public DWORD AddTag(Tag.TAGENTRY tTagEntry, DWORD relativeOffset, out Tag _refTag)
{
DWORD readOffset = 0;
DWORD writeOffset = 0;
DWORD nextAvailableDataOffset = 0; //offset for next data block
DWORD nextAvailableTagOffset = 0; //offset for next tag
Tag refTag; //= NULL;
Device refDevice = this;
//Create new Tag
refTag = new Tag(ref refDevice, tTagEntry, relativeOffset, GetSharedMemoryOffset());
_refTag = refTag;
if (refTag.Equals(null))
{
Trace.Assert(false);
return (relativeOffset); //re-use this offset for the next tag
}
//Determine register's read offset
if (refTag.IsReadable())
{
readOffset = Register.DATA_MIN_OFFSET;
nextAvailableDataOffset = readOffset + Register.DATA_SIZE_MIN + refTag.GetReadValueExtSize();
//Determine register's write offset
if (refTag.IsWriteable())
{
//read/write
writeOffset = nextAvailableDataOffset;
nextAvailableDataOffset = writeOffset + Register.DATA_SIZE_MIN + refTag.GetWriteValueExtSize();
}
else
{
//read-only
writeOffset = 0;
}
}
else
{
readOffset = 0;
//Determine register's write offset
if (refTag.IsWriteable())
{
//write-only
writeOffset = Register.DATA_MIN_OFFSET;
nextAvailableDataOffset = writeOffset + Register.DATA_SIZE_MIN + refTag.GetWriteValueExtSize();
}
else
{
//neither read or write
Debug.Assert(false);
writeOffset = 0;
}
}
//Prepare the register offset for the next tag (if applicable)
nextAvailableTagOffset = relativeOffset + nextAvailableDataOffset;
string msg = "";
//Check for Shared Memory file overrun
if ((GetSharedMemoryOffset() + nextAvailableTagOffset) > SharedMemServer.MAPSIZE)
{
//Reached the limits of our Shared Memory file
//Don't add tag
msg = string.Format("Tag {0,0:T} could not be added.", refTag.GetName()) +
string.Format("Register {0,0:D} with size ", refTag.GetSharedMemoryOffset()) +
string.Format("{0,0:D} bytes would exceed Shared Memory file size of ", (DWORD)(writeOffset + Register.DATA_SIZE_MIN + refTag.GetExtendedSize())) +
string.Format("{0,0:D}", SharedMemServer.MAPSIZE);
logger.Trace(msg);
return (relativeOffset);
}
int nRC = TagData.SMRC_NO_ERROR;
//Initialize register if we have access to shared memory
if (CID.memStream != null)
{
Register.SetReadOffset(CID.memStream, (long)refTag.GetSharedMemoryOffset(), readOffset);
Register.SetWriteOffset(CID.memStream, (long)refTag.GetSharedMemoryOffset(), writeOffset);
Register.SetReadValueType(CID.memStream, (long)refTag.GetSharedMemoryOffset(), refTag.GetReadValueType());
if (writeOffset != 0)
{
Register.SetWriteValueType(CID.memStream, (long)refTag.GetSharedMemoryOffset(), refTag.GetWriteValueType());
}
Register.SetReadValueExtSize(CID.memStream, (long)refTag.GetSharedMemoryOffset(), refTag.GetReadValueExtSize());
if (writeOffset != 0)
{
Register.SetWriteValueExtSize(CID.memStream, (long)refTag.GetSharedMemoryOffset(), refTag.GetWriteValueExtSize());
}
if (refTag.GetDataType() == (ushort)(Value.T_ARRAY | Value.T_STRING))
{
nRC = Register.SetReadValueArrayStringSize(CID.memStream, (long)refTag.GetSharedMemoryOffset(), refTag.GetReadValueArrayStringSize());
if (writeOffset != 0)
{
nRC = Register.SetWriteValueArrayStringSize(CID.memStream, (long)refTag.GetSharedMemoryOffset(), (WORD)refTag.GetWriteValueArrayStringSize());
}
}
} //if (pSharedMemoryBaseMem != null)
//Add tag to our tag set
tagSet.Add(refTag);
msg = string.Format("Tag {0,0:T}: assigned to Register " +
"{1,0:D} with size " +
"{2,0:D} bytes. Relative offset = " +
"{3,0:D}", refTag.GetName(), refTag.GetSharedMemoryOffset(),
nextAvailableDataOffset,
refTag.GetRelativeOffset());
logger.Trace(msg);
return (nextAvailableTagOffset);
}