add image.Store.Info() function

backend/_example/memory_store/server/image.go

@@ -54,3 +54,8 @@ func (s *RPC) imgCleanupHndl(id uint64, params json.RawMessage) (rr jrpc.Respons
 	err := s.img.Cleanup(context.TODO(), ttl)
 	return jrpc.EncodeResponse(id, nil, err)
 }
+
+func (s *RPC) imgInfoHndl(id uint64, _ json.RawMessage) (rr jrpc.Response) {
+	info, err := s.img.Info()
+	return jrpc.EncodeResponse(id, info, err)
+}

backend/_example/memory_store/server/image_test.go

@@ -124,3 +124,25 @@ func TestRPC_imgCleanupHndl(t *testing.T) {
 	_, err = ri.Load(id)
 	assert.EqualError(t, err, "image test_img not found")
 }
+
+func TestRPC_imgInfoHndl(t *testing.T) {
+	port, teardown := prepTestStore(t)
+	defer teardown()
+	api := fmt.Sprintf("http://localhost:%d/test", port)
+
+	ri := image.RPC{Client: jrpc.Client{API: api, Client: http.Client{Timeout: 1 * time.Second}}}
+
+	// get info on empty storage, should be zero
+	info, err := ri.Info()
+	assert.NoError(t, err)
+	assert.True(t, info.FirstStagingImageTS.IsZero())
+
+	// save
+	err = ri.Save("test_img", gopherPNGBytes())
+	assert.NoError(t, err)
+
+	// get info after saving, should be non-zero
+	info, err = ri.Info()
+	assert.NoError(t, err)
+	assert.False(t, info.FirstStagingImageTS.IsZero())
+}

backend/_example/memory_store/server/rpc.go

@@ -61,5 +61,6 @@ func (s *RPC) addHandlers() {
 		"load":         s.imgLoadHndl,
 		"commit":       s.imgCommitHndl,
 		"cleanup":      s.imgCleanupHndl,
+		"info":         s.imgInfoHndl,
 	})
 }