Function PrintStruct

be/src/util/debug-util.cc:189–225

Print a struct with field names, recursing to children. This is not intended to work with impala_udf::StructVal. Instead, it works with the representation of structs that is directly inside another tuple. Example: {a:1,b:2}

// that is directly inside another tuple.
// Example: {a:1,b:2}
static void PrintStruct(const Tuple* t, const SlotDescriptor& slot_d, stringstream* out) {
  DCHECK(t != nullptr);
  DCHECK(slot_d.type().IsStructType());
  const TupleDescriptor* child_tuple_d = slot_d.children_tuple_descriptor();
  DCHECK(child_tuple_d != nullptr);
  const ColumnType& struct_type = slot_d.type();
  const std::vector<SlotDescriptor*>& child_slots = child_tuple_d->slots();
  // The struct may have fields that are not being materialized, so the child_slots may
  // be a subset of the actual struct type.
  DCHECK_LE(child_slots.size(), struct_type.children.size());
  *out << "{";
  for (int i = 0; i < child_slots.size(); ++i) {
    if (i != 0) {
      *out << ",";
    }
    const SlotDescriptor& child_slot_desc = *child_slots[i];
    // To find the struct field name, we need the index into the ColumnType's
    // field_names. Structs can be partially materialized, so the slot's index
    // is not correct. The struct_field_idx contains the appropriate index into
    // the field_names.
    if (child_slot_desc.struct_field_idx().has_value()) {
      int struct_field_idx = child_slot_desc.struct_field_idx().value();
      if (struct_field_idx < struct_type.field_names.size()) {
        *out << struct_type.field_names[struct_field_idx] << ":";
      } else {
        // This is invalid. Assert on debug builds, but otherwise handle it for
        // release builds.
        DCHECK_LT(struct_field_idx, struct_type.field_names.size());
        *out << "invalid" << i << ":";
      }
    } else {
      *out << "unnamed" << i << ":";
    }
    PrintSlot(t, child_slot_desc, out);
  }
  *out << "}";
}

void PrintTuple(const Tuple* t, const TupleDescriptor& tuple_d, stringstream* out) {
  // The whole tuple is null