Subversion Repositories SmartDukaan

<?php

/**

 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)

 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)

 *

 * Licensed under The MIT License

 * Redistributions of files must retain the above copyright notice.

 *

 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)

 * @link          http://cakephp.org CakePHP(tm) Project

 * @since         DebugKit 1.0

 * @license       http://www.opensource.org/licenses/mit-license.php MIT License

 */

App::uses('String', 'Utility');

/**

 * Benchmark Shell Class

 *

 * Provides basic benchmarking of application requests

 * functionally similar to Apache AB

 *

 * @since         DebugKit 1.0

 * @todo Print/export time detail information

 * @todo Export/graphing of data to .dot format for graphviz visualization

 * @todo Make calculated results round to leading significant digit position of std dev.

 */

class BenchmarkShell extends Shell {

/**

 * Main execution of shell

 *

 * @return void

 */

	public function main() {

		$url = $this->args[0];

		$defaults = array('t' => 100, 'n' => 10);

		$options = array_merge($defaults, $this->params);

		$times = array();

		$this->out(String::insert(__d('debug_kit', '-> Testing :url'), compact('url')));

		$this->out("");

		for ($i = 0; $i < $options['n']; $i++) {

			if (floor($options['t'] - array_sum($times)) <= 0 || $options['n'] <= 1) {

				break;

			}

			$start = microtime(true);

			file_get_contents($url);

			$stop = microtime(true);

			$times[] = $stop - $start;

		}

		$this->_results($times);

	}

/**

 * Prints calculated results

 *

 * @param array $times Array of time values

 * @return void

 */

	protected function _results($times) {

		$duration = array_sum($times);

		$requests = count($times);

		$this->out(String::insert(__d('debug_kit', 'Total Requests made: :requests'), compact('requests')));

		$this->out(String::insert(__d('debug_kit', 'Total Time elapsed: :duration (seconds)'), compact('duration')));

		$this->out("");

		$this->out(String::insert(__d('debug_kit', 'Requests/Second: :rps req/sec'), array(

				'rps' => round($requests / $duration, 3)

		)));

		$this->out(String::insert(__d('debug_kit', 'Average request time: :average-time seconds'), array(

				'average-time' => round($duration / $requests, 3)

		)));

		$this->out(String::insert(__d('debug_kit', 'Standard deviation of average request time: :std-dev'), array(

				'std-dev' => round($this->_deviation($times, true), 3)

		)));

		$this->out(String::insert(__d('debug_kit', 'Longest/shortest request: :longest sec/:shortest sec'), array(

				'longest' => round(max($times), 3),

				'shortest' => round(min($times), 3)

		)));

		$this->out("");

	}

/**

 * One-pass, numerically stable calculation of population variance.

 *

 * Donald E. Knuth (1998).

 * The Art of Computer Programming, volume 2: Seminumerical Algorithms, 3rd edn.,

 * p. 232. Boston: Addison-Wesley.

 *

 * @param array $times Array of values

 * @param boolean $sample If true, calculates an unbiased estimate of the population

 * 						  variance from a finite sample.

 * @return float Variance

 */

	protected function _variance($times, $sample = true) {

		$n = $mean = $M2 = 0;

		foreach ($times as $time) {

			$n += 1;

			$delta = $time - $mean;

			$mean = $mean + $delta / $n;

			$M2 = $M2 + $delta * ($time - $mean);

		}

		if ($sample) {

			$n -= 1;

		}

		return $M2 / $n;

	}

/**

 * Calculate the standard deviation.

 *

 * @param array $times Array of values

 * @param boolean $sample

 * @return float Standard deviation

 */

	protected function _deviation($times, $sample = true) {

		return sqrt($this->_variance($times, $sample));

	}

	public function getOptionParser() {

		$parser = parent::getOptionParser();

		$parser->description(__d('debug_kit',

			'Allows you to obtain some rough benchmarking statistics' .

			'about a fully qualified URL.'

		))

		->addArgument('url', array(

			'help' => __d('debug_kit', 'The URL to request.'),

			'required' => true

		))

		->addOption('n', array(

			'default' => 10,

			'help' => __d('debug_kit', 'Number of iterations to perform.')

		))

		->addOption('t', array(

			'default' => 100,

			'help' => __d('debug_kit', 'Maximum total time for all iterations, in seconds.' .

				'If a single iteration takes more than the timeout, only one request will be made'

			)

		))

		->epilog(__d('debug_kit',

			'Example Use: `cake benchmark --n 10 --t 100 http://localhost/testsite`. ' .

			'<info>Note:</info> this benchmark does not include browser render times.'

		));

		return $parser;

	}

}