与readfile相比，下载速度要慢很多 [英] fread a lot slower for downloads than readfile

问题描述

我通过PHP脚本向用户提供从URL下载的内容。当我使用 readfile（）时，我得到我的连接可以支持的最大下载速度（约2.5MB / s），但是当我使用 fopen，fread， fclose 路由下载速度非常非常慢（约1-2KB / s）。

这是我的代码：

  header（'Content-Description：File Transfer'）; 
 header（'Content-Type：application / octet-stream'）; 
 header（'Content-Disposition：attachment; filename ='。$ filename）; 
 header（'Content-Transfer-Encoding：binary'）; 
 header（'Expires：0'）; 
 header（'Cache-Control：must-revalidate'）; 
 header（'Pragma：public'）; 
 header（'Content-Length：'。$ filesize）; 
 ob_clean（）; 
 flush（）; 
 
 $ file = fopen（$ url，'rb'）; 
 
 while（！feof（$ file））{
 echo fread（$ file，2014）; 
} 
  

，readfile代码只是 readfile（$ link ）; 。

我不能只使用 readfile（）函数，因为有两个原因，一个是我想限制用户下载速度（我可以通过读取这么多的数据来实现 fread ），我也想跟踪多少用户正在下载（我可以使用 readfile（），但不计入部分下载）。

有人知道为什么会发生这种情况吗？据我所知 readfile（）只是一个 fopen，fread和fclose 的包装器，所以我不会

编辑：结束了cURL。

  $ curl = curl_init（）; 
 $ options = array（
 CURLOPT_URL => $ rdLink，
 CURLOPT_FAILONERROR => true，
 CURLOPT_BINARYTRANSFER => true，
 CURLOPT_RETURNTRANSFER => true， 
 CURLOPT_WRITEFUNCTION =>'readResponse'
）; 
 curl_setopt_array（$ curl，$ options）; 
 
 if（！curl_exec（$ curl））{
 header（'Location：http://whatever.com'）; 
退出; 
} 
 curl_close（$ curl）; 
 
函数readResponse（$ ch，$ data）{
 $ length = mb_strlen（$ data，'8bit'）; 
 
 echo $ data; 
 
 return $ length; 
} 
  

解决方案

使用 stream_context_create（）和 stream_get_contents（）

  $ context = stream_context_create（）; 
 $ file = fopen（$ url，'rb'，FALSE，$ context）; 
 while（！feof（$ file））
 {
 // usleep（1000000）; 
 echo stream_get_contents（$ file，2014）; 
} 
  

您还可以尝试使文件读取长度更大并放入usleep ）缓慢执行。
似乎对于最新版本的PHP，似乎推荐使用流功能。
您可能还需要在fread（）或stream_get_contents（）前面添加一个@来抑制任何错误，至少在生产中。没有它，有点不幸，你有一个损坏的文件。

I'm serving downloads from a URL to my users through a PHP script. When using readfile() I get the maximum download speed my connection can support (about 2.5MB/s) however when I use the fopen, fread, fclose route the download speed is very, very slow (about 1-2KB/s).

Here's my code:

header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename=' . $filename);
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . $filesize);
ob_clean();
flush();

$file = fopen($url, 'rb');

while(!feof($file)) {
    echo fread($file, 2014);
}

and the readfile code is simply readfile($link);.

I can't just use the readfile() function because of two reasons, one is I want to restrict the users download speed (which I can do with fread by only reading so much data) and I also want to track how much a user is downloading (I can do this with readfile() but it doesn't count partial downloads).

Does anyone know why this might be happening or how I can fix it? As far as I know readfile() is just a wrapper for fopen, fread and fclose so I don't get what's going wrong.

Edit: Ended up going with cURL for this.

$curl = curl_init();
$options = array(
    CURLOPT_URL => $rdLink,
    CURLOPT_FAILONERROR => true,
    CURLOPT_BINARYTRANSFER => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_WRITEFUNCTION => 'readResponse'
);
curl_setopt_array($curl, $options);

if(!curl_exec($curl)) {
    header('Location: http://whatever.com');
    exit;
}
curl_close($curl);

function readResponse($ch, $data) {
    $length = mb_strlen($data, '8bit');

    echo $data;

    return $length;
}

解决方案

Use stream_context_create() and stream_get_contents()

$context = stream_context_create();
$file = fopen($url, 'rb', FALSE, $context);
while(!feof($file))
{
    //usleep(1000000);
    echo stream_get_contents($file, 2014);
}

You could also try making the file read length larger and putting in a usleep() to slow execution. The stream functions seem to be recommended over fread for the latest version of PHP anyway. You might want to also prepend an @ in front of the fread() or stream_get_contents() to suppress any errors, at least in production. Without it, and a little mishap, and you have a corrupted file.

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