Is a global string var better then smaller ones?

Is a global string var better then smaller ones? - Printable Version

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Is a global string var better then smaller ones? - Toni - 30.09.2010

Hello there, I was just curious about this one simple question I can't seem to figure out. I was discussing with Calgon about what would be better (in this case for code optimization). What I did was in my script, I created a large variable only for strings.

pawn Код:

new str[1024]; // This is also used for dialogs just saying (I know max is 128 for normal strings).

That is a global variable, that I put somewhere above/near the #include/#defines.

Now, that is all I use for string variables 1 var, globally. And I can't tell if declaring smaller string variables are better then global ones.

Imagine having to create small variables under every callback/function you use

pawn Код:

new str[128];

Please help me figure this out.

Re: Is a global string var better then smaller ones? - Scenario - 30.09.2010

I was told by somebody, who was told by a friend that it is better to have global variables. Although, I never really did any type of testing, etc...so I wouldn't take my word for it!

Re: Is a global string var better then smaller ones? - Norn - 30.09.2010

Obviously reusing one large one would save memory but it would also cause problems if misused.

Re: Is a global string var better then smaller ones? - Toni - 30.09.2010

Quote:

Originally Posted by Norn

Obviously reusing one large one would save memory but it would also cause problems if misused.

Would misusing it count as not clearing the variable?

Re: Is a global string var better then smaller ones? - bigcomfycouch - 30.09.2010

I'd assume using a global string wouldn't be terrible. PAWN is single-threaded, so two things can't happen at the exact same time. Therefore, one variable can't be in use in two places simultaneously.

Correct me if I'm wrong.

Re: Is a global string var better then smaller ones? - nemesis- - 30.09.2010

Quote:

Originally Posted by Norn

Obviously reusing one large one would save memory but it would also cause problems if misused.

Correct. I use 5 global strings spread throughout a 23K line gamemode. No problems here.

Quote:

Originally Posted by The Toni

Would misusing it count as not clearing the variable?

No. Misusing it would mean setting in, passing to a function that overwrites it, then back to the main function where it gets used again.

Quote:

Originally Posted by bigcomfycouch

I'd assume using a global string wouldn't be terrible. PAWN is single-threaded, so two things can't happen at the exact same time. Therefore, one variable can't be in use in two places simultaneously.

Correct me if I'm wrong.

Most people here preach using global strings as a tool of the devil. They usually do that because they're parroting what someone else said, because they have no clue what they're doing, or because they don't even run a server to begin with.

PAWN is single-threaded though plugins with multi-threaded features (i.e. G-Stylez MySQL) do exist. There you need to be careful.

Re: Is a global string var better then smaller ones? - RoBo - 01.10.2010

Quote:

Originally Posted by Norn

Obviously reusing one large one would save memory <snip>

Would it really?

With a global var the memory is always allocated, so no matter what PAWN is executing that string will be taking up memory. If it were in a function, only when that function is executing would the memory be used. PAWN only allocates enough memory for the biggest function + global vars, so you could potentially use more memory with a single global var.

Quote:

Originally Posted by bigcomfycouch

It's a bad coding practice, might as well scrap functions in return for goto while you're at it.

Re: Is a global string var better then smaller ones? - nemesis- - 03.10.2010

Quote:

Originally Posted by RoBo

Yes.. lets conserve a menial amount of memory. 4gb of it gets used up so quick, right?

Re: Is a global string var better then smaller ones? - RoBo - 03.10.2010

Quote:

Originally Posted by nemesis-

Yes.. lets conserve a menial amount of memory. 4gb of it gets used up so quick, right?

What? All I said is that using global vars may use more memory than local ones. Conserving memory is a good thing, you'd have to be a moron to think otherwise, but I'll leave you be in your fantasy world of PAWN being fine with 40mb of vars, let alone 4gb.