Method LoadFileList

Engine/source/EtCore/FileSystem/Package/FilePackage.cpp:102–175

--------------------------------- FilePackage::LoadFileList Load all the relevant data about the files without actually loading their content

// Load all the relevant data about the files without actually loading their content
//
void FilePackage::LoadFileList()
{
	ET_ASSERT(m_File != nullptr);

	// read the package header 
	//-------------------------
	uint64 offset = 0u;
	uint64 nextChunkSize = static_cast<uint64>(sizeof(PkgHeader));
	std::vector<uint8> readBinData(std::move(m_File->ReadChunk(offset, nextChunkSize)));
	offset += nextChunkSize;
	PkgHeader const pkgHeader(*reinterpret_cast<PkgHeader const*>(readBinData.data()));

	// read the central directory
	//----------------------------

	// read the entire data chunk for the central directory from the file
	nextChunkSize = static_cast<uint64>(sizeof(PkgFileInfo)) * pkgHeader.numEntries;
	readBinData = std::move(m_File->ReadChunk(offset, nextChunkSize));

	// map into that read data
	offset = 0u;
	std::vector<PkgFileInfo> centralDirectory;
	for (size_t infoIdx = 0u; infoIdx < pkgHeader.numEntries; ++infoIdx)
	{
		PkgFileInfo const* info = reinterpret_cast<PkgFileInfo const*>(readBinData.data() + static_cast<size_t>(offset));
		offset += static_cast<uint64>(sizeof(PkgFileInfo));

		centralDirectory.emplace_back(*info);
	}

	// read the files listed
	//----------------------------
	for (PkgFileInfo const& fileInfo : centralDirectory)
	{
		// start at the offset from the beginning of the package
		offset = fileInfo.offset;
		nextChunkSize = static_cast<uint64>(sizeof(PkgEntry));
		readBinData = std::move(m_File->ReadChunk(offset, nextChunkSize));
		offset += nextChunkSize;

		PkgEntry const* entry = reinterpret_cast<PkgEntry const*>(readBinData.data());

		// get and validate the fileId

		ET_ASSERT(entry->fileId == fileInfo.fileId,
			"File ID didn't match file info from central directory! Expected [%x] - found [%x]",
			fileInfo.fileId, entry->fileId);

		// Create our package file in the map and edit it after to avoid unnecessary file copying
		auto emplaceIt = m_Entries.try_emplace(entry->fileId, PackageEntry());

		if (!emplaceIt.second)
		{
			ET_ASSERT(false, "Entry list already contains a file with ID [%s] !", entry->fileId.ToStringDbg());
			continue;
		}

		PackageEntry& pkgEntry = emplaceIt.first->second;