Function TestInputStreamShrink

go/fory/stream_test.go:216–261

(t *testing.T)

}

func TestInputStreamShrink(t *testing.T) {
	// Create a large payload that easily escapes the bufferSize (4096)
	data := make([]byte, 10000)
	for i := range data {
		data[i] = byte(i % 256)
	}

	// Create a stream reader with a tiny bufferSize so we can trigger Shrink reliably
	buf := bytes.NewReader(data)
	sr := NewInputStreamWithBufferSize(buf, 100)

	// Force a read/fill to pull a chunk into memory
	err := sr.buffer.fill(5000, nil)
	if !err {
		t.Fatalf("Failed to fill buffer")
	}

	// Fake an artificial read that consumed a massive portion of the buffer
	originalCapacity := cap(sr.buffer.data)
	sr.buffer.readerIndex = 4500

	// Trigger Shrink
	sr.Shrink()

	// 1. Validate reader index was successfully reset
	if sr.buffer.readerIndex != 0 {
		t.Errorf("Expected readerIndex to reset to 0, got %d", sr.buffer.readerIndex)
	}

	// 2. Validate the capacity actually shrank (reclaimed memory)
	newCapacity := cap(sr.buffer.data)
	if newCapacity >= originalCapacity {
		t.Errorf("Expected capacity to shrink (was %d, now %d)", originalCapacity, newCapacity)
	}

	// 3. Validate the remaining unread data remained intact
	if sr.buffer.writerIndex != 500 {
		t.Errorf("Expected writerIndex to be 500 remaining bytes, got %d", sr.buffer.writerIndex)
	}
	for i := 0; i < 500; i++ {
		if sr.buffer.data[i] != byte((4500+i)%256) {
			t.Errorf("Data corruption post-shrink at index %d", i)
			break
		}
	}
}