repository: Use Size() to calculate repo size behind feature flagjc-accurate-calculation-of-repo-size

In the previous commit, we added a Size() method in localrepo that calls
git rev-list --all --objects --disk-usage to calculate the size of the
repository.

Add a feature flag that, when toggled on, will cause RepositorySize to
use this new way of calculating repository size.

Changelog: added

3 files changed, 46 insertions, 12 deletions

diff --git a/internal/gitaly/service/repository/size.go b/internal/gitaly/service/repository/size.go
index 261bb0417..94cf5a7c8 100644
--- a/internal/gitaly/service/repository/size.go
+++ b/internal/gitaly/service/repository/size.go
@@ -10,16 +10,30 @@ import (
 
 	"github.com/grpc-ecosystem/go-grpc-middleware/logging/logrus/ctxlogrus"
 	"gitlab.com/gitlab-org/gitaly/v14/internal/command"
+	"gitlab.com/gitlab-org/gitaly/v14/internal/metadata/featureflag"
 	"gitlab.com/gitlab-org/gitaly/v14/proto/go/gitalypb"
 )
 
 func (s *server) RepositorySize(ctx context.Context, in *gitalypb.RepositorySizeRequest) (*gitalypb.RepositorySizeResponse, error) {
-	path, err := s.locator.GetPath(in.Repository)
-	if err != nil {
-		return nil, err
+	repo := s.localrepo(in.GetRepository())
+	var size int64
+	var err error
+
+	if featureflag.RevlistForRepoSize.IsEnabled(ctx) {
+		size, err = repo.Size(ctx)
+		if err != nil {
+			return nil, err
+		}
+		size = size / 1024
+	} else {
+		path, err := repo.Path()
+		if err != nil {
+			return nil, err
+		}
+		size = getPathSize(ctx, path)
 	}
 
-	return &gitalypb.RepositorySizeResponse{Size: getPathSize(ctx, path)}, nil
+	return &gitalypb.RepositorySizeResponse{Size: size}, nil
 }
 
 func (s *server) GetObjectDirectorySize(ctx context.Context, in *gitalypb.GetObjectDirectorySizeRequest) (*gitalypb.GetObjectDirectorySizeResponse, error) {
diff --git a/internal/gitaly/service/repository/size_test.go b/internal/gitaly/service/repository/size_test.go
index 5aa51da73..b9c752723 100644
--- a/internal/gitaly/service/repository/size_test.go
+++ b/internal/gitaly/service/repository/size_test.go
@@ -1,12 +1,14 @@
 package repository
 
 import (
+	"context"
 	"testing"
 
 	"github.com/stretchr/testify/require"
 	"gitlab.com/gitlab-org/gitaly/v14/internal/git/gittest"
 	"gitlab.com/gitlab-org/gitaly/v14/internal/git/quarantine"
 	"gitlab.com/gitlab-org/gitaly/v14/internal/gitaly/config"
+	"gitlab.com/gitlab-org/gitaly/v14/internal/metadata/featureflag"
 	"gitlab.com/gitlab-org/gitaly/v14/internal/testhelper"
 	"gitlab.com/gitlab-org/gitaly/v14/proto/go/gitalypb"
 	"google.golang.org/grpc/codes"
@@ -17,10 +19,13 @@ import (
 // repository, even in optimally packed state, is greater than this.
 const testRepoMinSizeKB = 10000
 
-func TestSuccessfulRepositorySizeRequest(t *testing.T) {
+func TestRepositorySize_SuccessfulRequest(t *testing.T) {
 	t.Parallel()
+	testhelper.NewFeatureSets(featureflag.RevlistForRepoSize).
+		Run(t, testSuccessfulRepositorySizeRequest)
+}
 
-	ctx := testhelper.Context(t)
+func testSuccessfulRepositorySizeRequest(t *testing.T, ctx context.Context) {
 	_, repo, _, client := setupRepositoryService(ctx, t)
 
 	request := &gitalypb.RepositorySizeRequest{Repository: repo}
@@ -33,8 +38,13 @@ func TestSuccessfulRepositorySizeRequest(t *testing.T) {
 	)
 }
 
-func TestFailedRepositorySizeRequest(t *testing.T) {
+func TestRepositorySixe_FailedRequest(t *testing.T) {
 	t.Parallel()
+	testhelper.NewFeatureSets(featureflag.RevlistForRepoSize).
+		Run(t, testFailedRepositorySizeRequest)
+}
+
+func testFailedRepositorySizeRequest(t *testing.T, ctx context.Context) {
 	_, client := setupRepositoryServiceWithoutRepo(t)
 
 	testCases := []struct {
@@ -52,17 +62,19 @@ func TestFailedRepositorySizeRequest(t *testing.T) {
 			request := &gitalypb.RepositorySizeRequest{
 				Repository: testCase.repo,
 			}
-			ctx := testhelper.Context(t)
 			_, err := client.RepositorySize(ctx, request)
 			testhelper.RequireGrpcCode(t, err, codes.InvalidArgument)
 		})
 	}
 }
 
-func TestSuccessfulGetObjectDirectorySizeRequest(t *testing.T) {
+func TestRepositorySize_SuccessfulGetObjectDirectorySizeRequest(t *testing.T) {
 	t.Parallel()
+	testhelper.NewFeatureSets(featureflag.RevlistForRepoSize).
+		Run(t, testSuccessfulGetObjectDirectorySizeRequest)
+}
 
-	ctx := testhelper.Context(t)
+func testSuccessfulGetObjectDirectorySizeRequest(t *testing.T, ctx context.Context) {
 	_, repo, _, client := setupRepositoryService(ctx, t)
 	repo.GitObjectDirectory = "objects/"
 
@@ -76,12 +88,15 @@ func TestSuccessfulGetObjectDirectorySizeRequest(t *testing.T) {
 	)
 }
 
-func TestGetObjectDirectorySize_quarantine(t *testing.T) {
+func TestRepositorySize_GetObjectDirectorySize_quarantine(t *testing.T) {
 	t.Parallel()
+	testhelper.NewFeatureSets(featureflag.RevlistForRepoSize).
+		Run(t, testGetObjectDirectorySizeQuarantine)
+}
 
+func testGetObjectDirectorySizeQuarantine(t *testing.T, ctx context.Context) {
 	cfg, client := setupRepositoryServiceWithoutRepo(t)
 	locator := config.NewLocator(cfg)
-	ctx := testhelper.Context(t)
 
 	t.Run("quarantined repo", func(t *testing.T) {
 		repo, _ := gittest.CreateRepository(ctx, t, cfg, gittest.CreateRepositoryConfig{
diff --git a/internal/metadata/featureflag/ff_repo_size_revlist.go b/internal/metadata/featureflag/ff_repo_size_revlist.go
new file mode 100644
index 000000000..8be87e482
--- /dev/null
+++ b/internal/metadata/featureflag/ff_repo_size_revlist.go
@@ -0,0 +1,5 @@
+package featureflag
+
+// RevlistForRepoSize enables the RepositorySize RPC to use git rev-list to
+// calculate the disk usage of the repository.
+var RevlistForRepoSize = NewFeatureFlag("revlist_for_repo_size", false)