Online PHP editor | perf for QZYpQ

@ 2014-05-20T00:34:23Z

<?php

class TokenGenerator
{
    const ALPHABET = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';

    public function generateToken($length = 16)
    {
        $alphabetSize = strlen(self::ALPHABET);
        $token = '';

        while (strlen($token) < $length) {
            $randomBytes = $this->generateRandomBytes(32);
            $offset = abs(hexdec(bin2hex(substr($randomBytes, 0, 4)))) % $alphabetSize;
            $token .= substr(self::ALPHABET, $offset, 1);
        }

        return $token;
    }

    private function generateRandomBytes($length)
    {
        $bytes = '';

        // pre-fill with weak bytes
        while (strlen($bytes) < $length) {
            $bytes .= chr(mt_rand(0, 255));
        }

        // merge with mcrypt iv
        if (function_exists('mcrypt_create_iv')) {
            $bytes = hash_hmac('sha256', $bytes, mcrypt_create_iv($length, MCRYPT_DEV_URANDOM), true);
        }

        // merge with openssl bytes
        if (function_exists('openssl_random_pseudo_bytes')) {
            $bytes = hash_hmac('sha256', $bytes, openssl_random_pseudo_bytes($length), true);
        }

        // merge with urandom
        if (file_exists('/dev/urandom') && is_readable('/dev/urandom')) {
            $bytes = hash_hmac('sha256', $bytes, file_get_contents('/dev/urandom', null, null, null, $length), true);
        }

        return substr($bytes, 0, $bytes);
    }
}

$gen = new TokenGenerator();

var_dump($gen->generateToken(10));
var_dump($gen->generateToken(10));
var_dump($gen->generateToken(10));
var_dump($gen->generateToken(20));
var_dump($gen->generateToken(20));
var_dump($gen->generateToken(20));

Here you find the average performance (time & memory) of each version. A grayed out version indicates it didn't complete successfully (based on exit-code).

Version	System time (s)	User time (s)	Memory (MiB)
7.1.0	0.000	0.040	22.31
7.0.14	0.010	0.080	22.04
5.6.28	0.013	0.077	20.91
5.4.28	0.007	0.043	12.39
5.4.27	0.010	0.048	12.39
5.4.26	0.067	0.047	19.35
5.4.25	0.015	0.064	12.39
5.4.24	0.012	0.052	12.39
5.4.23	0.014	0.063	12.38
5.4.22	0.011	0.058	12.38
5.4.21	0.014	0.033	12.38
5.4.20	0.008	0.041	12.38
5.4.19	0.009	0.037	12.38
5.4.18	0.013	0.045	12.38
5.4.17	0.006	0.052	12.39
5.4.16	0.053	0.063	19.29
5.4.15	0.015	0.050	12.38
5.4.14	0.031	0.068	12.06
5.4.13	0.005	0.045	12.05
5.4.12	0.006	0.050	12.01
5.4.11	0.070	0.060	16.42
5.4.10	0.007	0.054	12.00
5.4.9	0.060	0.050	16.36
5.4.8	0.006	0.051	12.00
5.4.7	0.015	0.061	12.00
5.4.6	0.063	0.067	16.53
5.4.5	0.005	0.075	12.00
5.4.4	0.013	0.060	11.99
5.4.3	0.014	0.049	11.98
5.4.2	0.067	0.050	16.45
5.4.1	0.009	0.059	11.98
5.4.0	0.010	0.049	11.47
5.3.28	0.009	0.065	12.71
5.3.27	0.070	0.043	14.66
5.3.26	0.020	0.073	12.71
5.3.25	0.013	0.059	12.72
5.3.24	0.015	0.081	12.72
5.3.23	0.012	0.064	12.71
5.3.22	0.017	0.078	12.68
5.3.21	0.012	0.079	12.68
5.3.20	0.057	0.057	14.62
5.3.19	0.010	0.058	12.68
5.3.18	0.014	0.057	12.68
5.3.17	0.013	0.056	12.67
5.3.16	0.047	0.063	14.57
5.3.15	0.008	0.058	12.68
5.3.14	0.008	0.057	12.66
5.3.13	0.014	0.065	12.66
5.3.12	0.057	0.057	14.57
5.3.11	0.010	0.066	12.66
5.3.10	0.016	0.077	12.12
5.3.9	0.060	0.053	14.03
5.3.8	0.012	0.049	12.08
5.3.7	0.011	0.047	12.07

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