Method Finish

src/engine/shared/datafile.cpp:1147–1287

}

void CDataFileWriter::Finish()
{
	dbg_assert((bool)m_File, "File not open");

	// Compress data. This takes the majority of the time when saving a datafile,
	// so it's delayed until the end so it can be off-loaded to another thread.
	for(CDataInfo &DataInfo : m_vDatas)
	{
		unsigned long CompressedSize = compressBound(DataInfo.m_UncompressedSize);
		DataInfo.m_pCompressedData = malloc(CompressedSize);
		const int Result = compress2(static_cast<Bytef *>(DataInfo.m_pCompressedData), &CompressedSize, static_cast<Bytef *>(DataInfo.m_pUncompressedData), DataInfo.m_UncompressedSize, CompressionLevelToZlib(DataInfo.m_CompressionLevel));
		DataInfo.m_CompressedSize = CompressedSize;
		free(DataInfo.m_pUncompressedData);
		DataInfo.m_pUncompressedData = nullptr;
		dbg_assert(Result == Z_OK, "datafile zlib compression failed with error %d", Result);
	}

	// Calculate total size of items
	int64_t ItemSize = 0;
	for(const CItemInfo &ItemInfo : m_vItems)
	{
		ItemSize += ItemInfo.m_Size;
		ItemSize += sizeof(CDatafileItem);
	}

	// Calculate total size of data
	int64_t DataSize = 0;
	for(const CDataInfo &DataInfo : m_vDatas)
	{
		DataSize += DataInfo.m_CompressedSize;
	}

	// Calculate complete file size
	const int64_t TypesSize = m_ItemTypes.size() * sizeof(CDatafileItemType);
	const int64_t HeaderSize = sizeof(CDatafileHeader);
	const int64_t OffsetSize = (m_vItems.size() + m_vDatas.size() * 2) * sizeof(int); // ItemOffsets, DataOffsets, DataUncompressedSizes
	const int64_t SwapSize = HeaderSize + TypesSize + OffsetSize + ItemSize;
	const int64_t FileSize = SwapSize + DataSize;

	// This also ensures that SwapSize, ItemSize and DataSize are valid.
	dbg_assert(FileSize <= (int64_t)std::numeric_limits<int>::max(), "File size too large");

	// Construct and write header
	{
		CDatafileHeader Header;
		Header.m_aId[0] = 'D';
		Header.m_aId[1] = 'A';
		Header.m_aId[2] = 'T';
		Header.m_aId[3] = 'A';
		Header.m_Version = 4;
		Header.m_Size = FileSize - Header.SizeOffset();
		Header.m_Swaplen = SwapSize - Header.SizeOffset();
		Header.m_NumItemTypes = m_ItemTypes.size();
		Header.m_NumItems = m_vItems.size();
		Header.m_NumRawData = m_vDatas.size();
		Header.m_ItemSize = ItemSize;
		Header.m_DataSize = DataSize;