import test304;

Lets you detect if the current response will end up as a 304 Not Modified. Must only be used in vcl_deliver.

The 304 logic in Varnish depends on whether or not any of the relevant headers were altered in vcl_deliver, so in general we can't know until after vcl_deliver if this response will end up as a 304.

To rely on the result from the test304() function, you must not alter either of the following after the call:

req.http.if-modified-since
req.http.if-none-match

Varnish uses the headers of the fetched object (not the copy in resp.http.*) when deciding if it will do a 304, so stripping off resp.http.etag or resp.http.last-modified in vcl_deliver will prevent the client from seeing these, but will not prevent Varnish from serving a 304.

Prototype

test304()

Return value

BOOL

Description

Returns true if this response will end up as a 304. Do not invoke this from outside of vcl_deliver.

Example

sub vcl_deliver {
    if (test304.test304()) {
        set resp.http.foo = "this is a 304";
    }
}

The source tree is based on autotools to configure the building, and does also have the necessary bits in place to do functional unit tests using the varnishtest tool.

Usage:

autoreconf -vif
./configure VARNISHSRC=DIR [VMODDIR=DIR]

VARNISHSRC is the directory of the Varnish source tree for which to compile your vmod. Both the VARNISHSRC and VARNISHSRC/include will be added to the include search paths for your module.

Optionally you can also set the vmod install directory by adding VMODDIR=DIR (defaults to the pkg-config discovered directory from your Varnish installation).

Make targets:

• make - builds the vmod
• make install - installs your vmod in VMODDIR
• make check - runs the unit tests in src/tests/*.vtc

This document is licensed under the same license as the libvmod-example project. See LICENSE for details.

• Copyright (c) 2011 Varnish Software