private static Task <T> FromAsync <T>(Func <AsyncCallback, IAsyncResult> begin, Func <IAsyncResult, T> end)
{
var tcs = new DispatchingTaskCompletionSource <T>();
try
{
var result = begin(ar =>
{
if (!ar.CompletedSynchronously)
{
CompleteAsync(tcs, ar, end);
}
});
if (result.CompletedSynchronously)
{
CompleteAsync(tcs, result, end);
}
}
catch (Exception ex)
{
tcs.TrySetException(ex);
}
return(tcs.Task);
}
private static void CompleteAsync <T>(DispatchingTaskCompletionSource <T> tcs, IAsyncResult ar, Func <IAsyncResult, T> end)
{
try
{
tcs.TrySetResult(end(ar));
}
catch (OperationCanceledException)
{
tcs.TrySetCanceled();
}
catch (Exception ex)
{
tcs.TrySetException(ex);
}
}
private void ResolveTransport(IConnection connection, string data, CancellationToken disconnectToken, DispatchingTaskCompletionSource <object> tcs, int index)
{
// Pick the current transport
IClientTransport transport = _transports[index];
transport.Start(connection, data, disconnectToken).ContinueWith(task =>
{
if (task.IsFaulted || task.IsCanceled)
{
Exception ex;
if (task.IsCanceled)
{
ex = new OperationCanceledException(Resources.Error_TaskCancelledException);
}
else
{
ex = task.Exception.GetBaseException();
}
connection.Trace(TraceLevels.Events, "Auto: Failed to connect to using transport {0}. {1}", transport.Name, ex);
// If that transport fails to initialize, then fallback.
// If it is that /start request that failed, do not fallback.
var next = index + 1;
if (next < _transports.Count && !(ex is StartException))
{
// Try the next transport
ResolveTransport(connection, data, disconnectToken, tcs, next);
}
else
{
// If there's nothing else to try then just fail
tcs.TrySetException(ex);
}
}
else
{
// Set the active transport
_transport = transport;
// Complete the process
tcs.TrySetResult(null);
}
},
TaskContinuationOptions.ExecuteSynchronously);
}
private void ResolveTransport(
IConnection connection,
string data,
CancellationToken disconnectToken,
DispatchingTaskCompletionSource <object> tcs,
Exception lastError,
int index)
{
IClientTransport transport = null;
var next = index;
// Pick the current transport
while (next < _transports.Count && transport == null)
{
var candidateTransport = _transports[next++];
// If the current transport is WebSockets and it's not supported by the server, try the next transport.
if (_tryWebSockets || !"webSockets".Equals(candidateTransport.Name, StringComparison.Ordinal))
{
transport = candidateTransport;
}
}
if (transport is null)
{
// If there's nothing else to try, then just fail with the error from the last transport.
// For the lastError to be null, the AutoTransport must have been initialized with an empty transport list or only WebSockets.
tcs.TrySetException(lastError ?? new Exception(Resources.Error_NoCompatibleTransportFound));
return;
}
transport.Start(connection, data, disconnectToken).ContinueWith(task =>
{
if (task.IsFaulted || task.IsCanceled)
{
Exception ex;
if (task.IsCanceled)
{
ex = new OperationCanceledException(Resources.Error_TaskCancelledException);
}
else
{
ex = task.Exception.GetBaseException();
}
connection.Trace(TraceLevels.Events, "Auto: Failed to connect to using transport {0}. {1}", transport.Name, ex);
// If that transport fails to initialize, then fallback.
// If it is that /start request that failed, do not fallback.
