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/**
 * Copyright 2010 JogAmp Community. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 *
 *    2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``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 JogAmp Community 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.
 *
 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied, of JogAmp Community.
 */

package com.jogamp.common.util;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;

/**
 * Hashed ArrayList implementation of the List and Collection interface.
 *
 * Implementation properties are:
 *  
    *
  • Unique elements utilizing {@link java.lang.Object#hashCode()} for O(1) operations, see below.
  • *
  • Provides {@link java.util.List} functionality, * ie {@link java.util.List#indexOf(java.lang.Object)} * and {@link java.util.List#get(int)}, hence object identity can be implemented.
  • *
  • Object identity via {@link #get(java.lang.Object)}
  • *
  • Java 1.5 compatible
  • *
* * O(1) operations: *
    *
  • adding new element(s)
  • *
  • test for containment
  • *
  • identity
  • *
  • trying to remove non existent elements
  • *
* * O(n) operations: *
    *
  • removing existing elements
  • *
* * For thread safety, the application shall decorate access to instances via * {@link com.jogamp.common.util.locks.RecursiveLock}. * */ public class ArrayHashSet implements Cloneable, Collection, List { private final HashMap map; // object -> object private final ArrayList data; // list of objects public ArrayHashSet() { map = new HashMap(); data = new ArrayList(); } public ArrayHashSet(final int initialCapacity) { map = new HashMap(initialCapacity); data = new ArrayList(initialCapacity); } public ArrayHashSet(final int initialCapacity, final float loadFactor) { map = new HashMap(initialCapacity, loadFactor); data = new ArrayList(initialCapacity); } // // Cloneable // /** * @return a shallow copy of this ArrayHashSet, elements are not copied. */ @Override public final Object clone() { final ArrayList clonedList = new ArrayList(data); final ArrayHashSet newObj = new ArrayHashSet(); newObj.addAll(clonedList); return newObj; } /** Returns this object ordered ArrayList. Use w/ care, it's not a copy. */ public final ArrayList getData() { return data; } /** Returns this object hash map. Use w/ care, it's not a copy. */ public final HashMap getMap() { return map; } @Override public final String toString() { return data.toString(); } // // Collection // @Override public final void clear() { data.clear(); map.clear(); } /** * Add element at the end of this list, if it is not contained yet. *
* This is an O(1) operation * * @return true if the element was added to this list, * otherwise false (already contained). */ @Override public final boolean add(final E element) { final boolean exists = map.containsKey(element); if(!exists) { if(null != map.put(element, element)) { throw new InternalError("Already existing, but checked before: "+element); } if(!data.add(element)) { throw new InternalError("Couldn't add element: "+element); } } return !exists; } /** * Remove element from this list. *
* This is an O(1) operation, in case it does not exist, * otherwise O(n). * * @return true if the element was removed from this list, * otherwise false (not contained). */ @Override public final boolean remove(final Object element) { if ( null != map.remove(element) ) { if ( ! data.remove(element) ) { throw new InternalError("Couldn't remove prev mapped element: "+element); } return true; } return false; } /** * Add all elements of given {@link java.util.Collection} at the end of this list. *
* This is an O(n) operation, over the given Collection size. * * @return true if at least one element was added to this list, * otherwise false (completely container). */ @Override public final boolean addAll(final Collection c) { boolean mod = false; for (final E o : c) { mod |= add(o); } return mod; } /** * Test for containment *
* This is an O(1) operation. * * @return true if the given element is contained by this list using fast hash map, * otherwise false. */ @Override public final boolean contains(final Object element) { return map.containsKey(element); } /** * Test for containment of given {@link java.util.Collection} *
* This is an O(n) operation, over the given Collection size. * * @return true if the given Collection is completly contained by this list using hash map, * otherwise false. */ @Override public final boolean containsAll(final Collection c) { for (final Object o : c) { if (!this.contains(o)) { return false; } } return true; } /** * Remove all elements of given {@link java.util.Collection} from this list. *
* This is an O(n) operation. * * @return true if at least one element of this list was removed, * otherwise false. */ @Override public final boolean removeAll(final Collection c) { boolean mod = false; for (final Object o : c) { mod |= this.remove(o); } return mod; } /** * Retain all elements of the given {@link java.util.Collection} c, ie * remove all elements not contained by the given {@link java.util.Collection} c. *
