Merge branch 'feature/migrate-find-branch-to-gitaly' into 'master'

Migrate Gitlab::Git::Repository#find_branch to Gitaly

Closes gitaly#502

See merge request !13873

GITALY_SERVER_VERSION

-0.36.0
+0.37.0

Gemfile

@@ -397,7 +397,7 @@ group :ed25519 do
 end
 
 # Gitaly GRPC client
-gem 'gitaly-proto', '~> 0.31.0', require: 'gitaly'
+gem 'gitaly-proto', '~> 0.32.0', require: 'gitaly'
 
 gem 'toml-rb', '~> 0.3.15', require: false
 

Gemfile.lock

@@ -275,7 +275,7 @@ GEM
       po_to_json (>= 1.0.0)
       rails (>= 3.2.0)
     gherkin-ruby (0.3.2)
-    gitaly-proto (0.31.0)
+    gitaly-proto (0.32.0)
       google-protobuf (~> 3.1)
       grpc (~> 1.0)
     github-linguist (4.7.6)
@@ -1020,7 +1020,7 @@ DEPENDENCIES
   gettext (~> 3.2.2)
   gettext_i18n_rails (~> 1.8.0)
   gettext_i18n_rails_js (~> 1.2.0)
-  gitaly-proto (~> 0.31.0)
+  gitaly-proto (~> 0.32.0)
   github-linguist (~> 4.7.0)
   gitlab-flowdock-git-hook (~> 1.0.1)
   gitlab-markup (~> 1.5.1)

lib/gitlab/git/repository.rb

@@ -134,9 +134,11 @@ module Gitlab
       # This is to work around a bug in libgit2 that causes in-memory refs to
       # be stale/invalid when packed-refs is changed.
       # See https://gitlab.com/gitlab-org/gitlab-ce/issues/15392#note_14538333
-      #
-      # Gitaly migration: https://gitlab.com/gitlab-org/gitaly/issues/474
       def find_branch(name, force_reload = false)
+        gitaly_migrate(:find_branch) do |is_enabled|
+          if is_enabled
+            gitaly_ref_client.find_branch(name)
+          else
             reload_rugged if force_reload
 
             rugged_ref = rugged.branches[name]
@@ -145,6 +147,8 @@ module Gitlab
               Gitlab::Git::Branch.new(self, rugged_ref.name, rugged_ref.target, target_commit)
             end
           end
+        end
+      end
 
       def local_branches(sort_by: nil)
         gitaly_migrate(:local_branches) do |is_enabled|

lib/gitlab/gitaly_client/ref_service.rb

@@ -78,6 +78,20 @@ module Gitlab
         raise ArgumentError, e.message
       end
 
+      def find_branch(branch_name)
+        request = Gitaly::DeleteBranchRequest.new(
+          repository: @gitaly_repo,
+          name: GitalyClient.encode(branch_name)
+        )
+
+        response = GitalyClient.call(@repository.storage, :ref_service, :find_branch, request)
+        branch = response.branch
+        return unless branch
+
+        target_commit = Gitlab::Git::Commit.decorate(@repository, branch.target_commit)
+        Gitlab::Git::Branch.new(@repository, encode!(branch.name.dup), branch.target_commit.id, target_commit)
+      end
+
       private
 
       def consume_refs_response(response)

spec/lib/gitlab/git/repository_spec.rb

@@ -916,6 +916,7 @@ describe Gitlab::Git::Repository, seed_helper: true do
   end
 
   describe '#find_branch' do
+    shared_examples 'finding a branch' do
       it 'should return a Branch for master' do
         branch = repository.find_branch('master')
 
@@ -928,6 +929,14 @@ describe Gitlab::Git::Repository, seed_helper: true do
 
         expect(branch).to eq(nil)
       end
+    end
+
+    context 'when Gitaly find_branch feature is enabled' do
+      it_behaves_like 'finding a branch'
+    end
+
+    context 'when Gitaly find_branch feature is disabled', skip_gitaly_mock: true do
+      it_behaves_like 'finding a branch'
 
       it 'should reload Rugged::Repository and return master' do
         expect(Rugged::Repository).to receive(:new).twice.and_call_original
@@ -939,6 +948,7 @@ describe Gitlab::Git::Repository, seed_helper: true do
         expect(branch.name).to eq('master')
       end
     end
+  end
 
   describe '#ref_name_for_sha' do
     let(:ref_path) { 'refs/heads' }