/// <summary>
/// Checks if the subscription is ready to publish and returns a notification message.
/// </summary>
public NotificationMessage Publish()
{
lock (m_lock)
{
long currentTime = DateTime.UtcNow.Ticks / TimeSpan.TicksPerMillisecond;
// check of it is time for a publish.
if (m_lastPublishTime + m_publishingInterval < currentTime)
{
ListOfMonitoredItemNotification notifications = new ListOfMonitoredItemNotification();
ListOfDiagnosticInfo diagnosticInfos = new ListOfDiagnosticInfo();
// check each monitored item for data changes to send.
foreach (MonitoredItem monitoredItem in m_monitoredItems.Values)
{
while (monitoredItem.Values.Count > 0)
{
MonitoredItemNotification notification = new MonitoredItemNotification();
notification.ClientHandle = monitoredItem.Parameters.ClientHandle;
notification.Value = monitoredItem.Values.Dequeue();
notifications.Add(notification);
diagnosticInfos.Add(monitoredItem.DiagnosticInfos.Dequeue());
}
}
// check if any notifications were found.
if (notifications.Count > 0)
{
// subscriptions can produce different types of notifications so the notification parameter
// is an extensible parameter. This means the object must be manually serialized and wrapped in
// an ExtensionObject which specifies the type of data contained in the Body. The complete
// UA SDK takes care this housekeeping and will serialize extensible parameters automatically.
DataChangeNotification body = new DataChangeNotification();
body.MonitoredItems = notifications;
body.DiagnosticInfos = diagnosticInfos;
ExtensionObject extension = new ExtensionObject(
new ExpandedNodeId(Objects.DataChangeNotification_Encoding_DefaultXml),
body);
// construct the message and assign a new sequence number.
NotificationMessage message = new NotificationMessage();
message.SequenceNumber = ++m_nextSequenceNumber;
message.PublishTime = DateTime.UtcNow;
message.NotificationData = new ListOfExtensionObject();
message.NotificationData.Add(extension);
m_lastPublishTime = currentTime;
m_nextKeepAliveTime = (long)(currentTime + m_publishingInterval * m_keepAliveCount);
return message;
}
}
// check if it is time for a keep alive.
if (m_nextKeepAliveTime < currentTime)
{
NotificationMessage message = new NotificationMessage();
message.SequenceNumber = m_nextSequenceNumber;
message.PublishTime = DateTime.UtcNow;
message.NotificationData = new ListOfExtensionObject();
m_nextKeepAliveTime = (long)(currentTime + m_publishingInterval * m_keepAliveCount);
return message;
}
return null;
}
}
/// <summary>
/// Checks if the subscription is ready to publish and returns a notification message.
/// </summary>
public NotificationMessage Publish()
{
lock (m_lock)
{
long currentTime = DateTime.UtcNow.Ticks / TimeSpan.TicksPerMillisecond;
// check of it is time for a publish.
if (m_lastPublishTime + m_publishingInterval < currentTime)
{
ListOfMonitoredItemNotification notifications = new ListOfMonitoredItemNotification();
ListOfDiagnosticInfo diagnosticInfos = new ListOfDiagnosticInfo();
// check each monitored item for data changes to send.
foreach (MonitoredItem monitoredItem in m_monitoredItems.Values)
{
while (monitoredItem.Values.Count > 0)
{
MonitoredItemNotification notification = new MonitoredItemNotification();
notification.ClientHandle = monitoredItem.Parameters.ClientHandle;
notification.Value = monitoredItem.Values.Dequeue();
notifications.Add(notification);
diagnosticInfos.Add(monitoredItem.DiagnosticInfos.Dequeue());
}
}
// check if any notifications were found.
if (notifications.Count > 0)
{
// subscriptions can produce different types of notifications so the notification parameter
// is an extensible parameter. This means the object must be manually serialized and wrapped in
// an ExtensionObject which specifies the type of data contained in the Body. The complete
// UA SDK takes care this housekeeping and will serialize extensible parameters automatically.
DataChangeNotification body = new DataChangeNotification();
body.MonitoredItems = notifications;
body.DiagnosticInfos = diagnosticInfos;
ExtensionObject extension = new ExtensionObject(
new ExpandedNodeId(Objects.DataChangeNotification_Encoding_DefaultXml),
body);
// construct the message and assign a new sequence number.
NotificationMessage message = new NotificationMessage();
message.SequenceNumber = ++m_nextSequenceNumber;
message.PublishTime = DateTime.UtcNow;
message.NotificationData = new ListOfExtensionObject();
message.NotificationData.Add(extension);
m_lastPublishTime = currentTime;
m_nextKeepAliveTime = (long)(currentTime + m_publishingInterval * m_keepAliveCount);
return(message);
}
}
// check if it is time for a keep alive.
if (m_nextKeepAliveTime < currentTime)
{
NotificationMessage message = new NotificationMessage();
message.SequenceNumber = m_nextSequenceNumber;
message.PublishTime = DateTime.UtcNow;
message.NotificationData = new ListOfExtensionObject();
m_nextKeepAliveTime = (long)(currentTime + m_publishingInterval * m_keepAliveCount);
return(message);
}
return(null);
}
}
