backend: add onTraffic callback for serverless (#276)

Signed-off-by: xhe <xw897002528@gmail.com>

Makefile

@@ -44,8 +44,8 @@ golangci-lint:
 	GOBIN=$(GOBIN) go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
 
 lint: golangci-lint tidy
-	$(GOBIN)/golangci-lint run
 	cd lib && $(GOBIN)/golangci-lint run
+	$(GOBIN)/golangci-lint run
 
 gocovmerge:
 	GOBIN=$(GOBIN) go install github.com/wadey/gocovmerge@master

pkg/proxy/backend/backend_conn_mgr.go

@@ -266,6 +266,7 @@ func (mgr *BackendConnManager) getBackendIO(cctx ConnContext, auth *Authenticato
 func (mgr *BackendConnManager) ExecuteCmd(ctx context.Context, request []byte) (err error) {
 	defer func() {
 		mgr.setQuitSourceByErr(err)
+		mgr.handshakeHandler.OnTraffic(mgr)
 	}()
 	if len(request) < 1 {
 		err = mysql.ErrMalformPacket

pkg/proxy/backend/backend_conn_mgr_test.go

@@ -784,6 +784,46 @@ func TestHandlerReturnError(t *testing.T) {
 	}
 }
 
+func TestOnTraffic(t *testing.T) {
+	i := 0
+	inbytes, outbytes := []int{
+		0x99,
+	}, []int{
+		0xce,
+	}
+	ts := newBackendMgrTester(t, func(config *testConfig) {
+		config.proxyConfig.checkBackendInterval = 10 * time.Millisecond
+		config.proxyConfig.handler.onTraffic = func(cc ConnContext) {
+			require.Equal(t, uint64(inbytes[i]), cc.ClientInBytes())
+			require.Equal(t, uint64(outbytes[i]), cc.ClientOutBytes())
+			i++
+		}
+	})
+	runners := []runner{
+		// 1st handshake
+		{
+			client:  ts.mc.authenticate,
+			proxy:   ts.firstHandshake4Proxy,
+			backend: ts.handshake4Backend,
+		},
+		// query
+		{
+			client: func(packetIO *pnet.PacketIO) error {
+				ts.mc.sql = "select 1"
+				return ts.mc.request(packetIO)
+			},
+			proxy: ts.forwardCmd4Proxy,
+			backend: func(packetIO *pnet.PacketIO) error {
+				ts.mb.respondType = responseTypeResultSet
+				ts.mb.columns = 1
+				ts.mb.rows = 1
+				return ts.mb.respond(packetIO)
+			},
+		},
+	}
+	ts.runTests(runners)
+}
+
 func TestGetBackendIO(t *testing.T) {
 	addrs := make([]string, 0, 3)
 	listeners := make([]net.Listener, 0, cap(addrs))

pkg/proxy/backend/handshake_handler.go

@@ -65,6 +65,7 @@ func (es ErrorSource) String() string {
 }
 
 var _ HandshakeHandler = (*DefaultHandshakeHandler)(nil)
+var _ HandshakeHandler = (*CustomHandshakeHandler)(nil)
 
 type ConnContext interface {
 	ClientAddr() string
@@ -82,6 +83,7 @@ type HandshakeHandler interface {
 	GetRouter(ctx ConnContext, resp *pnet.HandshakeResp) (router.Router, error)
 	OnHandshake(ctx ConnContext, to string, err error)
 	OnConnClose(ctx ConnContext) error
+	OnTraffic(ctx ConnContext)
 	GetCapability() pnet.Capability
 	GetServerVersion() string
 }
@@ -117,6 +119,9 @@ func (handler *DefaultHandshakeHandler) GetRouter(ctx ConnContext, resp *pnet.Ha
 func (handler *DefaultHandshakeHandler) OnHandshake(ConnContext, string, error) {
 }
 
+func (handler *DefaultHandshakeHandler) OnTraffic(ConnContext) {
+}
+
 func (handler *DefaultHandshakeHandler) OnConnClose(ConnContext) error {
 	return nil
 }
@@ -135,6 +140,7 @@ func (handler *DefaultHandshakeHandler) GetServerVersion() string {
 type CustomHandshakeHandler struct {
 	getRouter           func(ctx ConnContext, resp *pnet.HandshakeResp) (router.Router, error)
 	onHandshake         func(ConnContext, string, error)
+	onTraffic           func(ConnContext)
 	onConnClose         func(ConnContext) error
 	handleHandshakeResp func(ctx ConnContext, resp *pnet.HandshakeResp) error
 	getCapability       func() pnet.Capability
@@ -154,6 +160,12 @@ func (h *CustomHandshakeHandler) OnHandshake(ctx ConnContext, addr string, err e
 	}
 }
 
+func (h *CustomHandshakeHandler) OnTraffic(ctx ConnContext) {
+	if h.onTraffic != nil {
+		h.onTraffic(ctx)
+	}
+}
+
 func (h *CustomHandshakeHandler) OnConnClose(ctx ConnContext) error {
 	if h.onConnClose != nil {
 		return h.onConnClose(ctx)