/// <summary>
/// Creates a channel for the purpose of consuming messages
/// </summary>
/// <typeparam name="T">The type of message to consume</typeparam>
/// <param name="exchange">The associated RabbitMQ exchange</param>
/// <param name="queue">The associated RabbitMQ queue</param>
/// <param name="autoDelete">True if the underlying queue should be deleted when the channel is closed</param>
/// <param name="exclusive">True if the underlying queue should only be accessible from the new channel</param>
/// <returns>The opened consumer channel</returns>
/// <remarks>
/// This method actually performs some optimization by realizing that we can have a single channel per RabbitMQ
/// endpoint.
/// Instead of opening multiple channels to the same queue (or multiple publish channels) we can reuse the existing
/// channel.
/// This appears to be thread-safe in my testing. Opening and closing channels adds considerable overhead, so resuing
/// the
/// existing channel adds a considerable performance improvement.
/// </remarks>
public RabbitMQConsumerChannel OpenConsumerChannel(string exchange, string queue, bool autoDelete = false, bool exclusive = true)
{
// we do not want to create a new channel unless the requested channel does not exist
var channel = Channels
.SingleOrDefault(c =>
c.AutoDelete == autoDelete &&
c.Exclusive == exclusive &&
c.GetType().IsAssignableFrom(typeof(RabbitMQConsumerChannel))
);
if (channel == null)
{
channel = new RabbitMQConsumerChannel(this, _container, exchange, queue, autoDelete, exclusive);
Channels.Add(channel);
}
return((RabbitMQConsumerChannel)channel);
}
/// <summary>
/// Construct a consumer for the specified channel
/// </summary>
/// <param name="channel">The associated channel for this consumer</param>
/// <param name="container">The AutoFac container for registering MediatR handlers</param>
public RabbitMQConsumer(RabbitMQConsumerChannel channel, IContainer container) : base(channel.Model)
{
Channel = channel;
_container = container;
Received += RabbitMQConsumer_Received;
}