Method Write

Engine/source/EtCooker/PackageWriter.cpp:117–200

--------------------------------- PackageWriter::Write Write the listed files to the data vector

// Write the listed files to the data vector
//
void PackageWriter::Write(std::vector<uint8>& data)
{
	// we do a first pass where we figure out the relative offset for all files
	//---------------------------
	uint64 offset = 0u;

	// as we go we can figure out the header
	core::PkgHeader header;
	header.numEntries = static_cast<uint64>(m_Files.size());
	offset += static_cast<uint64>(sizeof(core::PkgHeader));

	// and the size that our central directory will be
	offset += static_cast<uint64>(sizeof(core::PkgFileInfo)) * header.numEntries;

	// as we go we can fill in the entry information
	std::vector<core::PkgFileInfo> fileInfos;
	for (FileEntryInfo& entryFile : m_Files)
	{
		core::PkgFileInfo info;
		info.fileId = entryFile.entry.fileId;
		info.offset = offset;

		// we already know the offset so we can add the file entry
		fileInfos.emplace_back(info);

		// accumulate our offset
		core::PkgEntry& entry = entryFile.entry;
		offset += sizeof(core::PkgEntry) + static_cast<uint64>(entry.nameLength) + entry.size;
	}

	// now we know the total size of the package file will be our offset, so we can initialize our data vector starting with the right size
	//---------------------------
	data = std::vector<uint8>(static_cast<size_t>(offset), 0u);
	uint8* raw = data.data();

	// finally we can write our data to the vector
	//---------------------------

	// header
	memcpy(raw, &header, sizeof(core::PkgHeader));
	offset = sizeof(core::PkgHeader);	// we can reuse it now that our vector has bin initialized

	// central dir
	for (core::PkgFileInfo const& info : fileInfos)
	{
		memcpy(raw + offset, &info, sizeof(core::PkgFileInfo));
		offset += sizeof(core::PkgFileInfo);
	}

	// files
	for (size_t entryIndex = 0u; entryIndex < m_Files.size(); ++entryIndex)
	{
		FileEntryInfo& entryFile = m_Files[entryIndex];

		if (offset != fileInfos[entryIndex].offset)
		{
			LOG("PackageWriter::Write > Entry offset doesn't match expected offset - " + entryFile.relName, core::LogLevel::Error);
		}