/// <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);
}
}
}
