Function ParseHeader

dali/util/numpy.cc:250–274

}

void ParseHeader(HeaderData &parsed_header, InputStream *src) {
  // check if the file is actually a numpy file
  SmallVector<char, 128> token;
  int64_t nread = src->Read(token.data(), 10);
  DALI_ENFORCE(nread == 10, "Can not read header.");
  token[nread] = '\0';

  CheckNpyVersion(token.data());
  auto header_len = GetHeaderLen(token.data());

  // read header: the offset is a magic number
  int64_t offset = 6 + 1 + 1 + 2;
  // The header_len can have up to 2**16 - 1 bytes. We do not support V2 headers
  // (with up to 4GB - 4 byte header len), as those are used by numpy to save structured
  // arrays (where dtype can be different for each column and the columns have arbitrary names).
  // Parsing such a dtype in the header will fail.
  // https://numpy.org/neps/nep-0001-npy-format.html
  token.resize(header_len+1);
  src->SeekRead(offset);
  nread = src->Read(token.data(), header_len);
  DALI_ENFORCE(nread == static_cast<Index>(header_len), "Can not read header.");
  token[header_len] = '\0';

  ParseHeaderItself(parsed_header, token.data(), header_len);
}

void FromFortranOrder(SampleView<CPUBackend> output, ConstSampleView<CPUBackend> input) {
  int n_dims = input.shape().sample_dim();