Php-timeit estimates the execution time of php functions

: This article describes how to estimate the execution time of php functions using php-timeit. if you are interested in PHP tutorials, refer to it. First, I used the Japanese VPS to build a google proxy some time ago. the access speed was okay and I would like to share with you:

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Sometimes, when optimizing PHP performance, we need to know the execution time of a function. in Python, there is a timeit module. in PHP, we do not know whether there are similar modules?

Therefore, I wrote a simple timeit function as follows:

/** * Compute the delay to execute a function a number of time * @param $count    Number of time that the tests will execute the given function * @param $function        the function to test. Can be a string with parameters (ex: 'myfunc(123, 0, 342)') or a callback * @return float            Duration in seconds (as a float) */function timeit($count, $function) {    if ($count <= 0){        echo "Error: count have to be more than zero";        return -1;    }        $nbargs = func_num_args();    if ($nbargs < 2) {        echo 'Error: No Funciton!';        echo 'Usage:';        echo "\ttimeit(count, 'function(param)')";        echo "\te.g:timeit(100, 'function(0,2)')";        return -1;                        // no function to time    }        // Generate callback    $func = func_get_arg(1);    $func_name = current(explode('(', $func));    if (!function_exists($func_name)) {        echo 'Error: Unknown Function';        return -1;                    // can't test unknown function    }        $str_cmd = '';    $str_cmd .= '$start = microtime(true);';    $str_cmd .= 'for($i=0; $i<'.$count.'; $i++) '.$func.';';    $str_cmd .= '$end = microtime(true);';    $str_cmd .= 'return ($end - $start);';        return eval($str_cmd);}

Test the execution time of a self-written root algorithm and built-in root function as follows:

// Take the square root function sqrt_nd ($ num) {$ value = $ num; while (abs ($ value * $ value-$ num)> 0.001) {$ value = ($ value + $ num/$ value)/2;} return $ value;} print timeit (1000, 'sqrt _ nd (5 )'); print "\ n"; print timeit (1000, 'sqrt (5 )');

The test results are as follows:

0.0282800197601320.0041000843048096

It can be seen that the built-in root function is more than six times faster than the custom root function ~~

The preceding section describes how to estimate the execution time of php functions by using php-timeit, including the following content. I hope to help anyone who is interested in PHP tutorials.