Re: [MI400] Writing to a save file

["Mark Waterbury" <mark.s.waterbury@xxxxxxxxxxxxxxxx>]

Hello, Harry:

Your English is not that bad, as a second language... :-)

See my "embedded" remarks below...

----- Original Message -----
From: "Harry Williams" <planesmart@teleteam.net>
To: <mi400@midrange.com>
Sent: Wednesday, July 03, 2002 10:01 PM
Subject: RE: [MI400] Writing to a save file


> I guess I is a programmer. I think I need to learn English.
>
> I was converting a save file to a physical file by overrides, then
> compressing it.  Next I decompressed it to another physical file, then
wrote
> this physical file to a save file with overrides.
>
> I tried to go directly from a save file with the compression routine, but
> when I tried to take the compressed file to a save file I got an error.
The
> compression routine will write to a save file. So I was trying to figure
out
> how to do it.

I think this problem you had is because when writing to a save file, IBM's
OS/400 code enforces that only "valid" save file data (with proper record
level check-sums, etc.) is allowed to be written into a save file.  Any type
of compression of the entire record will alter the check-sums, etc., too.

So, you must continue to stick with using a physical file of some sort to
store the "compressed save file data", then, only when you want to use it
again, decompress it, and write the results back into a save file again,
then
you can "restore" your objects from the save file.  Does this "make sense"?

> if the compressor is learning, is it for the one compression or will it
save
> the learned compression routine for next time?
>
> I use spell checker this time.

That's nice, but these tools do not always help with "grammar". :-)
But I think your meaning is clear enough.

Regards,

Mark S. Waterbury

> -----Original Message-----
> From: mi400-admin@midrange.com [mailto:mi400-admin@midrange.com]On
> Behalf Of Leif Svalgaard
> Sent: Wednesday, July 03, 2002 10:50 PM
> To: mi400@midrange.com
> Subject: Re: [MI400] Writing to a save file
>
>
> From: Harry Williams <planesmart@teleteam.net>
> > Thought the compression is impressive, the time it takes is a little
long.
> ===>maybe you mean "Though"?
>
> > So I was trying to go ftom a save file directly from
> > save file to compress file, back to save file.
> ===>I'm not clear on what you want to do here. Have a small problem
> with sentence structure...
>
> >
> > By the way, why does the decompression take 1/3 the time as compression?
> ===> this is not unusual. During compression, the compressor is "learning"
> about the file which takes extra time.
>
>
> ===> bottom line: you write to a save file as to any other file, the
> only real problem is that you have to compute a checksum for each
> block and an overall checksum for the whole file. Chapter 27 of my
> eBook goes into some detail about this.
>
>
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