- From: Bjoern Hoehrmann <derhoermi@gmx.net>
- Date: Thu, 12 Sep 2013 14:52:32 +0200
- To: Barry van Oudtshoorn <bvanoudtshoorn@gmail.com>
- Cc: www-style@w3.org, Joey Bradshaw <joey_bradshaw@strandedpirate.com>
* Barry van Oudtshoorn wrote:
>Is this not what GZIP effectively does in any case? <plug>As someone
>who's written a CSS minifier
>(https://github.com/barryvan/CSSMin/)</plug>, I'd be interested to see
>what sort of reductions this approach would give over just gzipping the
>file.
The DEFLATE format encodes literal sequences of bytes and instructions
to copy bytes, and stores them efficiently ("LZ77"). So something like
abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz
may end up as `abcdefghijklmnopqrstuvwxyz<go back 26 bytes and copy 26
bytes>`, and the most frequent copy instructions are encoded concisely.
For structured text a fair rule of thumb is that you cannot do better
than half the compressed size of a good DEFLATE encoder, see e.g. the
results on <http://mattmahoney.net/dc/text.html>. That would mean no
more than the size of a small logo bitmap for typical web pages. We'd
most likely be better off adopting `xz` as `gzip` replacement as that
would also shrink other text resources.
--
Björn Höhrmann · mailto:bjoern@hoehrmann.de · http://bjoern.hoehrmann.de
Am Badedeich 7 · Telefon: +49(0)160/4415681 · http://www.bjoernsworld.de
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Received on Thursday, 12 September 2013 12:52:59 UTC