public async Task HandleAsync(IConnection connection, CancellationToken cancellationToken)
{
ConnectedClient connectedClient;
try
{
connectedClient = await _connectionInitializer.ConnectAsync(connection, cancellationToken).ConfigureAwait(false);
}
catch
{
try
{
await connection.SendAsync(new Disconnected($"Error during connection initialization."), cancellationToken)
.ConfigureAwait(false);
} catch { }
throw;
}
_connectedClients.Add(connectedClient);
if (!_connectedClients.IsClientConnected(connectedClient.ClientId))
{
throw new InvalidOperationException("Client was not added correctly.");
}
await TrySendPendingUpdates(connectedClient.Group, cancellationToken).ConfigureAwait(false);
while (_connectedClients.IsClientConnected(connectedClient.ClientId))
{
try
{
var message = await connection.ReceiveAsync(cancellationToken).ConfigureAwait(false);
await DispatchMessageAsync(connectedClient, message, cancellationToken).ConfigureAwait(false);
}
catch
{
_connectedClients.Remove(connectedClient.ClientId);
throw; // If you delete this line and have ncrunch, your PC will die.
}
finally
{
await TrySendPendingUpdates(connectedClient.Group, cancellationToken).ConfigureAwait(false);
}
}
}
public ValueTask HandleAsync(ConnectedClient sender, Disconnect message, CancellationToken cancellationToken)
{
_store.Remove(sender.ClientId);
return(sender.Connection.SendAsync(new Disconnected("Requested."), cancellationToken));
}
public async Task HandleAsync(IConnection connection, CancellationToken cancellationToken)
{
ConnectedClient connectedClient;
connection = connection.WithReceiveAcknowledgement();
var unwrapperConnection = new ServerMessageUnwrapperConnection(connection);
try
{
connectedClient = await _connectionInitializer.ConnectAsync(unwrapperConnection, cancellationToken).ConfigureAwait(false);
}
catch
{
try
{
await connection.SendAsync(new Disconnected($"Error during connection initialization."), cancellationToken)
.ConfigureAwait(false);
}
catch { }
throw;
}
_connectedClients.Add(connectedClient);
if (!_connectedClients.IsClientConnected(connectedClient.ClientId))
{
throw new InvalidOperationException("Client was not added correctly.");
}
foreach (var initializer in _connectedClientInitializers)
{
await initializer.InitializeAsync(connectedClient)
.ConfigureAwait(false);
}
// TODO: Unit test all the logic about idempotency.
var idempotencyKeys = new Dictionary <string, DateTime>();
// TODO: Send only to groups that were specified in Metadata from the client (if they were sent).
await TrySendPendingUpdates(connectedClient.Groups, cancellationToken).ConfigureAwait(false);
while (_connectedClients.IsClientConnected(connectedClient.ClientId))
{
MessageMetadata?metadata = null;
try
{
var message = await connection.ReceiveAsync(cancellationToken).ConfigureAwait(false);
if (message is not MessageWithMetadata messageWithMetadata)
{
throw new InvalidOperationException($"Message is not of {typeof(MessageWithMetadata).Name} type.");
}
metadata = messageWithMetadata.Metadata;
if (messageWithMetadata.Metadata?.MessageId != null && idempotencyKeys.ContainsKey(messageWithMetadata.Metadata.MessageId))
{
_logger.LogDebug(
"Message with id {MessageId} has already been handled. Skipping duplicate (idempotency).",
messageWithMetadata.Metadata.MessageId);
continue;
}
await DispatchMessageAsync(connectedClient, messageWithMetadata.Message, cancellationToken).ConfigureAwait(false);
// TODO: Unit test this.
if (messageWithMetadata.Metadata?.ResponseMessageTypeId != null)
{
// TODO: Send query response in background, do not block connection handling.
var responseType = _messageTypeCache.GetTypeById(messageWithMetadata.Metadata.ResponseMessageTypeId);
var response = await _queryDispatcher.DispatchAsync(connectedClient, messageWithMetadata.Message, responseType, cancellationToken)
.ConfigureAwait(false);
// TODO: Do this also in background.
await connectedClient.Connection.SendAsync(response, new MessageMetadata
{
MessageId = messageWithMetadata.Metadata.MessageId
}, cancellationToken)
.ConfigureAwait(false);
}
// If everything was dispatched successfully:
if (messageWithMetadata.Metadata?.MessageId != null && !idempotencyKeys.ContainsKey(messageWithMetadata.Metadata.MessageId))
{
idempotencyKeys.Add(messageWithMetadata.Metadata.MessageId, DateTime.UtcNow);
}
foreach (var item in idempotencyKeys.Where(x => x.Value < DateTime.UtcNow - TimeSpan.FromMinutes(1)))
{
idempotencyKeys.Remove(item.Key);
}
if (messageWithMetadata.Metadata?.AcknowledgementType == AcknowledgementType.Handled && messageWithMetadata.Metadata.MessageId != null)
{
var serverToClientMetadata = new MessageMetadata
{
MessageId = messageWithMetadata.Metadata.MessageId
};
await connectedClient.Connection.SendAsync(new AcknowledgeHandled(messageWithMetadata.Metadata.MessageId), serverToClientMetadata, cancellationToken)
.ConfigureAwait(false);
}
}
catch
{
_connectedClients.Remove(connectedClient.ClientId);
throw; // If you delete this line and have ncrunch, your PC will die.
}
finally
{
var groups = connectedClient.Groups;
// TODO: Unit test this (affected groups).
if ((metadata as ClientToServerMessageMetadata)?.AffectedGroups != null)
{
groups = groups.Where(group => (metadata as ClientToServerMessageMetadata)?.AffectedGroups?.Contains(group) ?? false);
}
// TODO: Do not empty groups if we came here from catch - when client is disconnected we need to notify everyone.
if (metadata == null || !metadata.SendUpdate)
{
groups = Enumerable.Empty <string>();
}
await TrySendPendingUpdates(groups, cancellationToken).ConfigureAwait(false);
}
}
}