agent/statemanager/state_manager.go
func NewStateManager(cfg *config.Config, options ...Option) (StateManager, error) {
	fi, err := os.Stat(cfg.DataDir)
	if err != nil {
		return nil, err
	}
	if !fi.IsDir() {
		return nil, errors.New("State manager DataDir must exist")
	}

	state := &state{
		Data:    make(saveableState),
		Version: ECSDataVersion,
	}
	manager := &basicStateManager{
		statePath: cfg.DataDir,
		state:     state,
	}

	for _, option := range options {
		option(manager)
	}

	manager.platformDependencies = newPlatformDependencies()

	return manager, nil
}
func NewStateManager(cfg *config.Config, options ...Option) (StateManager, error) {
	fi, err := os.Stat(cfg.DataDir)
	if err != nil {
		return nil, err
	}
	if !fi.IsDir() {
		return nil, errors.New("State manager DataDir must exist")
	}

	state := &state{
		Data:    make(saveableState),
		Version: ECSDataVersion,
	}
	manager := &basicStateManager{
		statePath: cfg.DataDir,
		state:     state,
	}

	for _, option := range options {
		option(manager)
	}

	manager.platformDependencies = newPlatformDependencies()

	return manager, nil
}
// NewStateManager constructs a new StateManager which saves data at the
// location specified in cfg and operates under the given options.
// The returned StateManager will not save more often than every 10 seconds and
// will not reliably return errors with Save, but will log them appropriately.