void pruneAndNormalize()

in torchaudio/csrc/decoder/src/decoder/Utils.h [231:260]

• 24 lines of code
• 7 McCabe index (conditional complexity)

void pruneAndNormalize(
    std::unordered_map<int, std::vector<DecoderState>>& hypothesis,
    const int startFrame,
    const int lookBack) {
  /* 1. Move things from back of hypothesis to front. */
  for (int i = 0; i < hypothesis.size(); i++) {
    if (i <= lookBack) {
      hypothesis[i].swap(hypothesis[i + startFrame]);
    } else {
      hypothesis[i].clear();
    }
  }

  /* 2. Avoid further back-tracking */
  for (DecoderState& hyp : hypothesis[0]) {
    hyp.parent = nullptr;
  }

  /* 3. Avoid score underflow/overflow. */
  double largestScore = hypothesis[lookBack].front().score;
  for (int i = 1; i < hypothesis[lookBack].size(); i++) {
    if (largestScore < hypothesis[lookBack][i].score) {
      largestScore = hypothesis[lookBack][i].score;
    }
  }

  for (int i = 0; i < hypothesis[lookBack].size(); i++) {
    hypothesis[lookBack][i].score -= largestScore;
  }
}