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#include "Archive.hpp"
constexpr uint8_t kMagicNumbers[] = { 0x98, 0xd8, 0xa4, 0x65, 0x18, 0xa2, 0xd6, 0xa0 };
constexpr size_t kMagicNumberCount = std::size(kMagicNumbers);
constexpr uint8_t kByteOrderMark = []() {
switch (std::endian::native) {
case std::endian::little: return 0;
case std::endian::big: return 1;
}
}();
std::optional<DataArchive> DataArchive::SaveFile(const std::filesystem::path& path)
{
auto archive = DataArchive(DataStream(std::fstream(path)));
auto& stream = archive.mStream;
stream.WriteBytes(kMagicNumberCount, kMagicNumbers);
stream.Write(kByteOrderMark);
stream.SetEndianness(std::endian::native);
return archive;
}
std::optional<DataArchive> DataArchive::LoadFile(const std::filesystem::path& path)
{
auto archive = DataArchive(DataStream(std::fstream(path)));
auto& stream = archive.mStream;
uint8_t magicNumbers[kMagicNumberCount];
stream.ReadBytes(kMagicNumberCount, magicNumbers);
for (size_t i = 0; i < kMagicNumberCount; ++i) {
if (magicNumbers[i] != kMagicNumbers[i]) {
return {};
}
}
uint8_t byteOrderMark;
stream.Read(byteOrderMark);
switch (byteOrderMark) {
case 0: stream.SetEndianness(std::endian::little); break;
case 1: stream.SetEndianness(std::endian::big); break;
default: std::abort();
}
return archive;
}
const DataStream& DataArchive::GetStream() const
{
return mStream;
}
DataStream& DataArchive::GetStream()
{
return mStream;
}
DataArchive::DataArchive(DataStream stream)
: mStream(std::move(stream))
{
}
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