Migrate Repository#can_be_merged? to Gitaly

app/models/repository.rb

@@ -831,13 +831,12 @@ class Repository
   end
 
   def can_be_merged?(source_sha, target_branch)
-    our_commit = rugged.branches[target_branch].target
-    their_commit = rugged.lookup(source_sha)
-
-    if our_commit && their_commit
-      !rugged.merge_commits(our_commit, their_commit).conflicts?
-    else
-      false
+    raw_repository.gitaly_migrate(:can_be_merged) do |is_enabled|
+      if is_enabled
+        gitaly_can_be_merged?(source_sha, find_branch(target_branch).target)
+      else
+        rugged_can_be_merged?(source_sha, target_branch)
+      end
     end
   end
 
@@ -1128,6 +1127,14 @@ class Repository
     Gitlab::Git::Repository.new(project.repository_storage, disk_path + '.git', Gitlab::GlRepository.gl_repository(project, is_wiki))
   end
 
+  def gitaly_can_be_merged?(their_commit, our_commit)
+    !raw_repository.gitaly_conflicts_client(our_commit, their_commit).conflicts?
+  end
+
+  def rugged_can_be_merged?(their_commit, our_commit)
+    !rugged.merge_commits(our_commit, their_commit).conflicts?
+  end
+
   def find_commits_by_message_by_shelling_out(query, ref, path, limit, offset)
     ref ||= root_ref
 

lib/gitlab/git/conflict/resolver.rb

@@ -15,7 +15,7 @@ module Gitlab
           @conflicts ||= begin
             @target_repository.gitaly_migrate(:conflicts_list_conflict_files) do |is_enabled|
               if is_enabled
-                gitaly_conflicts_client(@target_repository).list_conflict_files
+                gitaly_conflicts_client(@target_repository).list_conflict_files.to_a
               else
                 rugged_list_conflict_files
               end

lib/gitlab/gitaly_client/conflict_files_stitcher.rb

@@ -0,0 +1,47 @@
+module Gitlab
+  module GitalyClient
+    class ConflictFilesStitcher
+      include Enumerable
+
+      def initialize(rpc_response)
+        @rpc_response = rpc_response
+      end
+
+      def each
+        current_file = nil
+
+        @rpc_response.each do |msg|
+          msg.files.each do |gitaly_file|
+            if gitaly_file.header
+              yield current_file if current_file
+
+              current_file = file_from_gitaly_header(gitaly_file.header)
+            else
+              current_file.content << gitaly_file.content
+            end
+          end
+        end
+
+        yield current_file if current_file
+      end
+
+      private
+
+      def file_from_gitaly_header(header)
+        Gitlab::Git::Conflict::File.new(
+          Gitlab::GitalyClient::Util.git_repository(header.repository),
+          header.commit_oid,
+          conflict_from_gitaly_file_header(header),
+          ''
+        )
+      end
+
+      def conflict_from_gitaly_file_header(header)
+        {
+          ours: { path: header.our_path, mode: header.our_mode },
+          theirs: { path: header.their_path }
+        }
+      end
+    end
+  end
+end

lib/gitlab/gitaly_client/conflicts_service.rb

@@ -20,7 +20,11 @@ module Gitlab
         )
         response = GitalyClient.call(@repository.storage, :conflicts_service, :list_conflict_files, request)
 
-        files_from_response(response).to_a
+        GitalyClient::ConflictFilesStitcher.new(response)
+      end
+
+      def conflicts?
+        list_conflict_files.any?
       end
 
       def resolve_conflicts(target_repository, resolution, source_branch, target_branch)
@@ -58,38 +62,6 @@ module Gitlab
           user: Gitlab::Git::User.from_gitlab(resolution.user).to_gitaly
         )
       end
-
-      def files_from_response(response)
-        files = []
-
-        response.each do |msg|
-          msg.files.each do |gitaly_file|
-            if gitaly_file.header
-              files << file_from_gitaly_header(gitaly_file.header)
-            else
-              files.last.content << gitaly_file.content
-            end
-          end
-        end
-
-        files
-      end
-
-      def file_from_gitaly_header(header)
-        Gitlab::Git::Conflict::File.new(
-          Gitlab::GitalyClient::Util.git_repository(header.repository),
-          header.commit_oid,
-          conflict_from_gitaly_file_header(header),
-          ''
-        )
-      end
-
-      def conflict_from_gitaly_file_header(header)
-        {
-          ours: { path: header.our_path, mode: header.our_mode },
-          theirs: { path: header.their_path }
-        }
-      end
     end
   end
 end

