Function xread

module/src/main/cpp/utils.cpp:367–380

template <typename T>
std::unique_ptr<T> xread(int fd) {
	uint64_t size = 0;
	if (read(fd, &size, sizeof(size)) != sizeof(size)) {
		return nullptr;
	}
	if (size != sizeof(T)) {
		return nullptr;
	}
	auto data = std::make_unique<T>();
	if (read(fd, data.get(), size) != static_cast<ssize_t>(size)) {
		return nullptr;
	}
	return data;
}

template<>
std::unique_ptr<std::string> xread<std::string>(int fd) {