1 files changed, 160 insertions, 0 deletions

diff --git a/OpenSim/Region/ClientStack/LindenUDP/UnackedPacketCollection.cs b/OpenSim/Region/ClientStack/LindenUDP/UnackedPacketCollection.cs
new file mode 100644
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+++ b/OpenSim/Region/ClientStack/LindenUDP/UnackedPacketCollection.cs
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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
+ * (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.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Net;
+using OpenMetaverse;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+    /// <summary>
+    /// Special collection that is optimized for tracking unacknowledged packets
+    /// </summary>
+    public sealed class UnackedPacketCollection
+    {
+        /// <summary>Synchronization primitive. A lock must be acquired on this
+        /// object before calling any of the unsafe methods</summary>
+        public object SyncRoot = new object();
+
+        /// <summary>Holds the actual unacked packet data, sorted by sequence number</summary>
+        private SortedDictionary<uint, OutgoingPacket> packets = new SortedDictionary<uint, OutgoingPacket>();
+
+        /// <summary>Gets the total number of unacked packets</summary>
+        public int Count { get { return packets.Count; } }
+
+        /// <summary>
+        /// Default constructor
+        /// </summary>
+        public UnackedPacketCollection()
+        {
+        }
+
+        /// <summary>
+        /// Add an unacked packet to the collection
+        /// </summary>
+        /// <param name="packet">Packet that is awaiting acknowledgement</param>
+        /// <returns>True if the packet was successfully added, false if the
+        /// packet already existed in the collection</returns>
+        public bool Add(OutgoingPacket packet)
+        {
+            lock (SyncRoot)
+            {
+                if (!packets.ContainsKey(packet.SequenceNumber))
+                {
+                    packets.Add(packet.SequenceNumber, packet);
+                    return true;
+                }
+                return false;
+            }
+        }
+
+        /// <summary>
+        /// Removes a packet from the collection without attempting to obtain a
+        /// lock first
+        /// </summary>
+        /// <param name="sequenceNumber">Sequence number of the packet to remove</param>
+        /// <returns>True if the packet was found and removed, otherwise false</returns>
+        public bool RemoveUnsafe(uint sequenceNumber)
+        {
+            return packets.Remove(sequenceNumber);
+        }
+
+        /// <summary>
+        /// Removes a packet from the collection without attempting to obtain a
+        /// lock first
+        /// </summary>
+        /// <param name="sequenceNumber">Sequence number of the packet to remove</param>
+        /// <param name="packet">Returns the removed packet</param>
+        /// <returns>True if the packet was found and removed, otherwise false</returns>
+        public bool RemoveUnsafe(uint sequenceNumber, out OutgoingPacket packet)
+        {
+            if (packets.TryGetValue(sequenceNumber, out packet))
+            {
+                packets.Remove(sequenceNumber);
+                return true;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Gets the packet with the lowest sequence number
+        /// </summary>
+        /// <returns>The packet with the lowest sequence number, or null if the
+        /// collection is empty</returns>
+        public OutgoingPacket GetOldest()
+        {
+            lock (SyncRoot)
+            {
+                using (SortedDictionary<uint, OutgoingPacket>.ValueCollection.Enumerator e = packets.Values.GetEnumerator())
+                {
+                    if (e.MoveNext())
+                        return e.Current;
+                    else
+                        return null;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Returns a list of all of the packets with a TickCount older than
+        /// the specified timeout
+        /// </summary>
+        /// <param name="timeoutMS">Number of ticks (milliseconds) before a
+        /// packet is considered expired</param>
+        /// <returns>A list of all expired packets according to the given
+        /// expiration timeout</returns>
+        public List<OutgoingPacket> GetExpiredPackets(int timeoutMS)
+        {
+            List<OutgoingPacket> expiredPackets = null;
+
+            lock (SyncRoot)
+            {
+                int now = Environment.TickCount;
+                foreach (OutgoingPacket packet in packets.Values)
+                {
+                    if (packet.TickCount == 0)
+                        continue;
+
+                    if (now - packet.TickCount >= timeoutMS)
+                    {
+                        if (expiredPackets == null)
+                            expiredPackets = new List<OutgoingPacket>();
+                        expiredPackets.Add(packet);
+                    }
+                    else
+                    {
+                        break;
+                    }
+                }
+            }
+
+            return expiredPackets;
+        }
+    }
+}