/// <summary>
/// Unmarshals and deallocates a OPCITEMSTATE structures.
/// </summary>
internal static DaValue[] GetItemValues(ref IntPtr pInput, int count, bool deallocate)
{
DaValue[] output = null;
if (pInput != IntPtr.Zero && count > 0)
{
output = new DaValue[count];
IntPtr pos = pInput;
for (int ii = 0; ii < count; ii++)
{
OpcRcw.Da.OPCITEMSTATE result = (OpcRcw.Da.OPCITEMSTATE)Marshal.PtrToStructure(pos, typeof(OpcRcw.Da.OPCITEMSTATE));
DaValue value = new DaValue();
value.Value = ComUtils.ProcessComValue(result.vDataValue);
value.Quality = result.wQuality;
value.Timestamp = ComUtils.GetDateTime(result.ftTimeStamp);
output[ii] = value;
if (deallocate)
{
Marshal.DestroyStructure(pos, typeof(OpcRcw.Da.OPCITEMSTATE));
}
pos = (IntPtr)(pos.ToInt32() + Marshal.SizeOf(typeof(OpcRcw.Da.OPCITEMSTATE)));
}
if (deallocate)
{
Marshal.FreeCoTaskMem(pInput);
pInput = IntPtr.Zero;
}
}
return(output);
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^//
#region IOPCSyncIO Members
/// <summary>
/// IOPCSyncIO::Read - Reads the value, quality and timestamp information for one or more items in a group
/// </summary>
public void Read(
OpcRcw.Da.OPCDATASOURCE dwSource,
int dwCount,
int[] phServer,
out System.IntPtr ppItemValues,
out System.IntPtr ppErrors)
{
// validate arguments.
if (dwCount == 0 || phServer == null || dwCount != phServer.Length)
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDARG);
}
try
{
OpcRcw.Da.OPCITEMSTATE[] results = new OpcRcw.Da.OPCITEMSTATE[dwCount];
int[] errors = new int[dwCount];
VarEnum[] reqTypes = new VarEnum[dwCount];
// use the minimum max age for all items.
int maxAge = (dwSource == OPCDATASOURCE.OPC_DS_CACHE)?Int32.MaxValue:0;
// build list of values to read.
ReadValueIdCollection nodesToRead = new ReadValueIdCollection();
List<Item> itemsToRead = new List<Item>();
lock (m_lock)
{
if (m_subscription == null) throw ComUtils.CreateComException(ResultIds.E_FAIL);
for (int ii = 0; ii < dwCount; ii++)
{
results[ii].hClient = 0;
results[ii].vDataValue = null;
results[ii].wQuality = OpcRcw.Da.Qualities.OPC_QUALITY_BAD;
results[ii].ftTimeStamp = ComUtils.GetFILETIME(DateTime.MinValue);
results[ii].wReserved = 0;
Item itemToRead = null;
if (!m_items.TryGetValue(phServer[ii], out itemToRead))
{
errors[ii] = ResultIds.E_INVALIDHANDLE;
continue;
}
results[ii].hClient = itemToRead.ClientHandle;
// check if reading from the cache.
if (dwSource == OPCDATASOURCE.OPC_DS_CACHE)
{
// read the value from cache.
DataValue cachedValue = ReadCachedValue(itemToRead, Int32.MaxValue);
if (cachedValue != null)
{
// get value from the cache.
object value = null;
short quality = Qualities.OPC_QUALITY_BAD;
DateTime timestamp = DateTime.MinValue;
errors[ii] = ProcessReadResult(
phServer[ii],
itemToRead.ReqType,
cachedValue,
out value,
out quality,
out timestamp);
// all done if a suitable value is in the cache.
if (!m_active || !itemToRead.Active)
{
quality = Qualities.OPC_QUALITY_OUT_OF_SERVICE;
}
results[ii].vDataValue = value;
results[ii].wQuality = quality;
results[ii].ftTimeStamp = ComUtils.GetFILETIME(timestamp);
continue;
}
}
// save the requested data type.
reqTypes[ii] = itemToRead.ReqType;
ReadValueId nodeToRead = new ReadValueId();
nodeToRead.NodeId = itemToRead.MonitoredItem.ResolvedNodeId;
nodeToRead.AttributeId = Attributes.Value;
// needed to correlate results to input.
nodeToRead.Handle = ii;
nodesToRead.Add(nodeToRead);
itemsToRead.Add(itemToRead);
}
}
// read values from server.
DataValueCollection values = null;
DiagnosticInfoCollection diagnosticInfos = null;
if (nodesToRead.Count > 0)
{
m_session.Read(
null,
maxAge,
TimestampsToReturn.Both,
nodesToRead,
out values,
out diagnosticInfos);
// validate response from the UA server.
ClientBase.ValidateResponse(values, nodesToRead);
ClientBase.ValidateDiagnosticInfos(diagnosticInfos, nodesToRead);
}
for (int ii = 0; ii < nodesToRead.Count; ii++)
{
// get index in original array.
int index = (int)nodesToRead[ii].Handle;
// process the read result.
object value = null;
short quality = Qualities.OPC_QUALITY_BAD;
DateTime timestamp = DateTime.MinValue;
int error = ProcessReadResult(
phServer[index],
reqTypes[index],
values[ii],
out value,
out quality,
out timestamp);
// update the cache.
UpdateCachedValue(itemsToRead[ii], values[ii]);
// check for error.
if (error < 0)
{
errors[index] = error;
continue;
}
// update response.
results[index].vDataValue = value;
results[index].wQuality = quality;
results[index].ftTimeStamp = ComUtils.GetFILETIME(timestamp);
errors[index] = ResultIds.S_OK;
}
// marshal the results.
ppItemValues = Marshal.AllocCoTaskMem(Marshal.SizeOf(typeof(OPCITEMSTATE))*dwCount);
IntPtr pos = ppItemValues;
for (int ii = 0; ii < dwCount; ii++)
{
Marshal.StructureToPtr(results[ii], pos, false);
pos = (IntPtr)(pos.ToInt32() + Marshal.SizeOf(typeof(OpcRcw.Da.OPCITEMSTATE)));
}
// marshal error codes.
ppErrors = ComUtils.GetInt32s(errors);
}
catch (Exception e)
{
Utils.Trace(e, "Error reading items.");
throw ComUtils.CreateComException(e);
}
}