Class: Shadow

Inherits:
Mongrel::HttpHandler
  • Object
show all
Defined in:
lib/shadow.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config, environment, name, address = '0.0.0.0', port = '2001', sleep = nil) ⇒ Shadow

Returns a new instance of Shadow.



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# File 'lib/shadow.rb', line 10

def initialize(config, environment, name, address = '0.0.0.0', port = '2001', sleep = nil)
  ActiveRecord::Base.establish_connection(YAML.load_file(config)[environment.to_s])
  ActiveRecord::Base.allow_concurrency = false # AR doesn't release connections fast enough
  @sleep = sleep
  @sync = Sync.new
  @pid = serve(self, name, address, port)
end

Instance Attribute Details

#pid ⇒ Object (readonly)

Returns the value of attribute pid.



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# File 'lib/shadow.rb', line 8

def pid
  @pid
end

Instance Method Details

#find(table, id) ⇒ Object

Finds and returns an ActiveRecord instance (returns a new record if id is nil). Dynamically instantiates an ActiveRecord parent class for each call.



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# File 'lib/shadow.rb', line 47

def find(table, id)
  klass = Class.new(ActiveRecord::Base) { self.table_name = table }
  id ? klass.find(id) : klass.new
end

#process(request, response) ⇒ Object

Implement the mongrel event handler. Responds to all four HTTP methods.



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# File 'lib/shadow.rb', line 19

def process(request, response)
  sleep(rand * @sleep) if @sleep
  table, id = request.params["PATH_INFO"].split("/")

  obj, code = nil, 200
  @sync.synchronize(:EX) do # sad
    begin
      obj = find(table, id)
      case request.params["REQUEST_METHOD"]
        when "PUT", "POST"
          obj.update_attributes(YAML.load(request.body.read))
          obj.save!
        when "DELETE"
          obj.destroy
      end
      obj = obj.attributes
    rescue Object => e
      obj, code = e.to_s, 400
    end
  end
  
  response.start(code) do |head, out|
    head["Content-Type"] = "text/yaml"
    out.write obj.to_yaml
  end
end

#serve(me, name, address, port) ⇒ Object

Configure mongrel and start an instance of ourselves.



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# File 'lib/shadow.rb', line 53

def serve(me, name, address, port)
  fork do
    Mongrel::Configurator.new :host => address, :pid_file => "/tmp/shadow.#{name}.pid" do
      listener :port => port do
        puts "** Serving at #{address}:#{port}/#{name}/ (pid #{Process.pid})"
        uri "/#{name}/", :handler => me
        setup_signals or run and write_pid_file and join
      end
    end
  end
end