JNIEXPORT jlong JNICALL Java_org_apache_arrow_gandiva_evaluator_JniWrapper_buildProjector()

in gandiva/src/main/cpp/jni_common.cc [604:698]

• 76 lines of code
• 11 McCabe index (conditional complexity)

JNIEXPORT jlong JNICALL Java_org_apache_arrow_gandiva_evaluator_JniWrapper_buildProjector(
    JNIEnv* env, jobject obj, jbyteArray schema_arr, jbyteArray exprs_arr,
    jint selection_vector_type, jlong configuration_id) {
  jlong module_id = 0LL;
  std::shared_ptr<Projector> projector;
  std::shared_ptr<ProjectorHolder> holder;

  gandiva::types::Schema schema;
  jsize schema_len = env->GetArrayLength(schema_arr);
  jbyte* schema_bytes = env->GetByteArrayElements(schema_arr, 0);

  gandiva::types::ExpressionList exprs;
  jsize exprs_len = env->GetArrayLength(exprs_arr);
  jbyte* exprs_bytes = env->GetByteArrayElements(exprs_arr, 0);

  ExpressionVector expr_vector;
  SchemaPtr schema_ptr;
  FieldVector ret_types;
  gandiva::Status status;
  auto mode = gandiva::SelectionVector::MODE_NONE;

  std::shared_ptr<Configuration> config = ConfigHolder::MapLookup(configuration_id);
  std::stringstream ss;

  if (config == nullptr) {
    ss << "configuration is mandatory.";
    releaseProjectorInput(schema_arr, schema_bytes, exprs_arr, exprs_bytes, env);
    goto err_out;
  }

  if (!ParseProtobuf(reinterpret_cast<uint8_t*>(schema_bytes), schema_len, &schema)) {
    ss << "Unable to parse schema protobuf\n";
    releaseProjectorInput(schema_arr, schema_bytes, exprs_arr, exprs_bytes, env);
    goto err_out;
  }

  if (!ParseProtobuf(reinterpret_cast<uint8_t*>(exprs_bytes), exprs_len, &exprs)) {
    releaseProjectorInput(schema_arr, schema_bytes, exprs_arr, exprs_bytes, env);
    ss << "Unable to parse expressions protobuf\n";
    goto err_out;
  }

  // convert gandiva::types::Schema to arrow::Schema
  schema_ptr = ProtoTypeToSchema(schema);
  if (schema_ptr == nullptr) {
    ss << "Unable to construct arrow schema object from schema protobuf\n";
    releaseProjectorInput(schema_arr, schema_bytes, exprs_arr, exprs_bytes, env);
    goto err_out;
  }

  // create Expression out of the list of exprs
  for (int i = 0; i < exprs.exprs_size(); i++) {
    ExpressionPtr root = ProtoTypeToExpression(exprs.exprs(i));

    if (root == nullptr) {
      ss << "Unable to construct expression object from expression protobuf\n";
      releaseProjectorInput(schema_arr, schema_bytes, exprs_arr, exprs_bytes, env);
      goto err_out;
    }

    expr_vector.push_back(root);
    ret_types.push_back(root->result());
  }

  switch (selection_vector_type) {
    case gandiva::types::SV_NONE:
      mode = gandiva::SelectionVector::MODE_NONE;
      break;
    case gandiva::types::SV_INT16:
      mode = gandiva::SelectionVector::MODE_UINT16;
      break;
    case gandiva::types::SV_INT32:
      mode = gandiva::SelectionVector::MODE_UINT32;
      break;
  }
  // good to invoke the evaluator now
  status = Projector::Make(schema_ptr, expr_vector, mode, config, &projector);

  if (!status.ok()) {
    ss << "Failed to make LLVM module due to " << status.message() << "\n";
    releaseProjectorInput(schema_arr, schema_bytes, exprs_arr, exprs_bytes, env);
    goto err_out;
  }

  // store the result in a map
  holder = std::shared_ptr<ProjectorHolder>(
      new ProjectorHolder(schema_ptr, ret_types, std::move(projector)));
  module_id = projector_modules_.Insert(holder);
  releaseProjectorInput(schema_arr, schema_bytes, exprs_arr, exprs_bytes, env);
  return module_id;

err_out:
  env->ThrowNew(gandiva_exception_, ss.str().c_str());
  return module_id;
}