bo access from VFP

[Guillaume Quintard]

As usual, thanks a bunch for all your help!

Using the THR_* functions work:
https://github.com/gquintard/vmod_rers/blob/270a2f4272be49f8c1c904b899ec91dafcf2f873/src/lib.rs#L227
and they allow me to merge most of the vfp/vdp init code together (helped
by the fact the same rust structure is both a VDP and a VFP)

It would be even more legible if we had access to the vrt_ctx directly (for
both vfp AND vdp) so I wouldn't have to build my own, OR if we hade
VRT_priv_task_raw_parts(const req *, const busyobj *, const void *) so I
didn't have to build my own context, but that is already pretty sweet

Cheers!

-- 
Guillaume Quintard


On Mon, Jan 3, 2022 at 7:58 AM Dridi Boukelmoune <dridi at varni.sh> wrote:

> On Fri, Dec 31, 2021 at 11:48 PM Guillaume Quintard
> <guillaume.quintard at gmail.com> wrote:
> >
> > Small follow-up on that one: it would be nice for VFP to be able to
> disable streaming (bo->do_stream), so that's an extra argument to be able
> to access the busyobj
> >
> > --
> > Guillaume Quintard
> >
> >
> > On Sun, Dec 26, 2021 at 6:11 PM Guillaume Quintard <
> guillaume.quintard at gmail.com> wrote:
> >>
> >> Happy holidays to everyone,
>
> Happy new year !
>
> >> Unless I'm mistaken, there's no way for a VFP to access the busyobj,
> and was wondering if that could change as I need it to retrieve a vmod_priv.
>
> I think your statement is correct.
>
> >> For some context, I stumbled on this while working on this vmod:
> https://github.com/gquintard/vmod_rers/tree/v0.0.2
> >> (It's in rust, and I'm using it to explore what kind of bindings we
> need. I already have a couple of examples for VDP[1] and VFP[2] in the
> crate[3] repo, but of course they don't need as much as a real vmod.)
> >>
> >> With vmod_rers, the user is able to add regex/sub pairs on a
> per-request basis [4], and they will be acted upon by the VDP. To store and
> retrieve the pairs I use the regular "fake vrt_ctx trick"[4], since the VDP
> has access to the req struct, it's very easy to build.
> >> However, I'm unable to do the same thing on the VFP side since I have
> neither a req (fair) nor a bo.
>
> The big difference between both is that we only use VDPs to deliver
> client responses, but we use VFPs to fetch both beresp and req bodies,
> so the VFP operates at the objcore level.
>
> >> Is there a big reason for not having access to it, or is it just that
> nobody asked for it until now?
>
> Probably nobody never asked for it?
>
> Passing a VRT_CTX to the VFP init function could help grab a req or bo
> and stash it in vfp_entry::priv1, but I don't see a way to do that
> today without cheating.
>
> *cough* THR_GetBusyobj() *cough*
>
> Cheers,
> Dridi
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.varnish-cache.org/lists/pipermail/varnish-dev/attachments/20220106/6eaf4b41/attachment-0001.html>