PHP Function Timer with results caching, memoization

timer.php

<?php

// Implement a memoization function to cache results of expensive function calls.
$timer = function ($function) {
    // Create an array to store cached results based on function arguments.
    $cache = [];

    // Return a closure that wraps the original function.
    return function (...$args) use ($function, &$cache) {
        // Generate a unique key for the cache based on function arguments.
        $key = serialize($args);

        // Check if the result is already cached.
        if (isset($cache[$key])) {
            return $cache[$key];
        }

        // Measure the start time of the function execution.
        $start = microtime(true);

        // Call the original function with the provided arguments and store the result.
        $result = call_user_func_array($function, $args);
        
        // Calculate the duration of the function execution and print it.
        printf("Time taken: %f seconds\n", microtime(true) - $start);

        // Cache the result for future calls with the same arguments.
        $cache[$key] = $result;

        return $result;
    };
};

// Example usage:
function exampleFunction($x, $y) {
    sleep(1); // Simulate an expensive operation
    return $x + $y;
}

$timedExampleFunction = $timer('exampleFunction');

echo $timedExampleFunction(5, 3) . "\n"; // Outputs the result and time taken for first call
echo $timedExampleFunction(5, 3) . "\n"; // Outputs only the cached result without additional time