public override Task SendGroupAsync(string groupName, string methodName, object[] args)
{
if (groupName == null)
{
throw new ArgumentNullException(nameof(groupName));
}
var group = _groups[groupName];
if (group != null)
{
// Can't optimize for sending to a single connection in a group because
// group might be modified inbetween checking and sending
List <Task> tasks = null;
SerializedHubMessage message = null;
SendToGroupConnections(methodName, args, group, null, ref tasks, ref message);
if (tasks != null)
{
return(Task.WhenAll(tasks));
}
}
return(Task.CompletedTask);
}
public override Task SendGroupsAsync(IReadOnlyList <string> groupNames, string methodName, object[] args)
{
// Each task represents the list of tasks for each of the writes within a group
List <Task> tasks = null;
SerializedHubMessage message = null;
foreach (var groupName in groupNames)
{
if (string.IsNullOrEmpty(groupName))
{
throw new InvalidOperationException("Cannot send to an empty group name.");
}
var group = _groups[groupName];
if (group != null)
{
SendToGroupConnections(methodName, args, group, null, ref tasks, ref message);
}
}
if (tasks != null)
{
return(Task.WhenAll(tasks));
}
return(Task.CompletedTask);
}
// Tasks and message are passed by ref so they can be lazily created inside the method post-filtering,
// while still being re-usable when sending to multiple groups
private void SendToGroupConnections(string methodName, object[] args, ConcurrentDictionary <string, HubConnectionContext> connections, Func <HubConnectionContext, bool> include,
ref List <Task> tasks, ref SerializedHubMessage message, CancellationToken cancellationToken)
{
// foreach over ConcurrentDictionary avoids allocating an enumerator
foreach (var connection in connections)
{
if (include != null && !include(connection.Value))
{
continue;
}
if (message == null)
{
message = CreateSerializedInvocationMessage(methodName, args);
}
var task = connection.Value.WriteAsync(message, cancellationToken);
if (!task.IsCompletedSuccessfully)
{
if (tasks == null)
{
tasks = new List <Task>();
}
tasks.Add(task.AsTask());
}
}
}
private Task SendToAllConnections(string methodName, object[] args, Func <HubConnectionContext, bool> include)
{
List <Task> tasks = null;
SerializedHubMessage message = null;
// foreach over HubConnectionStore avoids allocating an enumerator
foreach (var connection in _connections)
{
if (include != null && !include(connection))
{
continue;
}
if (message == null)
{
message = CreateSerializedInvocationMessage(methodName, args);
}
var task = connection.WriteAsync(message);
if (!task.IsCompletedSuccessfully)
{
if (tasks == null)
{
tasks = new List <Task>();
}
tasks.Add(task.AsTask());
}
}
if (tasks == null)
{
return(Task.CompletedTask);
}
// Some connections are slow
return(Task.WhenAll(tasks));
}
public override Task SendGroupExceptAsync(string groupName, string methodName, object[] args, IReadOnlyList <string> excludedIds)
{
if (groupName == null)
{
throw new ArgumentNullException(nameof(groupName));
}
var group = _groups[groupName];
if (group != null)
{
List <Task> tasks = null;
SerializedHubMessage message = null;
SendToGroupConnections(methodName, args, group, connection => !excludedIds.Contains(connection.ConnectionId), ref tasks, ref message);
if (tasks != null)
{
return(Task.WhenAll(tasks));
}
}
return(Task.CompletedTask);
}