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From: Gautier write-only <gautier_niouzes@hotmail.com>
Newsgroups: comp.lang.ada
Subject: Re: Performance of the Streams 'Read and 'Write
Date: Sat, 31 Oct 2009 16:46:32 -0700 (PDT)
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Date: 2009-10-31T16:46:32-07:00
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On 30 oct, 20:12, "Jeffrey R. Carter" <spam.jrcarter....@spam.acm.org>
wrote:

> >> And if you overlay the Stream_Element_Array onto the Buffer, thus eliminating
> >> the copying and the stream attribute operations?
>     for S'Address use B'Address;

Bingo!

xxx'Write / xxx'Read (Stream attributes)................ 14.717895000
seconds
Workaround with Stream_Element_Array buffer and copy.... 0.435756000
seconds
Workaround with Stream_Element_Array buffer and overlay. 0.211830000
seconds
Factor (Copy)    33.775541816
Factor (Overlay) 69.479747911

This on a Linux 32 bit netbook, with a 32 MB file; GNAT GPL 2009, -
gnatp -O2.
So my "almost no time" assumption about the buffer copy was definitely
to be understood as "compared to the attribute version"...
_________________________________________________________
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