int region_attr_cmp(const void *e1, const void *e2, size_t size) {
region_attr *ra1 = (region_attr *)e1;
region_attr *ra2 = (region_attr *)e2;
int region_attr_cmp(const void *e1, const void *e2, size_t size) {
region_attr *ra1 = (region_attr *)e1;
region_attr *ra2 = (region_attr *)e2;