gistfile1.rb

require 'sinatra'
require 'dm-core'
require 'dm-types'

APP_ROOT = File.dirname(__FILE__)
DB_PATH = File.expand_path(File.join(APP_ROOT, 'db.sqlite3'))
DataMapper.setup(:default, "sqlite3://#{DB_PATH}")

class Media
  include DataMapper::Resource

  property :id, Serial
  property :path, String, :nullable => false
  property :clicks, Integer, :nullable => false, :default => 0
end

DataMapper.auto_migrate! unless ::File.exist?(DB_PATH)

get '/banners/:banner' do
  banner = params[:banner]
  media = Media.first(:path => banner) || Media.create(:path => banner)
  media.clicks += 1
  media.save
  response["X-Accel-Redirect"] = "...../files/images/#{banner}"
end

get '/stats' do
  stats = Media.all.inject({}) { |h,m| h[m.path] = m.clicks; h }
  "<pre>#{stats.inspect}</pre>"
end

run Sinatra::Application