Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!ecngs!feeder2.ecngs.de!newsfeed.freenet.ag!news2.euro.net!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Return-Path: <chris@rebertia.com>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.034
X-Spam-Evidence: '*H*': 0.93; '*S*': 0.00; 'subject:Python': 0.05; 'happily': 0.07; 'subject:missing': 0.07; 'python': 0.08; 'intern': 0.09; 'am,': 0.12; 'cc:addr:python-list': 0.15; 'randomize': 0.16; 'subject:String': 0.16; 'wrote:': 0.16; 'jan': 0.19; 'cheers,': 0.20; 'memory': 0.20; 'cc:no real name:2**0': 0.21; 'header:In-Reply-To:1': 0.22; 'stefan': 0.24; 'cc:2**0': 0.25; 'received:209.85.220': 0.27; 'message-id:@mail.gmail.com': 0.28; '24,': 0.28; 'explicitly': 0.28; 'cc:addr:python.org': 0.29; 'hash': 0.30; 'solved': 0.30; 'chris': 0.30; 'subject:?': 0.30; 'quite': 0.31; 'tue,': 0.32; 'it.': 0.33; 'anything': 0.34; 'it."': 0.34; 'reference': 0.37; "there's": 0.37; 'received:google.com': 0.37; 'used,': 0.38; 'received:209.85': 0.38; 'first.': 0.38; 'received:209': 0.39; 'subject:: ': 0.39; 'data': 0.40; 'worth': 0.61; 'your': 0.61; 'provided': 0.61; 'same,': 0.67; 'benefit': 0.68; '(based': 0.84; '12:17': 0.84; 'sender:addr:chris': 0.84; 'subject:moved': 0.84; 'attacks': 0.93; 'presumably': 0.93
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rebertia.com; s=google; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc :x-gm-message-state:content-type; bh=o+MXwR1kvbtr531ET1kO5PfR6SE79lnRPzcmxMZ29mc=; b=ABuw5Gv0WisdrnfC3cMzHMhkeRPTzhtr1jQcSXZ1L3k/nKAqT2HC6u196anPX83f7S UPRhvxDFv4C3NqhOVpFEWrozdN1LuQJ3wWE9hbJs7xcEhZ740YZ9Sb7Fg3vzAJ9pQ0/m jIoXoF8Fx//LP6snEqhbHBUge5BHgLT5BMEBc=
MIME-Version: 1.0
Sender: chris@rebertia.com
In-Reply-To: <jflpds$2o8$1@dough.gmane.org>
References: <CAPTjJmr5=8H9pmWMQ1Q==O1DFGe31ykOBXNzQ9YhS+W8aaAxfw@mail.gmail.com> <CAMZYqRQXfLTrwzqma=ryVKmJByzPtfQqQRa8OjGG7d+qZ7KNGA@mail.gmail.com> <jflbf2$l09$1@dough.gmane.org> <CAPTjJmrYgnYXstkdiN9T1ReV9KxjWN+wsmNita_oz4W_KzX78A@mail.gmail.com> <jflpds$2o8$1@dough.gmane.org>
Date: Tue, 24 Jan 2012 00:33:48 -0800
X-Google-Sender-Auth: RBK383ihJDkVwQuBDdtdNbLqkao
Subject: Re: String interning in Python 3 - missing or moved?
From: Chris Rebert <clp2@rebertia.com>
To: Stefan Behnel <stefan_ml@behnel.de>
X-Gm-Message-State: ALoCoQm98vH51DP0anvcOTuQm+nbttadSEP4G0xJ0oMQUnW3dKKZkhjzeYwTEHdlT719eh7KiIzV
Content-Type: text/plain; charset=UTF-8
Cc: python-list@python.org
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe: <http://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive: <http://mail.python.org/pipermail/python-list>
List-Post: <mailto:python-list@python.org>
List-Help: <mailto:python-list-request@python.org?subject=help>
List-Subscribe: <http://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups: comp.lang.python
Message-ID: <mailman.5021.1327394031.27778.python-list@python.org>
Lines: 18
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1327394031 news.xs4all.nl 6936 [2001:888:2000:d::a6]:54141
X-Complaints-To: abuse@xs4all.nl
Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:19332

On Tue, Jan 24, 2012 at 12:17 AM, Stefan Behnel <stefan_ml@behnel.de> wrote:
> Chris Angelico, 24.01.2012 05:47:
>> Lua and Pike both quite happily solved hash collision attacks in their
>> interning of strings by randomizing the hash used, because there's no
>> way to rely on it. Presumably (based on the intern() docs) Python can
>> do the same, if you explicitly intern your strings first. Is it worth
>> recommending that people do this with anything that is
>> client-provided, and then simply randomize the intern() hash?
>
> If you want to encourage them to fill up their memory with user provided
> data in a non-erasable way,

Actually, quoth intern()'s docs:
"Interned strings are not immortal; you must keep a reference to the
return value of intern() around to benefit from it."

Cheers,
Chris