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Re: ra_dav compression question

From: <cmpilato_at_collab.net>
Date: 2003-06-23 23:01:23 CEST

Chris Hecker <checker@d6.com> writes:

> A delta/diff is different from a compressed stream. Sure, it's not
> sending the parts that didn't change, but the changes aren't
> compressed (and, as someone said, adds are the special case where it
> all changes), if I understand things correctly. Not that sending
> diffs isn't great, but you really want the compression to go both
> ways, especially since that's part of the reason one is supposed to
> use apache as the server from the manual ("wire compression for free").

Generally speaking, you're correct. But Subversion uses a binary
diffing format that not only sends just the differences, but even
those differences are transmitted in a gzip-like fashion. I forget
the stats someone figured out, but there definitely is some
compression going on. In other words, if your differences are that
you added the phrase "Chris is a pleasant programmer" in ten different
places through a file, the trasmitted data might list that string only
once, and then refer to it ten times.

Additionally, as you noted, we can have real Zlib compression on top
of that, compliments of Apache and Neon.

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Received on Mon Jun 23 23:01:21 2003

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