cache: document negative ttls and add about ttl

We've long supported negative ttls, for infinite cache, except the
documentation incorrectly showed one of our defaults as being 5 and not
-1. As well, with a negative ttl, we were actually making the HTTP
expired header go backwards. This changes it to go ahead ten years
instead.

Further, we add an cache-about-ttl option to set a different ttl for
about pages, which are now increasingly being filtered through markdown
or just sent statically anyway.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 18 insertions, 10 deletions

diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index b4603ef..9d0c089 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -50,32 +50,40 @@ cache-root::
         Path used to store the cgit cache entries. Default value:
         "/var/cache/cgit". See also: "MACRO EXPANSION".
 
+cache-static-ttl::
+        Number which specifies the time-to-live, in minutes, for the cached
+        version of repository pages accessed with a fixed SHA1. Negative
+        values have infinite ttl. Default value: -1".
+
 cache-dynamic-ttl::
         Number which specifies the time-to-live, in minutes, for the cached
-        version of repository pages accessed without a fixed SHA1. Default
-        value: "5".
+        version of repository pages accessed without a fixed SHA1. Negative
+        values have infinite ttl. Default value: "5".
 
 cache-repo-ttl::
         Number which specifies the time-to-live, in minutes, for the cached
-        version of the repository summary page. Default value: "5".
+        version of the repository summary page. Negative values have infinite
+        ttl. Default value: "5".
 
 cache-root-ttl::
         Number which specifies the time-to-live, in minutes, for the cached
-        version of the repository index page. Default value: "5".
+        version of the repository index page. Negative values have infinite
+        ttl. Default value: "5".
 
 cache-scanrc-ttl::
         Number which specifies the time-to-live, in minutes, for the result
-        of scanning a path for git repositories. Default value: "15".
+        of scanning a path for git repositories. Negative values have infinite
+        ttl. Default value: "15".
+
+cache-about-ttl::
+        Number which specifies the time-to-live, in minutes, for the cached
+        version of the repository about page. Negative values have infinite
+        ttl. Default value: "15".
 
 cache-size::
         The maximum number of entries in the cgit cache. Default value: "0"
         (i.e. caching is disabled).
 
-cache-static-ttl::
-        Number which specifies the time-to-live, in minutes, for the cached
-        version of repository pages accessed with a fixed SHA1. Default value:
-        "5".
-
 case-sensitive-sort::
         Sort items in the repo list case sensitively. Default value: "1".
         See also: repository-sort, section-sort.