Ultimate callback hooks!

[Y_Less]

I think this may literally be the ultimate callback hooking method EVER! Those of you who write libraries should know about ALS:

public OnGameModeInit()
{
    // Do your code here...
    CallLocalFunction("S@@_OnGameModeInit", "");
}
#if defined _ALS_OnGameModeInit
    #undef OnGameModeInit
#else
    #define _ALS_OnGameModeInit
#endif
#define OnGameModeInit S@@_OnGameModeInit

forward OnGameModeInit();

This chunk of code allows people to use "OnGameModeInit" in multiple scripts, so that library writers don't need to worry about people correctly calling their setup functions.

This works quite well but it's VERY cumbersome, as a result "y_hooks" was developed:

Hook:S@@_OnGameModeInit()
{
    // Do your code here...
}

This is VASTLY nicer code to read and write, but it is slower than ALS - this is part of YSI but the YSI libraries themselves don't actually use it for speed reasons.

However the other day I was contacted by JoeBullet/Google63 about the use of the "SCTRL" OpCode to modify the current instruction pointer which I combined with existing knowledge of the AMX data structure to create the ULTIMATE callback hook system. This is nicer than y_hooks (or the old y_hooks, this is an update) and MUCH faster than ALS (no benchmarks available):

hook OnGameModeInit()
{
    // Do your code here...
}

That is now it! This completely bypasses CallLocalFunction, which is where the speed comes from, and you don't even need to define a prefix as with the old version (unless you have multiple versions of a single callback in one file). Note that the old syntax still works. If you are interested the code is here, but note also that you can't compile it because it uses some new libraries I've not released yet. The interesting code is lines 60-297, everything beyond that is just the same thing over and over and over again!

http://pastebin.com/KHtzcWVf

Note that you will need to get YSI from SVN - the official version hasn't been updated yet because I'm working on some big things!

[Kyosaur]

Dude, you're amazing man! This is really awesome, i can now stop being so hesitant to hook callbacks now.


Really nice idea, thank both you and google63.

[Y_Less]

I just did some basic test which put this at around 10x faster than the old y_hooks system, however it is only just faster than ALS - as in almost not faster:

1514 - New
15371 - Old
1732 - ALS

However the fact remains that it IS faster and it IS easier...

[Rivera]

what does this do? I mean, it's function...

[JaTochNietDan]

Originally Posted by Rivera

what does this do? I mean, it's function...

It allows you to hook callbacks easily and with better performance than previous callback hooking methods, this page gives a fairly good explanation of what you would need to use a callback hook for.

http://forum.sa-mp.com/showthread.php?t=166016

[Y_Less]

Originally Posted by Rivera

what does this do? I mean, it's function...

It's basically a development tool for library writers. Take this library for example:

http://forum.sa-mp.com/showthread.php?t=240436

Originally Posted by AH.1990

• Features / Functions

• AHSkin_GameModeInit();
  
  You Must put it under OnGameModeInit if its not a filterscript in order to use the include
  
  
• AHSkin_FilterScriptInit();
  
  You Must put it under OnFilterScriptInit if its not a game mode in order to use the include

Those two functions MUST be called for the script to work, but I know from experience that many users will not call those functions in the right places or at the right times and then will come complaining that their code doesn't work. Currently AHSkin_GameModeInit is defined as:

AHSkin_GameModeInit()
{   
    GrooveSkins[0] = 105;
    GrooveSkins[1] = 106;
    GrooveSkins[2] = 107;
    // [...]
    return 1;
}

If they were to define the function as:

#include <YSI\y_hooks>

hook OnGameModeInit()
{   
    GrooveSkins[0] = 105;
    GrooveSkins[1] = 106;
    GrooveSkins[2] = 107;
    // [...]
    return 1;
}

That would instantly remove the need for the user to have to manually call the function, so then you and they don't need to worry about it.

Also, the code for this is on the YSI SVN so if you do want to use it you can get a working copy from there:

Address: https://dedi.y-less.com/svn/ysi
Username: public
Password: public

That won't let you upload, but if you want to upload just ask me for an upload account.

Very nice efficient and fast, thanks

[Zh3r0]

Good job, you finally made it faster! You always impress me with your marvelous work.
This thing is really something new and hard for me to understand.

Keep on releasing more and more and impress people!

[Calgon]

Brilliant, time to try understand how you've done it and time to abuse it in a million includes I plan to make.

[AH.1990]

i downloaded YSI and i found y_hooks in the folder

thats it?? i mean thats the right include??