(MODCACHE)
 ap_cache_check_allowed,
 ap_cache_current_age,
 ap_cache_liststr,
 ap_cache_tokstr,
 ap_cache_hex2usec,
 ap_cache_usec2hex,
 ap_cache_generate_name,
 ap_cache_cacheable_headers,
 ap_cache_cacheable_headers_in,
 ap_cache_cacheable_headers_out