/// <summary>
/// Initializes a new instance of the <see cref="SubscriptionBase"/> class.
/// </summary>
/// <param name="application">The UaApplication.</param>
public SubscriptionBase(UaApplication application)
{
this.application = application ?? throw new ArgumentNullException(nameof(application));
this.application.Completion.ContinueWith(t => this.stateMachineCts?.Cancel());
this.logger = this.application.LoggerFactory?.CreateLogger(this.GetType());
this.errors = new ErrorsContainer <string>(p => this.ErrorsChanged?.Invoke(this, new DataErrorsChangedEventArgs(p)));
this.progress = new Progress <CommunicationState>(s => this.State = s);
this.propertyChanged += this.OnPropertyChanged;
this.whenSubscribed = new TaskCompletionSource <bool>();
this.whenUnsubscribed = new TaskCompletionSource <bool>();
this.whenUnsubscribed.TrySetResult(true);
// register the action to be run on the ui thread, if there is one.
if (SynchronizationContext.Current != null)
{
this.actionBlock = new ActionBlock <PublishResponse>(pr => this.OnPublishResponse(pr), new ExecutionDataflowBlockOptions {
SingleProducerConstrained = true, TaskScheduler = TaskScheduler.FromCurrentSynchronizationContext()
});
}
else
{
this.actionBlock = new ActionBlock <PublishResponse>(pr => this.OnPublishResponse(pr), new ExecutionDataflowBlockOptions {
SingleProducerConstrained = true
});
}
// read [Subscription] attribute.
var typeInfo = this.GetType().GetTypeInfo();
var sa = typeInfo.GetCustomAttribute <SubscriptionAttribute>();
if (sa != null)
{
this.endpointUrl = sa.EndpointUrl;
this.publishingInterval = sa.PublishingInterval;
this.keepAliveCount = sa.KeepAliveCount;
this.lifetimeCount = sa.LifetimeCount;
}
// read [MonitoredItem] attributes.
foreach (var propertyInfo in typeInfo.DeclaredProperties)
{
var mia = propertyInfo.GetCustomAttribute <MonitoredItemAttribute>();
if (mia == null || string.IsNullOrEmpty(mia.NodeId))
{
continue;
}
MonitoringFilter filter = null;
if (mia.AttributeId == AttributeIds.Value && (mia.DataChangeTrigger != DataChangeTrigger.StatusValue || mia.DeadbandType != DeadbandType.None))
{
filter = new DataChangeFilter()
{
Trigger = mia.DataChangeTrigger, DeadbandType = (uint)mia.DeadbandType, DeadbandValue = mia.DeadbandValue
};
}
var propType = propertyInfo.PropertyType;
if (propType == typeof(DataValue))
{
this.monitoredItems.Add(new DataValueMonitoredItem(
target: this,
property: propertyInfo,
nodeId: ExpandedNodeId.Parse(mia.NodeId),
indexRange: mia.IndexRange,
attributeId: mia.AttributeId,
samplingInterval: mia.SamplingInterval,
filter: filter,
queueSize: mia.QueueSize,
discardOldest: mia.DiscardOldest));
continue;
}
if (propType == typeof(BaseEvent) || propType.GetTypeInfo().IsSubclassOf(typeof(BaseEvent)))
{
this.monitoredItems.Add(new EventMonitoredItem(
target: this,
property: propertyInfo,
nodeId: ExpandedNodeId.Parse(mia.NodeId),
indexRange: mia.IndexRange,
attributeId: mia.AttributeId,
samplingInterval: mia.SamplingInterval,
filter: new EventFilter()
{
SelectClauses = EventHelper.GetSelectClauses(propType)
},
queueSize: mia.QueueSize,
discardOldest: mia.DiscardOldest));
continue;
}
if (propType == typeof(ObservableQueue <DataValue>))
{
this.monitoredItems.Add(new DataValueQueueMonitoredItem(
target: this,
property: propertyInfo,
nodeId: ExpandedNodeId.Parse(mia.NodeId),
indexRange: mia.IndexRange,
attributeId: mia.AttributeId,
samplingInterval: mia.SamplingInterval,
filter: filter,
queueSize: mia.QueueSize,
discardOldest: mia.DiscardOldest));
continue;
}
if (propType.IsConstructedGenericType && propType.GetGenericTypeDefinition() == typeof(ObservableQueue <>))
{
var elemType = propType.GenericTypeArguments[0];
if (elemType == typeof(BaseEvent) || elemType.GetTypeInfo().IsSubclassOf(typeof(BaseEvent)))
{
this.monitoredItems.Add((MonitoredItemBase)Activator.CreateInstance(
typeof(EventQueueMonitoredItem <>).MakeGenericType(elemType),
this,
propertyInfo,
ExpandedNodeId.Parse(mia.NodeId),
mia.AttributeId,
mia.IndexRange,
MonitoringMode.Reporting,
mia.SamplingInterval,
new EventFilter()
{
SelectClauses = EventHelper.GetSelectClauses(elemType)
},
mia.QueueSize,
mia.DiscardOldest));
continue;
}
}
this.monitoredItems.Add(new ValueMonitoredItem(
target: this,
property: propertyInfo,
nodeId: ExpandedNodeId.Parse(mia.NodeId),
indexRange: mia.IndexRange,
attributeId: mia.AttributeId,
samplingInterval: mia.SamplingInterval,
filter: filter,
queueSize: mia.QueueSize,
discardOldest: mia.DiscardOldest));
}
this.stateMachineCts = new CancellationTokenSource();
this.stateMachineTask = Task.Run(() => this.StateMachineAsync(this.stateMachineCts.Token));
}
/// <summary>
/// The state machine manages the state of the subscription.
