PHP passthrough slow

Question

For various reasons, I need to play the intermediary between an HTTP Request and a file on disk. My approach has been to populate headers and then perform a readfile('/path/to/file.jpg');

Now, everything works fine, except that it returns even a medium sized image very slowly.

Can anyone provide me with a more efficient way of streaming the file to the client once the headers have been sent?

Note: it's a linux box in a shared hosting environment if it matters

Answer 1

Several web servers allow an external script to tell them to do exactly this. X-Sendfile on Apache (with mod_xsendfile) is one.

In a nutshell, all you send is headers. The special X-Sendfile header instructs the web server to send the named file as the body of the response.