I ran into this problem a long time ago. StreamTokenizer can't be subclassed,
because of the way the class is set up. A bug has been submitted to Sun about
this, but I haven't heard anything. It's been over a year.
Anyway, my ReaderTokenizer class reads in numbers in exponential floating
point, and works just like StreamTokenizer (although I've added some
extensions, like hexadecimal). It doesn't allocate memory inside the loop
(unless it goes over the internal buffer size, which is pretty large, and
something I've never seen happen) or use deprecated classes. We use it for
most of our model loaders. See the .signature file for the location of NCSA
Portfolio. Hope this helps, and would be interested in hearing if this works
for you (or if it doesn't).
Steve
Martin Baker wrote:
> I have a supplementary question to a previous question about reading data.
>
> My question is: what is the most efficient way to read in large arrays of
> numbers? (such as a very big IndexedFaceSet)
>
> I think its relevant to this list because the loading time is proving a
> limitation on the size of mesh that I can use. I'd appreciate any help in
> speeding up the loading of my program at www.martinb.com
>
> I get the impression that the most 'architecturally sound' way to do
> formatted I/O is to use the java.text package. But that's no good because
> its hopelessly inefficient and does not support exponential floating point
> numbers. (Are the java.text programmers aware of the needs of Java3D ? is it
> on their wish list?)
>
> So I tend to read the file one line at a time, use StringTokenizer to split
> it up, then convert to a double floating point number using something like:
>
> value = (new Double(s)).doubleValue();
>
> But this is very slow because it does a memory allocation for every number
> read, so when I read in a big IFS the program slows down and starts garbage
> collecting and I have to wait ages for it to load.
>
> Would anyone like to suggest the fastest code to load and array of floating
> point numbers, which does not allocate memory inside the loop, or use
> deprecated classes.
>
> Martin
>
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--
Steve Pietrowicz - [EMAIL PROTECTED]
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Freely available for non-commercial use!
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