Opc.Ua.Server.CustomNodeManager2.HistoryRead C# (CSharp) Method

        public virtual void HistoryRead(
            OperationContext          context, 
            HistoryReadDetails        details, 
            TimestampsToReturn        timestampsToReturn, 
            bool                      releaseContinuationPoints, 
            IList<HistoryReadValueId> nodesToRead, 
            IList<HistoryReadResult>  results, 
            IList<ServiceResult>      errors)
        {
            ServerSystemContext systemContext = m_systemContext.Copy(context);
            IDictionary<NodeId,NodeState> operationCache = new NodeIdDictionary<NodeState>();
            List<NodeHandle> nodesToProcess = new List<NodeHandle>();

            lock (Lock)
            {
                for (int ii = 0; ii < nodesToRead.Count; ii++)
                {
                    HistoryReadValueId nodeToRead = nodesToRead[ii];

                    // skip items that have already been processed.
                    if (nodeToRead.Processed)
                    {
                        continue;
                    }

                    // check for valid handle.
                    NodeHandle handle = GetManagerHandle(systemContext, nodeToRead.NodeId, operationCache);

                    if (handle == null)
                    {
                        continue;
                    }

                    // owned by this node manager.
                    nodeToRead.Processed = true;

                    // create an initial result.
                    HistoryReadResult result = results[ii] = new HistoryReadResult();

                    result.HistoryData       = null;
                    result.ContinuationPoint = null;
                    result.StatusCode        = StatusCodes.Good;

                    // check if the node is a area in memory.
                    if (handle.Node == null)
                    {
                        errors[ii] = StatusCodes.BadNodeIdUnknown;

                        // must validate node in a seperate operation
                        handle.Index = ii;
                        nodesToProcess.Add(handle);

                        continue;
                    }

                    errors[ii] = StatusCodes.BadHistoryOperationUnsupported;

                    // check for data history variable.
                    BaseVariableState variable = handle.Node as BaseVariableState;

                    if (variable != null)
                    {
                        if ((variable.AccessLevel & AccessLevels.HistoryRead) != 0)
                        {
                            handle.Index = ii;
                            nodesToProcess.Add(handle);
                            continue;
                        }
                    }

                    // check for event history object.
                    BaseObjectState notifier = handle.Node as BaseObjectState;

                    if (notifier != null)
                    {
                        if ((notifier.EventNotifier & EventNotifiers.HistoryRead) != 0)
                        {
                            handle.Index = ii;
                            nodesToProcess.Add(handle);
                            continue;
                        }
                    }
                }

                // check for nothing to do.
                if (nodesToProcess.Count == 0)
                {
                    return;
                }
            }

            // validates the nodes (reads values from the underlying data source if required).
            HistoryRead(
                systemContext,
                details,
                timestampsToReturn,
                releaseContinuationPoints,
                nodesToRead,
                results,
                errors,
                nodesToProcess,
                operationCache);
        }