Partial Read From URL

Can anyone see a problem with this code to read only 20k from a URL? The
http connection will get closed, right?

Is there a better way to do this? My goal is to download the start of
mp3 files and then estimate their duration without downloading the
entire file.

def partial_uri_read(uri)
  u = URI.parse(uri)
  s = ""
  Net::HTTP.start(u.host, u.port) do |http|
    http.request_get(u.path) do |response|
      response.read_body do |chunk|
        s << chunk
        return s if s.size > 20000
      end
    end
  end
  s
end

Thanks
Elliot Temple

···

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Posted via http://www.ruby-forum.com/.

maybe try

require 'open-uri'

uri = ......

open(uri){|fd| fd.read 20000}

a @ http://codeforpeople.com/

···

On Nov 6, 2008, at 4:24 PM, Elliot Temple wrote:

Can anyone see a problem with this code to read only 20k from a URL? The
http connection will get closed, right?

Is there a better way to do this? My goal is to download the start of
mp3 files and then estimate their duration without downloading the
entire file.

def partial_uri_read(uri)
u = URI.parse(uri)
s = ""
Net::HTTP.start(u.host, u.port) do |http|
   http.request_get(u.path) do |response|
     response.read_body do |chunk|
       s << chunk
       return s if s.size > 20000
     end
   end
end
s
end

Thanks
Elliot Temple
--
Posted via http://www.ruby-forum.

--
we can deny everything, except that we have the possibility of being better. simply reflect on that.
h.h. the 14th dalai lama

Elliot Temple wrote:

Can anyone see a problem with this code to read only 20k from a URL? The
http connection will get closed, right?

Is there a better way to do this? My goal is to download the start of
mp3 files and then estimate their duration without downloading the
entire file.

def partial_uri_read(uri)
  u = URI.parse(uri)
  s = ""
  Net::HTTP.start(u.host, u.port) do |http|
    http.request_get(u.path) do |response|
      response.read_body do |chunk|
        s << chunk
        return s if s.size > 20000
      end
    end
  end
  s
end

Thanks
Elliot Temple

You can try using the Range header in HTTP. Not all servers have it enabled I think (or that's what 3 minutes playing with telnet tells me). Using range you can define which bytes of the file you want to download, so the whole file is not downloaded. You can use this to download the header and use the length of the file to estimate its length.

Ara Howard wrote:

s = ""

Thanks
Elliot Temple
--
Posted via http://www.ruby-forum.

maybe try

require 'open-uri'

uri = ......

open(uri){|fd| fd.read 20000}

I did try that, but it downloads the entire file in my tests. I tried it
on a large file and it takes minutes to return, whereas my code returns
in a couple seconds. Am I missing something?

ruby -v

ruby 1.8.6 (2008-03-03 patchlevel 114) [universal-darwin9.0]

Elliot

···

On Nov 6, 2008, at 4:24 PM, Elliot Temple wrote:

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Posted via http://www.ruby-forum.com/\.