Re: Header compression question: duplicate header entry and current index on computing working set

Martin Thomson <martin.thomson@gmail.com> Wed, 17 July 2013 16:37 UTC

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Date: Wed, 17 Jul 2013 09:36:22 -0700
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From: Martin Thomson <martin.thomson@gmail.com>
To: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
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Subject: Re: Header compression question: duplicate header entry and current index on computing working set
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On 17 July 2013 08:56, Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com> wrote:
> In 3.4, to compute working set from reference set of headers, the index of
> entry in header table is required.
> The question is, when the duplicate entries are in the header table, which
> index is used as the index of working set?

If, for some strange reason, a compressor created multiple identical
entries in the table, the decompressor is required to respect that
choice, even if it is likely to be a bug.  This prevents the
decompressor and compressor from getting out of sync.

The compressor can then reference any of the entries when using an index.