Re: http-request in a controller- is it possible?

[Nala Ginrut]

Hi Jaft!
Ragnarok is non-blocking co-routine based server-core, so you can never
put `sleep' or any longtime blocking operation into it. If you want to
schedule the current task out, till it's ready again, you should insert
(break-task).


Best regards.


Jaft writes:

>  I'm not sure if this is related (so I may be entirely incorrect here) but I 
> tried, while running with Ragnarok, adding (sleep 20) to one of the endpoints 
> in a controller and tried loading the endpoint.
> Throughout the duration of that 20 seconds, trying to load any other endpoint 
> for the Artanis instance hung until the sleep function finished (and, I 
> assume, the rest of the Guile code for the endpoint finished before running 
> the other endpoints).
> I know Ragnarok is supposed to be non-blocking so should this be the case? 
> Or, heh, is this expected behavior and I'm just misunderstanding how things 
> work?
> Jonathan
>     On Thursday, December 3, 2020, 11:48:36 AM CST, Nala Ginrut 
> <mulei@gnu.org> wrote:
>
>
> BTW, if you really want to call http-get at present, you may need to set the
> port to non-blocking manually:
> ---------------------cut-------------------
> (import (web client))
>
> (test-define
> "/"
> (lambda (rc)
> (define port (open-socket-for-uri "http://localhost:3000/123";))
> (fcntl port F_SETFL (logior O_NONBLOCK (fcntl port F_GETFL 0)))
> (call-with-values
> (lambda () (http-get "http://localhost:3000/123"; #:port port))
> (lambda (res body) body))))
> ---------------------end--------------------
>
> This works for me.
>
> Best regards.
>
>
>
> Nala Ginrut writes:
>
>> I've tested it, guile internal server-core doesn't work too.
>> So I believe Artanis has to implement its own client API to make it
>> work.
>> The client API is necessary, since people may need to make OAUTH.
>>
>> I'll add it to TODO.
>>
>> Best regards.
>>
>>
>> Nala Ginrut writes:
>>
>>> Hi Morimer!
>>> In theory, the API of (web client) like http-get should work in Ragnarok.
>>> Because Ragnaork based on suspendable-ports for co-routine, and when
>>> suspendable-ports is enabled, all the I/O ports defined in Guile should
>>> be affected to be non-blocking.
>>>
>>> I'm not sure about http-request function, where did you find it?
>>>
>>> Anyway, if you don't insist on non-blocking, you can use guile
>>> server-core to avoid non-blocking issue:
>>> ------------------------cut-----------------------
>>> art work -s guile
>>> ------------------------end-----------------------
>>>
>>>
>>>
>>> Best regards.
>>>
>>>
>>> Mortimer Cladwell writes:
>>>
>>>> Hi,
>>>> Given the controller:
>>>>
>>>> (register-define add
>>>>  (lambda (rc)
>>>>  (let* (
>>>>          ;;(btc-usd 18000)
>>>>            (btc-usd (string->number(receive (response-status response-body)
>>>>                                    (http-request "
>>>> https://blockchain.info/q/24hrprice";) response-body)))
>>>>          (btc-req (/ 5000 btc-usd))
>>>>                (currency-content (string-append " <option
>>>> value=\"btc\">Bitcoin " (number->string btc-req) " BTC</option>)))
>>>>  (view-render "add" (the-environment)))
>>>>  ))
>>>>
>>>> If I navigate to http://127.0.0.1:3000/register/add the browser hangs and
>>>> eventually times out.
>>>>
>>>> At the console:
>>>> Ragnarok: continue request
>>>> Error: (wrong-type-arg #f Wrong type (expecting ~A): ~S (resumable
>>>> continuation #<vm-continuation 7f768042f930>) (#<vm-continuation
>>>> 7f768042f930>))
>>>> Ingore it to avoid Ragnarok crash.
>>>> main-loop again
>>>>
>>>> If at the REPL I evaluate (string->number (receive (response-status
>>>> response-body)
>>>>      (http-request "https://blockchain.info/q/24hrprice";) response-body))
>>>> I get a number e.g 18,123.45
>>>>
>>>> If I comment out (btc-usd (string->number(receive.... ) and uncomment
>>>> (btc-usd 18000), the expected page is rendered properly.
>>>>
>>>> Is it possible to use (http-request... ) in a controller?
>>>> If not is there a workaround?
>>>> Thanks
>>>> Mortimer


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