func()

in go/showcase/pkg/showcase/part4/storage.go [62:94]

• 16 lines of code
• 2 McCabe index (conditional complexity)

func (s StateStorageFn) Invoke(ctx statefun.Context, msg statefun.Message) error {
	// each function invocation gets access to storage that is scoped to the current function
	// instance's address, i.e. (function typename, instance id). For example, if (UserFn, "Gordon")
	// was invoked, the values you get access to belongs specifically to user Gordon.
	storage := ctx.Storage()

	// you can think of the storage having several "columns", with each column identified by an
	// uniquely named ValueSpec. Using the ValueSpec instances, you can access the value of
	// individual columns. Get returns a boolean indicating whether there is an existing
	// value, so you can differentiate between missing and the zero value.
	var storedInt int32
	_ = storage.Get(s.IntValue, &storedInt)

	var boolValue bool
	exists := storage.Get(s.BoolValue, &boolValue)

	var login part1.UserLogin
	_ = storage.Get(s.UserLoginValue, &login)

	// the ValueSpec instance is also used for manipulating the stored values, e.g. updating ...
	storage.Set(s.IntValue, storedInt+1)

	if !exists {
		boolValue = true
	}

	storage.Set(s.BoolValue, boolValue)

	// ... or clearing the value!
	storage.Remove(s.UserLoginValue)

	return nil
}