package org.hibernate.internal.util.collections;
import java.util.Collection;
import java.util.IdentityHashMap;
import java.util.Iterator;
import java.util.Set;
public class IdentitySet implements Set {
private static final Object DUMP_VALUE = new Object();
private final IdentityHashMap map;
public IdentitySet() {
this.map = new IdentityHashMap();
}
public IdentitySet(int sizing) {
this.map = new IdentityHashMap( sizing );
}
public int size() {
return map.size();
}
public boolean isEmpty() {
return map.isEmpty();
}
public boolean contains(Object o) {
return map.get( o ) == DUMP_VALUE;
}
public Iterator iterator() {
return map.keySet().iterator();
}
public Object[] toArray() {
return map.keySet().toArray();
}
public Object[] toArray(Object[] a) {
return map.keySet().toArray( a );
}
public boolean add(Object o) {
return map.put( o, DUMP_VALUE ) == null;
}
public boolean remove(Object o) {
return map.remove( o ) == DUMP_VALUE;
}
public boolean containsAll(Collection c) {
Iterator it = c.iterator();
while ( it.hasNext() ) {
if ( !map.containsKey( it.next() ) ) {
return false;
}
}
return true;
}
public boolean addAll(Collection c) {
Iterator it = c.iterator();
boolean changed = false;
while ( it.hasNext() ) {
if ( this.add( it.next() ) ) {
changed = true;
}
}
return changed;
}
public boolean retainAll(Collection c) {
throw new UnsupportedOperationException();
}
public boolean removeAll(Collection c) {
Iterator it = c.iterator();
boolean changed = false;
while ( it.hasNext() ) {
if ( this.remove( it.next() ) ) {
changed = true;
}
}
return changed;
}
public void clear() {
map.clear();
}
}