diff --git a/app/models/language.rb b/app/models/language.rb
--- a/app/models/language.rb
+++ b/app/models/language.rb
@@ -1,2 +1,24 @@
 class Language < ActiveRecord::Base
+
+  @@languages_by_ext = {}
+
+  def self.cache_ext_hash
+    @@languages_by_ext = {}
+    Language.find(:all).each do |language|
+      language.common_ext.split(',').each do |ext|
+        @@languages_by_ext[ext] = language
+      end
+    end
+  end
+
+  def self.find_by_extension(ext)
+    if @@languages_by_ext.length == 0
+      Language.cache_ext_hash
+    end
+    if @@languages_by_ext.has_key? ext
+      return @@languages_by_ext[ext]
+    else
+      return nil
+    end
+  end
 end