Re: Alt-Svc alternative cache invalidation (ext#16)

[Erik Nygren <[e-mail]>]

On Fri, Aug 22, 2014 at 7:50 PM, Martin Thomson <[e-mail]>
wrote:

> On 22 August 2014 14:53, Erik Nygren <[e-mail]> wrote:
> > but does not define anything similar for the ALTSVC frame.  Aligning the
> > frame and the
> > header would allow this to apply to both.
>
> I think that we would want to move the Origin field up to the header
> with Max-Age.  Logically, you store alternatives for different origins
> separately, so requiring different frames makes sense there.  It also
> removes any potential for duplication.
>
> Also 8 bits of length is not sufficient for an HTTP origin if the name
> is maximum size.  I'd assume that the same applies to authority.
>


Agreed on both counts.  What about this, then:

  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                          Max-Age (32)                         |
 +---------------+---------------+-------------------------------+
 | Origin-Len (16)               |         Origin? (*)         ...
 +---------------------------------------------------------------+
 |Num-Alt-Auth(8)|
 +---------------+---------------+-------------------------------+
 | Proto-Len(8)  |        Protocol-ID (*)                        |
 +---------------+-----------------------------------------------+
 | Alt-Auth-Len (16)             |        Alt-Auth (*)         ...
 +---------------+-----------------------------------------------+
 |                        Ext-Param? (*)                       ...
 +---------------------------------------------------------------+

where Origin-Len=0 would be used in the case where this was part of a
Stream != 0
and Num-Alt-Auth>=1.  The {Proto-Len, Protocol-ID, Alt-Auth-Len, Alt-Auth}
would be
repeated Num-Alt-Auth times.  Alt-Auth is a string such as "
server.example.com:443"