* This is an O(n) operation. * * @return true if at least one element of this list was removed, * otherwise false. */ @Override public final boolean retainAll(final Collection c) { boolean mod = false; for (final Object o : c) { if (!c.contains(o)) { mod |= this.remove(o); } } return mod; } /** * This is an O(n) operation. * * @return true if arrayHashSet is of type ArrayHashSet and all entries are equal * Performance: arrayHashSet(1) */ @Override public final boolean equals(final Object arrayHashSet) { if ( !(arrayHashSet instanceof ArrayHashSet) ) { return false; } return data.equals(((ArrayHashSet)arrayHashSet).data); } /** * This is an O(n) operation over the size of this list. * * @return the hash code of this list as define in {@link java.util.List#hashCode()}, * ie hashing all elements of this list. */ @Override public final int hashCode() { return data.hashCode(); } @Override public final boolean isEmpty() { return data.isEmpty(); } @Override public final Iterator iterator() { return data.iterator(); } @Override public final int size() { return data.size(); } @Override public final Object[] toArray() { return data.toArray(); } @Override public final T[] toArray(final T[] a) { return data.toArray(a); } // // List // @Override public final E get(final int index) { return data.get(index); } @Override public final int indexOf(final Object element) { return data.indexOf(element); } /** * Add element at the given index in this list, if it is not contained yet. *
* This is an O(1) operation * * @throws IllegalArgumentException if the given element was already contained */ @Override public final void add(final int index, final E element) { if ( map.containsKey(element) ) { throw new IllegalArgumentException("Element "+element+" is already contained"); } if(null != map.put(element, element)) { throw new InternalError("Already existing, but checked before: "+element); } data.add(index, element); } /** * @throws UnsupportedOperationException */ @Override public final boolean addAll(final int index, final Collection c) { throw new UnsupportedOperationException("Not supported yet."); } /** * @throws UnsupportedOperationException */ @Override public final E set(final int index, final E element) { final E old = remove(index); if(null!=old) { add(index, element); } return old; } /** * Remove element at given index from this list. *
* This is an O(n) operation. * * @return the removed object */ @Override public final E remove(final int index) { final E o = get(index); if( null!=o && remove(o) ) { return o; } return null; } /** * Since this list is unique, equivalent to {@link #indexOf(java.lang.Object)}. *
* This is an O(n) operation. * * @return index of element, or -1 if not found */ @Override public final int lastIndexOf(final Object o) { return indexOf(o); } @Override public final ListIterator listIterator() { return data.listIterator(); } @Override public final ListIterator listIterator(final int index) { return data.listIterator(index); } @Override public final List subList(final int fromIndex, final int toIndex) { return data.subList(fromIndex, toIndex); } // // ArrayHashSet // /** * @return a shallow copy of this ArrayHashSet's ArrayList, elements are not copied. */ public final ArrayList toArrayList() { return new ArrayList(data); } /** * Identity method allowing to get the identical object, using the internal hash map. *
* This is an O(1) operation. * * @param key hash source to find the identical Object within this list * @return object from this list, identical to the given key hash code, * or null if not contained */ public final E get(final Object key) { return map.get(key); } /** * Identity method allowing to get the identical object, using the internal hash map.
* If the key is not yet contained, add it. *
* This is an O(1) operation. * * @param key hash source to find the identical Object within this list * @return object from this list, identical to the given key hash code, * or add the given key and return it. */ public final E getOrAdd(final E key) { final E identity = get(key); if(null == identity) { // object not contained yet, add it if(!this.add(key)) { throw new InternalError("Key not mapped, but contained in list: "+key); } return key; } return identity; } /** * Test for containment *
* This is an O(n) operation, using equals operation over the list. *
* You may utilize this method to verify your hash values,
* ie {@link #contains(java.lang.Object)} and {@link #containsSafe(java.lang.Object)} * shall have the same result.
* * @return true if the given element is contained by this list using slow equals operation, * otherwise false. */ public final boolean containsSafe(final Object element) { return data.contains(element); } }




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