php5.5 generator benchmark #2

php55-generator-bench2.php

<?php

///
/// generator benchmark
///

function create_datafile($filename, $filesize=1024) {
    $str = "Haruhi\tFemale\t16\tTeam Leader\n"
         . "Mikuru\tFemale\t17\tTime Traveler\n"
         . "Yuki\tFemale\t16\tHumanoid Interface\n"
         . "Itsuki\tMale\t16\tESPer Body\n"
         . "Kyon\tMale\t16\tStory Teller\n"
         ;
    $f = fopen($filename, 'w');
    $size = 0;
    do {
        fwrite($f, $str);
        $size += strlen($str);
    } while ($size < $filesize);
    fclose($f);
}


/// generator
function each_line($filename) {
    $f = fopen($filename, 'r');
    while (($line = fgets($f)) !== false) {
        yield $line;
    }
    fclose($f);
}


/// Benchmark
function run_benchmark($title, $block) {
    $begin = microtime(true);
    $block();
    $end = microtime(true);
    printf("%-30s %8.4f (sec)\n", $title, ($end - $begin));
}

function run_benchmarks($filename) {

    /// read file into disk cache
    $f = fopen($filename, 'r');
    do {
        $line = fgets($f);
    } while ($line !== false);
    fclose($f);


    /// not generator
    run_benchmark("no generator", function() use ($filename) {
        $f = fopen($filename, 'r');
        while (($line = fgets($f)) !== false) {
            // do nothing
        }
        fclose($f);
    });


    /// generator
    run_benchmark("generator", function() use ($filename) {
        foreach (each_line($filename) as $line) {
            // do nothing
        }
    });


    /// generator + explode()
    run_benchmark("generator+explode()", function() use ($filename) {
        foreach (each_line($filename) as $line) {
            $arr = explode("\t", $line);
        }
    });


    /// generator + explode() + array()
    run_benchmark("generator+explode()+array()", function() use ($filename) {
        foreach (each_line($filename) as $line) {
            $arr = explode("\t", $line);
            $assoc = array('name'=>$arr[0], 'gender'=>$arr[1],
                           'age'=>0+$arr[2], 'desc'=>$arr[3]);
        }
    });


}


$filename = "example.data";
if (! file_exists($filename)) {
    create_datafile($filename, 15*1024*1024);
}
run_benchmarks($filename);