Re: Interested in Abstract Extension API and Dependency Interface

Hi Varuna,

Varuna Jayasiri wrote:
> Hi,
>
> I went through most of the tutorials and presentations you've listed,
> and they were very helpful :). I coded a couple of simple extensions to
> get some hands on experience.

> I have started drafting the application form and will publish it soon,
> so that I can get your comments for improvements and adjustments.

Good to hear, looking forward to seeing it.


> Also, there's a small thing which I want to clarify about the API in the
> initial design in the gsoc ideas page. What are fetch and store
> functions?

Sorry this example probably isn't entirely clear, I'll try to add some more detail here so there's no confusion.  fetch() and store() are simply API functions that could be anything that the extension wants to expose or use.  I used fetch/store as this would apply to the APC extension which fetches and stores entries from cache.  This could easily be any functionality as defined on an extension specific basis such as encrypt, copy, send, query, etc.

Let me know if this still isn't clear as this is a pretty important piece to understand for this project.


> And how should  various other functions be registered. Is it
> ok if we you use some thing like,
> register_function(&api, str_function_name, function_pointer) for
> registering and
> call_api_function(api, "extension_function", parameters) to call those
> api_functions?

These probably will make more sense once you understand the previous question more, but these functions should register multiple functions at once rather than individual functions.  This will be done by creating a structure for the extension (in this case called api).  This contains multiple pointers to functions such as fetch, store, or anything else that needs to be exposed.  So in the above by passing &api, you're in fact passing many functions to be registered.

In regards to the call_api_function you've prototyped above, I want to note that an advantage of being able to retrieve this as a structure containing multiple file pointers is that you can call functions without the overhead of going through a wrapper function.  For example intsead of calling this call_api_function as you've listed above, it is much for efficient to grab a structure and call it with something like 'some_api.some_func()', especially if done in a loop.

Again, this is what we came up with, please continue to provide suggested alternatives if you see room for improvement or if it will help you understand the design considerations involved.

-shire