Merge Merge Requests via Gitaly

GITALY_SERVER_VERSION

-0.46.0
+0.47.0

Gemfile

@@ -398,7 +398,7 @@ group :ed25519 do
 end
 
 # Gitaly GRPC client
-gem 'gitaly-proto', '~> 0.41.0', require: 'gitaly'
+gem 'gitaly-proto', '~> 0.42.0', require: 'gitaly'
 
 gem 'toml-rb', '~> 0.3.15', require: false
 

Gemfile.lock

@@ -273,7 +273,7 @@ GEM
       po_to_json (>= 1.0.0)
       rails (>= 3.2.0)
     gherkin-ruby (0.3.2)
-    gitaly-proto (0.41.0)
+    gitaly-proto (0.42.0)
       google-protobuf (~> 3.1)
       grpc (~> 1.0)
     github-linguist (4.7.6)
@@ -1027,7 +1027,7 @@ DEPENDENCIES
   gettext (~> 3.2.2)
   gettext_i18n_rails (~> 1.8.0)
   gettext_i18n_rails_js (~> 1.2.0)
-  gitaly-proto (~> 0.41.0)
+  gitaly-proto (~> 0.42.0)
   github-linguist (~> 4.7.0)
   gitlab-flowdock-git-hook (~> 1.0.1)
   gitlab-markup (~> 1.6.2)

lib/gitlab/git/operation_service.rb

@@ -3,9 +3,17 @@ module Gitlab
     class OperationService
       include Gitlab::Git::Popen
 
-      WithBranchResult = Struct.new(:newrev, :repo_created, :branch_created) do
+      BranchUpdate = Struct.new(:newrev, :repo_created, :branch_created) do
         alias_method :repo_created?, :repo_created
         alias_method :branch_created?, :branch_created
+
+        def self.from_gitaly(branch_update)
+          new(
+            branch_update.commit_id,
+            branch_update.repo_created,
+            branch_update.branch_created
+          )
+        end
       end
 
       attr_reader :user, :repository
@@ -112,7 +120,7 @@ module Gitlab
         ref = Gitlab::Git::BRANCH_REF_PREFIX + branch_name
         update_ref_in_hooks(ref, newrev, oldrev)
 
-        WithBranchResult.new(newrev, was_empty, was_empty || Gitlab::Git.blank_ref?(oldrev))
+        BranchUpdate.new(newrev, was_empty, was_empty || Gitlab::Git.blank_ref?(oldrev))
       end
 
       def find_oldrev_from_branch(newrev, branch)

lib/gitlab/git/repository.rb

@@ -704,7 +704,17 @@ module Gitlab
         tags.find { |tag| tag.name == name }
       end
 
-      def merge(user, source_sha, target_branch, message)
+      def merge(user, source_sha, target_branch, message, &block)
+        gitaly_migrate(:operation_user_merge_branch) do |is_enabled|
+          if is_enabled
+            gitaly_operation_client.user_merge_branch(user, source_sha, target_branch, message, &block)
+          else
+            rugged_merge(user, source_sha, target_branch, message, &block)
+          end
+        end
+      end
+
+      def rugged_merge(user, source_sha, target_branch, message)
         committer = Gitlab::Git.committer_hash(email: user.email, name: user.name)
 
         OperationService.new(user, self).with_branch(target_branch) do |start_commit|

lib/gitlab/gitaly_client/operation_service.rb

@@ -74,6 +74,37 @@ module Gitlab
           raise Gitlab::Git::HooksService::PreReceiveError, pre_receive_error
         end
       end
+
+      def user_merge_branch(user, source_sha, target_branch, message)
+        request_enum = QueueEnumerator.new
+        response_enum = GitalyClient.call(
+          @repository.storage,
+          :operation_service,
+          :user_merge_branch,
+          request_enum.each
+        )
+
+        request_enum.push(
+          Gitaly::UserMergeBranchRequest.new(
+            repository: @gitaly_repo,
+            user: Util.gitaly_user(user),
+            commit_id: source_sha,
+            branch: GitalyClient.encode(target_branch),
+            message: GitalyClient.encode(message)
+          )
+        )
+
+        yield response_enum.next.commit_id
+
+        request_enum.push(Gitaly::UserMergeBranchRequest.new(apply: true))
+
+        branch_update = response_enum.next.branch_update
+        raise Gitlab::Git::CommitError.new('failed to apply merge to branch') unless branch_update.commit_id.present?
+
+        Gitlab::Git::OperationService::BranchUpdate.from_gitaly(branch_update)
+      ensure
+        request_enum.close
+      end
     end
   end
 end

lib/gitlab/gitaly_client/queue_enumerator.rb

+module Gitlab
+  module GitalyClient
+    class QueueEnumerator
+      def initialize
+        @queue = Queue.new
+      end
+
+      def push(elem)
+        @queue << elem
+      end
+
+      def close
+        push(:close)
+      end
+
+      def each
+        return enum_for(:each) unless block_given?
+
+        loop do
+          elem = @queue.pop
+          break if elem == :close
+
+          yield elem
+        end
+      end
+    end
+  end
+end

spec/lib/gitlab/git/repository_spec.rb

@@ -1525,6 +1525,45 @@ describe Gitlab::Git::Repository, seed_helper: true do
     end
   end
 
+  describe '#merge' do
+    let(:repository) do
+      Gitlab::Git::Repository.new('default', TEST_MUTABLE_REPO_PATH, '')
+    end
+    let(:source_sha) { '913c66a37b4a45b9769037c55c2d238bd0942d2e' }
+    let(:user) { build(:user) }
+    let(:target_branch) { 'test-merge-target-branch' }
+
+    before do
+      repository.create_branch(target_branch, '6d394385cf567f80a8fd85055db1ab4c5295806f')
+    end
+
+    after do
+      FileUtils.rm_rf(TEST_MUTABLE_REPO_PATH)
+      ensure_seeds
+    end
+
+    shared_examples '#merge' do
+      it 'can perform a merge' do
+        merge_commit_id = nil
+        result = repository.merge(user, source_sha, target_branch, 'Test merge') do |commit_id|
+          merge_commit_id = commit_id
+        end
+
+        expect(result.newrev).to eq(merge_commit_id)
+        expect(result.repo_created).to eq(false)
+        expect(result.branch_created).to eq(false)
+      end
+    end
+
+    context 'with gitaly' do
+      it_behaves_like '#merge'
+    end
+
+    context 'without gitaly', :skip_gitaly_mock do
+      it_behaves_like '#merge'
+    end
+  end
+
   def create_remote_branch(repository, remote_name, branch_name, source_branch_name)
     source_branch = repository.branches.find { |branch| branch.name == source_branch_name }
     rugged = repository.rugged

spec/models/repository_spec.rb

@@ -1286,6 +1286,7 @@ describe Repository do
 
     let(:message) { 'Test \r\n\r\n message' }
 
+    shared_examples '#merge' do
       it 'merges the code and returns the commit id' do
         expect(merge_commit).to be_present
         expect(repository.blob_at(merge_commit.id, 'files/ruby/feature.rb')).to be_present
@@ -1302,6 +1303,15 @@ describe Repository do
 
         expect(repository.commit(merge_commit_id).message).to eq(message.delete("\r"))
       end
+    end
+
+    context 'with gitaly' do
+      it_behaves_like '#merge'
+    end
+
+    context 'without gitaly', :skip_gitaly_mock do
+      it_behaves_like '#merge'
+    end
 
     def merge(repository, user, merge_request, message)
       repository.merge(user, merge_request.diff_head_sha, merge_request, message)