}

func (r *RingBuffer) write(p []byte) (n int, err error) {
	if r.isFull {
		return 0, ErrIsFull
	}

	var avail int
	if r.w >= r.r {
		avail = r.size - r.w + r.r
	} else {
		avail = r.r - r.w
	}

	if len(p) > avail {
		err = ErrTooMuchDataToWrite
		p = p[:avail]
	}
	n = len(p)

	if r.w >= r.r {
		c1 := r.size - r.w
		if c1 >= n {
			copy(r.buf[r.w:], p)
			r.w += n

  function fitText(t, avail, textList) {
    // Find first entry in textList that fits.
    let width = avail;
    textContext.font = FONT_SIZE + 'pt Arial';
    for (let i = 0; i < textList.length; i++) {
      let text = textList[i];
      width = textContext.measureText(text).width;
      if (width <= avail) {
        t.innerText = text;
        return;
      }
    }

				rt.name,
				rt.expectedError,
				(output != nil),
			)
		}
	}
}

func TestFileAvailableCheck(t *testing.T) {
	f, err := os.CreateTemp("", "file-avail-check")
	if err != nil {
		t.Fatalf("Failed to create file: %v", err)
	}
	defer utiltesting.CloseAndRemove(t, f)
	var tests = []struct {
		name          string
		check         FileAvailableCheck

	// current stack. The currently used stack includes everything
	// down to the SP plus the stack guard space that ensures
	// there's room for nosplit functions.
	avail := gp.stack.hi - gp.stack.lo
	if used := gp.stack.hi - gp.sched.sp + stackNosplit; used >= avail/4 {
		return
	}

	if stackDebug > 0 {
		print("shrinking stack ", oldsize, "->", newsize, "\n")
	}

	copystack(gp, newsize)
}