feat(gotenberg): add ConversionsSinceRestart accessor to ProcessSupervisor

pkg/gotenberg/mocks.go

@@ -159,6 +159,7 @@ type ProcessSupervisorMock struct {
 	ReqQueueSizeMock            func() int64
 	RestartsCountMock           func() int64
 	ActiveTasksCountMock        func() int64
+	ConversionsSinceRestartMock func() int64
 }
 
 func (s *ProcessSupervisorMock) Launch() error {
@@ -189,6 +190,10 @@ func (s *ProcessSupervisorMock) ActiveTasksCount() int64 {
 	return s.ActiveTasksCountMock()
 }
 
+func (s *ProcessSupervisorMock) ConversionsSinceRestart() int64 {
+	return s.ConversionsSinceRestartMock()
+}
+
 // MetricsProviderMock is a mock for the [MetricsProvider] interface.
 type MetricsProviderMock struct {
 	MetricsMock func() ([]Metric, error)

pkg/gotenberg/supervisor.go

@@ -76,6 +76,10 @@ type ProcessSupervisor interface {
 
 	// ActiveTasksCount returns the current number of active tasks.
 	ActiveTasksCount() int64
+
+	// ConversionsSinceRestart returns the number of tasks handled since the
+	// last process (re)start.
+	ConversionsSinceRestart() int64
 }
 
 // healthCheckCacheTTL caches successful health probe results so kubelet-
@@ -577,6 +581,13 @@ func (s *processSupervisor) ActiveTasksCount() int64 {
 	return s.activeTasks.Load()
 }
 
+// ConversionsSinceRestart returns the number of tasks handled since the last
+// process (re)start. reqCounter is reset to zero on every restart and idle
+// shutdown.
+func (s *processSupervisor) ConversionsSinceRestart() int64 {
+	return s.reqCounter.Load()
+}
+
 // Interface guards.
 var (
 	_ ProcessSupervisor = (*processSupervisor)(nil)

pkg/gotenberg/supervisor_test.go

@@ -1091,3 +1091,28 @@ func TestProcessSupervisor_IdleShutdownSkippedWhenActive(t *testing.T) {
 
 	close(taskDone)
 }
+
+func TestProcessSupervisor_ConversionsSinceRestart(t *testing.T) {
+	process := &ProcessMock{
+		StartMock:   func(*slog.Logger) error { return nil },
+		StopMock:    func(*slog.Logger) error { return nil },
+		HealthyMock: func(*slog.Logger) bool { return true },
+	}
+	s := NewProcessSupervisor(slog.New(slog.DiscardHandler), process, 0, 0, 1, 0).(*processSupervisor)
+
+	if got := s.ConversionsSinceRestart(); got != 0 {
+		t.Errorf("expected 0 conversions initially, got %d", got)
+	}
+
+	s.reqCounter.Store(7)
+	if got := s.ConversionsSinceRestart(); got != 7 {
+		t.Errorf("expected 7 conversions, got %d", got)
+	}
+
+	if err := s.restart(); err != nil {
+		t.Fatalf("restart: %v", err)
+	}
+	if got := s.ConversionsSinceRestart(); got != 0 {
+		t.Errorf("expected 0 conversions after restart, got %d", got)
+	}
+}