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Re: All changes but huffman encoding integrated + a question

From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Wed, 16 Oct 2013 11:43:13 +0900
Message-ID: <CAPyZ6=+sKRdMrA1b2SWsYZ74ZTFDNUPkkG37fXmyDVV9e9Xy6Q@mail.gmail.com>
To: Roberto Peon <grmocg@gmail.com>
Cc: HTTP Working Group <ietf-http-wg@w3.org>
On Wed, Oct 16, 2013 at 11:25 AM, Roberto Peon <grmocg@gmail.com> wrote:

> Just wanted to let people know that the github version of the compression
> spec includes all issues but huffman encoding (Herve and Jeff-- thanks)!
>
> I believe there is a potential ambiguity though, which I'm not sure if
> people realize or care about (and so asking here before potentially
> throwing mud in clear water)...
>
> When adding a new header to the header table, one must first evict entries.
> When using the indexed-name literal header representation, it is possible
> that one may be evicting the entry that contains the name which the new
> addition would need (and which needed to be examined in order to determine
> the amount of space to free up in the first place).
>
> There are two obvious resolutions:
> 1) Require that the name be kept in these circumstances (possibly by
> copying somewhere (ideally into the end of the buffer)). If the storage for
> the header table was a ring buffer, one would simply increment the '0'
> index without copying.
> This is my preference.
>
>
+1
I actually did this in nghttp2 implementation (well, it does not use ring
buffer at the moment, just keep reference of entry in indexed name, so that
I get no segmentation fault).

Best regards,

Tatsuhiro Tsujikawa

2) Make this illegal; This makes the encoder more complex as the encoder
> must attempt to do this encoding and then check to see if actually fit
> every time it does this kind of header representation.
>
>
> What do people think?
>
> -=R
>
Received on Wednesday, 16 October 2013 02:44:00 UTC

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