Problem with download script.

adam1

Hi, I'm new here!

Here is the problem, I wanted to to be able to offer a save as window for a known file type. After a bit of searching, it seemed some simple php would allow me to do this. To complicate things my main host does not support php, but I did have another free host that does.

So this is what I have, some code in a file called download.php

<?php
header('Content-disposition: attachment; filename="name of my file"');
header('Content-type: audio/mpeg3');
readfile('http://host-with-out-php/file.mp3');
?>

download.php is hosted on the php host.
The mp3 is hosted remotely. I have a page on the remote site with a link to download.php

Now it actually works, but something is not right, as the download speed is much slower, than if I download using a direct url from the remote site.

I suspect readfile() is not a good choice when reading from different domains.

What is the reason for the slowness, and what is simple solution ?

Thanks

-A

bretticus

If I were a betting man (and I'm not) I'd assume, that the readfile() function has to get the entire file before sending the contents to buffer. Maybe you can read the file into smaller chunks before writing each to the buffer. I have never done this, maybe you could fire up a packet analyzer (like wireshark) and see how the mp3 data comes down. Dunno if there's an easy answer. I'd just redirect them to the other website, but I'm sure you have a good reason not to or you wouldn't be doing it this way in the 1st place.

bradgrafelman

You could try manually chunking the data, e.g. outputting it every 1024 bytes or so:

$fp = fopen('http://url', 'rb');

while(!feof($fp))
    echo fread($fp, 1024);

fclose($fp);

bretticus

Yep, I agree with bradgrafelman, doesn't hurt to try. In fact, I can't think of why it wouldn't work. Your Web browser and the http protocol should be able to handle the data in chunks of whatever length I'd assume. Let us know if bradgrafelman's code works for you (curious.)

adam1

Thanks for the suggestion bradgrafelman I tried it, and I get the same result as before.

As an indication If I dl the file using the script, it takes 2 minutes @ ~130Kb/s
If I dl the file by just putting the URL into the browser it takes 30secs @ ~600Kb/s (my usual max speed)

bretticus

Well, there is also the possibility that the server where the script resides has either a slower upsteam (download to you) or a slower download (download for the server.) Why don't you try putting that mp3 on your website (same one that has the script) as a complete file and download it again. Compare download time between that server and the server where you are pulling mp3s from. If the time is disproportionate at roughly the same margin, then you'll have your answer (allbeit, there's nothing you can do about it at that point.) If the download times are similar then you'll have good reason to assume:

Your webserver has an asynchronous bandwidth. ie: the network connections provides adequate download capacity for clients (the servers upload capacity) but poor download capacity for the server itself. If you have a shell account, try downloading the mp3 file from wget and note the time.
The php wrapper functions require too much overhead. You may want to experiment more (try fsocketopen for example. I've noticed that this works even when allow_url_fopen is disabled I think suggesting that perhaps it uses a different mechanism.) OR maybe you could download the files and store them on your server. If that is impossible, at least cache the files that the users download (ie: download it once to your server for the first end user and then have it on the hard drive at your web server for the next request.)