/// <summary>
/// Reads the raw data history.
/// </summary>
/// <param name="request">The request.</param>
public StatusCode ReadAnnotationHistory(HdaHistoryReadAnnotationRequest request)
{
// check if nothing to do.
if (request == null)
{
return StatusCodes.BadNothingToDo;
}
// create the handle.
HdaItem[] items = GetItems(request.ItemId);
if (items == null || items[0].Error < 0)
{
return StatusCodes.BadNodeIdUnknown;
}
request.ServerHandle = items[0].ServerHandle;
try
{
// read modified not supported for annotations.
if (request.IsReadModified)
{
return StatusCodes.BadNoData;
}
// read the values and them in the request object.
return ReadAnnotations(request);
}
catch (Exception)
{
return StatusCodes.BadUnexpectedError;
}
finally
{
ReleaseItemHandles(request.ServerHandle);
request.ServerHandle = 0;
}
}
/// <summary>
/// Reads the annotation data for an item.
/// </summary>
private StatusCode ReadAnnotations(HdaHistoryReadAnnotationRequest request)
{
string methodName = "IOPCHDA_SyncAnnotations.Read";
OPCHDA_TIME htStartTime = ConvertTime(request.StartTime);
OPCHDA_TIME htEndTime = ConvertTime(request.EndTime);
IntPtr ppAnnotationValues;
IntPtr ppErrors;
try
{
IOPCHDA_SyncAnnotations server = BeginComCall<IOPCHDA_SyncAnnotations>(methodName, true);
server.Read(
ref htStartTime,
ref htEndTime,
1,
new int[] { request.ServerHandle },
out ppAnnotationValues,
out ppErrors);
}
catch (Exception e)
{
ComCallError(methodName, e);
return StatusCodes.BadUnexpectedError;
}
finally
{
EndComCall(methodName);
}
// check for error.
int[] errors = ComUtils.GetInt32s(ref ppErrors, 1, true);
if (errors[0] < 0)
{
return StatusCodes.BadNodeIdUnknown;
}
// unmarshal the results.
OPCHDA_ANNOTATION result = (OPCHDA_ANNOTATION)Marshal.PtrToStructure(ppAnnotationValues, typeof(OPCHDA_ANNOTATION));
if (result.dwNumValues > 0)
{
DateTime[] timestamps = ComUtils.GetDateTimes(ref result.ftTimeStamps, result.dwNumValues, true);
string[] annotations = ComUtils.GetUnicodeStrings(ref result.szAnnotation, result.dwNumValues, true);
DateTime[] annotationTimes = ComUtils.GetDateTimes(ref result.ftAnnotationTime, result.dwNumValues, true);
string[] userNames = ComUtils.GetUnicodeStrings(ref result.szUser, result.dwNumValues, true);
request.Annotations = new List<DataValue>(result.dwNumValues);
for (int ii = 0; ii < result.dwNumValues; ii++)
{
Annotation annotation = new Annotation();
annotation.AnnotationTime = annotationTimes[ii];
annotation.Message = annotations[ii];
annotation.UserName = userNames[ii];
DataValue value = new DataValue(new Variant(new ExtensionObject(annotation)));
value.SourceTimestamp = timestamps[ii];
request.Annotations.Add(value);
}
}
Marshal.FreeCoTaskMem(ppAnnotationValues);
return StatusCodes.Good;
}
/// <summary>
/// Reads the history of an HDA item annotations.
/// </summary>
private ServiceResult HistoryReadAnnotations(
ServerSystemContext context,
ComHdaClient client,
ReadRawModifiedDetails details,
TimestampsToReturn timestampsToReturn,
HistoryReadValueId nodeToRead,
HdaParsedNodeId parsedNodeId,
HistoryReadResult result)
{
// create the request or load it from a continuation point.
HdaHistoryReadAnnotationRequest request = null;
if (nodeToRead.ContinuationPoint == null)
{
// create a new request.
request = new HdaHistoryReadAnnotationRequest(parsedNodeId.RootId, details, nodeToRead);
// fetch all of the data at once.
result.StatusCode = client.ReadAnnotationHistory(request);
}
else
{
request = LoadContinuationPoint(context, nodeToRead.ContinuationPoint) as HdaHistoryReadAnnotationRequest;
if (request == null)
{
return StatusCodes.BadContinuationPointInvalid;
}
}
// select a subset of the results.
if (StatusCode.IsGood(result.StatusCode))
{
request.Results = new DataValueCollection();
request.GetHistoryResults(context, nodeToRead, request.Results);
}
// fill in the results.
if (request.Results != null)
{
HistoryData data = new HistoryData();
data.DataValues = request.Results;
result.HistoryData = new ExtensionObject(data);
}
// create a new continuation point.
if (!request.Completed)
{
result.ContinuationPoint = SaveContinuationPoint(context, request);
}
return result.StatusCode;
}
