PHP 下载 file_put_contents vs readfile

set_time_limit(0);

ini_set('memory_limit', '512M');

//获取当前时间

function getTime($convert = true)

{

    return microtime($convert);

}

//获取当前内存

function memory()

{

    return memory_get_usage();

}

$m = memory();

$s = getTime();

$file = file_get_contents("a.zip", true);

header("Content-type: application/octet-stream");

header("Accept-Ranges: bytes");

header("Accept-Length: " . filesize('a.zip'));

header('Content-Disposition: attachment; filename="a.zip"');

echo $file;

error_log('file_put_contents:         内存：'.(memory()-$m).',耗时:'.(getTime()-$s).'\r\n',3,'D:/1.txt');

/* readfile() benchmark */

$m = memory();

$s = getTime();

ob_start();

header('Content-Type: application/octet-stream');

header("Accept-Ranges: bytes");

header("Accept-Length: " . filesize('a.zip'));

header('Content-Disposition: attachment; filename="a.zip"');

header('Content-Transfer-Encoding: binary');

readfile('a.zip');

ob_end_clean();

error_log('readfile:         内存：'.(memory()-$m).',耗时:'.(getTime()-$s).'\r\n',3,'D:/1.txt');

结果如下：

2k文件

file_put_contents:         内存：2304,耗时:0.00099992752075195

readfile:                  内存：888,耗时: 0.002000093460083

20M文件

file_put_contents:         内存：50126256,耗时:0.21602201461792

readfile:                  内存：896,耗时:0.071007013320923

153M文件

file_put_contents:         内存：321370872,耗时:1.0341031551361

readfile:                  内存：840,耗时:1.9421939849854

结论：相同条件下在下载大文件时使用readfile更省内存，不容易导致php内存溢出问题。