int64_t elapsed_seconds = new_time.tv_sec - start_time.tv_sec;
int64_t total_seconds = elapsed_seconds * total_bytes / bytes_processed;
int64_t eta = total_seconds - elapsed_seconds;
int64_t elapsed_seconds = new_time.tv_sec - start_time.tv_sec;
int64_t total_seconds = elapsed_seconds * total_bytes / bytes_processed;
int64_t eta = total_seconds - elapsed_seconds;