Opc.Ua.Server.MasterNodeManager.Read C# (CSharp) Method

        public virtual void Read(
            OperationContext             context,
            double                       maxAge,
            TimestampsToReturn           timestampsToReturn,
            ReadValueIdCollection        nodesToRead,
            out DataValueCollection      values,
            out DiagnosticInfoCollection diagnosticInfos)
        {
            if (nodesToRead == null) throw new ArgumentNullException("nodesToRead");
            
            if (maxAge < 0)
            {
                throw new ServiceResultException(StatusCodes.BadMaxAgeInvalid);
            }

            if (timestampsToReturn < TimestampsToReturn.Source || timestampsToReturn > TimestampsToReturn.Neither)
            {
                throw new ServiceResultException(StatusCodes.BadTimestampsToReturnInvalid);
            }

            bool diagnosticsExist = false;
            values = new DataValueCollection(nodesToRead.Count);
            diagnosticInfos = new DiagnosticInfoCollection(nodesToRead.Count);

            // create empty list of errors.
            List<ServiceResult> errors = new List<ServiceResult>(values.Count);

            for (int ii = 0; ii < nodesToRead.Count; ii++)
            {
                errors.Add(null);
            }

            // add placeholder for each result.
            bool validItems = false;
        
            Utils.Trace(
                (int)Utils.TraceMasks.ServiceDetail, 
                "MasterNodeManager.Read - Count={0}", 
                nodesToRead.Count);

            for (int ii = 0; ii < nodesToRead.Count; ii++)
            {
                DataValue value = null;
                DiagnosticInfo diagnosticInfo = null;
                
                // pre-validate and pre-parse parameter.
                errors[ii] = ReadValueId.Validate(nodesToRead[ii]);
                
                // return error status.
                if (ServiceResult.IsBad(errors[ii]))
                {
                    nodesToRead[ii].Processed = true;
                }

                // found at least one valid item.
                else
                {
                    nodesToRead[ii].Processed = false;
                    validItems = true;
                }

                values.Add(value);
                diagnosticInfos.Add(diagnosticInfo);
            }

            // call each node manager.
            if (validItems)
            {                
                for (int ii = 0; ii < m_nodeManagers.Count; ii++)
                {
                    Utils.Trace(
                        (int)Utils.TraceMasks.ServiceDetail, 
                        "MasterNodeManager.Read - Calling NodeManager {0} of {1}", 
                        ii,
                        m_nodeManagers.Count);

                    m_nodeManagers[ii].Read(
                        context,
                        maxAge,
                        nodesToRead,
                        values,
                        errors);
                }
            }

            // process results.
            for (int ii = 0; ii < nodesToRead.Count; ii++)
            {
                DataValue value = values[ii];

                // set an error code for nodes that were not handled by any node manager.
                if (!nodesToRead[ii].Processed)
                {
                    value = values[ii] = new DataValue(StatusCodes.BadNodeIdUnknown, DateTime.UtcNow);
                    errors[ii] = new ServiceResult(values[ii].StatusCode);
                }

                // update the diagnostic info and ensure the status code in the data value is the same as the error code.
                if (errors[ii] != null && errors[ii].Code != StatusCodes.Good)
                {
                    if (value == null)
                    {
                        value = values[ii] = new DataValue(errors[ii].Code, DateTime.UtcNow);
                    }

                    value.StatusCode = errors[ii].Code;

                    if ((context.DiagnosticsMask & DiagnosticsMasks.OperationAll) != 0)
                    {
                        diagnosticInfos[ii] = ServerUtils.CreateDiagnosticInfo(m_server, context, errors[ii]);
                        diagnosticsExist = true;
                    }
                }

                // apply the timestamp filters.
                if (timestampsToReturn != TimestampsToReturn.Server && timestampsToReturn != TimestampsToReturn.Both)
                {
                    value.ServerTimestamp = DateTime.MinValue;
                }

                if (timestampsToReturn != TimestampsToReturn.Source && timestampsToReturn != TimestampsToReturn.Both)
                {
                    value.SourceTimestamp = DateTime.MinValue;
                }
            }

            // clear the diagnostics array if no diagnostics requested or no errors occurred.
            UpdateDiagnostics(context, diagnosticsExist, ref diagnosticInfos);
        }