public void remove() {
if (lastReturned == null) {
throw new IllegalStateException();
}
if (modCount != expectedModCount) {
throw new ConcurrentModificationException();
}
WeakEntry[] copyOfEntries = IdentityWeakHashMap.this.entries;
int index = (lastReturned.hash & 0x7FFFFFFF) % copyOfEntries.length;
for (WeakEntry e = copyOfEntries[index], prev = null; e != null; prev = e, e = e.next) {
if (e == lastReturned) {
modCount++;
expectedModCount++;
if (prev == null) {
copyOfEntries[index] = e.next;
} else {
prev.next = e.next;
}
count--;
lastReturned = null;
return;
}
}
throw new ConcurrentModificationException();
}
protected boolean removeEntry(WeakEntry o, boolean userModification) {
WeakEntry[] copyOfEntries = entries;
int index = (o.hash & 0x7FFFFFFF) % copyOfEntries.length;
for (WeakEntry e = copyOfEntries[index], prev = null; e != null; prev = e, e = e.next) {
if (e == o) {
// if this method was called as a result of a user action,
// increment the modification count
// this method is also called by our cleanup code and
// that code should not cause a concurrent modification
// exception
if (userModification) {
modCount++;
}
if (prev != null) {
prev.next = e.next;
} else {
copyOfEntries[index] = e.next;
}
count--;
e.value = null;
e.next = null;
return true;
}
}
return false;
}
/**
* Associate the given object with the given key in this <tt>IdentityWeakHashMap</tt>, replacing
* any existing mapping.
*
* @param key key to map to given object.
* @param obj object to be associated with key.
* @return the previous object for key or <tt>null</tt> if this <tt>IdentityWeakHashMap</tt> did
* not have one.
* @throws <tt>NullPointerException</tt> if obj is null</tt>.
*/
public V put(K key, V obj) {
if (obj == null || key == null) {
throw new IllegalArgumentException(
ExceptionLocalization.buildMessage("null_not_supported_identityweakhashmap"));
}
cleanUp();
WeakEntry[] copyOfEntries = entries;
int hash = System.identityHashCode(key);
int index = (hash & 0x7FFFFFFF) % copyOfEntries.length;
for (WeakEntry e = copyOfEntries[index]; e != null; e = e.next) {
if (e.key.get() == key) {
EntryReference<V> old = e.value;
if (key == obj) {
e.value = e.key;
} else {
e.value = new HardEntryReference<V>(obj);
}
return old.get();
}
}
modCount++;
if (count >= threshold) {
rehash();
copyOfEntries = entries;
index = (hash & 0x7FFFFFFF) % copyOfEntries.length;
}
WeakEntry<K, V> e = new WeakEntry<K, V>(hash, key, obj, copyOfEntries[index], referenceQueue);
copyOfEntries[index] = e;
count++;
return null;
}
/**
* INTERNAL: Re-builds the internal array of Entry's with a larger capacity. This method is called
* automatically when the number of objects in this IdentityWeakHashMap exceeds its current
* threshold.
*/
private void rehash() {
int oldCapacity = entries.length;
WeakEntry[] oldEntries = entries;
int newCapacity = (oldCapacity * 2) + 1;
WeakEntry[] newEntries = new WeakEntry[newCapacity];
modCount++;
threshold = (int) (newCapacity * loadFactor);
entries = newEntries;
for (int i = oldCapacity; i-- > 0; ) {
for (WeakEntry old = oldEntries[i]; old != null; ) {
WeakEntry e = old;
old = old.next;
int index = (e.hash & 0x7FFFFFFF) % newCapacity;
e.next = newEntries[index];
newEntries[index] = e;
}
}
}
/**
* Removes the mapping (key and its corresponding value) from this <tt>IdentityWeakHashMap</tt>,
* if present.
*
* @param key key whose mapping is to be removed from the map.
* @return the previous object for key or <tt>null</tt> if this <tt>IdentityWeakHashMap</tt> did
* not have one.
*/
public V remove(Object key) {
if (key == null) return null;
cleanUp();
WeakEntry[] copyOfEntries = entries;
int hash = System.identityHashCode(key);
int index = (hash & 0x7FFFFFFF) % copyOfEntries.length;
for (WeakEntry e = copyOfEntries[index], prev = null; e != null; prev = e, e = e.next) {
if (e.key.get() == key) {
if (prev != null) {
prev.next = e.next;
} else {
copyOfEntries[index] = e.next;
}
count--;
return (V) e.value.get();
}
}
return null;
}
protected Object clone(ReferenceQueue refQueue) {
WeakEntry current = this;
WeakEntry root =
new WeakEntry(current.hash, current.key.get(), current.value.get(), null, refQueue);
WeakEntry currentClone = root;
while (current.next != null) {
currentClone.next =
new WeakEntry(
current.next.hash,
current.next.key.get(),
current.next.value.get(),
null,
refQueue);
current = current.next;
currentClone = currentClone.next;
}
return root;
}
