<?php
/**
 * @defgroup Benchmark Benchmark
 * @ingroup  Maintenance
 */

/**
 * Base code for benchmark scripts.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup Benchmark
 */

require_once __DIR__ . '/../Maintenance.php';

/**
 * Base class for benchmark scripts.
 *
 * @ingroup Benchmark
 */
abstract class Benchmarker extends Maintenance {
	private $results;
	protected $defaultCount = 100;

	public function __construct() {
		parent::__construct();
		$this->addOption( 'count', 'How many times to run a benchmark', false, true );
	}

	public function bench( array $benchs ) {
		$count = $this->getOption( 'count', $this->defaultCount );
		foreach ( $benchs as $key => $bench ) {
			// Default to no arguments
			if ( !isset( $bench['args'] ) ) {
				$bench['args'] = [];
			}

			// Optional setup called outside time measure
			if ( isset( $bench['setup'] ) ) {
				call_user_func( $bench['setup'] );
			}
			$start = microtime( true );
			for ( $i = 0; $i < $count; $i++ ) {
				call_user_func_array( $bench['function'], $bench['args'] );
			}
			$delta = microtime( true ) - $start;

			// Name defaults to name of called function
			if ( is_string( $key ) ) {
				$name = $key;
			} else {
				if ( is_array( $bench['function'] ) ) {
					$name = get_class( $bench['function'][0] ) . '::' . $bench['function'][1];
				} else {
					$name = strval( $bench['function'] );
				}
				$name = sprintf( "%s(%s)",
					$name,
					implode( ', ', $bench['args'] )
				);
			}

			$this->results[] = [
				'name' => $name,
				'count' => $count,
				'total' => $delta,
				'average' => $delta / $count,
			];
		}
	}

	public function getFormattedResults() {
		$ret = sprintf( "Running PHP version %s (%s) on %s %s %s\n\n",
			phpversion(),
			php_uname( 'm' ),
			php_uname( 's' ),
			php_uname( 'r' ),
			php_uname( 'v' )
		);
		foreach ( $this->results as $res ) {
			// show function with args
			$ret .= sprintf( "%s times: %s\n",
				$res['count'],
				$res['name']
			);
			$ret .= sprintf( "   %6.2fms (%6.4fms each)\n",
				$res['total'] * 1e3,
				$res['average'] * 1e3
			);
		}

		return $ret;
	}
}