From: Alex Riesen <raa.lkml@gmail.com>
To: "Shawn O. Pearce" <spearce@spearce.org>
Cc: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>,
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 20:22:29 +0200 [thread overview]
Message-ID: <AANLkTilE7UI3zg180U9GCB6DsByu3B9pwlG6xIyR8uiG@mail.gmail.com> (raw)
In-Reply-To: <20100527180554.GM16470@spearce.org>
On Thu, May 27, 2010 at 20:05, Shawn O. Pearce <spearce@spearce.org> wrote:
> 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.
Just make sure the SHA1 data are properly aligned for your platform
next prev parent reply other threads:[~2010-05-27 18:28 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
2010-05-27 18:22 ` Alex Riesen [this message]
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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