Method GenerateFieldIDs

be/src/exec/orc/orc-metadata-utils.cc:330–366

}

Status OrcSchemaResolver::GenerateFieldIDs() {
  std::stack<const orc::Type*> nodes;

  nodes.push(root_);

  int fieldID = 1;

  while (!nodes.empty()) {
    const orc::Type* current = nodes.top();
    nodes.pop();

    uint64_t size = current->getSubtypeCount();

    for (uint64_t i = 0; i < size; i++) {
      auto retval = orc_type_to_field_id_.emplace(current->getSubtype(i), fieldID++);

      // Emplace has to be successful, otherwise we visited the same node twice
      DCHECK(retval.second);

      // Push children in reverse order to the stack so they are processed in the original
      // order
      const orc::Type* reverseOrderChild = current->getSubtype(size - i - 1);
      if (reverseOrderChild->getSubtypeCount() > 0) {
        nodes.push(reverseOrderChild);
      }
    }

    if (current == root_ && !nodes.empty()) {
      // Partition columns are not stored in file metadata, but they get field IDs
      // from Iceberg. Check if there are partition columns and adjust field ID
      // generation. It is only relevant for tables that have complex types.
      RETURN_IF_ERROR(
          file_metadata_utils_.AdjustFieldIdForMigratedPartitionedTables(&fieldID));
    }
  }
  return Status::OK();
}

int OrcSchemaResolver::GetGeneratedFieldID(const orc::Type* type) const {
  auto it = orc_type_to_field_id_.find(type);