A class that emulates a File object, but over HTTP.

webfile.rb

require 'net/http'
require 'uri'


module URI
  def ssl?; scheme == 'https'; end
end


class WebFile

  def self.open(url)
    connection = new(url)

    if block_given?
      yield connection
      connection.close
    else
      connection
    end
  end

  def initialize(url)
    @uri = URI(url)
    @pos = nil
  end

  def ensure_connected
    return if @read_thread

    http   = Net::HTTP.start(@uri.host, @uri.port, use_ssl: @uri.ssl?)
    @r, @w = IO.pipe

    @read_thread = Thread.new do

      http.request(Net::HTTP::Get.new @uri.request_uri) do |response|

        response.read_body do |chunk|
          @w.write chunk

          puts "HTTP got #{chunk.size} bytes"
          break if Thread.current[:terminate]
        end

        puts "done!"
        break
      end

    end
  end

  def read(*args)
    ensure_connected
    @r.read(*args)
  end

  def disconnect
    if @read_thread
      @read_thread[:terminate] = true
      @read_thread.join
      puts "Thread died"
      @read_thread = nil
    else
      raise "Not connected"
    end
  end

  def close
    disconnect
  end

  def seek(pos)
    @pos = pos
  end

end

if __FILE__ == $0
  WebFile.open('http://chris.ill-logic.com/files/arms-normalized.txt') do |conn|
    5.times do
      data = conn.read(40)
      puts "read #{data.size} bytes"
    end
  end
end