PHP5.5 generator benchmark #1

php55-generator-bench1.php

<?php

///
/// benchmark: loop vs array vs generator vs inner iterator vs closure
///

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);
}


/// simple loop
function loop_lines($filename) {
    $f = fopen($filename, 'r');
    while (($line = fgets($f)) !== false) {
        //$arr = explode("\t", $line);
        //var_dump($arr);
    }
    fclose($f);
}


/// array
function read_lines($filename) {
    $f = fopen($filename, 'r');
    $lines = [];
    while (($line = fgets($f)) !== false) {
        $lines[] = $line;
    }
    fclose($f);
    return $lines;
}


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


/// inner iterator
function do_each_line_with($filename, $block) {
    $f = fopen($filename, 'r');
    while (($line = fgets($f)) !== false) {
        $block($line);
    }
    fclose($f);
}


/// closure
function fetch_lines($filename) {
    $f = fopen($filename, 'r');
    return function() use ($f) {
        $line = fgets($f);
        //// or
        //if (($line = fgets($f)) === false) {
        //    fclose($f);
        //}
        return $line;
    };
}


/// Benchmark
function run_benchmark($title, $block) {
    $begin = microtime(true);
    $block();
    $end = microtime(true);
    printf("%-15s %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);

    /// simple loop
    run_benchmark("loop", function() use ($filename) {
        loop_lines($filename);
    });

    /// array
    run_benchmark("array", function() use ($filename) {
        foreach (read_lines($filename) as $line) {
            //$arr = explode("\t", $line);
            //var_dump($arr);
        }
    });

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

    /// inner iterator
    run_benchmark("inner iterator", function() use ($filename) {
        do_each_line_with($filename, function($line) {
            //$arr = explode("\t", $line);
            //var_dump($arr);
        });
    });

    /// closure
    run_benchmark("closure", function() use ($filename) {
        $fetch = fetch_lines($filename);
        while (($line = $fetch()) !== false) {
            //$arr = explode("\t", $line);
            //var_dump($arr);
        }
    });

}


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