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NNTP-Posting-Date: Wed, 05 Oct 2011 17:15:43 -0500
Date: Wed, 05 Oct 2011 15:15:44 -0700
From: Patricia Shanahan <pats@acm.org>
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Subject: Re: DataInputStream
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On 10/5/2011 2:52 PM, Lew wrote:
...
> As another respondent suggested, NIO lets you alias typed
> 'ByteBuffer' instances as other types of 'Buffer'.
>
> But this defeats the purpose of 'DataInputStream', which handles
> those mechanics for you under the hood, so why in the world reinvent
> the wheel?  Just read your array of floats from the DIS.

I don't know whether this is one of those cases, but there are
situations in which the main limitation on data read speed is data
copying. There are two things that can reduce copy cost:

1. Do as few copies as possible.

2. When a copy is necessary, do it in bulk rather than element-by-element.

I think the NIO buffer aliasing may be a way of eliminating some
element-by-element copying.

Sometimes, in trade-offs between performance and code simplicity,
performance has to win.

Patricia