issue 7211: support concatenate objects

Signed-off-by: Lyndon-Li <[email protected]>

pkg/repository/udmrepo/kopialib/lib_repo.go

@@ -366,6 +366,40 @@ func (kr *kopiaRepository) Flush(ctx context.Context) error {
 	return nil
 }
 
+func (kr *kopiaRepository) GetAdvancedFeatures() udmrepo.AdvancedFeatureInfo {
+	return udmrepo.AdvancedFeatureInfo{
+		MultiPartBackup: true,
+	}
+}
+
+func (kr *kopiaRepository) ConcatenateObjects(ctx context.Context, objectIDs []udmrepo.ID) (udmrepo.ID, error) {
+	if kr.rawWriter == nil {
+		return "", errors.New("repo writer is closed or not open")
+	}
+
+	if len(objectIDs) == 0 {
+		return udmrepo.ID(""), errors.New("object list is empty")
+	}
+
+	rawIDs := []object.ID{}
+	for _, id := range objectIDs {
+		rawID, err := object.ParseID(string(id))
+		if err != nil {
+			return udmrepo.ID(""), errors.Wrapf(err, "error to parse object ID from %v", id)
+		}
+
+		rawIDs = append(rawIDs, rawID)
+	}
+
+	result, err := kr.rawWriter.ConcatenateObjects(ctx, rawIDs)
+	if err != nil {
+		return udmrepo.ID(""), errors.Wrap(err, "error to concatenate objects")
+	}
+
+	return udmrepo.ID(result.String()), nil
+
+}
+
 // updateProgress is called when the repository writes a piece of blob data to the storage during data write
 func (kr *kopiaRepository) updateProgress(uploaded int64) {
 	total := atomic.AddInt64(&kr.uploaded, uploaded)

pkg/repository/udmrepo/kopialib/lib_repo_test.go

@@ -716,6 +716,65 @@ func TestFlush(t *testing.T) {
 	}
 }
 
+func TestConcatenateObjects(t *testing.T) {
+	testCases := []struct {
+		name            string
+		rawWriter       *repomocks.DirectRepositoryWriter
+		rawWriterRetErr error
+		objectIDs       []udmrepo.ID
+		expectedErr     string
+	}{
+		{
+			name:        "empty object list",
+			expectedErr: "object list is empty",
+		},
+		{
+			name: "invalid object id",
+			objectIDs: []udmrepo.ID{
+				"I123456",
+				"fake-id",
+				"I678901",
+			},
+			expectedErr: "error to parse object ID from fake-id: malformed content ID: \"fake-id\": invalid content prefix",
+		},
+		{
+			name:            "concatenate error",
+			rawWriter:       repomocks.NewDirectRepositoryWriter(t),
+			rawWriterRetErr: errors.New("fake-concatenate-error"),
+			objectIDs: []udmrepo.ID{
+				"I123456",
+			},
+			expectedErr: "error to concatenate objects: fake-concatenate-error",
+		},
+		{
+			name:      "succeed",
+			rawWriter: repomocks.NewDirectRepositoryWriter(t),
+			objectIDs: []udmrepo.ID{
+				"I123456",
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			kr := &kopiaRepository{}
+			if tc.rawWriter != nil {
+				tc.rawWriter.On("ConcatenateObjects", mock.Anything, mock.Anything).Return(object.ID{}, tc.rawWriterRetErr)
+			}
+
+			kr.rawWriter = tc.rawWriter
+
+			_, err := kr.ConcatenateObjects(context.Background(), tc.objectIDs)
+
+			if tc.expectedErr == "" {
+				assert.NoError(t, err)
+			} else {
+				assert.EqualError(t, err, tc.expectedErr)
+			}
+		})
+	}
+}
+
 func TestNewObjectWriter(t *testing.T) {
 	rawObjWriter := repomocks.NewWriter(t)
 	testCases := []struct {