Re: byte stream vs char stream buffer
On 10.05.2014 22:18, Roedy Green wrote:
On Fri, 09 May 2014 09:34:09 -0700, Roedy Green
<see_website@mindprod.com.invalid> wrote, quoted or indirectly quoted
someone who said :
On Thu, 8 May 2014 13:30:15 +0000 (UTC), Andreas Leitgeb
<avl@auth.logic.tuwien.ac.at> wrote, quoted or indirectly quoted
someone who said :
I'm wondering, if your lego stack is higher than necessary. Are you
placing BufferedWriter over BufferedOutputStream? I think you can
put the BufferedOutputStream back into the lego bag in that case. ;)
I think some experiments are in order.
There are the results:
Using a file of random characters of 400 MB and buffers of 32K bytes
HunkIO 1.20 seconds <-- does an all at once read.
using BufferedReader backed with BufferedInputStream ratio 0.50
buffsize 32768 bytes 1.65 seconds
plain BufferedReader buffsize 32768 bytes 1.76 seconds
I find this a fairly unspecific description of the test you did. We do
not know what your test did to ensure file system caching or GC effects
did not influence the measurement etc.
The bottom line is either use HunkIO when you have the RAM or give 50%
of your buffer space to the inputstream and 50% to the Reader
in other works 100K of buffer space would have a 50K inputstream
buffer and the reader would have a 25K buffer because it is measured
in chars. I tried ratios from .1 to .9. 50% was best.
If I'm not mistaken you did not test cases where there is just a
BufferedReader OR a BufferedInputStream - that was what Andreas was
hinting at if I'm not mistaken. I don't think duplicate buffering will
make things better. I had expected at least three tests (double
buffering, byte buffering, char buffering) plus the code.
Cheers
robert