache)->blk_nr_item;
nr_item = BLOCKHEAD (LEAF)->blk_nr_item;