C++ FilePtr::getFileClass方法代码示例

//---------------------------------------------------------------------------
long File::open (FilePtr _parent, unsigned long fileSize, long numChild)
{
	if (_parent && (_parent->fastFile == NULL))
	{
		parent = _parent;
		if (parent->getFileMode() != READ)
		{
			return(CANT_WRITE_TO_CHILD);
		}
		
		physicalLength = fileSize;
		parentOffset = parent->getLogicalPosition();
		logicalPosition = 0;

		//-------------------------------------------------------------
		fileName = parent->getFilename();
		fileMode = parent->getFileMode();
		
		handle = parent->getFileHandle();
		
		if (logFileTraffic)
		{
			if (!fileTrafficLog)
			{
				createTrafficLog();
			}
		
			char msg[300];
			sprintf(msg,"CHILD     Length: %010d    File: %s",fileSize,_parent->getFilename());
			fileTrafficLog->writeLine(msg);
		}

		long result = parent->addChild(this);
		if (result != NO_ERR)
			return(result);

		//------------------------------------------------------------
		// NEW FUNCTIONALITY!!!
		// 
		// Each file may have a number of files open as children which
		// use the parent's handle for reads and writes.  This would
		// allow us to open a packet file and read a packet as a fitIni
		// or allow us to write a packet as a fit ini and so forth.
		//
		// It also allows us to use the packet file extensions as tree
		// files to avoid the ten thousand file syndrome.
		//
		// There is now an open which takes a FilePtr and a size.
		// 
		// IF a numChild parameter is passed in as -1, we want this file in RAM!!
		// This means NO CHILDREN!!!!!!!!!!!!!
		if (numChild != -1)
		{
			maxChildren = numChild;
			childList = (FilePtr *)systemHeap->Malloc(sizeof(FilePtr) * maxChildren);
			
			gosASSERT(childList != NULL);

			numChildren = 0;
			for (long i=0;i<(long)maxChildren;i++)
			{
				childList[i] = NULL;
			}	
		}
		else
		{
			maxChildren = 0;
			inRAM = TRUE;
			unsigned long result = 0;

			fileImage = (MemoryPtr)malloc(fileSize);
			if (!fileImage)
				inRAM = FALSE;

			if (_parent->getFileClass() == PACKETFILE)
			{
				result = ((PacketFilePtr)_parent)->readPacket(((PacketFilePtr)_parent)->getCurrentPacket(),fileImage);
			}
			else
			{
				result = _read(handle,fileImage,fileSize);
				if (result != fileSize)
					lastError = errno;
			}
		}
	}
	else
	{
		return(PARENT_NULL);
	}
	
	return(NO_ERR);
}