Re: [Tarantool-patches] [PATCH v4 0/6] box/func: implement cfunc Lua module

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

Thanks for the answer!

On 05.10.2020 13:51, Cyrill Gorcunov wrote:
> On Sat, Oct 03, 2020 at 03:55:23PM +0200, Vladislav Shpilevoy wrote:
>> Hi! Thanks for the patchset!
>>
>> On 01.10.2020 15:51, Cyrill Gorcunov wrote:
>>> The cfunc module provide a way to execute C stored procedures
>>> on read only nodes without registring them in `_func` system space.
>>>
>>> The series implements a bare minimum. There was a request to make
>>> cfunc been Lua object with appropriate methods. If this is really
>>> preferred then I'll implement this wrapping Lua code on top. I mean
>>> that currently all operations are done via
>>>
>>>  > require('cfunc').[create|drop|call|reload]
>>>
>>> interface while there was a proposal to operate as
>>>
>>>  > a = require('cfunc').create
>>>  > a:call(args)
>>
>> No, the proposal was rather
>>
>> 	cfunc = require('cfunc')
>> 	f = cfunc.load('test_box_c_function')
>> 	f(1, 2, 3)
>>
>> Sorry I didn't describe it properly anywhere. But it is easy to fix
>> anyway.
>>
>> In Lua you can define __call and make an object look exactly
>> like a function. That is the idea behind making it possible to
>> use Lua and C functions in the same way.
>>
>> 	if load_c then
>> 		f = cfunc.load('test_box_c_function')
>> 	else
>> 		f = function(a, b, c) return a + b + c end
>> 	end
>> 	f(1, 2, 3) -- Works and looks the same for C and Lua.
>>
>> With this way even IPROTO_CALL should work on such functions, if the
>> function object is global and the user has access to executing everything
>> here.
> 
> OK, so here is a proposal. The module get called cbox, where we will be
> implementing all C related features.
> 
> cbox.func.create(name)		-- create a function
> cbox.func.drop(name)		-- delete a function
> cbox.module.reload(name)	-- reload module
> 
> f = cbox.func.create(name)
> f(1,2,3)			-- create and call a function
> 
> Comments?

Looks good.