void set_data(const char *d, size_t len) { data = d; data_len = len; }
// Write an object to a segment, thus making it permanent. This function
// can be called at most once.
void write(TarSegmentStore *store);
void set_data(const char *d, size_t len) { data = d; data_len = len; }
// Write an object to a segment, thus making it permanent. This function
// can be called at most once.
void write(TarSegmentStore *store);