Speedup user lookup by also caching if user could not be found

Gemfile.lock

@@ -1,25 +1,25 @@
 PATH
   remote: .
   specs:
-    warden (1.1.1)
+    warden (1.2.0)
       rack (>= 1.0)
 
 GEM
   remote: http://rubygems.org/
   specs:
-    diff-lcs (1.1.2)
+    diff-lcs (1.1.3)
     rack (1.3.0)
     rack-test (0.6.0)
       rack (>= 1.0)
     rake (0.8.7)
-    rspec (2.5.0)
-      rspec-core (~> 2.5.0)
-      rspec-expectations (~> 2.5.0)
-      rspec-mocks (~> 2.5.0)
-    rspec-core (2.5.1)
-    rspec-expectations (2.5.0)
-      diff-lcs (~> 1.1.2)
-    rspec-mocks (2.5.0)
+    rspec (2.10.0)
+      rspec-core (~> 2.10.0)
+      rspec-expectations (~> 2.10.0)
+      rspec-mocks (~> 2.10.0)
+    rspec-core (2.10.1)
+    rspec-expectations (2.10.0)
+      diff-lcs (~> 1.1.3)
+    rspec-mocks (2.10.1)
 
 PLATFORMS
   ruby

lib/warden/proxy.rb

@@ -192,10 +192,12 @@ def user(argument = {})
       opts  = argument.is_a?(Hash) ? argument : { :scope => argument }
       scope = (opts[:scope] ||= @config.default_scope)
 
-      @users[scope] ||= begin
+      if @users.has_key?(scope)
+        @users[scope]
+      else
         user = session_serializer.fetch(scope)
         opts[:event] = :fetch
-        set_user(user, opts) if user
+        @users[scope] = user ? set_user(user, opts) : nil
       end
     end
 

spec/warden/proxy_spec.rb

@@ -417,6 +417,16 @@
       setup_rack(app).call(@env)
     end
 
+    it "should cache unfound user" do
+      Warden::SessionSerializer.any_instance.should_receive(:fetch).once
+      app = lambda do |env|
+        env['warden'].user.should be_nil
+        env['warden'].user.should be_nil
+        valid_response
+      end
+      setup_rack(app).call(@env)
+    end
+
     describe "previously logged in" do
       before(:each) do
         @env['rack.session']['warden.user.default.key'] = "A Previous User"
@@ -431,6 +441,16 @@
         setup_rack(app).call(@env)
       end
 
+      it "should cache found user" do
+        Warden::SessionSerializer.any_instance.should_receive(:fetch).once.and_return "A Previous User"
+        app = lambda do |env|
+          env['warden'].user.should == "A Previous User"
+          env['warden'].user.should == "A Previous User"
+          valid_response
+        end
+        setup_rack(app).call(@env)
+      end
+
       it "should not run strategies when the user exists in the session" do
         app = lambda do |env|
           env['warden'].authenticate!(:pass)