Re: [PATCH] Put sha1dc on a diet

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Mar 2, 2017, 14:39 UTC
Message-ID: <alpine.DEB.2.20.1703021538060.3767@virtualbox>
In-Reply-To: <20170301231921.2puf7o7jkrujscwn@sigill.intra.peff.net>

Hi Peff,

On Wed, 1 Mar 2017, Jeff King wrote:

Show 6 quoted lines

> I do think that could argue for turning on the collision detection only
> during object-write operations, which is where it matters. It would be
> really trivial to flip the "check collisions" bit on sha1dc. But I
> suspect you could go faster still by compiling against two separate
> implementations: the fast-as-possible one (which could be openssl or
> blk-sha1), and the slower-but-careful sha1dc.

Given the speed difference between OpenSSL and sha1dc, it would be a wise thing indeed to do sha1dc only where objects enter from possibly untrusted sources, and use OpenSSL for all other hashing.

Ciao, Johannes