--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -89,14 +89,14 @@ module ApplicationHelper
   end
   
   def commit_graph_tag(repository, ref = "master")
-    filename = "#{repository.project.slug}_#{repository.name}_#{h(ref)}_commit_count.png"
+    filename = Gitorious::Graphs::CommitsBuilder.filename(repository, ref)
     if File.exist?(File.join(Gitorious::Graphs::Builder.graph_dir, filename))
       image_tag("graphs/#{filename}")
     end
   end
   
   def commit_graph_by_author_tag(repository, ref = "master")    
-    filename = "#{repository.project.slug}_#{repository.name}_#{h(ref)}_commit_count_by_author.png"
+    filename = Gitorious::Graphs::CommitsByAuthorBuilder.filename(repository, ref)
     if File.exist?(File.join(Gitorious::Graphs::Builder.graph_dir, filename))
       image_tag("graphs/#{filename}")
     end

--- a/lib/gitorious/graphs/builder.rb
+++ b/lib/gitorious/graphs/builder.rb
@@ -6,10 +6,12 @@ end
 
 module Gitorious
   module Graphs    
-    class Builder      
+    class Builder
+      GENERATORS = [CommitsBuilder, CommitsByAuthorBuilder] 
       def self.generate_all_for(repository)
-        CommitsBuilder.generate_for(repository)
-        CommitsByAuthorBuilder.generate_for(repository)
+        GENERATORS.each do |generator|
+          generator.generate_for(repository)
+        end
       end
       
       def self.graph_dir