PERF: reduce storage requirements for incoming links

Only store incoming links for topics.

spec/controllers/application_controller_spec.rb

@@ -24,13 +24,6 @@ describe TopicsController do
     lambda { get :show, {id: topic.id} }.should_not raise_error
   end
 
-  it "stores an incoming link when there is an off-site referer" do
-    lambda {
-      set_referer("http://google.com/search")
-      get :show, {id: topic.id}
-    }.should change(IncomingLink, :count).by(1)
-  end
-
   describe "has_escaped_fragment?" do
     render_views
 
@@ -92,19 +85,6 @@ describe TopicsController do
 
   end
 
-  describe 'after inserting an incoming link' do
-
-    it 'sets last link correctly' do
-      set_referer("http://google.com/search")
-      get :show, {topic_id: topic.id}
-
-      last_link = IncomingLink.last
-      last_link.topic_id.should == topic.id
-      last_link.post_number.should == 1
-    end
-
-  end
-
   describe 'set_locale' do
     it 'sets the one the user prefers' do
       SiteSetting.stubs(:allow_user_locale).returns(true)

spec/controllers/topics_controller_spec.rb

@@ -590,6 +590,24 @@ describe TopicsController do
       lambda { xhr :get, :show, topic_id: topic.id, slug: topic.slug }.should change(View, :count).by(1)
     end
 
+    it 'records incoming links' do
+      user = Fabricate(:user)
+      get :show, topic_id: topic.id, slug: topic.slug, u: user.username
+
+      IncomingLink.count.should == 1
+    end
+
+    it 'records redirects' do
+      @request.env['HTTP_REFERER'] = 'http://twitter.com'
+      get :show, { id: topic.id }
+
+      @request.env['HTTP_REFERER'] = nil
+      get :show, topic_id: topic.id, slug: topic.slug
+
+      link = IncomingLink.first
+      link.referer.should == 'http://twitter.com'
+    end
+
     it 'tracks a visit for all html requests' do
       current_user = log_in(:coding_horror)
       TopicUser.expects(:track_visit!).with(topic.id, current_user.id)