Re: [dispatch] Zstandard compression

Harald Alvestrand <harald@alvestrand.no> Thu, 14 December 2017 14:48 UTC

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To: "Murray S. Kucherawy" <superuser@gmail.com>
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From: Harald Alvestrand <harald@alvestrand.no>
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Subject: Re: [dispatch] Zstandard compression
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Den 14. des. 2017 15:22, skrev Murray S. Kucherawy:
> On Tue, Nov 14, 2017 at 4:25 PM, Harald Alvestrand <harald@alvestrand.no
> <mailto:harald@alvestrand.no>> wrote:
> 
>     > Yes. But I think what Sean is saying is that above and beyond that,
>     > you'd (in many if not most use cases) also want to know what the
>     > decoded octet stream is about. Otherwise, this information has to be
>     > transmitted on a side channel.
> 
>     One (horribly ugly) way of doing this is to have something like a
>     "contains" parameter:
> 
>     mime-type: application/zstandard; contains="text/plain; charset=utf-8"
> 
>     That's one form of side channel for passing the data around. Not sure if
>     anyone would use it.
>     But it's such an ugly way of doing things that it should definitely be
>     suggested on the media-types list, not here.
> 
> 
> Interesting.  I haven't seen this technique used before.  Do other
> compression methods have such a mechanism described and registered?
> 

No - it's been quite controversial the times (long ago) that it's been
proposed.

I think it was suggested for RFC 6713 (application/gzip), but it didn't
survive the discussion. Probably that RFC should be taken as precedent.