From 8041a87288906e4b10b86a9a2ab9039036243a5d Mon Sep 17 00:00:00 2001
From: Douwe Maan <douwe@selenight.nl>
Date: Fri, 24 Nov 2017 11:23:14 +0100
Subject: [PATCH] Drastically improve project search performance by no longer
 searching namespace name

---
 app/models/project.rb                         | 28 +++++--------------
 .../dm-project-search-performance.yml         |  6 ++++
 lib/gitlab/search_results.rb                  |  2 +-
 spec/finders/admin/projects_finder_spec.rb    |  2 +-
 spec/models/project_spec.rb                   | 18 ------------
 spec/services/search/global_service_spec.rb   |  4 +--
 6 files changed, 17 insertions(+), 43 deletions(-)
 create mode 100644 changelogs/unreleased/dm-project-search-performance.yml

diff --git a/app/models/project.rb b/app/models/project.rb
index 43a4d86c138..e276bd2422d 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -18,6 +18,7 @@ class Project < ActiveRecord::Base
   include SelectForProjectAuthorization
   include Routable
   include GroupDescendant
+  include Gitlab::SQL::Pattern
 
   extend Gitlab::ConfigHelper
   extend Gitlab::CurrentSettings
@@ -424,32 +425,17 @@ class Project < ActiveRecord::Base
     #
     # query - The search query as a String.
     def search(query)
-      ptable  = arel_table
-      ntable  = Namespace.arel_table
-      pattern = "%#{query}%"
+      pattern = to_pattern(query)
 
-      # unscoping unnecessary conditions that'll be applied
-      # when executing `where("projects.id IN (#{union.to_sql})")`
-      projects = unscoped.select(:id).where(
-        ptable[:path].matches(pattern)
-          .or(ptable[:name].matches(pattern))
-          .or(ptable[:description].matches(pattern))
+      where(
+        arel_table[:path].matches(pattern)
+          .or(arel_table[:name].matches(pattern))
+          .or(arel_table[:description].matches(pattern))
       )
-
-      namespaces = unscoped.select(:id)
-        .joins(:namespace)
-        .where(ntable[:name].matches(pattern))
-
-      union = Gitlab::SQL::Union.new([projects, namespaces])
-
-      where("projects.id IN (#{union.to_sql})") # rubocop:disable GitlabSecurity/SqlInjection
     end
 
     def search_by_title(query)
-      pattern = "%#{query}%"
-      table   = Project.arel_table
-
-      non_archived.where(table[:name].matches(pattern))
+      non_archived.where(arel_table[:name].matches(to_pattern(query)))
     end
 
     def visibility_levels
diff --git a/changelogs/unreleased/dm-project-search-performance.yml b/changelogs/unreleased/dm-project-search-performance.yml
new file mode 100644
index 00000000000..b533043b163
--- /dev/null
+++ b/changelogs/unreleased/dm-project-search-performance.yml
@@ -0,0 +1,6 @@
+---
+title: Drastically improve project search performance by no longer searching namespace
+  name
+merge_request:
+author:
+type: performance
diff --git a/lib/gitlab/search_results.rb b/lib/gitlab/search_results.rb
index efe8095beea..fef9d3e31d4 100644
--- a/lib/gitlab/search_results.rb
+++ b/lib/gitlab/search_results.rb
@@ -30,7 +30,7 @@ module Gitlab
     def initialize(current_user, limit_projects, query)
       @current_user = current_user
       @limit_projects = limit_projects || Project.all
-      @query = Shellwords.shellescape(query) if query.present?
+      @query = query
     end
 
     def objects(scope, page = nil)
diff --git a/spec/finders/admin/projects_finder_spec.rb b/spec/finders/admin/projects_finder_spec.rb
index 4b67203a0df..7901d5fee28 100644
--- a/spec/finders/admin/projects_finder_spec.rb
+++ b/spec/finders/admin/projects_finder_spec.rb
@@ -136,7 +136,7 @@ describe Admin::ProjectsFinder do
     context 'filter by name' do
       let(:params) { { name: 'C' } }
 
-      it { is_expected.to match_array([shared_project, public_project, private_project]) }
+      it { is_expected.to match_array([public_project]) }
     end
 
     context 'sorting' do
diff --git a/spec/models/project_spec.rb b/spec/models/project_spec.rb
index f7f19d464d1..549c97a9afd 100644
--- a/spec/models/project_spec.rb
+++ b/spec/models/project_spec.rb
@@ -1254,24 +1254,6 @@ describe Project do
       expect(described_class.search(project.path.upcase)).to eq([project])
     end
 
-    it 'returns projects with a matching namespace name' do
-      expect(described_class.search(project.namespace.name)).to eq([project])
-    end
-
-    it 'returns projects with a partially matching namespace name' do
-      expect(described_class.search(project.namespace.name[0..2])).to eq([project])
-    end
-
-    it 'returns projects with a matching namespace name regardless of the casing' do
-      expect(described_class.search(project.namespace.name.upcase)).to eq([project])
-    end
-
-    it 'returns projects when eager loading namespaces' do
-      relation = described_class.all.includes(:namespace)
-
-      expect(relation.search(project.namespace.name)).to eq([project])
-    end
-
     describe 'with pending_delete project' do
       let(:pending_delete_project) { create(:project, pending_delete: true) }
 
diff --git a/spec/services/search/global_service_spec.rb b/spec/services/search/global_service_spec.rb
index 1309240b430..d8dba26e194 100644
--- a/spec/services/search/global_service_spec.rb
+++ b/spec/services/search/global_service_spec.rb
@@ -35,8 +35,8 @@ describe Search::GlobalService do
         expect(results.objects('projects')).to match_array [internal_project, public_project]
       end
 
-      it 'namespace name is searchable' do
-        results = described_class.new(user, search: found_project.namespace.path).execute
+      it 'project name is searchable' do
+        results = described_class.new(user, search: found_project.name).execute
 
         expect(results.objects('projects')).to match_array [found_project]
       end