ro_node
struct btree_node *ro_node(struct ro_spine *s);
flags = le32_to_cpu(ro_node(s)->header.flags);
i = le32_to_cpu(ro_node(s)->header.nr_entries);
*result_key = le64_to_cpu(ro_node(s)->keys[i]);
*result_key = le64_to_cpu(ro_node(s)->keys[0]);
block = value64(ro_node(s), i);
block = value64(ro_node(s), 0);
i = search_fn(ro_node(s), key);
flags = le32_to_cpu(ro_node(s)->header.flags);
nr_entries = le32_to_cpu(ro_node(s)->header.nr_entries);
block = value64(ro_node(s), i);
*result_key = le64_to_cpu(ro_node(s)->keys[i]);
memcpy(v, value_ptr(ro_node(s), i), value_size);