if (ex is StartException)
{
tcs.TrySetException(ex);
}
else
{
// Try the next transport
ResolveTransport(connection, data, disconnectToken, tcs, ex, next);
}
}
else
{
// Set the active transport
_transport = transport;
// Complete the process
tcs.TrySetResult(null);
}
},
TaskContinuationOptions.ExecuteSynchronously);
}
public Task <TResult> Invoke <TResult, TProgress>(string method, Action <TProgress> onProgress, params object[] args)
{
if (method == null)
{
throw new ArgumentNullException("method");
}
if (args == null)
{
throw new ArgumentNullException("args");
}
var tokenifiedArguments = new JToken[args.Length];
for (int i = 0; i < tokenifiedArguments.Length; i++)
{
tokenifiedArguments[i] = args[i] != null
? JToken.FromObject(args[i], JsonSerializer)
: JValue.CreateNull();
}
var tcs = new DispatchingTaskCompletionSource <TResult>();
var callbackId = _connection.RegisterCallback(result =>
{
if (result != null)
{
if (result.Error != null)
{
if (result.IsHubException.HasValue && result.IsHubException.Value)
{
// A HubException was thrown
tcs.TrySetException(new HubException(result.Error, result.ErrorData));
}
else
{
tcs.TrySetException(new InvalidOperationException(result.Error));
}
}
else
{
try
{
if (result.State != null)
{
foreach (var pair in result.State)
{
this[pair.Key] = pair.Value;
}
}
if (result.ProgressUpdate != null)
{
onProgress(result.ProgressUpdate.Data.ToObject <TProgress>(JsonSerializer));
}
else if (result.Result != null)
{
tcs.TrySetResult(result.Result.ToObject <TResult>(JsonSerializer));
}
else
{
tcs.TrySetResult(default(TResult));
}
}
catch (Exception ex)
{
// If we failed to set the result for some reason or to update
// state then just fail the tcs.
tcs.TrySetUnwrappedException(ex);
}
}
}
else
{
tcs.TrySetCanceled();
}
});
var hubData = new HubInvocation
{
Hub = _hubName,
Method = method,
Args = tokenifiedArguments,
CallbackId = callbackId
};
if (_state.Count != 0)
{
hubData.State = _state;
}
var value = _connection.JsonSerializeObject(hubData);
_connection.Send(value).ContinueWith(task =>
{
if (task.IsCanceled)
{
_connection.RemoveCallback(callbackId);
tcs.TrySetCanceled();
}
else if (task.IsFaulted)
{
_connection.RemoveCallback(callbackId);
tcs.TrySetUnwrappedException(task.Exception);
}
},
TaskContinuationOptions.NotOnRanToCompletion);
return(tcs.Task);
}
public Task <JSONNode> Invoke(string method, Action <JSONNode> onProgress, params object[] args)
{
if (method == null)
{
throw new ArgumentNullException("method");
}
if (args == null)
{
throw new ArgumentNullException("args");
}
JSONArray ArgsArray = new JSONArray();
for (int i = 0; i < args.Length; i++)
{
ArgsArray.Add(JSON.FromData(args[i]));
}
var tcs = new DispatchingTaskCompletionSource <JSONNode>();
var callbackId = _connection.RegisterCallback(result =>
{
if (result != null)
{
if (result.Error != null)
{
if (result.IsHubException)
{
// A HubException was thrown
tcs.TrySetException(new HubException(result.Error, result.ErrorData));
}
else
{
tcs.TrySetException(new InvalidOperationException(result.Error));
}
}
else
{
try
{
if (result.State != null)
{
foreach (var pair in result.State)
{
this[pair.Key] = pair.Value;
}
}
if (result.ProgressUpdate != null)
{
onProgress?.Invoke(result.ProgressUpdate.Data);
}
else if (result.Result != null)
{
tcs.TrySetResult(result.Result);
}
else
{
tcs.TrySetResult(new JSONNonexistent());
}
}
catch (Exception ex)
{
// If we failed to set the result for some reason or to update
// state then just fail the tcs.
tcs.TrySetUnwrappedException(ex);
}
}
}
else
{
tcs.TrySetCanceled();
}
});
var hubData = new HubInvocation
{
Hub = _hubName,
Method = method,
Args = ArgsArray,
CallbackId = callbackId
};
if (_state.Count != 0)
{
hubData.State = _state;
}
var value = hubData.ToJson().Serialize();
_connection.Send(value).ContinueWith(task =>
{
if (task.IsCanceled)
{
_connection.RemoveCallback(callbackId);
tcs.TrySetCanceled();
}
else if (task.IsFaulted)
{
_connection.RemoveCallback(callbackId);
tcs.TrySetUnwrappedException(task.Exception);
}
},
TaskContinuationOptions.NotOnRanToCompletion);
return(tcs.Task);
}
