Client Implementation: RefService::RefExists

GITALY_SERVER_VERSION

-0.31.0
+0.32.0

Gemfile

@@ -401,7 +401,7 @@ group :ed25519 do
 end
 
 # Gitaly GRPC client
-gem 'gitaly', '~> 0.27.0'
+gem 'gitaly', '~> 0.29.0'
 
 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 (0.27.0)
+    gitaly (0.29.0)
       google-protobuf (~> 3.1)
       grpc (~> 1.0)
     github-linguist (4.7.6)
@@ -1019,7 +1019,7 @@ DEPENDENCIES
   gettext (~> 3.2.2)
   gettext_i18n_rails (~> 1.8.0)
   gettext_i18n_rails_js (~> 1.2.0)
-  gitaly (~> 0.27.0)
+  gitaly (~> 0.29.0)
   github-linguist (~> 4.7.0)
   gitlab-flowdock-git-hook (~> 1.0.1)
   gitlab-markup (~> 1.5.1)

changelogs/unreleased/gitaly_ref_exists.yml

+---
+title: Implement the Gitaly RefService::RefExists endpoint
+merge_request: 13528
+author: Andrew Newdigate

lib/gitlab/git/repository.rb

@@ -204,21 +204,26 @@ module Gitlab
       #
       # name - The name of the tag as a String.
       def tag_exists?(name)
-        !!rugged.tags[name]
+        gitaly_migrate(:ref_exists_tags) do |is_enabled|
+          if is_enabled
+            gitaly_ref_exists?("refs/tags/#{name}")
+          else
+            rugged_tag_exists?(name)
+          end
+        end
       end
 
       # Returns true if the given branch exists
       #
       # name - The name of the branch as a String.
       def branch_exists?(name)
-        rugged.branches.exists?(name)
-
-      # If the branch name is invalid (e.g. ".foo") Rugged will raise an error.
-      # Whatever code calls this method shouldn't have to deal with that so
-      # instead we just return `false` (which is true since a branch doesn't
-      # exist when it has an invalid name).
-      rescue Rugged::ReferenceError
-        false
+        gitaly_migrate(:ref_exists_branches) do |is_enabled|
+          if is_enabled
+            gitaly_ref_exists?("refs/heads/#{name}")
+          else
+            rugged_branch_exists?(name)
+          end
+        end
       end
 
       # Returns an Array of branch and tag names
@@ -995,6 +1000,34 @@ module Gitlab
         raw_output.compact
       end
 
+      # Returns true if the given ref name exists
+      #
+      # Ref names must start with `refs/`.
+      def gitaly_ref_exists?(ref_name)
+        gitaly_ref_client.ref_exists?(ref_name)
+      end
+
+      # Returns true if the given tag exists
+      #
+      # name - The name of the tag as a String.
+      def rugged_tag_exists?(name)
+        !!rugged.tags[name]
+      end
+
+      # Returns true if the given branch exists
+      #
+      # name - The name of the branch as a String.
+      def rugged_branch_exists?(name)
+        rugged.branches.exists?(name)
+
+      # If the branch name is invalid (e.g. ".foo") Rugged will raise an error.
+      # Whatever code calls this method shouldn't have to deal with that so
+      # instead we just return `false` (which is true since a branch doesn't
+      # exist when it has an invalid name).
+      rescue Rugged::ReferenceError
+        false
+      end
+
       def gitaly_copy_gitattributes(revision)
         gitaly_repository_client.apply_gitattributes(revision)
       end

lib/gitlab/gitaly_client/ref_service.rb

@@ -70,6 +70,14 @@ module Gitlab
         consume_tags_response(response)
       end
 
+      def ref_exists?(ref_name)
+        request = Gitaly::RefExistsRequest.new(repository: @gitaly_repo, ref: ref_name)
+        response = GitalyClient.call(@storage, :ref_service, :ref_exists, request)
+        response.value
+      rescue GRPC::InvalidArgument => e
+        raise ArgumentError, e.message
+      end
+
       private
 
       def consume_refs_response(response)

spec/lib/gitlab/git/repository_spec.rb

@@ -1098,6 +1098,7 @@ describe Gitlab::Git::Repository, seed_helper: true do
   end
 
   describe '#tag_exists?' do
+    shared_examples 'checks the existence of tags' do
       it 'returns true for an existing tag' do
         tag = repository.tag_names.first
 
@@ -1109,7 +1110,17 @@ describe Gitlab::Git::Repository, seed_helper: true do
       end
     end
 
+    context 'when Gitaly ref_exists_tags feature is enabled' do
+      it_behaves_like 'checks the existence of tags'
+    end
+
+    context 'when Gitaly ref_exists_tags feature is disabled', skip_gitaly_mock: true do
+      it_behaves_like 'checks the existence of tags'
+    end
+  end
+
   describe '#branch_exists?' do
+    shared_examples 'checks the existence of branches' do
       it 'returns true for an existing branch' do
         expect(repository.branch_exists?('master')).to eq(true)
       end
@@ -1123,6 +1134,15 @@ describe Gitlab::Git::Repository, seed_helper: true do
       end
     end
 
+    context 'when Gitaly ref_exists_branches feature is enabled' do
+      it_behaves_like 'checks the existence of branches'
+    end
+
+    context 'when Gitaly ref_exists_branches feature is disabled', skip_gitaly_mock: true do
+      it_behaves_like 'checks the existence of branches'
+    end
+  end
+
   describe '#local_branches' do
     before(:all) do
       @repo = Gitlab::Git::Repository.new('default', File.join(TEST_MUTABLE_REPO_PATH, '.git'))

spec/lib/gitlab/gitaly_client/ref_service_spec.rb

 require 'spec_helper'
 
 describe Gitlab::GitalyClient::RefService do
-  let(:project) { create(:project) }
+  let(:project) { create(:project, :repository) }
   let(:storage_name) { project.repository_storage }
   let(:relative_path) { project.disk_path + '.git' }
-  let(:client) { described_class.new(project.repository) }
+  let(:repository) { project.repository }
+  let(:client) { described_class.new(repository) }
 
   describe '#branches' do
     it 'sends a find_all_branches message' do
@@ -84,11 +85,23 @@ describe Gitlab::GitalyClient::RefService do
   end
 
   describe '#find_ref_name', seed_helper: true do
-    let(:repository) { Gitlab::Git::Repository.new('default', TEST_REPO_PATH) }
-    let(:client) { described_class.new(repository) }
     subject { client.find_ref_name(SeedRepo::Commit::ID, 'refs/heads/master') }
 
     it { is_expected.to be_utf8 }
     it { is_expected.to eq('refs/heads/master') }
   end
+
+  describe '#ref_exists?', seed_helper: true do
+    it 'finds the master branch ref' do
+      expect(client.ref_exists?('refs/heads/master')).to eq(true)
+    end
+
+    it 'returns false for an illegal tag name ref' do
+      expect(client.ref_exists?('refs/tags/.this-tag-name-is-illegal')).to eq(false)
+    end
+
+    it 'raises an argument error if the ref name parameter does not start with refs/' do
+      expect { client.ref_exists?('reXXXXX') }.to raise_error(ArgumentError)
+    end
+  end
 end