From: "Jörn Engel" <joern@logfs.org>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [RFC] B+Tree library V2
Date: Thu, 8 Jan 2009 20:46:38 +0100 [thread overview]
Message-ID: <20090108194638.GC24884@logfs.org> (raw)
In-Reply-To: <1231433404.8398.1.camel@johannes>
On Thu, 8 January 2009 17:50:04 +0100, Johannes Berg wrote:
>
> I see this:
>
>
> - * Second trick is to special-case the key "0" or NUL. As seen above, this
> - * value indicates an unused slot, so such a value should not be stored in the
> - * tree itself. Instead it is stored in the null_ptr field in the btree_head.
>
> Does that mean that wasn't true, and I can store a 0 key?
Ahh, don't look at that! The embarrassment is unbearable! Go away!
Yes, I used to have a special exception for a 0 key. But I also have
a special exception for a NULL value and can test against that instead
of testing against a 0 key. It is even faster, because the value is not
variable-sized. In hindsight it is hard to explain why I ever did that.
Jörn
--
Unless something dramatically changes, by 2015 we'll be largely
wondering what all the fuss surrounding Linux was really about.
-- Rob Enderle
next prev parent reply other threads:[~2009-01-08 19:46 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-26 12:46 [RFC] B+Tree library Jörn Engel
2008-10-28 1:25 ` Dave Chinner
2008-10-30 17:43 ` Pavel Machek
2008-10-30 17:58 ` Jörn Engel
2008-10-30 19:14 ` Pavel Machek
2008-10-30 20:20 ` Jörn Engel
2008-10-31 6:38 ` Christian Borntraeger
2008-10-31 7:35 ` Jörn Engel
2008-10-31 9:16 ` Geert Uytterhoeven
2008-10-31 9:20 ` Jörn Engel
2008-10-31 10:35 ` Johannes Berg
2008-10-31 11:26 ` Jörn Engel
2008-10-31 11:32 ` Johannes Berg
2008-10-31 12:54 ` Jörn Engel
2008-10-31 13:07 ` Johannes Berg
2008-10-31 13:15 ` Jörn Engel
2008-11-01 15:59 ` [RFC] B+Tree library V2 Jörn Engel
2008-11-05 19:57 ` Johannes Berg
2008-11-05 20:06 ` Jörn Engel
2008-11-05 20:12 ` Johannes Berg
2008-11-05 20:21 ` Jörn Engel
2008-11-05 20:25 ` Johannes Berg
2008-11-07 7:52 ` Jörn Engel
2009-01-08 0:57 ` Johannes Berg
2009-01-08 16:24 ` Jörn Engel
2009-01-08 16:34 ` Johannes Berg
2009-01-08 19:40 ` Jörn Engel
2009-01-08 16:50 ` Johannes Berg
2009-01-08 19:46 ` Jörn Engel [this message]
2009-01-08 17:10 ` Johannes Berg
2009-01-08 20:02 ` Jörn Engel
2009-01-08 20:18 ` Johannes Berg
2009-01-08 21:09 ` Jörn Engel
2008-10-31 13:16 ` [RFC] B+Tree library Johannes Berg
2008-10-31 13:29 ` Jörn Engel
2008-10-31 13:45 ` Bert Wesarg
2008-10-31 15:18 ` Tim Gardner
2008-10-31 15:35 ` Jörn Engel
2008-10-31 20:17 ` Sean Young
2008-10-31 23:36 ` Jörn Engel
2008-11-01 10:17 ` Sean Young
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