Method scan_central_directory

src/zip_archive.cpp:201–247

void zip_archive::scan_central_directory(std::uint16_t const p_num_entries, std::uint32_t const p_central_dir_size, std::uint32_t const p_central_dir_pos)
{
	m_input.seekg(p_central_dir_pos, std::ios::beg);

	for (std::uint16_t i = 0; i < p_num_entries; ++i)
	{
		entry new_entry;
		std::uint16_t fn_length, extra_field_length, file_comment_length;

		m_input.seekg(4 + 3*2, std::ios::cur); // skipping signature, version, required version, bit flag
		read_binary(m_input, new_entry.m_compression_method);
		m_input.seekg(2*2, std::ios::cur); // skipping last mod file time & date
		read_binary(m_input, new_entry.m_CRC32_checksum);
		read_binary(m_input, new_entry.m_compressed_size);
		read_binary(m_input, new_entry.m_uncompressed_size);
		read_binary(m_input, fn_length);
		read_binary(m_input, extra_field_length);
		read_binary(m_input, file_comment_length);
		m_input.seekg(2*2 + 4, std::ios::cur); // skipping disk nr. start, internal & external file attributes
		read_binary(m_input, new_entry.m_offset_to_local_header);

		// copy the filename
		new_entry.m_filename.resize(fn_length);
		m_input.read(&(new_entry.m_filename[0]), new_entry.m_filename.size());
		new_entry.m_filename = normalize_path(new_entry.m_filename);

		// skip extra field & file comment so we are at the next file header in the central directory
		m_input.seekg(extra_field_length + file_comment_length, std::ios::cur);

		// check compression method
		// checking here, to ensure filename, comments etc have been read/skipped
		// and the input position is at the right place for reading the next header
		if ((new_entry.m_compression_method != 0) && (new_entry.m_compression_method != 8))
		{
			LOG_MSG(warning, "zip entry \"" << new_entry.m_filename << "\" uses unsupported compression method " << new_entry.m_compression_method << " - skipping this entry");
			continue;
		}

		// the offset is computed on-demand; 0 means "not computed yet"
		new_entry.m_offset_to_data = 0;

		m_entries[new_entry.m_filename] = new_entry;

		// check if we are outside of the bounds of the central directory
		assert((std::uint32_t(m_input.tellg()) - p_central_dir_pos) <= p_central_dir_size);
	}
}


std::streamoff zip_archive::find_end_of_central_directory()