NServiceBus.MsmqFailureInfoStorage.RecordFailureInfoForMessage C# (CSharp) Method

        public void RecordFailureInfoForMessage(string messageId, Exception exception)
        {
            lock (lockObject)
            {
                FailureInfoNode node;
                if (failureInfoPerMessage.TryGetValue(messageId, out node))
                {
                    // We have seen this message before, just update the counter and store exception.
                    node.FailureInfo = new ProcessingFailureInfo(node.FailureInfo.NumberOfProcessingAttempts + 1, ExceptionDispatchInfo.Capture(exception));

                    // Maintain invariant: leastRecentlyUsedMessages.First contains the LRU item.
                    leastRecentlyUsedMessages.Remove(node.LeastRecentlyUsedEntry);
                    leastRecentlyUsedMessages.AddLast(node.LeastRecentlyUsedEntry);
                }
                else
                {
                    if (failureInfoPerMessage.Count == maxElements)
                    {
                        // We have reached the maximum allowed capacity. Remove the LRU item.
                        var leastRecentlyUsedEntry = leastRecentlyUsedMessages.First;
                        failureInfoPerMessage.Remove(leastRecentlyUsedEntry.Value);
                        leastRecentlyUsedMessages.RemoveFirst();
                    }

                    var newNode = new FailureInfoNode(
                        messageId,
                        new ProcessingFailureInfo(1, ExceptionDispatchInfo.Capture(exception)));

                    failureInfoPerMessage[messageId] = newNode;

                    // Maintain invariant: leastRecentlyUsedMessages.First contains the LRU item.
                    leastRecentlyUsedMessages.AddLast(newNode.LeastRecentlyUsedEntry);
                }
            }
        }