public IAsyncEnumerable <StockTickerUpdate> Subscribe(IAsyncEnumerable <SymbolRequest> request, CallContext context)
{
var cancellationToken = CancellationTokenSource.CreateLinkedTokenSource(_cts.Token, context.CancellationToken).Token;
var buffer = Channel.CreateUnbounded <StockTickerUpdate>();
_subscriber = _subscriberFactory.GetSubscriber();
_subscriber.Update += async(sender, args) =>
{
try
{
await buffer.Writer.WriteAsync(new StockTickerUpdate
{
Symbol = args.Symbol,
Price = args.Price,
Time = DateTime.UtcNow
});
}
catch (Exception e)
{
_logger.LogError($"Failed to write message: {e.Message}");
}
};
_processRequestTask = ProcessRequests(request, buffer.Writer, cancellationToken);
return(buffer.AsAsyncEnumerable(cancellationToken));
}
public override async Task Subscribe(IAsyncStreamReader <ActionMessage> requestStream, IServerStreamWriter <StockTickerUpdate> responseStream, ServerCallContext context)
{
using var subscriber = _subscriberFactory.GetSubscriber();
subscriber.Update += async(sender, args) =>
await WriteUpdateAsync(responseStream, args.Symbol, args.Price);
var actionsTask = HandleActions(requestStream, subscriber, context.CancellationToken);
_logger.LogInformation("Subscription started.");
await AwaitCancellation(context.CancellationToken);
try { await actionsTask; } catch { /* Ignored */ }
_logger.LogInformation("Subscription finished.");
}