From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00
	autolearn=unavailable autolearn_force=no version=3.4.4
Path: 
 eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail
From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: A little trouble with very large arrays.
Date: Fri, 5 Oct 2018 22:31:25 +0200
Organization: Aioe.org NNTP Server
Message-ID: <pp8hmr$1a1s$1@gioia.aioe.org>
References: <3f2828df-d54a-4427-bc3c-dc5ef0dc8069@googlegroups.com>
 <g1oe5gFjk04U1@mid.individual.net>
 <c457fabd-54ab-4294-a268-f3af228b241e@googlegroups.com>
 <g1plu7Frjb1U1@mid.individual.net>
 <13fa128f-5ec7-453e-9231-2260dd4adcbc@googlegroups.com>
NNTP-Posting-Host: IzvqdhUtDGKIMCldyDtZ+w.user.gioia.aioe.org
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
X-Complaints-To: abuse@aioe.org
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101
 Thunderbird/52.9.1
X-Notice: Filtered by postfilter v. 0.8.3
Content-Language: en-US
Xref: reader02.eternal-september.org comp.lang.ada:54496
Date: 2018-10-05T22:31:25+02:00
List-Id: <comp.lang.ada>

On 2018-10-05 21:49, Shark8 wrote:

> Most of the anticipated usage for where I am right now would be producing FITS files, likely in something that would boil down to a coupling like this:
> 
>    Count      : Positive := 1;
>    Today      : Ada.Calendar.Time renames Ada.Calendar.Clock;
>    New_Image  : Camera_Image renames Normalize( Get_Camera_Image );
>    New_Object : FITS.Object := FITS.Create_w_Defaults( New_Image );
>    --..
>    -- Writes data out to "Observation(YYYY-MM-DD)_00X.FITS".
>    New_Object.Write( Base => "Observation", Date => Today, Count => X );
> 
> I'd rather not tie things to a memory-mapped file at a high level, but it may be that my ideal abstraction is non-tenable.

You still can do this. The object can have any representation, the 
stream attribute will encode/decode it as required by FITS:

    Object : FITS.Image :=
       Create
       (  Base  => "Observation",
          Date  => Clock,
          Image => Get_Camera_Image
       );
begin
    FITS.Image'Write (Stream, Object);

Or without any intermediate objects:

    FITS.Store
    (  File  => Stream,
       Base  => "Observation",
       Date  => Clock,
       Image => Get_Camera_Image
    );

The problem with intermediate objects is copying bulky data like images 
unless you deploy some complex reference-counting schema. Good bindings 
support provide in-place I/O operations.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de