Allow to configure connect timeout separately

[VincentLanglet]

Hi @daniel-jones-deepl,

Currently, Deepl only allow one option: TranslatorOptions::TIMEOUT.
This one is used for both

• \CURLOPT_CONNECTTIMEOUT
• \CURLOPT_TIMEOUT_MS

But we might accept a CURLOPT_TIMEOUT_MS of 30s while we want a low CURLOPT_CONNECTTIMEOUT.
In general it doesn't make a lot of sens to have more than a few seconds for the connect timeout.

So it should be better to split both option

• TranslatorOptions::CONNECT_TIMEOUT
• TranslatorOptions::EXEC_TIMEOUT

To keep the old behavior, I kept the TranslatorOptions::TIMEOUT option which is used as a default value for both CONNECT_TIMEOUT and EXEC_TIMEOUT

Also, the doc was saying

timeout: the number of seconds used as connection timeout for each HTTP request retry. The default value is 10.0 (10 seconds).

So I changed it to connect_timeout. (Even if timeout will still work for the BC compatibility).

I'm open to any feedback :)

[VincentLanglet]

Friendly ping @daniel-jones-deepl, @JanEbbing.
Does someone have time to take a look ? :)

[JanEbbing]

Hi @VincentLanglet , sorry, Daniel is out at the moment.
For context, we get several requests to configure certain HTTP parameters/behaviours - if we add them all as a member variable of TranslatorOption, I feel things are going to get unwieldy. Hence, I'd rather expose the HttpClient.

I see 2 broad ways to achieve this.

1. Allow users to configure the $curlOptions variable in HttpClient (we would ignore/overwrite some values, e.g. URL, or anything that is set explicitly as an option, like proxy).
2. Exposing the entire HttpClient class and allowing users to pass their own HttpClient into Translator. We would still provide the current client as the default and for users to subclass to change certain behaviour (e.g. when to retry, changing the backoff algorithm, etc).

My asks:

• Do both of these approaches cover your use case for this PR?
• Do you foresee anything you would want to do that would not be possible with 1) or 2) or both? (e.g. changing the backoff algorithm isn't possible with 1, but I don't think that's a big concern - maybe something like "I want to have multiple translator objects with a common HTTP Client so I can rate-limit how many outgoing requests I make" is something users would run into?)
• Any comments/reasons you'd prefer one over the other?

[VincentLanglet]

Hi @VincentLanglet , sorry, Daniel is out at the moment. For context, we get several requests to configure certain HTTP parameters/behaviours - if we add them all as a member variable of TranslatorOption, I feel things are going to get unwieldy. Hence, I'd rather expose the HttpClient.

Yes, I understand. I tried to introduce as few changes as possible:

• Because it was easier to be BC this way
• To me the connect and exec timeout were two really specific options because they are computed/different on every call because of the backOff (https://github.com/DeepLcom/deepl-php/blob/main/src/HttpClient.php#L80) ; unlike this issue (Adding curl-options #14) which want to pass hardcoded values as curl options, I like to modify the default timeout options, but still allow the Deepl lib to use another timeout when doing the retries.

I see 2 broad ways to achieve this.

1. Allow users to configure the $curlOptions variable in HttpClient (we would ignore/overwrite some values, e.g. URL, or anything that is set explicitly as an option, like proxy).
2. Exposing the entire HttpClient class and allowing users to pass their own HttpClient into Translator. We would still provide the current client as the default and for users to subclass to change certain behaviour (e.g. when to retry, changing the backoff algorithm, etc).

My asks:

• Do both of these approaches cover your use case for this PR?
• Do you foresee anything you would want to do that would not be possible with 1) or 2) or both? (e.g. changing the backoff algorithm isn't possible with 1, but I don't think that's a big concern - maybe something like "I want to have multiple translator objects with a common HTTP Client so I can rate-limit how many outgoing requests I make" is something users would run into?)
• Any comments/reasons you'd prefer one over the other?

For context, I currently use the following code (with this PR)

$client = new Translator($apiKey, [
     TranslatorOptions::DEFAULT_MAX_RETRIES => 0,
     TranslatorOptions::CONNECT_TIMEOUT => 5,
     TranslatorOptions::EXEC_TIMEOUT => 30,
]);
$translations = $client->translateText($payload, $languageFrom, $languageTo, []);
$languages = $client->getTargetLanguages();

For the "better" solution, I would say it depends on the amount of time/work/changes you want to take @JanEbbing.

Allowing to pass the HttpClient to the Translator seems to be the more flexible solution (with a default http implementation) ; but to me it's also the solution which might require the more change in the Deepl codebase.

• It would require something like an HttpClientInterface to expose and implement
• Then, people might request to use the same Interface than some PSR or Symfony HttpClientInterface (https://github.com/symfony/symfony/blob/6.2/src/Symfony/Contracts/HttpClient/HttpClientInterface.php)
• So I might need some re-writing in the implementation of the current HttpClient

Even if the HttpClient is now an entry-point, it still could be helpful to allow people to pass some curl options to the HttpClient, in order to not having to rewrite a whole HttpClient if they want to change the timeout. So to me the solutions 1 and 2 are not incompatible. You could have a

class HttpClientFactory
{
     public function static create($authKey, $options)
     {
          // Logic which are inside Translator::construct
     }
}

And people could write either

new Translator(HttpClientFactory::create($authKey, $options));
new Translator($customHttpClient);

Still, this could require a way to override curlOptions with the factory or construct of the HttpClient if I just want to keep all the logic from Deepl except one specific curl options (like the connect timeout).

