Function lookup_fee

src/simplicity/elements/elementsJets.c:176–189

Lookup the assetFee from a sorted array of feeOutputs by the given assetid, returning 0 if no entry is found. * * Precondition: NULL != assetid; * feeOutputs is uniquely sorted by it asset.data.s field, which is to say * for all 0 <= i < j < len, * 0 < memcmp(feeOutputs[j]->asset.data.s, feeOutputs[i]->asset.data.s, sizeof(feeOutputs[i]->asset.data.

 *                 0 < memcmp(feeOutputs[j]->asset.data.s, feeOutputs[i]->asset.data.s, sizeof(feeOutputs[i]->asset.data.s));
 */
static uint_fast64_t lookup_fee(const sha256_midstate* assetid, const sigOutput* const * feeOutputs, uint_fast32_t len) {
  /* This loop runs in O(log(len)) time. */
  while(len) {
    int cmp = memcmp(assetid->s, feeOutputs[len/2]->asset.data.s, sizeof(assetid->s));
    if (0 == cmp) return feeOutputs[len/2]->assetFee;
    if (0 < cmp) {
      feeOutputs += len/2 + 1;
      len -= len/2 + 1;
    } else {
      len /= 2;
    }
  }
  return 0;
}

/* version : ONE |- TWO^32 */
bool simplicity_version(frameItem* dst, frameItem src, const txEnv* env) {