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RE: What is Content-Length?

From: Josh Cohen <joshco@microsoft.com>
Date: Tue, 16 Dec 1997 14:59:57 -0800
Message-Id: <21FD6499922DD111A4F600805FCCD6F2BC352C@red-86-msg.dns.microsoft.com>
To: "'koen@win.tue.nl'" <koen@win.tue.nl>, mogul@pa.dec.com
Cc: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
why not make the spec say something like:

( the mode of http is to specify length whenever possible )

If there is no content length header and if the outermost TE is not chunked
and the client/server doesnt understand that TE, it may respond
4XX unsupported transfer encoding..

Josh Cohen <joshco@microsoft.com>
Program Manager - Internet Technologies

> -----Original Message-----
> From:	koen@win.tue.nl [SMTP:koen@win.tue.nl]
> Sent:	Tuesday, December 16, 1997 4:26 AM
> To:	mogul@pa.dec.com
> Cc:	http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
> Subject:	Re: What is Content-Length?
> 
> Jeffrey Mogul:
> >
> >    > 	If a message is sent on a persistent connection using
> >    > 	a transfer-coding that does not exactly preserve the
> >    > 	length of the data being encoding, then the "chunked"
> >    > 	transfer-coding MUST be used, and MUST be the last
> >    > 	transfer-coding applied.
> >    > 
> >    
> >    Is there a reason to require that chunked be applied after a
> >    self-delimiting transfer encoding?  There would be a (probably
> >    slight)  performance penality for doing it and I don't see the
> >    purpose.
> >
> >It seems like a mistake to get into the business of specifying
> >self-delimiting transfer codings (aside from chunked, which is
> >a generic way to do that).
> 
> I agree, but requiring chunked on top will get us in the much nastier
> business of forbidding self-delimiting transfer codings specified by
> others.
> 
> It should be legal to use something like gzip as the top transfer
> encoding.  If a server has to put chunking on top of a gzipped stream
> without knowing the size of the zipped data beforehand, this could be
> quite expensive in terms of either memory copy operations or software
> complexity.  The same is true for decoding such a thing.
> 
> >-Jeff
> 
> Koen.
Received on Tuesday, 16 December 1997 15:04:11 EST

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