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

        public virtual void HistoryRead(
            OperationContext                context,
            ExtensionObject                 historyReadDetails, 
            TimestampsToReturn              timestampsToReturn, 
            bool                            releaseContinuationPoints, 
            HistoryReadValueIdCollection    nodesToRead, 
            out HistoryReadResultCollection results, 
            out DiagnosticInfoCollection    diagnosticInfos)
        {
            // validate history details parameter.
            if (ExtensionObject.IsNull(historyReadDetails))
            {
                throw new ServiceResultException(StatusCodes.BadHistoryOperationInvalid);
            }

            HistoryReadDetails details = historyReadDetails.Body as HistoryReadDetails;

            if (details == null)
            {
                throw new ServiceResultException(StatusCodes.BadHistoryOperationUnsupported);
            }
            
            // create result lists.
            bool diagnosticsExist = false;
            results = new HistoryReadResultCollection(nodesToRead.Count);
            diagnosticInfos = new DiagnosticInfoCollection(nodesToRead.Count);

            // pre-validate items.
            bool validItems = false;

            for (int ii = 0; ii < nodesToRead.Count; ii++)
            {
                HistoryReadResult result = null;
                DiagnosticInfo diagnosticInfo = null;

                // pre-validate and pre-parse parameter.
                ServiceResult error = HistoryReadValueId.Validate(nodesToRead[ii]);
                
                // return error status.
                if (ServiceResult.IsBad(error))
                {
                    nodesToRead[ii].Processed = true;
                    result = new HistoryReadResult();
                    result.StatusCode = error.Code;
                    
                    // add diagnostics if requested.
                    if ((context.DiagnosticsMask & DiagnosticsMasks.OperationAll) != 0)
                    {
                        diagnosticInfo = ServerUtils.CreateDiagnosticInfo(m_server, context, error);
                        diagnosticsExist = true;
                    }
                }

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

                results.Add(result);
                diagnosticInfos.Add(diagnosticInfo);
            } 
            
            // call each node manager.
            if (validItems)
            {
                List<ServiceResult> errors = new List<ServiceResult>(results.Count);

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

                foreach (INodeManager nodeManager in m_nodeManagers)
                {
                    nodeManager.HistoryRead(
                        context,
                        details,
                        timestampsToReturn,
                        releaseContinuationPoints,
                        nodesToRead,
                        results,
                        errors);
                }
                                
                for (int ii = 0; ii < nodesToRead.Count; ii++)
                {
                    HistoryReadResult result = results[ii];
 
                    // set an error code for nodes that were not handled by any node manager.
                    if (!nodesToRead[ii].Processed)
                    {
                        nodesToRead[ii].Processed = true;
                        result = results[ii] = new HistoryReadResult();
                        result.StatusCode = StatusCodes.BadNodeIdUnknown;
                        errors[ii] = results[ii].StatusCode;
                    }
                    
                    // update the diagnostic info and ensure the status code in the result is the same as the error code.
                    if (errors[ii] != null && errors[ii].Code != StatusCodes.Good)
                    {
                        if (result == null)
                        {
                            result = results[ii] = new HistoryReadResult();
                        }

                        result.StatusCode = errors[ii].Code;
                        
                        // add diagnostics if requested.
                        if ((context.DiagnosticsMask & DiagnosticsMasks.OperationAll) != 0)
                        {
                            diagnosticInfos[ii] = ServerUtils.CreateDiagnosticInfo(m_server, context, errors[ii]);
                            diagnosticsExist = true;
                        }
                    }
                }
            }

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