/// <summary>
/// Validates the nodes and reads the values from the underlying source.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="nodesToRead">The nodes to read.</param>
/// <param name="values">The values.</param>
/// <param name="errors">The errors.</param>
/// <param name="nodesToValidate">The nodes to validate.</param>
/// <param name="cache">The cache.</param>
protected override void Read(
ServerSystemContext context,
IList<ReadValueId> nodesToRead,
IList<DataValue> values,
IList<ServiceResult> errors,
List<NodeHandle> nodesToValidate,
IDictionary<NodeId, NodeState> cache)
{
ComHdaClientManager system = (ComHdaClientManager)this.SystemContext.SystemHandle;
ComHdaClient client = (ComHdaClient)system.SelectClient((ServerSystemContext)SystemContext, false);
HdaReadRequestCollection requests = new HdaReadRequestCollection();
for (int ii = 0; ii < nodesToValidate.Count; ii++)
{
NodeHandle handle = nodesToValidate[ii];
lock (Lock)
{
NodeState source = ValidateNode(context, handle, cache);
if (source == null)
{
continue;
}
DataValue value = values[handle.Index];
ReadValueId nodeToRead = nodesToRead[handle.Index];
// determine if request can be sent to the server.
bool queued = false;
errors[handle.Index] = requests.Add(source, nodeToRead, out queued);
if (queued)
{
continue;
}
// read built-in metadata.
errors[handle.Index] = source.ReadAttribute(
context,
nodeToRead.AttributeId,
nodeToRead.ParsedIndexRange,
nodeToRead.DataEncoding,
value);
}
}
// read the attributes.
if (requests.Count > 0)
{
client.Read(requests, false);
}
// extract the values from the results.
for (int ii = 0; ii < nodesToValidate.Count; ii++)
{
NodeHandle handle = nodesToValidate[ii];
DataValue value = values[handle.Index];
ReadValueId nodeToRead = nodesToRead[handle.Index];
lock (Lock)
{
if (!requests.HasResult(nodeToRead))
{
continue;
}
errors[handle.Index] = requests.GetResult(context, handle.Node, nodeToRead, value, context.DiagnosticsMask);
}
}
}
/// <summary>
/// Reads the specified requests.
/// </summary>
/// <param name="requests">The requests.</param>
/// <param name="useExistingHandles">if set to <c>true</c> use the handles specified in the request objects.</param>
public void Read(HdaReadRequestCollection requests, bool useExistingHandles)
{
// check if nothing to do.
if (requests == null || requests.Count == 0)
{
return;
}
int[] serverHandles = new int[requests.Count];
int[] itemErrors = null;
HdaItem[] items = null;
// check if using existing handles.
if (useExistingHandles)
{
for (int ii = 0; ii < requests.Count; ii++)
{
serverHandles[ii] = requests[ii].ServerHandle;
}
}
// create new handles to use for the request.
else
{
string[] itemIds = new string[requests.Count];
itemErrors = new int[requests.Count];
for (int ii = 0; ii < requests.Count; ii++)
{
itemIds[ii] = requests[ii].ItemId;
}
items = GetItems(itemIds);
for (int ii = 0; ii < requests.Count; ii++)
{
serverHandles[ii] = items[ii].ServerHandle;
itemErrors[ii] = items[ii].Error;
}
}
// read attributes.
try
{
for (int ii = 0; ii < serverHandles.Length; ii++)
{
HdaReadRequest request = requests[ii];
if (itemErrors != null && itemErrors[ii] < 0)
{
request.SetError(request.AttributeIds.Count);
continue;
}
try
{
int[] attributeIds = new int[request.AttributeIds.Count];
for (int jj = 0; jj < attributeIds.Length; jj++)
{
attributeIds[jj] = Utils.ToInt32(request.AttributeIds[jj]);
}
request.AttributeValues = ReadAttributeValues(serverHandles[ii], attributeIds);
}
catch (Exception e)
{
request.SetError(Marshal.GetHRForException(e));
}
}
}
finally
{
if (items != null)
{
ReleaseItemHandles(items);
}
}
}
/// <summary>
/// Called when the scan attributes timer expires.
/// </summary>
private void DoScan(Dictionary<string, HdaSubscribeAttributeRequest> requests, bool initialUpdate)
{
try
{
ComHdaClientManager system = (ComHdaClientManager)m_context.SystemHandle;
ComHdaClient client = (ComHdaClient)system.SelectClient(m_context, false);
// ensure all requests have valid handles.
AssignHandles(client, requests);
// collect the list of attributes that need reading.
HdaReadRequestCollection itemsToRead = new HdaReadRequestCollection();
List<HdaSubscribeAttributeRequest> subscribeRequests = new List<HdaSubscribeAttributeRequest>();
List<HdaReadRequest> readRequestsForSubscribeRequests = new List<HdaReadRequest>();
lock (m_lock)
{
DateTime now = DateTime.UtcNow;
foreach (KeyValuePair<string,HdaSubscribeAttributeRequest> entry in requests)
{
// check if it is time for an update.
if (!initialUpdate && entry.Value.NextUpdateTime > now)
{
continue;
}
// create a read request for each monitored item.
bool somethingToDo = false;
for (int ii = 0; ii < entry.Value.MonitoredItems.Count; ii++)
{
MonitoredItem monitoredItem = entry.Value.MonitoredItems[ii];
NodeHandle handle = monitoredItem.ManagerHandle as NodeHandle;
if (handle == null)
{
continue;
}
// check if item is not valid.
if (entry.Value.ServerHandle == null)
{
monitoredItem.QueueValue(null, StatusCodes.BadNodeIdUnknown);
continue;
}
ReadValueId valueToRead = monitoredItem.GetReadValueId();
bool queued = false;
StatusCode error = itemsToRead.Add(handle.Node, valueToRead, out queued);
if (StatusCode.IsBad(error))
{
monitoredItem.QueueValue(null, error);
continue;
}
if (!somethingToDo && queued)
{
// add server handle to read request.
HdaReadRequest request = (HdaReadRequest)valueToRead.Handle;
request.ServerHandle = entry.Value.ServerHandle.Value;
// save mapping between subscribe request and read requests.
subscribeRequests.Add(entry.Value);
readRequestsForSubscribeRequests.Add(request);
somethingToDo = true;
}
}
}
// check if nothing to do.
if (requests.Count == 0)
{
return;
}
}
// read the attributes from the server.
client.Read(itemsToRead, true);
// update the monitored items.
lock (m_lock)
{
for (int ii = 0; ii < subscribeRequests.Count; ii++)
{
subscribeRequests[ii].QueueValues(m_context, readRequestsForSubscribeRequests[ii], initialUpdate);
}
}
}
catch (Exception e)
{
Utils.Trace(e, "Unexpected error scanning attributes in HDA COM server.");
}
}