Improve performance of tree rendering in repositories with lots of items

Rails is slow to generate paths dynamically especially when called
hundreds/thousands of times. Also, rendering many partials hundreds
of times can be slower. This change reduces the number of partials
rendered and introduces two fast path methods to speed up path
generation.

1 files changed, 17 insertions, 3 deletions

diff --git a/app/helpers/tree_helper.rb b/app/helpers/tree_helper.rb
index 6d2da5699fb..78a11616d4c 100644
--- a/app/helpers/tree_helper.rb
+++ b/app/helpers/tree_helper.rb
@@ -31,11 +31,21 @@ module TreeHelper
   # mode - File unix mode
   # name - File name
   def tree_icon(type, mode, name)
-    icon("#{file_type_icon_class(type, mode, name)} fw")
+    icon([file_type_icon_class(type, mode, name), 'fw'])
   end
 
-  def tree_hex_class(content)
-    "file_#{hexdigest(content.name)}"
+  # Using Rails `*_path` methods can be slow, especially when generating
+  # many paths, as with a repository tree that has thousands of items.
+  def fast_project_blob_path(project, blob_path)
+    Addressable::URI.escape(
+      File.join(relative_url_root, project.path_with_namespace, 'blob', blob_path)
+    )
+  end
+
+  def fast_project_tree_path(project, tree_path)
+    Addressable::URI.escape(
+      File.join(relative_url_root, project.path_with_namespace, 'tree', tree_path)
+    )
   end
 
   # Simple shortcut to File.join
@@ -142,4 +152,8 @@ module TreeHelper
   def selected_branch
     @branch_name || tree_edit_branch
   end
+
+  def relative_url_root
+    Gitlab.config.gitlab.relative_url_root.presence || '/'
+  end
 end