[RFC] Make troubleshooting stuck tasks easier

[greg0ire]

Hi! I'm working with @julienpa to get the applications of my company on a new Algolia architecture, and I'm facing issues where some of the cronjobs I have to run appear to be stuck sometimes.

I'd like to be able to easily implement custom logic where I start logging the taskID with an increasingly high log level when exceeded an arbitrary duration, and I would like that logic to kick in whenever I call wait() on a response.

This seems to result in this method being called:

algoliasearch-client-php/src/SearchIndex.php

Lines 604 to 620 in ffef644

	public function waitTask($taskId, $requestOptions = [])
	{
	$retry = 1;
	$time = $this->config->getWaitTaskTimeBeforeRetry();
	do {
	$res = $this->getTask($taskId, $requestOptions);
	if ('published' === $res['status']) {
	return;
	}
	$retry++;
	$factor = ceil($retry / 10);
	usleep($factor * $time); // 0.1 second
	} while (true);
	}

It would be great if the current implementation of the retry logic could be extracted in a separate class, and if there was an interface I could implement with my custom logic and if I was able to inject my custom implementation in the configuration so that it replaces the default implementation.

Right now, the workaround would be to extend the SearchIndex, override that method, extend SearchClient and override initIndex so that it returns the overridden SearchIndex.