/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.collections4.map;
import java.lang.ref.WeakReference;
import java.util.Iterator;
import java.util.Map;
import junit.framework.Test;
import org.apache.commons.collections4.BulkTest;
import org.apache.commons.collections4.IterableMap;
import org.apache.commons.collections4.map.AbstractReferenceMap.ReferenceStrength;
/**
* Tests for ReferenceIdentityMap.
*
* @version $Id$
*/
public class ReferenceIdentityMapTest<K, V> extends AbstractIterableMapTest<K, V> {
private static final Integer I1A = new Integer(1); // Cannot use valueOf here
private static final Integer I1B = new Integer(1);
private static final Integer I2A = new Integer(2);
private static final Integer I2B = new Integer(2);
public ReferenceIdentityMapTest(final String testName) {
super(testName);
}
public static Test suite() {
return BulkTest.makeSuite(ReferenceIdentityMapTest.class);
}
@Override
public ReferenceIdentityMap<K, V> makeObject() {
return new ReferenceIdentityMap<K, V>(ReferenceStrength.WEAK, ReferenceStrength.WEAK);
}
@Override
public Map<K, V> makeConfirmedMap() {
// Testing against another [collections] class generally isn't a good idea,
// but the closest alternative is IdentityHashMap, which propagates reference-equality down to keySet and values.
// arguably ReferenceIdentityMap should do the same but that's a later discussion.
return new IdentityMap<K, V>();
}
@Override
public boolean isAllowNullKey() {
return false;
}
@Override
public boolean isAllowNullValue() {
return false;
}
@Override
public String getCompatibilityVersion() {
return "4";
}
// public void testCreate() throws Exception {
// resetEmpty();
// writeExternalFormToDisk(
// (java.io.Serializable) map,
// "src/test/resources/data/test/ReferenceIdentityMap.emptyCollection.version4.obj");
// resetFull();
// writeExternalFormToDisk(
// (java.io.Serializable) map,
// "src/test/resources/data/test/ReferenceIdentityMap.fullCollection.version4.obj");
// }
//-----------------------------------------------------------------------
@SuppressWarnings("unchecked")
public void testBasics() {
final IterableMap<K, V> map = new ReferenceIdentityMap<K, V>(ReferenceStrength.HARD, ReferenceStrength.HARD);
assertEquals(0, map.size());
map.put((K) I1A, (V) I2A);
assertEquals(1, map.size());
assertSame(I2A, map.get(I1A));
assertSame(null, map.get(I1B));
assertEquals(true, map.containsKey(I1A));
assertEquals(false, map.containsKey(I1B));
assertEquals(true, map.containsValue(I2A));
assertEquals(false, map.containsValue(I2B));
map.put((K) I1A, (V) I2B);
assertEquals(1, map.size());
assertSame(I2B, map.get(I1A));
assertSame(null, map.get(I1B));
assertEquals(true, map.containsKey(I1A));
assertEquals(false, map.containsKey(I1B));
assertEquals(false, map.containsValue(I2A));
assertEquals(true, map.containsValue(I2B));
map.put((K) I1B, (V) I2B);
assertEquals(2, map.size());
assertSame(I2B, map.get(I1A));
assertSame(I2B, map.get(I1B));
assertEquals(true, map.containsKey(I1A));
assertEquals(true, map.containsKey(I1B));
assertEquals(false, map.containsValue(I2A));
assertEquals(true, map.containsValue(I2B));
}
//-----------------------------------------------------------------------
@SuppressWarnings("unchecked")
public void testHashEntry() {
final IterableMap<K, V> map = new ReferenceIdentityMap<K, V>(ReferenceStrength.HARD, ReferenceStrength.HARD);
map.put((K) I1A, (V) I2A);
map.put((K) I1B, (V) I2A);
final Map.Entry<K, V> entry1 = map.entrySet().iterator().next();
final Iterator<Map.Entry<K, V>> it = map.entrySet().iterator();
final Map.Entry<K, V> entry2 = it.next();
final Map.Entry<K, V> entry3 = it.next();
assertEquals(true, entry1.equals(entry2));
assertEquals(true, entry2.equals(entry1));
assertEquals(false, entry1.equals(entry3));
}
//-----------------------------------------------------------------------
@SuppressWarnings("unchecked")
public void testNullHandling() {
resetFull();
assertEquals(null, getMap().get(null));
assertEquals(false, getMap().containsKey(null));
assertEquals(false, getMap().containsValue(null));
assertEquals(null, getMap().remove(null));
assertEquals(false, getMap().entrySet().contains(null));
assertEquals(false, getMap().keySet().contains(null));
assertEquals(false, getMap().values().contains(null));
try {
getMap().put(null, null);
fail();
} catch (final NullPointerException ex) {}
try {
getMap().put((K) new Object(), null);
fail();
} catch (final NullPointerException ex) {}
try {
getMap().put(null, (V) new Object());
fail();
} catch (final NullPointerException ex) {}
}
//-----------------------------------------------------------------------
/*
// Tests often fail because gc is uncontrollable
