/// <summary>
/// Reads the history for a single node which has already been validated.
/// </summary>
protected virtual ServiceResult HistoryRead(
ISystemContext context,
NodeState source,
HistoryReadDetails details,
TimestampsToReturn timestampsToReturn,
bool releaseContinuationPoints,
HistoryReadValueId nodesToRead,
HistoryReadResult result)
{
// check for variable.
BaseVariableState variable = source as BaseVariableState;
if (variable == null)
{
return StatusCodes.BadHistoryOperationUnsupported;
}
// check for access.
lock (Lock)
{
if ((variable.AccessLevel & AccessLevels.HistoryRead) == 0)
{
return StatusCodes.BadNotReadable;
}
}
// handle read raw.
ReadRawModifiedDetails readRawDetails = details as ReadRawModifiedDetails;
if (readRawDetails != null)
{
return HistoryReadRaw(
context,
variable,
readRawDetails,
timestampsToReturn,
releaseContinuationPoints,
nodesToRead,
result);
}
// handle read processed.
ReadProcessedDetails readProcessedDetails = details as ReadProcessedDetails;
if (readProcessedDetails != null)
{
return HistoryReadProcessed(
context,
variable,
readProcessedDetails,
timestampsToReturn,
releaseContinuationPoints,
nodesToRead,
result);
}
// handle read processed.
ReadAtTimeDetails readAtTimeDetails = details as ReadAtTimeDetails;
if (readAtTimeDetails != null)
{
return HistoryReadAtTime(
context,
variable,
readAtTimeDetails,
timestampsToReturn,
releaseContinuationPoints,
nodesToRead,
result);
}
return StatusCodes.BadHistoryOperationUnsupported;
}
/// <summary>
/// Reads the history for the specified nodes.
/// </summary>
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<ReadWriteOperationState> nodesToValidate = new List<ReadWriteOperationState>();
List<ReadWriteOperationState> readsToComplete = new List<ReadWriteOperationState>();
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.
NodeState source = GetManagerHandle(systemContext, nodeToRead.NodeId, operationCache) as NodeState;
if (source == null)
{
continue;
}
// owned by this node manager.
nodeToRead.Processed = true;
// only variables supported.
BaseVariableState variable = source as BaseVariableState;
if (variable == null)
{
errors[ii] = StatusCodes.BadHistoryOperationUnsupported;
continue;
}
results[ii] = new HistoryReadResult();
ReadWriteOperationState operation = new ReadWriteOperationState();
operation.Source = source;
operation.Index = ii;
// check if the node is ready for reading.
if (source.ValidationRequired)
{
// must validate node in a seperate operation.
errors[ii] = StatusCodes.BadNodeIdUnknown;
nodesToValidate.Add(operation);
continue;
}
// read the data.
readsToComplete.Add(operation);
}
// validates the nodes (reads values from the underlying data source if required).
for (int ii = 0; ii < nodesToValidate.Count; ii++)
{
ReadWriteOperationState operation = nodesToValidate[ii];
if (!ValidateNode(systemContext, operation.Source))
{
continue;
}
readsToComplete.Add(operation);
}
}
// reads the data without holding onto the lock.
for (int ii = 0; ii < readsToComplete.Count; ii++)
{
ReadWriteOperationState operation = readsToComplete[ii];
errors[operation.Index] = HistoryRead(
systemContext,
operation.Source,
details,
timestampsToReturn,
releaseContinuationPoints,
nodesToRead[operation.Index],
results[operation.Index]);
}
}
