Re: gnuplot slow on BIG files

[Dimitrios A. <ji...@gm...>]

Hello.

It would be nice if gnuplot parsed only the numbers it needed, but I 
understand this is not a priority. This is indeed a problem that can 
(should?) be corrected in the datafile.

However, the second problem I noticed in gnuplot was the very slow 
parsing. I believe this is something that needs to be corrected.

I tried to improve the parsing speed but I couldn't understand *many* 
things in the existing code. I 'm sure those are used somewhere but 
since I couldn't I understand them, I rewrote all the parser, the 
simplest way possible.

So I submit to you a patch (against the v. 4.0 gnuplot) for the file 
src/datafile.c as a proof of concept, that the current parser is slow 
and can be improved. And you 'll see that this version is faster more 
than 10 times. Please forgive any silly programming mistakes, I'm not 
much experienced in C.

There are many things in my code that you 'll not probably like. They 
were added to bypass several problems that the old codebase created. 
After all I only wrote this code as a proof of concept. However, if you 
think that this can replace the existing parser, tell me so, because 
there are a few things that need to change. Of course you may improve it 
as you wish.

Dimitris