Method TarFile

src/core/vfs/TarFile.cpp:59–150

static_assert(sizeof(header_posix_ustar) == 512);

TarFile::TarFile(const std::filesystem::path& archivePath)
{
    m_ArchivePath = archivePath.lexically_normal().generic_string();
    m_ArchiveFile = fopen(m_ArchivePath.c_str(), "rb");

    if (m_ArchiveFile)
    {
        bool errors = false;

        fseek(m_ArchiveFile, 0, SEEK_END);
        size_t archiveSize = ftello(m_ArchiveFile);
        
        size_t currentPosition = 0;

        while (currentPosition + sizeof(header_posix_ustar) <= archiveSize)
        {
            fseeko(m_ArchiveFile, currentPosition, SEEK_SET);

            header_posix_ustar header{};
            if (fread(&header, sizeof(header), 1, m_ArchiveFile) != 1)
                break;

            currentPosition += sizeof(header);

            // check if this is a regular file
            if (header.typeflag != '0' && header.typeflag != 0)
                continue;

            // combine the file name from prefix and name
            char fileName[sizeof(header.name) + sizeof(header.prefix) + 2];
            size_t prefixLength = strnlen(header.prefix, sizeof(header.prefix));
            size_t nameLength = strnlen(header.name, sizeof(header.name));
            if (prefixLength)
            {
                memcpy(fileName, header.prefix, prefixLength);
                fileName[prefixLength] = '/';
                ++prefixLength;
            }
            if (nameLength)
            {
                memcpy(fileName + prefixLength, header.name, nameLength);
            }
            fileName[nameLength + prefixLength] = 0;

            if (fileName[0] == 0)
                continue;

            // parse the octal size
            size_t fileSize = 0;
            for (char c : header.size)
            {
                if (c < '0' || c > '7')
                    break;

                fileSize = (fileSize << 3) | (c - '0');
            }

            if (fileSize == 0)