Super dumbed-down ad server - serving a random image every-time.

RandomAd.cs

using Manos;
using System;
using System.IO;

public class RandomAd : ManosApp {

    public RandomAd () {
        var ads = Directory.GetFiles(".", "*.gif");
        var random = new Random();
        Route ("/", ctx=> {
            var idx = random.Next(ads.Length);
            ctx.Response.Headers.SetNormalizedHeader ("Content-Type", "image/gif");
            ctx.Response.SendFile(ads[idx]);
            ctx.Response.End();
        });
    }

}

randomad.py

import tornado.ioloop
import tornado.web
import glob
import random

class AdsHandler(tornado.web.RequestHandler):
  # future: a proper storage instead of local folder
  # future: set cache policy
  #         we actually do not want to cache that as we want to keep it random
  #         but the images themselves should be cached.
  #         perhaps replace it with a redirect (with no-cache) to a url of the image (on CDN with far-away cache)
  ads = glob.glob("./*.gif")
  def get(self):
    self.set_header("Content-Type", "image/gif")
    ad = random.choice(self.ads)
    # future: add location aware/user aware logic 
    self.write_binary(ad)
        
  def write_binary(self, filename):
    # there probably is a better way of doing that with async io
    with open(filename, "rb") as f:
      while True:
        # and there probably is a better way to chunk the reads.
        # half a kb feels right, however for real-scenario I'd be
        # reasearching + trial/err to optimise *if needed*
        bytes = f.read(500)
        print len(bytes)
        if not bytes: break
        self.write(bytes)
    
        
application = tornado.web.Application([
  (r"/", AdsHandler),
])

if __name__ == "__main__":
  application.listen(8888)
  tornado.ioloop.IOLoop.instance().start()