/// <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)
{
ComDaClientManager system = (ComDaClientManager)this.SystemContext.SystemHandle;
ComDaClient client = system.SelectClient((ServerSystemContext)SystemContext, false);
ReadRequestCollection requests = new ReadRequestCollection();
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, value, out queued);
if (queued)
{
continue;
}
// read built-in metadata.
errors[handle.Index] = source.ReadAttribute(
context,
nodeToRead.AttributeId,
nodeToRead.ParsedIndexRange,
nodeToRead.DataEncoding,
value);
}
}
// read the values from the server.
client.Read(requests);
// 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);
}
}
}
