Why does Mozilla Extension like downthemall cause requests to a URL to appear hitting multiple times?

[ChandraPraksh]

I develop a PHP code and count how much data was downloaded by the client. My code is working fine if someone directly requests my file from a browser. But if someone installs a Mozilla extensions like ‘’downthemall’’ and then the url is requested by that extension then it requests the file URL 4 times so I get the downloaded data 4 times. How do I fix this? The same happened when the user is using jDownloader software or any software.

<?php
 
function getMimeType($fileName)
{
    $c_type_default = "application/octet-stream";
    $content_types = array(
        "exe" => "application/octet-stream",
        "zip" => "application/zip",
        "mp3" => "audio/mpeg",
        "mpg" => "video/mpeg",
        "avi" => "video/x-msvideo",
		 "mp4" => "video/mp4",
    );
// 	echo isset($content_types[pathinfo($fileName, PATHINFO_EXTENSION)]) ? $content_types[pathinfo($fileName, PATHINFO_EXTENSION)] : $c_type_default;     
    return isset($content_types[pathinfo($fileName, PATHINFO_EXTENSION)]) ? $content_types[pathinfo($fileName, PATHINFO_EXTENSION)] : $c_type_default;
}
function output_file($file, $name)
{
 
 /*
 This function takes a path to a file to output ($file),  the filename that the browser will see ($name) and  the MIME type of the file ($mime_type, optional).
 */
 
 //Check the file premission
 if(!is_readable($file)) die('File not found or inaccessible!');
 
 $size = filesize($file);
 
 $name = rawurldecode($name);

 //turn off output buffering to decrease cpu usage
	 @ob_end_clean(); 
	include('../includes/configg.php');
 
	// Start Code  For Total Downloaded Data Size by The LoggedIn User
	    $user="select * from $TBusers where id=".$_SESSION['log_id'];
		$result_user = mysqli_query($conn, $user) ;
		$row = mysqli_fetch_assoc($result_user);
	 	$lastsotrage = $row['down'];  
	 	$curr_date= $row['curr_date'];
	 	$today_date= date('d-m-y');
	 	$daily_downloaded_data= $row['daily_downloaded_data'];
		if($curr_date != $today_date)
		{ 
			  $update_curr_date="update $TBusers set curr_date ='$today_date', daily_downloaded_data =0 where id=".$_SESSION['log_id'];  // Set Curr_date by Today Date For check Daily Downloaded Data Limit
			  
			  mysqli_query($conn,$update_curr_date) ;
			  $daily_downloaded_data=0;
		}
		/*else
		{
			 if($daily_downloaded_data>=(20*1024*1024*1024)){ 			// Check Daily  Download Data Limit 20GB Exceed or not
			 header('Location: http://idownload.club/members/download.php');
			 exit;}
		}*/

 
 // required for IE, otherwise Content-Disposition may be ignored
 if(ini_get('zlib.output_compression'))
 ini_set('zlib.output_compression', 'Off');
 
 header('Content-Type: ' . getMimeType($name));
 header('Content-Disposition: attachment; filename="'.$name.'"');
 header("Content-Transfer-Encoding: binary");
 header('Accept-Ranges: bytes');
 
 /* The three lines below basically make the 
    download non-cacheable */
 header("Cache-control: private");
 header('Pragma: private');
 header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
 
 // multipart-download and download resuming support
 if(isset($_SERVER['HTTP_RANGE']))
 {
	list($a, $range) = explode("=",$_SERVER['HTTP_RANGE'],2);
	list($range) = explode(",",$range,2);
	list($range, $range_end) = explode("-", $range);
	$range=intval($range);
	if(!$range_end) {
		$range_end=$size-1;
	} else {
		$range_end=intval($range_end);
	}

	$new_length = $range_end-$range+1;
	header("HTTP/1.1 206 Partial Content");
	header("Content-Length: $new_length");
	header("Content-Range: bytes $range-$range_end/$size");
 } else {
	$new_length=$size;
	header("Content-Length: ".$size);
 }
 
 /* Will output the file itself */
 $chunksize = 1*(1024*1024); //you may want to change this
 $bytes_send = 0;
 if ($file = fopen($file, 'r'))
 {
	if(isset($_SERVER['HTTP_RANGE']))
	fseek($file, $range);
 
	while(!feof($file) && 
		(!connection_aborted()) && 
		($bytes_send<$new_length)
	      )
	{
		$buffer = fread($file, $chunksize);
		print($buffer); //echo($buffer); // can also possible
		flush();
		$bytes_send += strlen($buffer);
	}
 fclose($file);
 			 
 			$lastsotrage= $lastsotrage + $size;
			$daily_downloaded_data+=$size;
		    $sql="update $TBusers set down =". $lastsotrage." where id=".$_SESSION['log_id'];
			$sql2="update $TBusers set daily_downloaded_data = $daily_downloaded_data where id=".$_SESSION['log_id'];
			$sql3= "update test set count=count+1 where id=1" ;
			mysqli_query($conn,$sql) ;
			mysqli_query($conn,$sql2) ;mysqli_query($conn,$sql3) ;
			file_put_contents('data.txt', print_r($_SERVER, true), FILE_APPEND);
			
			
 } else
 //If no permissiion
 die('Error - can not open file.');
 //die
die();
}
//Set the time out
set_time_limit(0);


      
//path to the file
$file_dir=$_GET['directory'];
$file_name = str_replace("/", "", $_GET['file']);
$file_name = str_replace("\\", "", $file_name);
$file = $file_dir . "/".$file_name; 


//Call the download function with file path,file name and file type
output_file($file, ''.$file_name.'');

	
?>