speed up ExternalWikiService#get_project_wiki_path

* This method previously iterated over all services in a project.  Now it
will directly query the ExternalWikiService for the project and filter
by active state.
* The presence of an external wiki is also cached
* When an external wiki is added or removed, the cached value is updated

2 files changed, 9 insertions, 1 deletions

diff --git a/db/migrate/20160718153603_add_has_external_wiki_to_projects.rb b/db/migrate/20160718153603_add_has_external_wiki_to_projects.rb
new file mode 100644
index 00000000000..55a3e954292
--- /dev/null
+++ b/db/migrate/20160718153603_add_has_external_wiki_to_projects.rb
@@ -0,0 +1,7 @@
+class AddHasExternalWikiToProjects < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  def change
+    add_column :projects, :has_external_wiki, :boolean
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 8882377f9f4..ebf31ded369 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20160716115710) do
+ActiveRecord::Schema.define(version: 20160718153603) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -842,6 +842,7 @@ ActiveRecord::Schema.define(version: 20160716115710) do
     t.boolean  "only_allow_merge_if_build_succeeds", default: false,     null: false
     t.boolean  "has_external_issue_tracker"
     t.string   "repository_storage",                 default: "default", null: false
+    t.boolean  "has_external_wiki"
   end
 
   add_index "projects", ["builds_enabled", "shared_runners_enabled"], name: "index_projects_on_builds_enabled_and_shared_runners_enabled", using: :btree