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Groups > comp.lang.java.programmer > #28433

Re: byte stream vs char stream buffer

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On Sat, 10 May 2014 17:21:19 -0700, Roedy Green wrote:

> On Sat, 10 May 2014 23:24:57 +0200, Robert Klemme
> <shortcutter@googlemail.com> wrote, quoted or indirectly quoted someone
> who said :
> 
>>I don't think duplicate buffering will make things better.
> 
> It does. And allocating your space exactly 50:50 makes a noticeable
> difference.
> 
> the plain Buffered reader was done like this:
> 
> final BufferedReader ibr = new BufferedReader( new FileReader(
> sampleDataFile ), buffsize / 2 );
>
You said earlier that you were partitioning a fixed amount of buffer 
space between the BufferedInputStream and the BufferedReader, but that's 
not what your code shows.

Instead the BufferedInputStream  is getting part of a 'buffer space 
allocation', which is set to 32K. This part varies from 10% to 90% of the 
32K while the BufferedReader always gets 16K. This means that the total 
buffer space used by the combination of BufferedInputStream and 
BufferedReader varies from 19.2 KB to 60.8 KB as the 'ratio' varies from 
0.1 to 0.9. 

In other words, you're not measuring what you thought you're measuring 
because the total buffer space used by each test varies by a factor of 
three during the tests and will almost certainly affect your results.



-- 
martin@   | Martin Gregorie
gregorie. | Essex, UK
org       |

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Thread

byte stream vs char stream buffer Roedy Green <see_website@mindprod.com.invalid> - 2014-05-06 23:48 -0700
  Re: byte stream vs char stream buffer Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-05-08 13:30 +0000
    Re: byte stream vs char stream buffer Roedy Green <see_website@mindprod.com.invalid> - 2014-05-09 09:34 -0700
      Re: byte stream vs char stream buffer Roedy Green <see_website@mindprod.com.invalid> - 2014-05-10 13:18 -0700
        Re: byte stream vs char stream buffer Robert Klemme <shortcutter@googlemail.com> - 2014-05-10 23:24 +0200
          Re: byte stream vs char stream buffer Roedy Green <see_website@mindprod.com.invalid> - 2014-05-10 16:08 -0700
            Re: byte stream vs char stream buffer Robert Klemme <shortcutter@googlemail.com> - 2014-05-11 16:02 +0200
              Re: byte stream vs char stream buffer markspace <markspace@nospam.nospam> - 2014-05-11 11:50 -0700
                Re: byte stream vs char stream buffer markspace <markspace@nospam.nospam> - 2014-05-11 12:10 -0700
                Re: byte stream vs char stream buffer Robert Klemme <shortcutter@googlemail.com> - 2014-05-11 21:34 +0200
                Re: byte stream vs char stream buffer markspace <markspace@nospam.nospam> - 2014-05-11 12:55 -0700
                Re: byte stream vs char stream buffer Roedy Green <see_website@mindprod.com.invalid> - 2014-05-16 16:55 -0700
                Re: byte stream vs char stream buffer markspace <markspace@nospam.nospam> - 2014-05-16 17:36 -0700
                Re: byte stream vs char stream buffer Roedy Green <see_website@mindprod.com.invalid> - 2014-05-16 19:52 -0700
              Re: byte stream vs char stream buffer Roedy Green <see_website@mindprod.com.invalid> - 2014-05-16 16:37 -0700
          Re: byte stream vs char stream buffer Roedy Green <see_website@mindprod.com.invalid> - 2014-05-10 17:21 -0700
            Re: byte stream vs char stream buffer Martin Gregorie <martin@address-in-sig.invalid> - 2014-05-11 09:05 +0000
              Re: byte stream vs char stream buffer Roedy Green <see_website@mindprod.com.invalid> - 2014-05-12 02:07 -0700
                Re: byte stream vs char stream buffer Silvio <silvio@internet.com> - 2014-05-12 12:20 +0200
                Re: byte stream vs char stream buffer Roedy Green <see_website@mindprod.com.invalid> - 2014-05-16 20:19 -0700
                Re: byte stream vs char stream buffer Roedy Green <see_website@mindprod.com.invalid> - 2014-05-18 05:28 -0700
                Re: byte stream vs char stream buffer Silvio <silvio@internet.com> - 2014-05-18 23:54 +0200

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