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, 44 insertions, 1 deletions

diff --git a/spec/helpers/tree_helper_spec.rb b/spec/helpers/tree_helper_spec.rb
index ffdf6561a53..ab4566e261b 100644
--- a/spec/helpers/tree_helper_spec.rb
+++ b/spec/helpers/tree_helper_spec.rb
@@ -3,7 +3,7 @@ require 'spec_helper'
 describe TreeHelper do
   let(:project) { create(:project, :repository) }
   let(:repository) { project.repository }
-  let(:sha) { 'ce369011c189f62c815f5971d096b26759bab0d1' }
+  let(:sha) { 'c1c67abbaf91f624347bb3ae96eabe3a1b742478' }
 
   describe '.render_tree' do
     before do
@@ -32,6 +32,49 @@ describe TreeHelper do
     end
   end
 
+  describe '.fast_project_blob_path' do
+    it 'generates the same path as project_blob_path' do
+      blob_path = repository.tree(sha, 'with space').entries.first.path
+      fast_path = fast_project_blob_path(project, blob_path)
+      std_path  = project_blob_path(project, blob_path)
+
+      expect(fast_path).to eq(std_path)
+    end
+
+    it 'generates the same path with encoded file names' do
+      tree = repository.tree(sha, 'encoding')
+      blob_path = tree.entries.find { |entry| entry.path == 'encoding/テスト.txt' }.path
+      fast_path = fast_project_blob_path(project, blob_path)
+      std_path  = project_blob_path(project, blob_path)
+
+      expect(fast_path).to eq(std_path)
+    end
+
+    it 'respects a configured relative URL' do
+      allow(Gitlab.config.gitlab).to receive(:relative_url_root).and_return('/gitlab/root')
+      blob_path = repository.tree(sha, '').entries.first.path
+      fast_path = fast_project_blob_path(project, blob_path)
+
+      expect(fast_path).to start_with('/gitlab/root')
+    end
+  end
+
+  describe '.fast_project_tree_path' do
+    let(:tree_path) { repository.tree(sha, 'with space').path }
+    let(:fast_path) { fast_project_tree_path(project, tree_path) }
+    let(:std_path) { project_tree_path(project, tree_path) }
+
+    it 'generates the same path as project_tree_path' do
+      expect(fast_path).to eq(std_path)
+    end
+
+    it 'respects a configured relative URL' do
+      allow(Gitlab.config.gitlab).to receive(:relative_url_root).and_return('/gitlab/root')
+
+      expect(fast_path).to start_with('/gitlab/root')
+    end
+  end
+
   describe 'flatten_tree' do
     let(:tree) { repository.tree(sha, 'files') }
     let(:root_path) { 'files' }