Updates to for Halcyon compatibility

- OutgoingPacket moved back to OpenMetaverse scope (separate file) from
NetworkManager, and now restores the pool- and refcount-related
functionality.
- UDPPacketBuffer BufferSize is a constant so now DEFAULT_BUFFER_SIZE.
- Added a Halcyon-compatible UDPPacketBuffer constructor that accepts a
specific buffer, etc.
- Added CopyFrom methods to assign UDPPacketBuffer Data.

OpenMetaverse/ObjectPool.cs

@@ -9,7 +9,7 @@ namespace OpenMetaverse
     public class UDPPacketBuffer
     {
         /// <summary>Size of the byte array used to store raw packet data</summary>
-        public const int BufferSize = 4096;
+        public const int DEFAULT_BUFFER_SIZE = 4096;
         /// <summary>Raw packet data buffer</summary>
         public readonly byte[] Data;
         /// <summary>Length of the data to transmit</summary>
@@ -26,7 +26,7 @@ namespace OpenMetaverse
         /// </summary>
         public UDPPacketBuffer()
         {
-            Data = new byte[BufferSize];
+            Data = new byte[DEFAULT_BUFFER_SIZE];
             // Will be modified later by BeginReceiveFrom()
             RemoteEndPoint = new IPEndPoint(Settings.BIND_ADDR, 0);
         }
@@ -37,7 +37,7 @@ namespace OpenMetaverse
         /// <param name="endPoint">EndPoint of the remote host</param>
         public UDPPacketBuffer(IPEndPoint endPoint)
         {
-            Data = new byte[BufferSize];
+            Data = new byte[DEFAULT_BUFFER_SIZE];
             RemoteEndPoint = endPoint;
         }
 
@@ -52,6 +52,40 @@ namespace OpenMetaverse
             RemoteEndPoint = endPoint;
         }
 
+        /// <summary>
+        /// Create an allocated UDP packet buffer for sending a packet
+        /// </summary>
+        public UDPPacketBuffer(byte[] buffer, int bufferSize, IPEndPoint destination, int category, bool fromBufferPool)
+        {
+            Data = new byte[bufferSize];
+            this.CopyFrom(buffer, bufferSize);
+            DataLength = bufferSize;
+
+            RemoteEndPoint = destination;
+            BytesLeasedFromPool = fromBufferPool;
+        }
+
+        /// <summary>
+        /// Create an allocated UDP packet buffer for sending a packet
+        /// </summary>
+        /// <param name="endPoint">EndPoint of the remote host</param>
+        /// <param name="data">The actual buffer to use for packet data (no allocation).</param>
+        public UDPPacketBuffer(IPEndPoint endPoint, byte[] data)
+        {
+            Data = data;
+            RemoteEndPoint = endPoint;
+        }
+
+        public void CopyFrom(Array src, int length)
+        {
+            Buffer.BlockCopy(src, 0, this.Data, 0, length);
+        }
+
+        public void CopyFrom(Array src)
+        {
+            this.CopyFrom(src, src.Length);
+        }
+
         public void ResetEndpoint()
         {
             RemoteEndPoint = new IPEndPoint(Settings.BIND_ADDR, 0);