MSMQWriter

using System.IO;
using System.Text;

namespace System.Messaging {
    /// <summary>
    /// MSMQ Writer, Can be used a trace writer
    /// </summary>
    public class MSMQWriter:TextWriter {
        /// <summary>
        /// Used to to purge all messages when token is found in dequeuing messages
        /// </summary>
        public const string PURGE_TOKEN = "[PURGE]";

        MessageQueue _msmq;
        bool _setup;
        public Exception SetupError { get; set; }
        readonly ActiveXMessageFormatter _formater;

        public bool IsAvailable { get; set; }
        public string MessageQueuePath { get; set; }

        public MSMQWriter()
            : this(null) {

            _formater = new ActiveXMessageFormatter();

        }
        public MSMQWriter(string msmqPath)
            : base() {
            this.MessageQueuePath = msmqPath ?? @".\private$\dbmon";
        }
        void SetupQueue() {
            try {
                if(_setup)
                    return;

                if(!MessageQueue.Exists(this.MessageQueuePath))
                    MessageQueue.Create(this.MessageQueuePath);

                _msmq = new MessageQueue();
                _msmq.Path = this.MessageQueuePath;
                _msmq.Formatter = _formater;
                IsAvailable = _msmq.CanWrite;
            }
            catch(Exception err) {
                SetupError = err;
                IsAvailable = false;
                throw;
            }
            finally {
                _setup = true;
            }
        }
        public override void Write(char[] buffer,int index,int count) {
            Send(new String(buffer,index,count));
        }
        public override void Write(string value) {
            Send(value);
        }
        public void Write(string value,MessagePriority priority) {
            Send(value,priority);
        }
        void Send(string value) {
            Send(value,MessagePriority.Normal);
        }

        void Send(string value,MessagePriority priority) {
            if(!_setup)
                SetupQueue();

            if(!IsAvailable) {
                return;
            }

            var message = new Message(value);
            message.Formatter = _formater;
            message.Priority = priority;
            _msmq.Send(message);
        }
        public void WritePurgeMessage() {
            if(!_setup)
                SetupQueue();

            if(!IsAvailable) {
                return;
            }

            string body = _msmq.Path + PURGE_TOKEN;
            var message = new Message(body);
            message.Formatter = _formater;
            message.Priority = MessagePriority.Highest;
            _msmq.Send(message);
        }
        public override Encoding Encoding {
            get { return Encoding.Default; }
        }
    }
}