Want to create and load plugins written in D into a D app at run-time, the kind that can make api calls or extended main app with other functionality.

I'm currently interested in it for a vibe.d app. How does these stuff work?

On Thursday, 1 June 2017 at 23:24:13 UTC, aberba wrote:
> Want to create and load plugins written in D into a D app at run-time, the kind that can make api calls or extended main app with other functionality.
>
> I'm currently interested in it for a vibe.d app. How does these stuff work?

It works using shared libraries.

On Friday, 2 June 2017 at 02:05:23 UTC, Stefan Koch wrote:
> On Thursday, 1 June 2017 at 23:24:13 UTC, aberba wrote:
>> Want to create and load plugins written in D into a D app at run-time, the kind that can make api calls or extended main app with other functionality.
>>
>> I'm currently interested in it for a vibe.d app. How does these stuff work?
>
> It works using shared libraries.

Oops

On Friday, 2 June 2017 at 02:05:23 UTC, Stefan Koch wrote:
> On Thursday, 1 June 2017 at 23:24:13 UTC, aberba wrote:
>> Want to create and load plugins written in D into a D app at run-time, the kind that can make api calls or extended main app with other functionality.
>>
>> I'm currently interested in it for a vibe.d app. How does these stuff work?
>
> It works using shared libraries.

I just read it on Wikipedia. An alternative is to use a scripting/interpreted language. Working with such approach feels unnatural in D (considering pyd, lua-d).


A more sustanable approach would be:

1. Get shared libs to work in D (the best approach for all D code)

1. some kind of embeddable interpreter for a scripting language like (a mini js engine) which exposes callable native D APIs at runtime

None of which is within my current ability.

On Friday, 2 June 2017 at 11:09:05 UTC, aberba wrote:
> 1. Get shared libs to work in D (the best approach for all D code)

I have done very little with this myself but other people have so it is doable.

> 1. some kind of embeddable interpreter for a scripting language like (a mini js engine) which exposes callable native D APIs at runtime

My script.d does this kind of thing
http://dpldocs.info/experimental-docs/arsd.script.html#examples

it is slow though.

On Friday, 2 June 2017 at 12:19:48 UTC, Adam D. Ruppe wrote:
> On Friday, 2 June 2017 at 11:09:05 UTC, aberba wrote:
>> 1. Get shared libs to work in D (the best approach for all D code)
>
> I have done very little with this myself but other people have so it is doable.
>
>> 1. some kind of embeddable interpreter for a scripting language like (a mini js engine) which exposes callable native D APIs at runtime
>
> My script.d does this kind of thing
> http://dpldocs.info/experimental-docs/arsd.script.html#examples
>
> it is slow though.

Performance doesn't matter now.

Can source of script be reloaded at runtime?

Do I have to wrap external APIs in the "global" object passed as argument to "interpreter()"

I'm trying to implement a plugin system for a vibe.d server where plugins can be installed to provide additional http routes: extending server functionality.

On Friday, 2 June 2017 at 13:05:41 UTC, aberba wrote:
> Can source of script be reloaded at runtime?

It is just an ordinary string.

> Do I have to wrap external APIs in the "global" object passed as argument to "interpreter()"

Yes, anything the script calls must be exposed through that. It does a decent job automatically wrapping functions though, so just assigning them in a list might work.

> I'm trying to implement a plugin system for a vibe.d server where plugins can be installed to provide additional http routes: extending server functionality.

might work.

On Fri, Jun 02, 2017 at 12:19:48PM +0000, Adam D. Ruppe via Digitalmars-d-learn wrote:
> On Friday, 2 June 2017 at 11:09:05 UTC, aberba wrote:
> > 1. Get shared libs to work in D (the best approach for all D code)
> 
> I have done very little with this myself but other people have so it is doable.
[...]

This is not directly related to the OP's question, but recently I wrote a program that, given a user-specified string, transforms it into D code using a code template, invokes dmd to compile it into a shared object, loads the shared object using dlopen(), and looks up the generated function with dlsym() to obtain a function pointer that can be used for calling the function. The shared object is unloaded after it's done.

So it's definitely doable, in the sense that I've successfully generated D code, compiled it into a shared library, loaded it into the running executable, and can call the code.  Of course, in my case, the code template is relatively simple so I don't have to worry about things like module ctors, shared data, non-TLS globals, or GC use.  If you're planning to support those features, you might need to do a bit more work after calling dlopen(). At the very least you'd have to use dlsym() to look up module ctor symbols and run them before calling any other functions in the shared object, and you may have to initialize druntime in the shared object too, if it's statically linked.  I'm not sure what happens if it's dynamically linked, or if it uses its own copy of the GC.

In any case, this is all possible, it just takes someone to dig into the details and write the code to make it all work.  Then publish it on github or dub, and the rest of us can reap the benefits too. ;-)


T

-- 
PNP = Plug 'N' Pray

On Thursday, 1 June 2017 at 23:24:13 UTC, aberba wrote:
> Want to create and load plugins written in D into a D app at run-time, the kind that can make api calls or extended main app with other functionality.
>
> I'm currently interested in it for a vibe.d app. How does these stuff work?

Plugin system c++ http://blog.nuclex-games.com/tutorials/cxx/plugin-architecture/

On Friday, 2 June 2017 at 12:19:48 UTC, Adam D. Ruppe wrote:
> On Friday, 2 June 2017 at 11:09:05 UTC, aberba wrote:
>> 1. Get shared libs to work in D (the best approach for all D code)
>
> I have done very little with this myself but other people have so it is doable.
>
>> 1. some kind of embeddable interpreter for a scripting language like (a mini js engine) which exposes callable native D APIs at runtime
>
> My script.d does this kind of thing
> http://dpldocs.info/experimental-docs/arsd.script.html#examples
>
> it is slow though.


You should put a link on the help somewhere so one can get to the github page easily to view the source(or have the ability to go from the module to the github source easily(small icon next to module name in modules list).

This would help peruse the source to see how you came up with some of your stuff ;)