no inline C needed for custom TTL

Author: dbu

CHANGELOG.md

@@ -12,6 +12,8 @@ See also the [GitHub releases page](https://github.com/FriendsOfSymfony/FOSHttpC
 * Added support for the more efficient xkey cache tag system. BAN remains the
   default cache tagging system, but if you can install the varnish modules in
   your system, it is recommended to update to xkey.
+* No inline C is needed for the custom TTL header with Varnish 4 or better. use
+  `std.duration()` instead.
 
 ### Symfony user context
 * You can now also specify which headers are used for

doc/varnish-configuration.rst

@@ -384,10 +384,7 @@ Custom TTL
 .. include:: includes/custom-ttl.rst
 
 Subroutines are provided in ``resources/config/varnish-[version]/fos_custom_ttl.vcl``.
-The configuration needs to use inline C, which is disabled by default since
-Varnish 4.0. To use the custom TTL feature, you need to start your Varnish with
-inline C enabled: ``-p vcc_allow_inline_c=on``. Then add the following to
-``your_varnish.vcl``:
+Add the following to ``your_varnish.vcl``:
 
 .. configuration-block::
 
@@ -409,6 +406,14 @@ inline C enabled: ``-p vcc_allow_inline_c=on``. Then add the following to
 
 The custom TTL header is removed before sending the response to the client.
 
+.. note::
+
+    If you are using Varnish 3, this feature is using inline C. Inline C is
+    enabled for Varnish 3 by default. Check for the ``vcc_allow_inline_c``
+    setting.
+    If you are using Varnish 4 or newer, you are using the
+    ``varnish/fos_custom_ttl.vcl`` which uses a vmod function instead of inline C.
+
 .. _varnish_debugging:
 
 Debugging

resources/config/varnish/fos_custom_ttl.vcl

@@ -6,32 +6,16 @@
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
  */
-C{
-    #include <stdlib.h>
-}C
+
+import std;
 
 /**
  * Read a custom TTL header for the time to live information, to be used
  * instead of s-maxage.
  */
 sub fos_custom_ttl_backend_response {
     if (beresp.http.X-Reverse-Proxy-TTL) {
-        /*
-         * Note that there is a ``beresp.ttl`` field in VCL but unfortunately
-         * it can only be set to absolute values and not dynamically. Thus we
-         * have to resort to an inline C code fragment.
-         *
-         * As of Varnish 4.0, inline C is disabled by default. To use this
-         * feature, you need to add `-p vcc_allow_inline_c=on` to your Varnish
-         * startup command.
-         */
-        C{
-            const char *ttl;
-            const struct gethdr_s hdr = { HDR_BERESP, "\024X-Reverse-Proxy-TTL:" };
-            ttl = VRT_GetHdr(ctx, &hdr);
-            VRT_l_beresp_ttl(ctx, atoi(ttl));
-        }C
-
+        set beresp.ttl = std.duration(beresp.http.X-Reverse-Proxy-TTL + "s", 0s);
         unset beresp.http.X-Reverse-Proxy-TTL;
     }
 }

tests/Functional/Varnish/CustomTtlTest.php

@@ -19,14 +19,6 @@
  */
 class CustomTtlTest extends VarnishTestCase
 {
-    public function setUp()
-    {
-        if ($this->getVarnishVersion() >= 4) {
-            $this->getProxy()->setAllowInlineC(true);
-        }
-        parent::setUp();
-    }
-
     protected function getConfigFile()
     {
         switch ((int) $this->getVarnishVersion()) {