Containers/TreeSet.cs

/* $Id$
 *
 * OpenMAMA: The open middleware agnostic messaging API
 * Copyright (C) 2011 NYSE Technologies, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

using System;

namespace Wombat.Containers
{
    // implemented on top of TreeMap
    public class TreeSet : SortedSet, ICloneable
    {
        private TreeSet(SortedMap m)
        {
            mSortedMap = m;
            mKeySet = m.keySet();
        }

        public TreeSet() : this(new TreeMap())
        {
        }

        public TreeSet(Comparator c) : this(new TreeMap(c))
        {
        }

        public TreeSet(Collection c) : this()
        {
            addAll(c);
        }

        public TreeSet(SortedSet s) : this(s.comparator())
        {
            addAll(s);
        }

        #region SortedSet Members

        public Comparator comparator()
        {
            return mSortedMap.comparator();
        }

        public SortedSet subSet(object from, object to)
        {
            return new TreeSet(mSortedMap.subMap(from, to));
        }

        public SortedSet headSet(object to)
        {
            return new TreeSet(mSortedMap.headMap(to));
        }

        public SortedSet tailSet(object from)
        {
            return new TreeSet(mSortedMap.tailMap(from));
        }

        public object first()
        {
            return mSortedMap.firstKey();
        }

        public object last()
        {
            return mSortedMap.lastKey();
        }

        #endregion

        #region Collection Members

        public int size()
        {
            return mSortedMap.size();
        }

        public bool isEmpty()
        {
            return mSortedMap.isEmpty();
        }

        public bool contains(object o)
        {
            return mSortedMap.containsKey(o);
        }

        public object[] toArray()
        {
            return mKeySet.toArray();
        }

        public bool add(object o)
        {
            return mSortedMap.put(o, PRESENT) == null;
        }

        public bool remove(object o)
        {
            return mSortedMap.remove(o) == PRESENT;
        }

        public bool containsAll(Collection c)
        {
            Iterator i = c.iterator();
            while (i.hasNext())
            {
                object o = i.next();
                if (!contains(o))
                    return false;
            }
            return true;
        }

        public bool addAll(Collection c)
        {
            int count = size();
            Iterator i = c.iterator();
            while (i.hasNext())
            {
                object o = i.next();
                add(o);
            }
            return count != size();
        }

        public bool removeAll(Collection c)
        {
            int count = size();
            Iterator i = c.iterator();
            while (i.hasNext())
            {
                object o = i.next();
                remove(o);
            }
            return count != size();
        }

        public bool retainAll(Collection c)
        {
            int count = size();
            Iterator i = c.iterator();
            while (i.hasNext())
            {
                object o = i.next();
                if (!contains(o))
                    add(o);
                else
                    remove(o);
            }
            return count != size();
        }

        public void clear()
        {
            mSortedMap.clear();
        }

        #endregion

        #region Iterable Members

        public Iterator iterator()
        {
            return mKeySet.iterator();
        }

        #endregion

        #region ICloneable Members

        public object Clone()
        {
            // the cast to Map is necessary, otherwise TreeMap will just
            // get backed by the original map, instead of copying it
            TreeSet copy = new TreeSet(new TreeMap((Map)mSortedMap));
            return copy;
        }

        #endregion

        private SortedMap mSortedMap;
        private Set mKeySet;
        private static readonly object PRESENT = new object();
    }
}