Method

class Method

A method that can be benchmarked with optional parameters.

The closure is called with a single integer $n. It is best to let $n control a simple loop in your closure e.g. while ($n--) { ... }

Your closure may optionally accept a second parameter. In this case you must add parameters to the Unit object. You must omit the second parameter if you do not add any parameters to your Unit object.

This library will try to figure out the optimal values for $n for each method. That way stable measurements can be taken that are easy to compare.

If your test is computationally intensive by nature this might not work for you. In this case use $n to control the cost or difficulty of your algorithm.

It is important that you do not use a loop in addition when doing this because the duration is not expected to increase exponentially.

Methods

Details

Source code

<?php

/*
 * This file is part of nochso/benchmark.
 *
 * @copyright Copyright (c) 2015 Marcel Voigt <mv@noch.so>
 * @license   https://github.com/nochso/benchmark/blob/master/LICENSE ISC
 * @link      https://github.com/nochso/benchmark
 */

namespace nochso\Benchmark;

/**
 * A method that can be benchmarked with optional parameters.
 *
 * The closure is called with a single integer $n. It is best to let $n
 * control a simple loop in your closure e.g. `while ($n--) { ... }`
 *
 * Your closure may optionally accept a second parameter. In this case you must
 * add parameters to the Unit object. You must omit the second parameter if you
 * do not add any parameters to your Unit object.
 *
 * This library will try to figure out the optimal values for $n for each
 * method. That way stable measurements can be taken that are easy to compare.
 *
 * If your test is computationally intensive by nature this might not work
 * for you. In this case use $n to control the cost or difficulty of your
 * algorithm.
 *
 * It is important that you **do not use a loop in addition** when doing
 * this because the duration is not expected to increase exponentially.
 *
 * @author Marcel Voigt <mv@noch.so>
 * @copyright Copyright (c) 2015 Marcel Voigt <mv@noch.so>
 */
class Method
{
    /**
     * @var callable|\Closure
     */
    private $method;
    /**
     * @var string
     */
    private $name;
    /**
     * @var string
     */
    private $description;

    /**
     * @param callable|\Closure $method
     * @param string            $name
     * @param string            $description Optional description
     */
    public function __construct($method, $name, $description = '')
    {
        $this->method = $method;
        $this->name = $name;
        $this->description = $description;
    }

    /**
     * Return the name of the method.
     *
     * @return string
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * Return the description of the method.
     *
     * @return string
     */
    public function getDescription()
    {
        return $this->description;
    }

    /**
     * @return callable|\Closure
     */
    public function getMethod()
    {
        return $this->method;
    }

    /**
     * Returns the source code of the closure.
     *
     * The beginning of each line will be trimmed uniformly to remove excessive
     * whitespace.
     *
     * e.g.
     * ```
     *     while {
     *         do();
     *     }
     * ```
     * becomes
     * ```
     * while {
     *     do();
     * }
     * ```
     *
     * @return string
     */
    public function getSourceCode()
    {
        $reflection = new \ReflectionFunction($this->method);
        $source = file($reflection->getFileName(), FILE_IGNORE_NEW_LINES);
        $startLine = $reflection->getStartLine();
        $endLine = $reflection->getEndLine() - 1;
        $lines = array_slice($source, $startLine, $endLine - $startLine);
        return implode(PHP_EOL, $this->trimSourceLines($lines));
    }

    /**
     * @param Parameter $parameter
     *
     * @return Result
     */
    public function time(Parameter $parameter = null)
    {
        $timer = new Timer();
        return $timer->time($this, $parameter);
    }

    /**
     * @param $lines
     *
     * @return array
     */
    private function trimSourceLines($lines)
    {
        $minSpaces = PHP_INT_MAX;
        foreach ($lines as $line) {
            $spaces = strlen($line) - strlen(ltrim($line, ' '));
            $minSpaces = min($minSpaces, $spaces);
        }
        $trimmedLines = array();
        foreach ($lines as $line) {
            $trimmedLines[] = substr($line, $minSpaces);
        }
        return $trimmedLines;
    }
}