DistributedFileSystem.DFS.IncomingChunkInterestReplyData C# (CSharp) Method

        private static void IncomingChunkInterestReplyData(PacketHeader packetHeader, Connection connection, byte[] incomingData)
        {
            try
            {
                if (DFS.loggingEnabled) DFS._DFSLogger.Trace("IncomingChunkInterestReplyData from " + connection + " containing " + incomingData.Length + " bytes.");

                if (connection.ConnectionInfo.ConnectionType != ConnectionType.TCP)
                    throw new Exception("IncomingChunkInterestReplyData should only be received using TCP.");

                ChunkAvailabilityReply existingChunkAvailabilityReply = null;

                try
                {
                    lock (chunkDataCacheLocker)
                    {
                        if (!chunkDataCache.ContainsKey(connection.ConnectionInfo.NetworkIdentifier))
                            chunkDataCache.Add(connection.ConnectionInfo.NetworkIdentifier, new Dictionary<string, ChunkDataWrapper>());

                        if (!packetHeader.ContainsOption(PacketHeaderLongItems.PacketSequenceNumber))
                            throw new Exception("The dataSequenceNumber option appears to missing from the packetHeader. What has been changed?");

                        string packetIdentifier = packetHeader.PacketIdentifier;
                        if (packetIdentifier == null) throw new ArgumentException("The packetHeader.PacketIdentifier should not be null.");

                        //If we already have the info then we can finish this chunk off
                        if (chunkDataCache[connection.ConnectionInfo.NetworkIdentifier].ContainsKey(packetIdentifier))
                        {
                            if (chunkDataCache[connection.ConnectionInfo.NetworkIdentifier][packetIdentifier] == null)
                                throw new Exception("An entry existed for the desired dataSequenceNumber but the entry was null.");
                            else if (chunkDataCache[connection.ConnectionInfo.NetworkIdentifier][packetIdentifier].ChunkAvailabilityReply == null)
                                throw new Exception("An entry existed for the desired ChunkAvailabilityReply but the entry was null."+
                                    " This exception can be thrown if the 'IncomingChunkInterestReplyData' packet handler has been added more than once.");

                            //The info beat the data so we handle it here
                            existingChunkAvailabilityReply = chunkDataCache[connection.ConnectionInfo.NetworkIdentifier][packetIdentifier].ChunkAvailabilityReply;
                            existingChunkAvailabilityReply.SetChunkData(incomingData);

                            chunkDataCache[connection.ConnectionInfo.NetworkIdentifier].Remove(packetIdentifier);

                            if (chunkDataCache[connection.ConnectionInfo.NetworkIdentifier].Count == 0)
                                chunkDataCache.Remove(connection.ConnectionInfo.NetworkIdentifier);
                        }
                        else
                        {
                            //If we don't have the info we just need to log the data
                            chunkDataCache[connection.ConnectionInfo.NetworkIdentifier].Add(packetIdentifier, new ChunkDataWrapper(packetIdentifier, incomingData));
                            if (DFS.loggingEnabled) DFS._DFSLogger.Trace("Added ChunkData to chunkDataCache from " + connection + ", packet identifier:" + packetIdentifier + " , containing " + incomingData.Length + " bytes.");
                        }
                    }

                    //Only true if we have both the data and info
                    if (existingChunkAvailabilityReply != null)
                    {
                        existingChunkAvailabilityReply.SetSourceConnectionInfo(connection.ConnectionInfo);

                        DistributedItem item = null;
                        lock (globalDFSLocker)
                        {
                            if (swarmedItemsDict.ContainsKey(existingChunkAvailabilityReply.ItemCheckSum))
                                item = swarmedItemsDict[existingChunkAvailabilityReply.ItemCheckSum];
                        }

                        if (item != null)
                            item.HandleIncomingChunkReply(existingChunkAvailabilityReply);
                    }
                }
                catch (Exception ex)
                {
                    LogTools.LogException(ex, "Error_IncomingChunkInterestReplyDataInner");
                }

                CheckForChunkDataCacheTimeouts();
            }
            catch (Exception e)
            {
                LogTools.LogException(e, "Error_IncomingChunkInterestReplyData");
            }
        }