From: Yaron Minsky <yminsky@janestreet.com>
To: Goswin von Brederlow <goswin-v-b@web.de>
Cc: "caml-list@inria.fr" <caml-list@inria.fr>
Subject: Re: [Caml-list] Hardening [Perl's] hash function further
Date: Mon, 25 Nov 2013 09:43:34 -0500 [thread overview]
Message-ID: <CACLX4jSHsgsuz7KJJ2pE2aU50L2a==-vU9y9z=es8aFocoKTbw@mail.gmail.com> (raw)
In-Reply-To: <20131125135124.GF3610@frosties>
For what it's worth, Core's Hashtbl module uses AVL trees for the
buckets, so the behavior on large numbers of collisions degrades to
logarithmic rather than linear.
y
On Mon, Nov 25, 2013 at 8:51 AM, Goswin von Brederlow <goswin-v-b@web.de> wrote:
> On Wed, Nov 20, 2013 at 10:47:10PM +0100, Gerd Stolpmann wrote:
>> Generally, I think it is better to change the hash table algorithm in
>> situations where data from untrusted sources is processed. That means
>> using balanced trees for the buckets. Consumes more RAM, but is provably
>> safe. (Or, at minimum, limit the length of the buckets.)
>>
>> Gerd
>
> If you truely have hash collisions then you can't limit the length of
> the buckets. There is no way to make 2 keys with identical hash not
> land in the same bucket.
>
> Or did you mean use a list up to N items and then switch to a tree?
>
> MfG
> Goswin
>
> --
> Caml-list mailing list. Subscription management and archives:
> https://sympa.inria.fr/sympa/arc/caml-list
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs
next prev parent reply other threads:[~2013-11-25 14:43 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-18 20:44 Richard W.M. Jones
2013-11-19 0:08 ` Gerd Stolpmann
2013-11-19 7:53 ` David MENTRE
2013-11-19 8:50 ` Richard W.M. Jones
2013-11-19 9:14 ` Gabriel Scherer
2013-11-19 11:19 ` Dario Teixeira
2013-11-19 12:55 ` rixed
2013-11-19 22:18 ` Nicolas Braud-Santoni
2013-11-19 22:39 ` Eric Cooper
2013-11-19 22:55 ` Nicolas Braud-Santoni
2013-11-25 13:46 ` Goswin von Brederlow
2013-11-19 22:31 ` Nicolas Braud-Santoni
2013-11-20 18:56 ` Florian Weimer
2013-11-20 21:47 ` Gerd Stolpmann
2013-11-25 13:51 ` Goswin von Brederlow
2013-11-25 14:43 ` Yaron Minsky [this message]
2013-11-19 22:15 ` Nicolas Braud-Santoni
2013-11-25 13:38 ` Goswin von Brederlow
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CACLX4jSHsgsuz7KJJ2pE2aU50L2a==-vU9y9z=es8aFocoKTbw@mail.gmail.com' \
--to=yminsky@janestreet.com \
--cc=caml-list@inria.fr \
--cc=goswin-v-b@web.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox