smuuf/primi

<?php

declare(strict_types=1);

$t = hrtime(true);

ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
error_reporting(E_ALL);
const MAX_ITER = 50000;
const TENTH_ITER = MAX_ITER / 10;

//
// Run some CPU intensive tasks and measure their duration in pure PHP.
//

function decor($fn) {
    return function() use ($fn) {
        echo "(";
        $fn();
        echo ")";
    };
}

function measure($fn) {
    $start = microtime(true);
    $fn();
    return microtime(true) - $start;
}

function bench_function_calls() {

    $adder = function($x, $y) {
        return $x + $y;
    };

    $result = -1024;
    $c = 0;
    while ($c < MAX_ITER) {
        $result = $result + $adder($c, 1);
        $c = $c + 1;
        if ($c % TENTH_ITER === 0) {
            echo ":";
        }
    }

    return $c;

}

function bench_regex_matches() {

    $haystack = "Když začínáme myslet, nemáme k dispozici nic jiného než myšlenku v " .
                "její čisté neurčenosti, neboť k určení již patří jedno nebo nějaké " .
                "jiné, ale na začátku ještě nemáme žádné jiné...";

    $result = 0;
    $c = 0;
    while ($c < MAX_ITER) {
        $result += preg_match('#^.*(zač).*(,)?.*?(\.)$#', $haystack, $m);
        $c = $c + 1;
        if ($c % TENTH_ITER === 0) {
            echo ":";
        }
    }

    return $c;

}

function bench_dicts() {

    $c = 0;
    $result = [];

    while ($c < MAX_ITER) {

        $dict = [
            'a' => true,
            'b' => false,
            'c' => null,
            'd' => 'áhojky, plantážníku!',
            'keys' => ['a', 'b', 'c'],
        ];

        foreach ($dict['keys'] as $name) {
            $result[] = $dict[$name];
        }

        $c = $c + 1;

        if ($c % TENTH_ITER === 0) {
            echo ":";
        }

    }

    return $result;

}

measure(decor('bench_function_calls'));
measure(decor('bench_regex_matches'));
measure(decor('bench_dicts'));

$mempeak = memory_get_peak_usage() / 1_000_000;
$time = (hrtime(true) - $t) / 1_000_000_000;

echo "\n";
echo "$time\n$mempeak";