Utils - save only unique deprecations to avoid memory issues

[PetrHeinz]

With the #5674 merged, we have run into exhaustion of allowed memory pretty quickly, see https://github.com/shopsys/shopsys/pull/2308/checks?check_run_id=2511509379

Even though it would be better for us to fix all the deprecations, and we definitely plan to do it in the future, it will be rather time consuming and we would like to use the newer version in the meantime.

I propose to save the deprecation message only if it's unique. Because array_unique is called on the result afterwards, I see no issues with this approach.

[PetrHeinz]

Running array_search for every trigger of deprecation message might be inefficient as it's O(n).

Maybe using a key for ensuring the uniqueness would be better as it's O(1), but it would introduce a change of meaning into Utils::$deprecations:

    /**
     * Handle triggering deprecation error.
     *
     * @param string $message
     * @param string $exceptionClass
     */
    public static function triggerDeprecation($message, $exceptionClass = \RuntimeException::class)
    {
        if (getenv('PHP_CS_FIXER_FUTURE_MODE')) {
            throw new $exceptionClass("{$message} This check was performed as `PHP_CS_FIXER_FUTURE_MODE` env var is set.");
        }

-       if (false === array_search($message, self::$deprecations, true)) {
-           self::$deprecations[] = $message;
-       }
+       self::$deprecations[$message] = true;
        @trigger_error($message, E_USER_DEPRECATED);
    }

    public static function getTriggeredDeprecations()
    {
-       return self::$deprecations;
+       return array_keys(self::$deprecations);
    }

Not sure which approach is preferable for this project, so I'm just putting it there...

[keradus]

I like the proposal with assyc array. shitty we don't have native Set support

[keradus]

maybe just sort the array in getTriggeredDeprecations too

[PetrHeinz]

@keradus Sure thing, done in a034c9b

[coveralls]

Coverage decreased (-0.005%) to 91.525% when pulling b9a839e on PetrHeinz:patch-1 into 1f0af68 on FriendsOfPHP:2.19.

[keradus]

Thank you @PetrHeinz.