"unsafe"
)

var (
	// ErrTooMuchDataToWrite is returned when the data to write is more than the buffer size.
	ErrTooMuchDataToWrite = errors.New("too much data to write")

	// ErrIsFull is returned when the buffer is full and not blocking.
	ErrIsFull = errors.New("ringbuffer is full")

	// ErrIsEmpty is returned when the buffer is empty and not blocking.
	ErrIsEmpty = errors.New("ringbuffer is empty")

	// write more 4 bytes, should reject
	n, err = rb.Write([]byte(strings.Repeat("abcd", 1)))
	if err == nil {
		t.Fatalf("expect an error but got nil. n=%d, r.w=%d, r.r=%d", n, rb.w, rb.r)
	}
	if err != ErrIsFull {
		t.Fatalf("expect ErrIsFull but got nil")
	}
	if n != 0 {
		t.Fatalf("expect write 0 bytes but got %d", n)
	}
	if rb.Length() != 64 {
		t.Fatalf("expect len 64 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)