public static async Task PublishMessage(Message message, IPrincipal principal, IModel channel,
QueueName queueName, string exchange = "", Encoding encoding = null, int attempts = 0)
{
if (message == null) throw new ArgumentNullException("message");
if (channel == null) throw new ArgumentNullException("channel");
if (encoding == null)
{
encoding = Encoding.UTF8;
}
var senderPrincipal = principal as SenderPrincipal;
if (senderPrincipal == null && principal != null)
{
senderPrincipal = new SenderPrincipal(principal);
}
using (var stringWriter = new StringWriter())
using (var messageWriter = new MessageWriter(stringWriter))
{
await messageWriter.WritePrincipal(senderPrincipal);
await messageWriter.WriteMessage(message);
var messageBody = stringWriter.ToString();
var properties = channel.CreateBasicProperties();
properties.SetPersistent(true);
properties.ContentEncoding = Encoding.UTF8.HeaderName;
properties.ContentType = message.Headers.ContentType;
properties.MessageId = message.Headers.MessageId.ToString();
properties.CorrelationId = message.Headers.RelatedTo.ToString();
var headers = properties.Headers;
if (headers == null)
{
headers = new Dictionary<string, object>();
properties.Headers = headers;
}
headers["x-platibus-attempts"] = attempts;
var body = encoding.GetBytes(messageBody);
var ex = exchange ?? "";
var q = (string) queueName ?? "";
channel.BasicPublish(ex, q, properties, body);
}
}
private async Task HandleMessageImmediately(Message message, SenderPrincipal senderPrincipal, bool isReply)
{
var messageContext = new BusMessageContext(this, message.Headers, senderPrincipal);
var handlers = _handlingRules
.Where(r => r.Specification.IsSatisfiedBy(message))
.Select(rule => rule.MessageHandler)
.ToList();
if (!handlers.Any() && isReply)
{
// TODO: Figure out what to do here.
return;
}
await MessageHandler.HandleMessage(_messageNamingService, _serializationService,
handlers, message, messageContext, _cancellationTokenSource.Token);
if (!messageContext.MessageAcknowledged)
{
throw new MessageNotAcknowledgedException();
}
}
protected virtual string SerializePrincipal(IPrincipal principal)
{
if (principal == null) return null;
var senderPrincipal = new SenderPrincipal(principal);
using (var memoryStream = new MemoryStream())
{
var formatter = new BinaryFormatter();
formatter.Serialize(memoryStream, senderPrincipal);
var base64String = Convert.ToBase64String(memoryStream.GetBuffer());
return base64String;
}
}
/// <summary>
/// Called by the host when a new message arrives to handle the message
/// </summary>
/// <param name="message">The new message</param>
/// <param name="principal">The sender principal</param>
/// <returns>Returns a task that completes when message handling is complete</returns>
public async Task HandleMessage(Message message, IPrincipal principal)
{
if (_messageJournalingService != null)
{
await _messageJournalingService.MessageReceived(message);
}
// Make sure that the principal is serializable before enqueuing
var senderPrincipal = principal as SenderPrincipal;
if (senderPrincipal == null && principal != null)
{
senderPrincipal = new SenderPrincipal(principal);
}
var tasks = new List<Task>();
var relatedToMessageId = message.Headers.RelatedTo;
var isReply = relatedToMessageId != default(MessageId);
if (isReply)
{
tasks.Add(NotifyReplyReceived(message));
}
var importance = message.Headers.Importance;
if (importance.RequiresQueueing)
{
// Message expiration handled in MessageHandlingListener
tasks.AddRange(_handlingRules
.Where(r => r.Specification.IsSatisfiedBy(message))
.Select(rule => rule.QueueName)
.Distinct()
.Select(q => _messageQueueingService.EnqueueMessage(q, message, senderPrincipal)));
}
else
{
tasks.Add(HandleMessageImmediately(message, senderPrincipal, isReply));
}
await Task.WhenAll(tasks);
}
