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 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * 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 OpenSimulator Project 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 DEVELOPERS ``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 THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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 * 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.
 */

using System;
using System.Collections.Generic;
using System.Net;
using OpenSim.Framework;
using OpenMetaverse;
using BclExtras.Collections;

using ReaderWriterLockImpl = OpenMetaverse.ReaderWriterLockSlim;

namespace OpenSim.Region.ClientStack.LindenUDP
{
    public sealed class UDPClientCollection
    {
        #region IComparers

        private sealed class UUIDComparer : IComparer<UUID>
        {
            public int Compare(UUID x, UUID y)
            {
                return x.Guid.CompareTo(y.Guid);
            }
        }

        private sealed class IPEndPointComparer : IComparer<IPEndPoint>
        {
            public int Compare(IPEndPoint x, IPEndPoint y)
            {
                int result = x.Address.Address.CompareTo(y.Address.Address);
                if (result == 0) result = x.Port.CompareTo(y.Port);
                return result;
            }
        }

        #endregion IComparers

        private ImmutableMap<UUID, LLUDPClient> m_dict1;
        private ImmutableMap<IPEndPoint, LLUDPClient> m_dict2;
        private LLUDPClient[] m_array;

        public UDPClientCollection()
        {
            m_dict1 = new ImmutableMap<UUID, LLUDPClient>(new UUIDComparer());
            m_dict2 = new ImmutableMap<IPEndPoint, LLUDPClient>(new IPEndPointComparer());
            m_array = new LLUDPClient[0];
        }

        public void Add(UUID key1, IPEndPoint key2, LLUDPClient value)
        {
            m_dict1 = m_dict1.Add(key1, value);
            m_dict2 = m_dict2.Add(key2, value);

            // Copy the array by hand
            LLUDPClient[] oldArray = m_array;
            int oldLength = oldArray.Length;
            LLUDPClient[] newArray = new LLUDPClient[oldLength + 1];

            for (int i = 0; i < oldLength; i++)
                newArray[i] = oldArray[i];
            newArray[oldLength] = value;
            
            m_array = newArray;
        }

        public void Remove(UUID key1, IPEndPoint key2)
        {
            m_dict1 = m_dict1.Delete(key1);
            m_dict2 = m_dict2.Delete(key2);

            LLUDPClient[] oldArray = m_array;
            int oldLength = oldArray.Length;

            // Copy the array by hand

            LLUDPClient[] newArray = new LLUDPClient[oldLength - 1];
            int j = 0;

            for (int i = 0; i < oldLength; i++)
            {
                if (oldArray[i].AgentID != key1)
                    newArray[j++] = oldArray[i];
            }

            m_array = newArray;
        }

        public void Clear()
        {
            m_dict1 = new ImmutableMap<UUID, LLUDPClient>(new UUIDComparer());
            m_dict2 = new ImmutableMap<IPEndPoint, LLUDPClient>(new IPEndPointComparer());
            m_array = new LLUDPClient[0];
        }

        public int Count
        {
            get { return m_array.Length; }
        }

        public bool ContainsKey(UUID key)
        {
            return m_dict1.ContainsKey(key);
        }

        public bool ContainsKey(IPEndPoint key)
        {
            return m_dict2.ContainsKey(key);
        }

        public bool TryGetValue(UUID key, out LLUDPClient value)
        {
            return m_dict1.TryGetValue(key, out value);
        }

        public bool TryGetValue(IPEndPoint key, out LLUDPClient value)
        {
            return m_dict2.TryGetValue(key, out value);
        }

        public void ForEach(Action<LLUDPClient> action)
        {
            Parallel.ForEach<LLUDPClient>(m_array, action); 
        }
    }
}