private ICollection <IMessageReceiveBuffer> CreateBuffers(
ReceiveMiddleware receiveMiddleware,
SubscriptionGroupSettings subscriptionGroupSettings)
{
var buffers = new List <IMessageReceiveBuffer>();
var logger = _loggerFactory.CreateLogger <MessageReceiveBuffer>();
foreach (ISqsQueue queue in subscriptionGroupSettings.Queues)
{
var buffer = new MessageReceiveBuffer(
subscriptionGroupSettings.Prefetch,
subscriptionGroupSettings.BufferSize,
subscriptionGroupSettings.ReceiveBufferReadTimeout,
subscriptionGroupSettings.ReceiveMessagesWaitTime,
queue,
receiveMiddleware,
_monitor,
logger);
buffers.Add(buffer);
}
return(buffers);
}
private ICollection <IMultiplexerSubscriber> CreateSubscribers(SubscriptionGroupSettings settings)
{
var logger = _loggerFactory.CreateLogger <MultiplexerSubscriber>();
return(Enumerable.Range(0, settings.ConcurrencyLimit)
.Select(index => (IMultiplexerSubscriber) new MultiplexerSubscriber(
_messageDispatcher,
$"{settings.Name}-subscriber-{index}",
logger))
.ToList());
}
/// <summary>
/// Coordinates reading messages from a collection of <see cref="IMessageReceiveBuffer"/>
/// and dispatching using a collection of <see cref="IMultiplexerSubscriber"/>.
/// </summary>
/// <param name="settings">The <see cref="SubscriptionGroupSettings"/> to use.</param>
/// <param name="receiveBuffers">The collection of <see cref="IMessageReceiveBuffer"/> to read from.</param>
/// <param name="multiplexer">The <see cref="IMultiplexer"/> to aggregate all messages into one stream.</param>
/// <param name="subscribers">The collection of <see cref="IMultiplexerSubscriber"/> that will dispatch the messages</param>
/// <param name="logger">The <see cref="ILogger"/> to be used.</param>
public SubscriptionGroup(
SubscriptionGroupSettings settings,
ICollection <IMessageReceiveBuffer> receiveBuffers,
IMultiplexer multiplexer,
ICollection <IMultiplexerSubscriber> subscribers,
ILogger <SubscriptionGroup> logger)
{
_receiveBuffers = receiveBuffers;
_settings = settings;
_multiplexer = multiplexer;
_subscribers = subscribers;
_logger = logger;
}
/// <summary>
/// Given a set of defaults and overrides from this builder, builds a concrete <see cref="SubscriptionGroupSettings"/>
/// that can be passed to an <see cref="ISubscriptionGroupFactory"/> to build an <see cref="ISubscriptionGroup"/>.
/// </summary>
/// <param name="defaults">The default values to use if no override given.</param>
/// <returns>A <see cref="SubscriptionGroupSettings"/>.</returns>
public SubscriptionGroupSettings Build(SubscriptionGroupSettingsBuilder defaults)
{
if (defaults == null)
{
throw new InvalidOperationException("Defaults must be set before building settings.");
}
var settings = new SubscriptionGroupSettings(
_groupName,
_concurrencyLimit ?? defaults.ConcurrencyLimit,
_bufferSize ?? defaults.BufferSize,
_receiveBufferReadTimeout ?? defaults.ReceiveBufferReadTimeout,
_recieveMessagesWaitTime ?? defaults.ReceiveMessagesWaitTime,
_multiplexerCapacity ?? defaults.MultiplexerCapacity,
_prefetch ?? defaults.Prefetch,
_sqsQueues);
settings.Validate();
return(settings);
}
private ISubscriptionGroup Create(ReceiveMiddleware receiveMiddleware, SubscriptionGroupSettings settings)
{
IMultiplexer multiplexer = CreateMultiplexer(settings.MultiplexerCapacity);
ICollection <IMessageReceiveBuffer> receiveBuffers = CreateBuffers(receiveMiddleware, settings);
ICollection <IMultiplexerSubscriber> subscribers = CreateSubscribers(settings);
foreach (IMessageReceiveBuffer receiveBuffer in receiveBuffers)
{
multiplexer.ReadFrom(receiveBuffer.Reader);
}
foreach (IMultiplexerSubscriber subscriber in subscribers)
{
subscriber.Subscribe(multiplexer.GetMessagesAsync());
}
return(new SubscriptionGroup(
settings,
receiveBuffers,
multiplexer,
subscribers,
_loggerFactory.CreateLogger <SubscriptionGroup>()));
}