Function MakeExtMemForTest

tests/cpp/c_api/test_c_api.cc:458–479

}

auto MakeExtMemForTest(bst_idx_t n_samples, bst_feature_t n_features, Json dconfig) {
  std::size_t n_batches{4};
  NumpyArrayIterForTest iter_0{0.0f, n_samples, n_features, n_batches};
  std::string s_dconfig;
  dconfig["cache_prefix"] = String{"cache"};
  Json::Dump(dconfig, &s_dconfig);
  DMatrixHandle p_fmat;
  CHECK_EQ(XGDMatrixCreateFromCallback(static_cast<DataIterHandle>(&iter_0), iter_0.Proxy(), Reset,
                                       Next, s_dconfig.c_str(), &p_fmat),
           0);

  NumpyArrayIterForTest iter_1{0.0f, n_samples, n_features, n_batches};
  auto config = ExtMemConfig{"",
                             false,
                             cuda_impl::AutoHostRatio(),
                             cuda_impl::MatchingPageBytes(),
                             std::numeric_limits<float>::quiet_NaN(),
                             0};
  auto Xy = std::make_shared<data::SparsePageDMatrix>(&iter_1, iter_1.Proxy(), Reset, Next, config);
  MakeLabelForTest(Xy, p_fmat);
  return std::pair{p_fmat, Xy};
}

template <typename Page>
void CheckResult(Context const *ctx, bst_feature_t n_features, std::shared_ptr<DMatrix> Xy,