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*
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
/*
* @test
* @bug 8148174
* @summary brittle white box test of internal array management
* @run testng ArrayManagement
*/
import java.lang.reflect.Field;
import java.util.AbstractList;
import java.util.Vector;
import java.util.Collections;
import java.util.List;
import java.util.SplittableRandom;
import org.testng.annotations.Test;
import static org.testng.Assert.*;
public class ArrayManagement {
/**
* A Vector that exposes all protected elements, and checks class
* invariants.
*/
static class PublicVector<E> extends Vector<E> {
public PublicVector() { super(); }
public PublicVector(int capacity) { super(capacity); }
public PublicVector(int capacity, int capacityIncrement) {
super(capacity, capacityIncrement);
}
public Object[] elementData() { return elementData; }
public int modCount() { return modCount; }
public int capacityIncrement() { return capacityIncrement; }
public int capacity() { return elementData.length; }
public void ensureCapacity(int minCapacity) {
int oldCapacity = capacity();
int oldModCount = modCount();
super.ensureCapacity(minCapacity);
assertTrue(capacity() >= minCapacity);
if (minCapacity <= oldCapacity)
assertEquals(capacity(), oldCapacity);
if (minCapacity > 0)
assertEquals(modCount(), oldModCount + 1);
}
}
static final int DEFAULT_CAPACITY = 10;
static final SplittableRandom rnd = new SplittableRandom();
static int newCapacity(int oldCapacity) {
return 2 * oldCapacity;
}
static List<Object> singletonList() {
return Collections.singletonList(Boolean.TRUE);
}
/** Opportunistically randomly test various add operations. */
static void addOneElement(PublicVector<Object> list) {
int size = list.size();
int modCount = list.modCount();
switch (rnd.nextInt(4)) {
case 0: assertTrue(list.add(Boolean.TRUE)); break;
case 1: list.add(size, Boolean.TRUE); break;
case 2: assertTrue(list.addAll(singletonList())); break;
case 3: assertTrue(list.addAll(size, singletonList())); break;
default: throw new AssertionError();
}
assertEquals(list.modCount(), modCount + 1);
assertEquals(list.size(), size + 1);
}
@Test public void defaultCapacity() {
PublicVector<Object> list = new PublicVector<>();
assertEquals(new PublicVector<Object>().capacity(), DEFAULT_CAPACITY);
for (int i = 0; i < DEFAULT_CAPACITY; i++) {
addOneElement(list);
assertEquals(list.capacity(), DEFAULT_CAPACITY);
}
addOneElement(list);
assertEquals(list.capacity(), newCapacity(DEFAULT_CAPACITY));
}
@Test public void defaultCapacityEnsureCapacity() {
PublicVector<Object> list = new PublicVector<>();
for (int i = 0; i <= DEFAULT_CAPACITY; i++) {
list.ensureCapacity(i); // no-op!
assertEquals(list.capacity(), DEFAULT_CAPACITY);
}
for (int i = 0; i < DEFAULT_CAPACITY; i++) {
addOneElement(list);
assertEquals(list.capacity(), DEFAULT_CAPACITY);
}
addOneElement(list);
assertEquals(list.capacity(), newCapacity(DEFAULT_CAPACITY));
{
int capacity = list.capacity();
list.ensureCapacity(capacity + 1);
assertEquals(list.capacity(), newCapacity(capacity));
}
{
int capacity = list.capacity();
list.ensureCapacity(3 * capacity);
assertEquals(list.capacity(), 3 * capacity);
}
}
@Test public void ensureCapacityBeyondDefaultCapacity() {
PublicVector<Object> list = new PublicVector<>();
list.ensureCapacity(DEFAULT_CAPACITY + 1);
assertEquals(list.capacity(), newCapacity(DEFAULT_CAPACITY));
}
@Test public void explicitZeroCapacity() {
PublicVector<Object> list = new PublicVector<>(0);
assertEquals(list.capacity(), 0);
addOneElement(list);
assertEquals(list.capacity(), 1);
addOneElement(list);
assertEquals(list.capacity(), 2);
addOneElement(list);
assertEquals(list.capacity(), 4);
addOneElement(list);
assertEquals(list.capacity(), 4);
addOneElement(list);
assertEquals(list.capacity(), 8);
addOneElement(list);
assertEquals(list.capacity(), 8);
addOneElement(list);
assertEquals(list.capacity(), 8);
list.clear();
assertEquals(list.capacity(), 8);
}
@Test public void explicitZeroCapacityWithCapacityIncrement() {
PublicVector<Object> list = new PublicVector<>(0, 2);
assertEquals(list.capacity(), 0);
addOneElement(list);
assertEquals(list.capacity(), 2);
addOneElement(list);
assertEquals(list.capacity(), 2);
addOneElement(list);
assertEquals(list.capacity(), 4);
addOneElement(list);
assertEquals(list.capacity(), 4);
addOneElement(list);
assertEquals(list.capacity(), 6);
addOneElement(list);
assertEquals(list.capacity(), 6);
addOneElement(list);
assertEquals(list.capacity(), 8);
list.clear();
assertEquals(list.capacity(), 8);
}
@Test public void explicitLargeCapacity() {
int n = DEFAULT_CAPACITY * 3;
PublicVector<Object> list = new PublicVector<>(n);
assertEquals(list.capacity(), n);
list.ensureCapacity(0);
list.ensureCapacity(n);
for (int i = 0; i < n; i++) addOneElement(list);
assertEquals(list.capacity(), n);
addOneElement(list);
assertEquals(list.capacity(), newCapacity(n));
}
@Test public void explicitLargeCapacityWithCapacityIncrement() {
int n = DEFAULT_CAPACITY * 3;
PublicVector<Object> list = new PublicVector<>(n, 2);
assertEquals(list.capacity(), n);
list.ensureCapacity(0);
list.ensureCapacity(n);
for (int i = 0; i < n; i++) addOneElement(list);
assertEquals(list.capacity(), n);
addOneElement(list);
assertEquals(list.capacity(), n + 2);
}
@Test public void emptyArraysAreNotShared() {
assertNotSame(new PublicVector<Object>(0).elementData(),
new PublicVector<Object>(0).elementData());
}
@Test public void negativeCapacity() {
for (int capacity : new int[] { -1, Integer.MIN_VALUE }) {
try {
new Vector<Object>(capacity);
fail("should throw");
} catch (IllegalArgumentException success) {}
}
}
}