public async Task SubscribePriceStream(PriceSubscriptionRequestDto request)
{
_contextHolder.PricingHubClient = Clients;
Log.InfoFormat("Received subscription request {0} from connection {1}", request, Context.ConnectionId);
if (!_currencyPairRepository.Exists(request.CurrencyPair))
{
Log.WarnFormat("Received a subscription request for an invalid currency pair '{0}', it was ignored.", request.CurrencyPair);
return;
}
// simulate slow response for EURCHF
if (request.CurrencyPair == "EURCHF")
{
await Task.Delay(TimeSpan.FromSeconds(2));
}
// add client to this group
var groupName = string.Format(PriceStreamGroupPattern, request.CurrencyPair);
await Groups.Add(Context.ConnectionId, groupName);
Log.InfoFormat("Connection {0} added to group '{1}'", Context.ConnectionId, groupName);
// send current price to client
var lastValue = _priceLastValueCache.GetLastValue(request.CurrencyPair);
await Clients.Caller.OnNewPrice(lastValue);
Log.InfoFormat("Snapshot published to {0}: {1}", Context.ConnectionId, lastValue);
}
public async Task UnsubscribePriceStream(PriceSubscriptionRequestDto request)
{
Log.InfoFormat("Received unsubscription request {0} from connection {1}", request, Context.ConnectionId);
if (!_currencyPairRepository.Exists(request.CurrencyPair))
{
Log.WarnFormat("Received an unsubscription request for an invalid currency pair '{0}', it was ignored.", request.CurrencyPair);
return;
}
// remove client from the group
var groupName = string.Format(PriceStreamGroupPattern, request.CurrencyPair);
await Groups.Remove(Context.ConnectionId, groupName);
Log.InfoFormat("Connection {0} removed from group '{1}'", Context.ConnectionId, groupName);
}