spec/lib/gitlab/gitaly_client/conflict_files_stitcher_spec.rb

@@ -0,0 +1,54 @@
+require 'spec_helper'
+
+describe Gitlab::GitalyClient::ConflictFilesStitcher do
+  describe 'enumeration' do
+    it 'combines segregated ConflictFile messages together' do
+      target_project = create(:project, :repository)
+      target_repository = target_project.repository.raw
+      target_gitaly_repository = target_repository.gitaly_repository
+
+      our_path_1 = 'our/path/1'
+      their_path_1 = 'their/path/1'
+      our_mode_1 = 0744
+      commit_oid_1 = 'f00'
+      content_1 = 'content of the first file'
+
+      our_path_2 = 'our/path/2'
+      their_path_2 = 'their/path/2'
+      our_mode_2 = 0600
+      commit_oid_2 = 'ba7'
+      content_2 = 'content of the second file'
+
+      header_1 = double(repository: target_gitaly_repository, commit_oid: commit_oid_1,
+                        our_path: our_path_1, their_path: their_path_1, our_mode: our_mode_1)
+      header_2 = double(repository: target_gitaly_repository, commit_oid: commit_oid_2,
+                        our_path: our_path_2, their_path: their_path_2, our_mode: our_mode_2)
+
+      messages = [
+        double(files: [double(header: header_1), double(header: nil, content: content_1[0..5])]),
+        double(files: [double(header: nil, content: content_1[6..-1])]),
+        double(files: [double(header: header_2)]),
+        double(files: [double(header: nil, content: content_2[0..5]), double(header: nil, content: content_2[6..10])]),
+        double(files: [double(header: nil, content: content_2[11..-1])])
+      ]
+
+      conflict_files = described_class.new(messages).to_a
+
+      expect(conflict_files.size).to be(2)
+
+      expect(conflict_files[0].content).to eq(content_1)
+      expect(conflict_files[0].their_path).to eq(their_path_1)
+      expect(conflict_files[0].our_path).to eq(our_path_1)
+      expect(conflict_files[0].our_mode).to be(our_mode_1)
+      expect(conflict_files[0].repository).to eq(target_repository)
+      expect(conflict_files[0].commit_oid).to eq(commit_oid_1)
+
+      expect(conflict_files[1].content).to eq(content_2)
+      expect(conflict_files[1].their_path).to eq(their_path_2)
+      expect(conflict_files[1].our_path).to eq(our_path_2)
+      expect(conflict_files[1].our_mode).to be(our_mode_2)
+      expect(conflict_files[1].repository).to eq(target_repository)
+      expect(conflict_files[1].commit_oid).to eq(commit_oid_2)
+    end
+  end
+end

spec/lib/gitlab/gitaly_client/conflicts_service_spec.rb

@@ -19,41 +19,12 @@ describe Gitlab::GitalyClient::ConflictsService do
         their_commit_oid: their_commit_oid
       )
     end
-    let(:our_path) { 'our/path' }
-    let(:their_path) { 'their/path' }
-    let(:our_mode) { 0744 }
-    let(:header) do
-      double(repository: target_gitaly_repository, commit_oid: our_commit_oid,
-             our_path: our_path, our_mode: 0744, their_path: their_path)
-    end
-    let(:response) do
-      [
-        double(files: [double(header: header), double(content: 'foo', header: nil)]),
-        double(files: [double(content: 'bar', header: nil)])
-      ]
-    end
-    let(:file) { subject[0] }
-
-    subject { client.list_conflict_files }
 
     it 'sends an RPC request' do
       expect_any_instance_of(Gitaly::ConflictsService::Stub).to receive(:list_conflict_files)
-        .with(request, kind_of(Hash)).and_return([])
+        .with(request, kind_of(Hash)).and_return([].to_enum)
 
-      subject
-    end
-
-    it 'forms a Gitlab::Git::ConflictFile collection from the response' do
-      allow_any_instance_of(Gitaly::ConflictsService::Stub).to receive(:list_conflict_files)
-        .with(request, kind_of(Hash)).and_return(response)
-
-      expect(subject.size).to be(1)
-      expect(file.content).to eq('foobar')
-      expect(file.their_path).to eq(their_path)
-      expect(file.our_path).to eq(our_path)
-      expect(file.our_mode).to be(our_mode)
-      expect(file.repository).to eq(target_repository)
-      expect(file.commit_oid).to eq(our_commit_oid)
+      client.list_conflict_files
     end
   end
 

spec/models/repository_spec.rb

@@ -358,28 +358,38 @@ describe Repository do
   end
 
   describe '#can_be_merged?' do
-    context 'mergeable branches' do
-      subject { repository.can_be_merged?('0b4bc9a49b562e85de7cc9e834518ea6828729b9', 'master') }
+    shared_examples 'can be merged' do
+      context 'mergeable branches' do
+        subject { repository.can_be_merged?('0b4bc9a49b562e85de7cc9e834518ea6828729b9', 'master') }
 
-      it { is_expected.to be_truthy }
+        it { is_expected.to be_truthy }
+      end
+
+      context 'non-mergeable branches' do
+        subject { repository.can_be_merged?('bb5206fee213d983da88c47f9cf4cc6caf9c66dc', 'feature') }
+
+        it { is_expected.to be_falsey }
+      end
+
+      context 'non merged branch' do
+        subject { repository.merged_to_root_ref?('fix') }
+
+        it { is_expected.to be_falsey }
+      end
+
+      context 'non existent branch' do
+        subject { repository.merged_to_root_ref?('non_existent_branch') }
+
+        it { is_expected.to be_nil }
+      end
     end
 
-    context 'non-mergeable branches' do
-      subject { repository.can_be_merged?('bb5206fee213d983da88c47f9cf4cc6caf9c66dc', 'feature') }
-
-      it { is_expected.to be_falsey }
+    context 'when Gitaly can_be_merged feature is enabled' do
+      it_behaves_like 'can be merged'
     end
 
-    context 'non merged branch' do
-      subject { repository.merged_to_root_ref?('fix') }
-
-      it { is_expected.to be_falsey }
-    end
-
-    context 'non existent branch' do
-      subject { repository.merged_to_root_ref?('non_existent_branch') }
-
-      it { is_expected.to be_nil }
+    context 'when Gitaly can_be_merged feature is disabled', :disable_gitaly do
+      it_behaves_like 'can be merged'
     end
   end