/// <summary>
/// Returns a new temporal <see cref="IaonSession"/> for a <see cref="IClientSubscription"/>.
/// </summary>
/// <param name="clientSubscription"><see cref="IClientSubscription"/> instance to create temporal <see cref="IaonSession"/> for.</param>
/// <returns>New temporal <see cref="IaonSession"/> for a <see cref="IClientSubscription"/>.</returns>
public static IaonSession CreateTemporalSession(this IClientSubscription clientSubscription)
{
IaonSession session;
// Cache the specified input measurement keys requested by the remote subscription
// internally since these will only be needed in the private Iaon session
MeasurementKey[] inputMeasurementKeys = clientSubscription.InputMeasurementKeys;
IMeasurement[] outputMeasurements = clientSubscription.OutputMeasurements;
// Since historical data is requested, we "turn off" interaction with the outside real-time world
// by removing this adapter from external routes. To accomplish this we expose I/O demands for an
// undefined measurement. Note: assigning to null would mean "broadcast" of all data is desired.
clientSubscription.InputMeasurementKeys = new MeasurementKey[] { MeasurementKey.Undefined };
clientSubscription.OutputMeasurements = new IMeasurement[] { Measurement.Undefined };
// Create a new Iaon session
session = new IaonSession();
session.Name = "<" + clientSubscription.HostName.ToNonNullString("unavailable") + ">@" + clientSubscription.StartTimeConstraint.ToString("yyyy-MM-dd HH:mm:ss");
// Assign requested input measurement keys as a routing restriction
session.InputMeasurementKeysRestriction = inputMeasurementKeys;
// Setup default bubbling event handlers associated with the client session adapter
EventHandler<EventArgs<string, UpdateType>> statusMessageHandler = (sender, e) =>
{
if (e.Argument2 == UpdateType.Information)
clientSubscription.OnStatusMessage(e.Argument1);
else
clientSubscription.OnStatusMessage("0x" + (int)e.Argument2 + e.Argument1);
};
EventHandler<EventArgs<Exception>> processExceptionHandler = (sender, e) => clientSubscription.OnProcessException(e.Argument);
EventHandler processingCompletedHandler = (sender, e) => clientSubscription.OnProcessingCompleted(sender, e);
// Cache dynamic event handlers so they can be detached later
s_statusMessageHandlers[clientSubscription] = statusMessageHandler;
s_processExceptionHandlers[clientSubscription] = processExceptionHandler;
s_processingCompletedHandlers[clientSubscription] = processingCompletedHandler;
// Attach handlers to new session - this will proxy all temporal session messages through the client session adapter
session.StatusMessage += statusMessageHandler;
session.ProcessException += processExceptionHandler;
session.ProcessingComplete += processingCompletedHandler;
// Send the first message indicating a new temporal session is being established
statusMessageHandler(null, new EventArgs<string, UpdateType>(
string.Format("Initializing temporal session for host \"{0}\" spanning {1} to {2} processing data {3}...",
clientSubscription.HostName.ToNonNullString("unknown"),
clientSubscription.StartTimeConstraint.ToString("yyyy-MM-dd HH:mm:ss.fff"),
clientSubscription.StopTimeConstraint.ToString("yyyy-MM-dd HH:mm:ss.fff"),
clientSubscription.ProcessingInterval == 0 ? "as fast as possible" :
clientSubscription.ProcessingInterval == -1 ? "at the default rate" : "at " + clientSubscription.ProcessingInterval + "ms intervals"),
UpdateType.Information));
// Duplicate current real-time session configuration for adapters that report temporal support
session.DataSource = IaonSession.ExtractTemporalConfiguration(clientSubscription.DataSource);
// Define an in-situ action adapter for the temporal Iaon session used to proxy data back to the client subscription
DataTable actionAdapters = session.DataSource.Tables["ActionAdapters"];
DataRow proxyAdapterRow = actionAdapters.NewRow();
// Define connection string for proxy adapter based on original inputs and ouputs as requested by client subscription
StringBuilder connectionString = new StringBuilder();
if (inputMeasurementKeys != null && inputMeasurementKeys.Length > 0)
connectionString.AppendFormat("inputMeasurementKeys={{{0}}}", inputMeasurementKeys.Select(key => key.SignalID).ToDelimitedString(";"));
if (outputMeasurements != null && outputMeasurements.Length > 0)
{
if (connectionString.Length > 0)
connectionString.Append("; ");
connectionString.AppendFormat("outputMeasurements={{{0}}}", outputMeasurements.Select(m => m.ID).ToDelimitedString(";"));
}
// Assign critical adapter properties
proxyAdapterRow["ID"] = 0;
proxyAdapterRow["AdapterName"] = "PROXY!SERVICES";
proxyAdapterRow["AssemblyName"] = "TimeSeriesFramework.dll";
proxyAdapterRow["TypeName"] = "TimeSeriesFramework.Transport.TemporalClientSubscriptionProxy";
proxyAdapterRow["ConnectionString"] = connectionString.ToString();
// Add proxy row to Iaon action adapter definitions
actionAdapters.Rows.Add(proxyAdapterRow);
// Initialize temporal session adapters without starting them
session.Initialize(false);
// Get reference to temporal session proxy adapter to it can be associated with the client subscription
TemporalClientSubscriptionProxy proxyAdapter = null;
IActionAdapter adapter0;
// Lookup proxy adapter defined with reserved ID zero
if (session.ActionAdapters.TryGetAdapterByID(0, out adapter0))
proxyAdapter = adapter0 as TemporalClientSubscriptionProxy;
if ((object)proxyAdapter == null)
throw new InvalidOperationException("Failed to define temporal subscription proxy adapter - cannot complete temporal session initialization.");
// Associate proxy with client subscription
proxyAdapter.Parent = clientSubscription;
// Load current temporal constraint parameters
Dictionary<string, string> settings = clientSubscription.Settings;
string startTime, stopTime, parameters;
settings.TryGetValue("startTimeConstraint", out startTime);
settings.TryGetValue("stopTimeConstraint", out stopTime);
settings.TryGetValue("timeConstraintParameters", out parameters);
// Assign requested temporal constraints to all private session adapters
session.AllAdapters.SetTemporalConstraint(startTime, stopTime, parameters);
session.AllAdapters.ProcessingInterval = clientSubscription.ProcessingInterval;
// Start temporal session adapters
session.AllAdapters.Start();
// Recalculate routing tables to accomodate addtion of proxy adapter and handle
// input measurement keys restriction
session.RecalculateRoutingTables();
return session;
}
