下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。
VARNISH_STATUS_SYNTAX
(integer)
VARNISH_STATUS_UNKNOWN
(integer)
VARNISH_STATUS_UNIMPL
(integer)
VARNISH_STATUS_TOOFEW
(integer)
VARNISH_STATUS_TOOMANY
(integer)
VARNISH_STATUS_PARAM
(integer)
VARNISH_STATUS_AUTH
(integer)
VARNISH_STATUS_OK
(integer)
VARNISH_STATUS_CANT
(integer)
VARNISH_STATUS_COMMS
(integer)
VARNISH_STATUS_CLOSE
(integer)
VARNISH_CONFIG_IDENT
(string)
VARNISH_CONFIG_HOST
(string)
VARNISH_CONFIG_PORT
(string)
VARNISH_CONFIG_TIMEOUT
(string)
VARNISH_CONFIG_SECRET
(string)
VARNISH_CONFIG_COMPAT
(string)
VARNISH_COMPAT_2
(integer)
VARNISH_COMPAT_3
(integer)