[PATCH 1 of 2] Cache: remove unused valid_msec fields

[Maxim Dounin]

Hello!

On Wed, Nov 19, 2014 at 01:06:22PM -0800, Piotr Sikora wrote:

> Hey Maxim,
> 
> > I would rather not, for two reasons:
> >
> > - I would actually like to see support for subsecond cache
> >   validity times added eventually (unlikely to happen in the near
> >   future, but still).
> 
> That's valid reason, but it's going to be of rather limited use,
> because neither "Expires" nor "Cache-Control" can request such
> validity.

I've seen more than one attempt to use nginx for microcaching, and 
this looks like a perfectly valid use case which will benefit from 
subsecond times a lot.

> Also, this field has been there since the introduction of cache over 5
> years ago, just wasting I/O, so I'd argue that there is no reason to
> keep it, unless it's being used (which is not). It can always be added
> later on, when it's needed.

>From I/O point of view, there is no difference as there is a 
padding anyway.

-- 
Maxim Dounin
http://nginx.org/