Resuming File Downloads in Ruby on Rails

Question

Finally found out how to achieve this!

Turned out it is as simple as enabling xsendfile and setting header parameter Accept-Range

Read my answer below

(by the way, in the block quote below I wrote a common pitfall newbies - like I did - made. We tend to think it should be manually programmed)

URL must be something like: mysite.com/get_file?file_point=100 -> this will read from byte 100

1. Get the offset from parameter (file_point parameter in our example)
2. Find out size of file (File.size)
3. Read the file from offset to length (Equivalent of fseek in PHP)
4. Send the file using send_file

I dont know how to do step #3 in Ruby in the steps above.

Answer 1

This was how I did it:

response.header["Accept-Ranges"] = "bytes"
send_file product.pack.path, :type => product.pack_content_type, :x_sendfile=>true

I asked our server guy to set up mod_xsendfile, I don't know how to set it myself.

Tutorial here: http://www.devsource.com/c/a/Techniques/Resumable-File-Downloads-with-ASPNet/2/

Read about content-length here: http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.13

About streaming is available here: http://api.rubyonrails.org/classes/ActionController/Streaming.html