EM_EXPORT void urlstream_on_open(int stream, void* ud);
EM_EXPORT void urlstream_on_progress(int stream, void* ud, int loaded, int total);
EM_EXPORT void urlstream_on_error(int stream, void* ud, int code, const char* message);
EM_EXPORT void urlstream_on_data(int stream, void* ud, void* ptr, size_t len);
EM_EXPORT void urlstream_on_complete(int stream, void* ud);