Magento：每次循环运行时都要创建一个辅助类的新实例？

Question

I created a custom helper class module which I'm calling thusly:

$bench = Mage::helper('benchmark');
// ... do stuff ...
$bench->addBenchmark();
// ... more stuff ...
$bench->logResults();

This outputs the results of time benchmarks in an array.

The class is really simple, it basically just adds the current microtime() to an array then spits that array out when logResults() is called.

The problem is, I have a loop where I'm calling the code above, but instead of logging a "fresh" set of benchmark figures each loop, it's compounding itself and adding to the existing benchmarks array!

I want it to create a new set of benchmarks each time Mage::helper('benchmark'); is called.

Any help is appreciated.

Answer 1

With a helper that is not possible, unless you manually flush the content of the array upon calling the addBenchmark method.

The problem lies in the following. Within Mage.php your requested helper is stored in the registry. Upon next call the exact same helper object will be retrieved from the registry, instead of a new one. It only creates an instance the first time the helper is called.

/**
 * Retrieve helper object
 *
 * @param string $name the helper name
 * @return Mage_Core_Helper_Abstract
 */
public static function helper($name)
{
    if (strpos($name, '/') === false) {
        $name .= '/data';
    }

    $registryKey = '_helper/' . $name;
    if (!self::registry($registryKey)) {
        $helperClass = self::getConfig()->getHelperClassName($name);
        self::register($registryKey, new $helperClass);
    }
    return self::registry($registryKey);
}

You could opt for a model, since getModel() returns a new instance each time the factory method is called. Though in my opinion that is a case of bad programming and also hurts you on performance.

I would opt for flushing the latest data upon making a new call to addBenchmark . If you want to store all data in the helper for later processing perhaps always return the latest key in the array? Though, thats a matter of choice and flavor, so I will leave that part up to you.

Hopefully this helps you a bit!

Answer 2

Add benchmark key and make something like

$this->benchmarks[$key]['start'] = microtime(true);
// ... 
$this->benchmarks[$key]['finish'] = microtime(true);

so you'll have array of start-finish pairs for every iteration

Why don't you want to use Varien_Profiler?

Varien_Profiler::start($_profilerKey);
// ...
Varien_Profiler::stop($_profilerKey);