下载大文件会冻结网站

Question

我正在尝试从网站下载文件。

当下载正在进行时，网站冻结，当我点击页面上的任何内容时没有任何反应。当我取消下载时，一切正常。

以下是我下载文件的代码：

<?php
@session_start();
error_reporting(0);
$upload_dir =$_SESSION['SITE_IMG_PATH']."/digital_products/";
$upload_dirthumb =$_SESSION['SITE_IMG_PATH']."user/thumb/"; 


// Allow direct file download (hotlinking)?
// Empty - allow hotlinking
// If set to nonempty value (Example: example.com) will only allow downloads when referrer contains this text
define('ALLOWED_REFERRER', '');

// Download folder, i.e. folder where you keep all files for download.
// MUST end with slash (i.e. "/" )
define('BASE_DIR',$upload_dir);

// log downloads?  true/false
define('LOG_DOWNLOADS',true);

// log file name
define('LOG_FILE','downloads_video.log');

// Allowed extensions list in format 'extension' => 'mime type'
// If myme type is set to empty string then script will try to detect mime type 
// itself, which would only work if you have Mimetype or Fileinfo extensions
// installed on server.
$allowed_ext = array (

  // archives
  'zip' => 'application/zip',
  'rar' => 'application/rar',
  // documents
  'pdf' => 'application/pdf',
  'txt' => 'application/text',
  'doc' => 'application/msword',
  'xls' => 'application/vnd.ms-excel',
  'ppt' => 'application/vnd.ms-powerpoint',
  'xlsx' => 'application/vnd.ms-excel',

  // executables
  'exe' => 'application/octet-stream',

  // images
  'gif' => 'image/gif',
  'png' => 'image/png',
  'jpg' => 'image/jpeg',
  'jpeg' => 'image/jpeg',

  // audio
  'mp3' => 'audio/mpeg',
  'wav' => 'audio/x-wav',

  // video
  'mpeg' => 'video/mpeg',
  'mpg' => 'video/mpeg',
  'mpe' => 'video/mpeg',
  'mov' => 'video/quicktime',
  'avi' => 'video/x-msvideo'

);




// If hotlinking not allowed then make hackers think there are some server problems
if (ALLOWED_REFERRER !== ''
&& (!isset($_SERVER['HTTP_REFERER']) || strpos(strtoupper($_SERVER['HTTP_REFERER']),strtoupper(ALLOWED_REFERRER)) === false)
) {
  die("Internal server error. Please contact system administrator.");
}

// Make sure program execution doesn't time out
// Set maximum script execution time in seconds (0 means no limit)
set_time_limit(0);

if (!isset($_GET['f']) || empty($_GET['f'])) {
  die("Please specify file name for download.");
}

// Nullbyte hack fix
if (strpos($_GET['f'], "\0") !== FALSE) die('');

// Get real file name.
// Remove any path info to avoid hacking by adding relative path, etc.
$fname = basename($_GET['f']);
// Check if the file exists
// Check in subfolders too
function find_file ($dirname, $fname, &$file_path) {

  $dir = opendir($dirname);

  while ($file = readdir($dir)) {
    if (empty($file_path) && $file != '.' && $file != '..') {
      if (is_dir($dirname.'/'.$file)) {
        find_file($dirname.'/'.$file, $fname, $file_path);
      }
      else {
        if (file_exists($dirname.'/'.$fname)) {
          $file_path = $dirname.'/'.$fname;
          return;
        }
      }
    }
  }

} // find_file

// get full file path (including subfolders)
$file_path = '';
find_file(BASE_DIR, $fname, $file_path);

if (!is_file($file_path)) {
  die("File does not exist. Make sure you specified correct file name."); 
}

// file size in bytes
$fsize = filesize($file_path); 

// file extension
$fext = strtolower(substr(strrchr($fname,"."),1));

// check if allowed extension
if (!array_key_exists($fext, $allowed_ext)) {
  die("Not allowed file type."); 
}

// get mime type
if ($allowed_ext[$fext] == '') {
  $mtype = '';
  // mime type is not set, get from server settings
  if (function_exists('mime_content_type')) {
    $mtype = mime_content_type($file_path);
  }
  else if (function_exists('finfo_file')) {
    $finfo = finfo_open(FILEINFO_MIME); // return mime type
    $mtype = finfo_file($finfo, $file_path);
    finfo_close($finfo);  
  }
  if ($mtype == '') {
    $mtype = "application/force-download";
  }
}
else {
  // get mime type defined by admin
  $mtype = $allowed_ext[$fext];
}

// Browser will try to save file with this filename, regardless original filename.
// You can override it if needed.

if (!isset($_GET['fc']) || empty($_GET['fc'])) {
  $asfname = $fname;
}
else {
  // remove some bad chars
  $asfname = str_replace(array('"',"'",'\\','/'), '', $_GET['fc']);
  if ($asfname === '') $asfname = 'NoName';
}

// set headers
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: public");
header("Content-Description: File Transfer");
header("Content-Type: $mtype");
header("Content-Disposition: attachment; filename=\"$asfname\"");
header("Content-Transfer-Encoding: binary");
header("Content-Length: " . $fsize);

// download
// @readfile($file_path);
$file = @fopen($file_path,"rb");
if ($file) {
  while(!feof($file)) {
    print(fread($file, 1024*8));
    flush();
    if (connection_status()!=0) {
      @fclose($file);
      die();
    }
  }
  @fclose($file);
}

// log downloads
if (!LOG_DOWNLOADS) die();

$f = @fopen(LOG_FILE, 'a+');
if ($f) {
  @fputs($f, date("m.d.Y g:ia")."  ".$_SERVER['REMOTE_ADDR']."  ".$fname."");
  $conn=new mysqli("localhost","root","","pmipla5_pmiplanet");
  if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} 


  $chechkexists = "SELECT * FROM tbl_user_product_attempt where userid = '".$_SESSION['pmi']['ID']."' and productid = '".$_GET['proid']."' and status = 1 and (payment_id= '".$_GET['decrypt_invoiceid']."' or 0=0)";
  $result_chechkexist = $conn->query($chechkexists);//$controller_class->getfetchRow($chechkexists);
$attempt=0;
    if($result_chechkexist->num_rows > 0)
    {
        while($result_chechkexists = $result_chechkexist->fetch_assoc()) {
        $attempt = $result_chechkexists['attempt'] + 1;
        $updateattempts = "UPDATE tbl_user_product_attempt SET attempt = '".$attempt."',cr_date=NOW() WHERE userid = '".$_SESSION['pmi']['ID']."' and productid = '".$_GET['proid']."' and (payment_id = '".$_REQUEST['decrypt_invoiceid']."' or 0=0)";
        $result = $result = $conn->query($updateattempts);//$controller_class->getInsertUpdateQry($updateattempts);
        }

    }else {
        $attemp = $attempt + 1;
        $updateattempts = "INSERT INTO tbl_user_product_attempt (userid,productid,attempt,status,cr_date,payment_id) VALUES ('".$_SESSION['pmi']['ID']."','".

$_GET['proid']."','".$attemp."','1',NOW(),'".$_GET['decrypt_invoiceid']."')";

$result = $conn->query($updateattempts); //$controller_class->getInsertUpdateQry($updateattempts);
  @fclose($f);

}
}

?>

因此，当下载开始时，它冻结屏幕并且链接停止工作。 有关此处发生了什么的建议或有关从服务器下载文件的更好方法的建议吗？