Function simplicity_decodeMallocDag

src/simplicity/deserialize.c:188–216

Decode a length-prefixed Simplicity DAG from 'stream'. * Returns 'SIMPLICITY_ERR_DATA_OUT_OF_RANGE' the length prefix's value is too large. * Returns 'SIMPLICITY_ERR_DATA_OUT_OF_RANGE' if some node's child isn't a reference to one of the preceding nodes. * Returns 'SIMPLICITY_ERR_FAIL_CODE' if the encoding of a fail expression is encountered * (all fail subexpressions ought to have been prune

 *                NULL == *dag when the return value is negative.
 */
int_fast32_t simplicity_decodeMallocDag(dag_node** dag, simplicity_callback_decodeJet decodeJet, combinator_counters* census, bitstream* stream) {
  *dag = NULL;
  int32_t dagLen = simplicity_decodeUptoMaxInt(stream);
  if (dagLen <= 0) return dagLen;
  static_assert(DAG_LEN_MAX <= (uint32_t)INT32_MAX, "DAG_LEN_MAX exceeds supported parsing range.");
  if (DAG_LEN_MAX < (uint32_t)dagLen) return SIMPLICITY_ERR_DATA_OUT_OF_RANGE;
  static_assert(DAG_LEN_MAX <= SIZE_MAX / sizeof(dag_node), "dag array too large.");
  static_assert(1 <= DAG_LEN_MAX, "DAG_LEN_MAX is zero.");
  static_assert(DAG_LEN_MAX - 1 <= UINT32_MAX, "dag array index does not fit in uint32_t.");
  *dag = simplicity_malloc((size_t)dagLen * sizeof(dag_node));
  if (!*dag) return SIMPLICITY_ERR_MALLOC;

  if (census) *census = (combinator_counters){0};
  simplicity_err error = decodeDag(*dag, decodeJet, (uint_fast32_t)dagLen, census, stream);

  if (IS_OK(error)) {
    error = HIDDEN == (*dag)[dagLen - 1].tag
          ? SIMPLICITY_ERR_HIDDEN_ROOT
          : simplicity_verifyCanonicalOrder(*dag, (uint_fast32_t)(dagLen));
  }

  if (IS_OK(error)) {
    return dagLen;
  } else {
    simplicity_free(*dag);
    *dag = NULL;
    return (int_fast32_t)error;
  }
}