Something like

class HttpClient
{
     public function __construct($url, ..., $defaultCurlOptions) {
         ...
         $this->defaultCurlOptions = $defaultCurlOptions;
     }

     public function sendRequestWithBackOff(...) {
         ...
         while ($backoff->getNumRetries() <= $this->maxRetries) {
              $response = $this->sendRequest(
                    $method,
                    $url,
                    $backoff->getTimeUntilDeadline(),
                    $headers,
                    $params,
                    $file,
                    $outFile
                );
                ...
         }
     }
     
     private function sendRequest(..., $timeUntilDeadline) {
         $curlOptions = $this->defaultCurlOptions;
         if (isset($curlOptions[\CURLOPT_CONNECTTIMEOUT_MS]) {
             $curlOptions[\CURLOPT_CONNECTTIMEOUT_MS] = max($curlOptions[\CURLOPT_CONNECTTIMEOUT_MS], $timeUntilDeadline * 1000));
         } else {
             $curlOptions[\CURLOPT_CONNECTTIMEOUT] = max($curlOptions[\CURLOPT_CONNECTTIMEOUT], $timeUntilDeadline));
         }
         if (isset($curlOptions[\CURLOPT_TIMEOUT_MS]) {
             $curlOptions[\CURLOPT_TIMEOUT_MS] = max($curlOptions[\CURLOPT_TIMEOUT_MS], $timeUntilDeadline * 1000));
         } else {
             $curlOptions[\CURLOPT_TIMEOUT] = max($curlOptions[\CURLOPT_TIMEOUT], $timeUntilDeadline));
         }
     }
}

Does it answer all your questions ? Do you plan to implements such change alone/with your team or should/can I help ?

[VincentLanglet]

Hi @JanEbbing, is there anything to do on my side ?

I would have expected a short answer to know

• If you planned to implement something on your side
• Or if I should develop a different implementation, specifying which one based is preferred from my different propositions in my comment Allow to configure connect timeout separately #22 (comment)

[JanEbbing]

Hi Vincent, sorry for the lack of transparency here. We'll ultimately move all development to GitHub, then it's easier to see what we're working on.
For your questions, I'm working on allowing users to configure which HTTP Client is used, using either a PSR-18 compliant one or the symfony client. So, nothing expected from your side.

[VincentLanglet]

Hi Vincent, sorry for the lack of transparency here. We'll ultimately move all development to GitHub, then it's easier to see what we're working on. For your questions, I'm working on allowing users to configure which HTTP Client is used, using either a PSR-18 compliant one or the symfony client. So, nothing expected from your side.

Thanks for your quick answer, I'm impatient to try this feature (and stop using a temporary fork).
Feel free to ping me if you need review/beta-testing before an official release :)

[JanEbbing]

Hi @VincentLanglet , I added support for custom clients in a new branch. We plan to merge this in the next version, please let me know what you think.

[VincentLanglet]

Hi @VincentLanglet , I added support for custom clients in a new branch. We plan to merge this in the next version, please let me know what you think.

Hi, this seems an ok implementation.
It should indeed solve our issue, allowing us to configure timeout by ourself.

The only things I see which might be improve (but I'm not certain how), would be to remove the hard dependency to guzzlehttp/psr7.
338c123#diff-d2ab9925cad7eac58e0ff4cc0d251a937ecf49e4b6bf57f8b95aab76648a9d34R15

I saw @nicolas-grekas promoting https://github.com/php-http/discovery which does an auto-discovery of the right psr implementation. The goal would be to use

• Psr17FactoryDiscovery::findRequestFactory()::createRequest() instead of new Request()
• Psr17FactoryDiscovery::findStreamFactory()::createStreamFromFile() instead of new MultipartStream()

but I'm not sure how easy it is to use this ; and this can still be done in another PR if needed.

[JanEbbing]

Thanks, that seems like a great way to avoid a dependency on a PSR-7 implementation!

[daniel-jones-deepl]

Another idea: We could also require a PSR-7/PSR-17 HTTP factory to be passed in with the PSR-18 HTTP client. This would mean no direct dependencies(*), but it would make the library interface a little harder to use.

*: edited-to-add: actually there would need to be a psr/http-factory dependency.

[nicolas-grekas]

I would definitely recommend relying on php-http/discovery and using its Psr18Client. It's an adapter that knows how to use whatever PSR-17+PSR-18 implementations are available.

As far as timeout is concerned, this could be considered out of scope from an SDK pov (aka let users that care do the timeout configuration as part of their wiring) or we could also discuss a way to make Psr18Client configurable somehow.

You might want to check helpscout/helpscout-api-php#311 for inspiration.

[JanEbbing]

@nicolas-grekas Thanks for the code example. We use POST requests with multipart/form-data. Based on the docs I would use this, but using it in the code the StreamFactoryDiscovery::find() is marked as deprecated and to be removed in 2.0 (actually the entire class).

Is there any way around using that?

[nicolas-grekas]

Instead of this discovery class, you should use https://github.com/php-http/multipart-stream-builder
and use the Psr18Client as a stream factory (it does implement what's needed):

$client = new Psr18Client();
$builder = new MultipartStreamBuilder($client);

[JanEbbing]

Thanks! I implemented that change and removed the guzzle dependency on the branch.

[VincentLanglet]

Thanks! I implemented that change and removed the guzzle dependency on the branch.

Hi @JanEbbing,
I tried your branch (with the recent changes) on my project and it works fine.
Thanks :)

[VincentLanglet]

Hi @JanEbbing, what are the next step for your branch ? Is it ready to be reviewed/merged/released ? :)

[JanEbbing]

Yes, this (with some other fixes) will be released today.

[VincentLanglet]

Thanks