public void testPurge() {
ReferenceIdentityMap map = new ReferenceIdentityMap(ReferenceIdentityMap.WEAK, ReferenceIdentityMap.WEAK);
Object[] hard = new Object[10];
for (int i = 0; i < hard.length; i++) {
hard[i] = new Object();
map.put(hard[i], new Object());
}
gc();
assertTrue("map should be empty after purge of weak values", map.isEmpty());
for (int i = 0; i < hard.length; i++) {
map.put(new Object(), hard[i]);
}
gc();
assertTrue("map should be empty after purge of weak keys", map.isEmpty());
for (int i = 0; i < hard.length; i++) {
map.put(new Object(), hard[i]);
map.put(hard[i], new Object());
}
gc();
assertTrue("map should be empty after purge of weak keys and values", map.isEmpty());
}
public void testGetAfterGC() {
ReferenceIdentityMap map = new ReferenceIdentityMap(ReferenceIdentityMap.WEAK, ReferenceIdentityMap.WEAK);
for (int i = 0; i < 10; i++) {
map.put(Integer.valueOf(i), Integer.valueOf(i));
}
gc();
for (int i = 0; i < 10; i++) {
Integer I = Integer.valueOf(i);
assertTrue("map.containsKey should return false for GC'd element", !map.containsKey(I));
assertTrue("map.get should return null for GC'd element", map.get(I) == null);
}
}
public void testEntrySetIteratorAfterGC() {
ReferenceIdentityMap map = new ReferenceIdentityMap(ReferenceIdentityMap.WEAK, ReferenceIdentityMap.WEAK);
Object[] hard = new Object[10];
for (int i = 0; i < 10; i++) {
hard[i] = Integer.valueOf(10 + i);
map.put(Integer.valueOf(i), Integer.valueOf(i));
map.put(hard[i], hard[i]);
}
gc();
Iterator iterator = map.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry entry = (Map.Entry)iterator.next();
Integer key = (Integer)entry.getKey();
Integer value = (Integer)entry.getValue();
assertTrue("iterator should skip GC'd keys", key.intValue() >= 10);
assertTrue("iterator should skip GC'd values", value.intValue() >= 10);
}
}
public void testMapIteratorAfterGC() {
ReferenceIdentityMap map = new ReferenceIdentityMap(ReferenceIdentityMap.WEAK, ReferenceIdentityMap.WEAK);
Object[] hard = new Object[10];
for (int i = 0; i < 10; i++) {
hard[i] = Integer.valueOf(10 + i);
map.put(Integer.valueOf(i), Integer.valueOf(i));
map.put(hard[i], hard[i]);
}
gc();
MapIterator iterator = map.mapIterator();
while (iterator.hasNext()) {
Object key1 = iterator.next();
Integer key = (Integer) iterator.getKey();
Integer value = (Integer) iterator.getValue();
assertTrue("iterator keys should match", key == key1);
assertTrue("iterator should skip GC'd keys", key.intValue() >= 10);
assertTrue("iterator should skip GC'd values", value.intValue() >= 10);
}
}
public void testMapIteratorAfterGC2() {
ReferenceIdentityMap map = new ReferenceIdentityMap(ReferenceIdentityMap.WEAK, ReferenceIdentityMap.WEAK);
Object[] hard = new Object[10];
for (int i = 0; i < 10; i++) {
hard[i] = Integer.valueOf(10 + i);
map.put(Integer.valueOf(i), Integer.valueOf(i));
map.put(hard[i], hard[i]);
}
MapIterator iterator = map.mapIterator();
while (iterator.hasNext()) {
Object key1 = iterator.next();
gc();
Integer key = (Integer) iterator.getKey();
Integer value = (Integer) iterator.getValue();
assertTrue("iterator keys should match", key == key1);
assertTrue("iterator should skip GC'd keys", key.intValue() >= 10);
assertTrue("iterator should skip GC'd values", value.intValue() >= 10);
}
}
*/
WeakReference<K> keyReference;
WeakReference<V> valueReference;
@SuppressWarnings("unchecked")
private Map<K, V> buildRefMap() {
final K key = (K) new Object();
final V value = (V) new Object();
keyReference = new WeakReference<K>(key);
valueReference = new WeakReference<V>(value);
final Map<K, V> testMap = new ReferenceIdentityMap<K, V>(ReferenceStrength.WEAK, ReferenceStrength.HARD, true);
testMap.put(key, value);
assertEquals("In map", value, testMap.get(key));
assertNotNull("Weak reference released early (1)", keyReference.get());
assertNotNull("Weak reference released early (2)", valueReference.get());
return testMap;
}
/** Tests whether purge values setting works */
public void testPurgeValues() throws Exception {
// many thanks to Juozas Baliuka for suggesting this method
final Map<K, V> testMap = buildRefMap();
int iterations = 0;
int bytz = 2;
while (true) {
System.gc();
if (iterations++ > 50) {
fail("Max iterations reached before resource released.");
}
testMap.isEmpty();
if (
keyReference.get() == null &&
valueReference.get() == null) {
break;
} else {
// create garbage:
@SuppressWarnings("unused")
final byte[] b = new byte[bytz];
bytz = bytz * 2;
}
}
}
@SuppressWarnings("unused")
private static void gc() {
try {
// trigger GC
final byte[][] tooLarge = new byte[1000000000][1000000000];
fail("you have too much RAM");
} catch (final OutOfMemoryError ex) {
System.gc(); // ignore
}
}
}