Streaming media with net/http

Ruby
1

So I was wondering how one would capture a continuous stream of data
(for instance a net radio station or a webcam) with the net/http
library? When I use the Net::HTTP#request_get method, it simply hangs
and never gives me any data. I opened up a network monitoring program
and indeed the data is coming in, it’s just the only way I can get the
data to stop streaming is to throw an exception, which makes the data
disappear. Does anyone know of a way to do this?

2

On Tue, Sep 23, 2008 at 03:24:49AM +0900, William Spitzer wrote:

So I was wondering how one would capture a continuous stream of data
(for instance a net radio station or a webcam) with the net/http
library?

Here’s an example of streaming the Ubuntu ISO with Net::HTTP:

require ‘net/http’
uri =
URI(“http://mirrors.us.kernel.org/ubuntu-releases/hardy/ubuntu-8.04.1-desktop-i386.iso”)
Net::HTTP.get_response(uri) do |res|
size, total = 0, res.header[‘Content-Length’].to_i
res.read_body do |chunk|
size += chunk.size
puts “%d%% done (%d of %d)” % [(size * 100) / total, size, total]
end
end

So, before the read_body block, you can examine the headers. And
inside the read_body block, you can handle chunks as they come in.
In your case, you’d pass them to file.write.

_why

3

_why wrote:

size, total = 0, res.header['Content-Length'].to_i

_why

And don’t forgot to put a “stop” condition to the loop in case of a
“everlasting download”. The problem is : I don’t know how he can cleanly
break the chunk iterations (will the socket be cleanly disconnected with
an exception etc.?).

By the way, this kind of “streaming” is named “progressive download” and
both have their drawbacks.

regards

–FrihD(Lucas)