ProfAvery/shorten.rb

## shorten.rb
#!/usr/bin/env ruby

require 'sinatra'
require 'redis'
require 'enumerator'

configure do
  REDIS = Redis.new
  REDIS.setnx 'next', 10 * 36 ** 3
end

helpers do
  def next_key
    incr = rand(10) + 1
    value = REDIS.incrby 'next', incr
    value.to_s(36)
  end
end

before '/' do
  @popular = REDIS.zrevrange 'hits', 0, 9, :with_scores => true
end

get '/' do
  erb :index
end

post '/' do
  @input_url = params[:input_url]

  return erb :index if @input_url.empty?

  base_url = "http://#{request.host_with_port}/"

  if @input_url =~ %r[^#{base_url}(.*)$]
    @output_url = REDIS.get 'short:' + $1
    return erb :index
  end

  @output_url = REDIS.get 'long:' + @input_url
  return erb :index unless @output_url.nil?

  key = next_key
  @output_url = base_url + key

  REDIS.set 'short:' + key, @input_url
  REDIS.setnx 'long:' + @input_url, @output_url

  erb :index
end

get '/:key' do
  key = params[:key]

  @input_url = REDIS.get 'short:' + key
  if @input_url.nil?
    halt 404, '404 No such shortened URL'
  end

  @output_url = REDIS.get 'long:' + @input_url
  link = %[<a href="#{@output_url}">#{@input_url}</a>]
  REDIS.zincrby 'hits', 1, link
  redirect @input_url #, 301
end

__END__
@@index
<!DOCTYPE html>
<html>
  <head>
    <title>Crazy Eddie's discount URL shortener</title>
  </head>
  <body>
    <h1>Enter an URL to shorten</h1>
    <p>(or a shortened URL to preview)</p>
    <form method="POST">
      <input type="text" name="input_url" size="50"
             value="<%= @input_url %>"/>
      <input type="submit" value="Go" />
    </form>
    <% if @output_url %>
      <h2><a href="<%= @output_url %>"><%= @output_url %></a></h2>
    <% end %>
    <% if !@popular.empty? %>
      <h3>Popular Links</h3>
      <ul>
      <% @popular.each_slice(2) do |link, hits| %>
        <li><%= link %> (<%= hits %> <%= hits.to_i > 1? 'hits' : 'hit' %>)</li>
      <% end %>
      </ul>
    <% end %>
  </body>
</html>
	#!/usr/bin/env ruby

	require 'sinatra'
	require 'redis'
	require 'enumerator'

	configure do
	REDIS = Redis.new
	REDIS.setnx 'next', 10 * 36 ** 3
	end

	helpers do
	def next_key
	incr = rand(10) + 1
	value = REDIS.incrby 'next', incr
	value.to_s(36)
	end
	end

	before '/' do
	@popular = REDIS.zrevrange 'hits', 0, 9, :with_scores => true
	end

	get '/' do
	erb :index
	end

	post '/' do
	@input_url = params[:input_url]

	return erb :index if @input_url.empty?

	base_url = "http://#{request.host_with_port}/"

	if @input_url =~ %r[^#{base_url}(.*)$]
	@output_url = REDIS.get 'short:' + $1
	return erb :index
	end

	@output_url = REDIS.get 'long:' + @input_url
	return erb :index unless @output_url.nil?

	key = next_key
	@output_url = base_url + key

	REDIS.set 'short:' + key, @input_url
	REDIS.setnx 'long:' + @input_url, @output_url

	erb :index
	end

	get '/:key' do
	key = params[:key]

	@input_url = REDIS.get 'short:' + key
	if @input_url.nil?
	halt 404, '404 No such shortened URL'
	end

	@output_url = REDIS.get 'long:' + @input_url
	link = %[<a href="#{@output_url}">#{@input_url}</a>]
	REDIS.zincrby 'hits', 1, link
	redirect @input_url #, 301
	end

	__END__
	@@index
	<!DOCTYPE html>
	<html>
	<head>
	<title>Crazy Eddie's discount URL shortener</title>
	</head>
	<body>
	<h1>Enter an URL to shorten</h1>
	<p>(or a shortened URL to preview)</p>
	<form method="POST">
	<input type="text" name="input_url" size="50"
	value="<%= @input_url %>"/>
	<input type="submit" value="Go" />
	</form>
	<% if @output_url %>
	<h2><a href="<%= @output_url %>"><%= @output_url %></a></h2>
	<% end %>
	<% if !@popular.empty? %>
	<h3>Popular Links</h3>
	<ul>
	<% @popular.each_slice(2) do \|link, hits\| %>
	<li><%= link %> (<%= hits %> <%= hits.to_i > 1? 'hits' : 'hit' %>)</li>
	<% end %>
	</ul>
	<% end %>
	</body>
	</html>