From: "Shawn O. Pearce" <spearce@spearce.org>
To: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
Cc: Vicent Marti <tanoku@gmail.com>,
git@vger.kernel.org, srabbelier@gmail.com
Subject: Re: Libgit2 on the Summer of Code
Date: Thu, 27 May 2010 11:05:54 -0700 [thread overview]
Message-ID: <20100527180554.GM16470@spearce.org> (raw)
In-Reply-To: <20100527174636.GB9909@LK-Perkele-V2.elisa-laajakaista.fi>
Ilari Liusvaara <ilari.liusvaara@elisanet.fi> wrote:
> * Where algorithm in git_revpool_table__hash() is from? Since it appears to
> hash binary object IDs, wouldn't just simple sum/xor over words be sufficient
> (all SHA-1 output bits are very nearly independent). Or do you need to be
> compatible with some other implementation (doesn't appear so, because hash
> is computed differently depending on endianess)?
If you need a hash value for a SHA-1, why not just cast the unsigned
char* to unsigned int* and load the first int as the hash code?
The output of SHA-1 is pretty evenly distributed, using the first
few bytes as an int should yield a sufficient distribution throughout
the hashtable.
--
Shawn.
next prev parent reply other threads:[~2010-05-27 18:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-27 16:25 Libgit2 on the Summer of Code Vicent Marti
2010-05-27 17:46 ` Ilari Liusvaara
2010-05-27 18:05 ` Shawn O. Pearce [this message]
2010-05-27 18:22 ` Alex Riesen
2010-06-02 18:42 ` Junio C Hamano
2010-05-27 18:35 ` Ilari Liusvaara
2010-05-28 0:15 ` Vicent Marti
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