bug#7556: 24.0.50; visiting an EPS file with preview TIFF image and with one long line

[Peter Dyballa <Peter_Dyballa@Freenet.DE>]

Am 05.12.2010 um 05:06 schrieb Eli Zaretskii:

>> I have an EPS file created by Adobe Illustrator 15 with a "DOS EPS
>> Binary File Header" according to 5002.EPSF_Spec and a TIFF preview at
>> the end, in mac-roman-mac encoding. Size: 643 KB. When I visit that
>> file from a dired buffer in PostScript DocView View mode
>
> Visiting binary files with anything but find-file-literally is not a
> good idea.

Yes, find-file-literally works very fine, and fast! Although it  
produces a backup file and does not open the file read-only...

>
>> Rendering this in a window of 55 lines and around 120 columns takes
>> these 7 h.
>
> Emacs display engine is known to be very slow with very long lines.
> Does it help to set truncate-lines non-nil?

I did not wait the whole seven hours, just a few minutes, until the  
CPU became hot enough that the fan started to spin... Not really a  
change or improvement in speed, probably.

>
>> And more: GNU Emacs creates a #file.eps# backup file,
>> larger in size (50 %) than the original file. Is that the expected
>> behaviour?
>
> I'm guessing that this is because raw bytes are decoded into internal
> format that makes them take 5 bytes.  The auto-save file is written in
> this internal format.


The backup file was created while I opened the file read-only, just  
visiting it!

--
Greetings

   Pete

The future will be much better tomorrow.
				– George W. Bush