Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.java.programmer > #21588

Re: idea for more efficient HashMap

Show all headers | View raw

On 18.01.2013 04:30, Kevin McMurtrie wrote:
> In article <50F7C307.7060407@telia.com>,
>   Lars Enderin <lars.enderin@telia.com> wrote:
>
>> 2013-01-16 23:31, Robert Klemme skrev:
>>> On Tuesday, January 15, 2013 6:56:29 AM UTC+1, Kevin McMurtrie wrote:
>>>> In article <9hc2f8ltgn1bmdsrk8vb9kuu1vi5dkl2r5@4ax.com>,
>>>>   Roedy Green <see_website@mindprod.com.invalid> wrote:
>>>>> Inside HashMap are little glue Entry objects that point to the key and
>>>>> value.
>>>>
>>>>> What if you could implement an interface on your objects so that
>>>>> HashMap could use them directly without separate key or Entry glue?.
>>>>>
>>>>
>>>>> e.g. getKey()
>>>>>         getPrev()
>>>>>         getNext()
>>>>>         setPrev()
>>>>>         setNext()
>>>>>
>>>>
>>>>> One drawback would be your objects could live on only one such
>>>>> space-efficient HashMap.
>>>>
>>>> I've done this when efficiency demanded it.  The downside is that you
>>>> can't implement java.util.Map or java.util.Dictionary because of the way
>>>> put(K,V) is declared.
>>>
>>> Why that?  I actually have done that implementation (see above) and it is
>>> consistent with the Map interface.
>>>
>>>> I will not see posts from Google because I must filter them as spam
>>>
>>> That might be a mistake - you'll might lose valuable feedback that way.
>>
>> He will not see your post then...

As I said above... :-)

> The Google filter is real.  Google doesn't maintain their systems so
> they're employed by Chinese crime gangs to flood many Usenet groups.

My Usenet provider does a pretty decent job filtering spam for around 10 
EUR / year.  So there are definitively ways to handle that.

> My original point is that you can't gracefully enforce insertion of an
> object having the key, value, and collision link together when put(K,V)
> takes two arguments.

What exactly do you mean by "collision link"?

>  It's unfortunate that Dictionary defines setter
> methods.  There are so many cases where I want a widely supported
> implementation of V get(K) without the other things.

Are you referring to the setter of Map.Entry<K,V>?

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

idea for more efficient HashMap Roedy Green <see_website@mindprod.com.invalid> - 2013-01-12 01:55 -0800
  Re: idea for more efficient HashMap v_borchert@despammed.com (Volker Borchert) - 2013-01-12 14:21 +0000
  Re: idea for more efficient HashMap Robert Klemme <shortcutter@googlemail.com> - 2013-01-13 19:44 +0100
  Re: idea for more efficient HashMap Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2013-01-14 21:56 -0800
    Re: idea for more efficient HashMap Robert Klemme <shortcutter@googlemail.com> - 2013-01-16 14:31 -0800
      Re: idea for more efficient HashMap Lars Enderin <lars.enderin@telia.com> - 2013-01-17 10:23 +0100
        Re: idea for more efficient HashMap Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2013-01-17 19:30 -0800
          Re: idea for more efficient HashMap Robert Klemme <shortcutter@googlemail.com> - 2013-01-20 20:28 +0100
          Re: idea for more efficient HashMap Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-01-20 14:49 -0500
          Re: idea for more efficient HashMap Roedy Green <see_website@mindprod.com.invalid> - 2013-01-29 01:41 -0800
            Re: idea for more efficient HashMap Arne Vajhøj <arne@vajhoej.dk> - 2013-01-29 22:03 -0500
              Re: idea for more efficient HashMap Gene Wirchenko <genew@telus.net> - 2013-01-30 11:34 -0800
                Re: idea for more efficient HashMap Arne Vajhøj <arne@vajhoej.dk> - 2013-01-30 21:35 -0500
                Re: idea for more efficient HashMap Gene Wirchenko <genew@telus.net> - 2013-01-31 10:47 -0800
                Re: idea for more efficient HashMap Arne Vajhøj <arne@vajhoej.dk> - 2013-02-01 19:57 -0500

csiph-web