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HSQLDB - Lightweight 100% Java SQL Database Engine
/* Copyright (c) 2001-2021, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.hsqldb.lib;
import org.hsqldb.map.BaseHashMap;
/**
* This class does not store null keys.
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 2.6.0
* @since 1.7.2
*/
public class HashSet extends BaseHashMap implements Set {
public HashSet() {
this(8);
}
public HashSet(int initialCapacity) throws IllegalArgumentException {
super(initialCapacity, BaseHashMap.objectKeyOrValue,
BaseHashMap.noKeyOrValue, false);
}
public HashSet(int initialCapacity,
ObjectComparator comparator)
throws IllegalArgumentException {
this(initialCapacity);
this.comparator = comparator;
}
public boolean contains(Object key) {
return super.containsKey(key);
}
public boolean containsAll(Collection col) {
Iterator it = col.iterator();
while (it.hasNext()) {
if (contains(it.next())) {
continue;
}
return false;
}
return true;
}
public E getOrAdd(E key) {
if (key == null) {
throw new NullPointerException();
}
E value = get(key);
if (value == null) {
value = key;
add(key);
}
return value;
}
public E get(E key) {
if (key == null) {
throw new NullPointerException();
}
int lookup = getLookup(key);
if (lookup < 0) {
return null;
} else {
return (E) objectKeyTable[lookup];
}
}
/**
* returns true if element is added
*
* @param key the element
* @return true if added
*/
public boolean add(E key) {
if (key == null) {
throw new NullPointerException();
}
return (Boolean) super.addOrUpdate(0, 0, key, null);
}
/** returns true if any element is added
*
* @param c the Collection to add
* @return true if any element is added
*/
public boolean addAll(Collection c) {
boolean changed = false;
Iterator it = c.iterator();
while (it.hasNext()) {
changed |= add(it.next());
}
return changed;
}
/** returns true if any element is added
*
* @param keys the array of elements to add
* @return true if any element is added
*/
public boolean addAll(E[] keys) {
boolean changed = false;
for (int i = 0; i < keys.length; i++) {
changed |= add(keys[i]);
}
return changed;
}
/**
* returns true if any added
*
* @param keys array of keys to add
* @param start first index to add
* @param limit limit of index to add
* @return true if any element was added
*/
public boolean addAll(E[] keys, int start, int limit) {
boolean changed = false;
for (int i = start; i < keys.length && i < limit; i++) {
changed |= add(keys[i]);
}
return changed;
}
/**
* returns true if removed
*
* @param key Object to remove
* @return true if removed
*/
public boolean remove(Object key) {
if (key == null) {
throw new NullPointerException();
}
return (Boolean) super.remove(0, 0, key, null, false, false);
}
/**
* returns true if all were removed
*
* @param c Collection of elements to remove
* @return true if all removed
*/
public boolean removeAll(Collection c) {
Iterator it = c.iterator();
boolean result = true;
while (it.hasNext()) {
result &= remove(it.next());
}
return result;
}
public boolean retainAll(Collection c) {
boolean changed = false;
Iterator it = iterator();
while (it.hasNext()) {
if (!c.contains(it.next())) {
it.remove();
changed = true;
}
}
return changed;
}
/**
* returns true if all were removed
*
* @param keys E[]
* @return boolean
*/
public boolean removeAll(E[] keys) {
boolean result = true;
for (int i = 0; i < keys.length; i++) {
result &= remove(keys[i]);
}
return result;
}
public int getCommonElementCount(Set other) {
int count = 0;
Iterator it = iterator();
while (it.hasNext()) {
if (other.contains(it.next())) {
count++;
}
}
return count;
}
public T[] toArray(T[] a) {
return toArray(a, true);
}
public Object[] toArray() {
return toArray(true);
}
public Iterator iterator() {
return new BaseHashIterator(true);
}
/**
* Returns a String like "[Drei, zwei, Eins]", exactly like
* java.util.HashSet.
*
* @return String representation
*/
public String toString() {
Iterator it = iterator();
StringBuilder sb = new StringBuilder();
while (it.hasNext()) {
if (sb.length() > 0) {
sb.append(", ");
} else {
sb.append('[');
}
sb.append(it.next());
}
return sb.toString() + ']';
}
}
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