/// </summary>
/// <param name="token">A cancellation token.</param>
/// <returns>A task.</returns>
private async Task StateMachineAsync(CancellationToken token = default)
{
while (!token.IsCancellationRequested)
{
await this.whenSubscribed.Task;
this.progress.Report(CommunicationState.Opening);
try
{
// get a channel.
this.innerChannel = await this.application.GetChannelAsync(this.endpointUrl, token);
try
{
// create the subscription.
var subscriptionRequest = new CreateSubscriptionRequest
{
RequestedPublishingInterval = this.publishingInterval,
RequestedMaxKeepAliveCount = this.keepAliveCount,
RequestedLifetimeCount = Math.Max(this.lifetimeCount, 3 * this.keepAliveCount),
PublishingEnabled = true
};
var subscriptionResponse = await this.innerChannel.CreateSubscriptionAsync(subscriptionRequest).ConfigureAwait(false);
// link up the dataflow blocks
var id = this.subscriptionId = subscriptionResponse.SubscriptionId;
var linkToken = this.innerChannel.LinkTo(this.actionBlock, pr => pr.SubscriptionId == id);
try
{
// create the monitored items.
var items = this.monitoredItems.ToList();
if (items.Count > 0)
{
var requests = items.Select(m => new MonitoredItemCreateRequest {
ItemToMonitor = new ReadValueId {
NodeId = ExpandedNodeId.ToNodeId(m.NodeId, this.InnerChannel.NamespaceUris), AttributeId = m.AttributeId, IndexRange = m.IndexRange
}, MonitoringMode = m.MonitoringMode, RequestedParameters = new MonitoringParameters {
ClientHandle = m.ClientId, DiscardOldest = m.DiscardOldest, QueueSize = m.QueueSize, SamplingInterval = m.SamplingInterval, Filter = m.Filter
}
}).ToArray();
var itemsRequest = new CreateMonitoredItemsRequest
{
SubscriptionId = id,
ItemsToCreate = requests,
};
var itemsResponse = await this.innerChannel.CreateMonitoredItemsAsync(itemsRequest);
for (int i = 0; i < itemsResponse.Results.Length; i++)
{
var item = items[i];
var result = itemsResponse.Results[i];
item.OnCreateResult(result);
if (StatusCode.IsBad(result.StatusCode))
{
this.logger?.LogError($"Error creating MonitoredItem for {item.NodeId}. {StatusCodes.GetDefaultMessage(result.StatusCode)}");
}
}
}
this.progress.Report(CommunicationState.Opened);
// wait here until channel is closing, unsubscribed or token cancelled.
try
{
await Task.WhenAny(
this.WhenChannelClosingAsync(this.innerChannel, token),
this.whenUnsubscribed.Task);
}
catch
{
}
finally
{
this.progress.Report(CommunicationState.Closing);
}
}
catch (Exception ex)
{
this.logger?.LogError($"Error creating MonitoredItems. {ex.Message}");
this.progress.Report(CommunicationState.Faulted);
}
finally
{
linkToken.Dispose();
}
if (this.innerChannel.State == CommunicationState.Opened)
{
try
{
// delete the subscription.
var deleteRequest = new DeleteSubscriptionsRequest
{
SubscriptionIds = new uint[] { id }
};
await this.innerChannel.DeleteSubscriptionsAsync(deleteRequest);
}
catch (Exception ex)
{
this.logger?.LogError($"Error deleting subscription. {ex.Message}");
await Task.Delay(2000);
}
}
this.progress.Report(CommunicationState.Closed);
}
catch (Exception ex)
{
this.logger?.LogError($"Error creating subscription. {ex.Message}");
this.progress.Report(CommunicationState.Faulted);
await Task.Delay(2000);
}
}
catch (Exception ex)
{
this.logger?.LogTrace($"Error getting channel. {ex.Message}");
this.progress.Report(CommunicationState.Faulted);
await Task.Delay(2000);
}
}
}
public Variant(ExpandedNodeId value)
{
this.Value = value;
this.Type = VariantType.ExpandedNodeId;
this.ArrayDimensions = null;
}
public XmlEncodingIdAttribute(string s)
{
this.NodeId = ExpandedNodeId.Parse(s);
}
public DataTypeIdAttribute(string s)
{
this.NodeId = ExpandedNodeId.Parse(s);
}
