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From: Stefan Monnier <monnier@iro.umontreal.ca>
To: caml-list@inria.fr
Subject: Re: Hashtbls with physical equality?
Date: Mon, 15 Nov 2004 18:42:21 -0500	[thread overview]
Message-ID: <jwvd5yeel8a.fsf-monnier+gmane.comp.lang.caml.inria@gnu.org> (raw)
In-Reply-To: <Pine.LNX.4.44.0411151400080.19815-100000@localhost.localdomain>

> Starting with the  fact that it returns a 32-bit *int* (and what happens
> when you have more  than 4 billion objects?  Possible in a 64-bit
> system!).

It's not an object-id, it's a hash code.  I.e. it does not guarantee that

     a != b  ==>  a.hashCode() != b.hashCode()

so the 32bit restriction is only a serious problem once the size of your
hashtable gets close to a billion of buckets.
Sure that can happen, but not nearly as soon as a 4GB Java process or even
a Java process with 4 billion objects.


        Stefan


      parent reply	other threads:[~2004-11-15 23:42 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-11-14 22:29 Wheeler Ruml
2004-11-15  0:33 ` [Caml-list] " Christian Szegedy
     [not found] ` <20041115012212.GA6561@artisan.com>
2004-11-15  2:20   ` Wheeler Ruml
2004-11-15 10:24     ` Alex Baretta
2004-11-15 16:45       ` Wheeler Ruml
2004-11-15 20:34         ` Marcin 'Qrczak' Kowalczyk
2004-11-15 20:37 ` Brian Hurt
2004-11-15 21:03   ` Wheeler Ruml
2004-11-15 21:30   ` Marcin 'Qrczak' Kowalczyk
2004-11-15 23:42   ` Stefan Monnier [this message]

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