ArrowErrorCode SetSchema()

in c/driver/postgresql/postgres_type.h [216:325]
85 lines of code
29 McCabe index (conditional complexity)

  ArrowErrorCode SetSchema(ArrowSchema* schema,
                           const std::string& vendor_name = "PostgreSQL") const {
    switch (type_id_) {
      // ---- Primitive types --------------------
      case PostgresTypeId::kBool:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_BOOL));
        break;
      case PostgresTypeId::kInt2:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_INT16));
        break;
      case PostgresTypeId::kInt4:
      case PostgresTypeId::kOid:
      case PostgresTypeId::kRegproc:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_INT32));
        break;
      case PostgresTypeId::kInt8:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_INT64));
        break;
      case PostgresTypeId::kFloat4:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_FLOAT));
        break;
      case PostgresTypeId::kFloat8:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_DOUBLE));
        break;
      case PostgresTypeId::kCash:
        // PostgreSQL appears to send an int64, without decimal point information
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_INT64));
        break;

      // ---- Numeric/Decimal-------------------
      case PostgresTypeId::kNumeric:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_STRING));
        NANOARROW_RETURN_NOT_OK(AddPostgresTypeMetadata(schema, vendor_name));

        break;

      // ---- Binary/string --------------------
      case PostgresTypeId::kChar:
      case PostgresTypeId::kBpchar:
      case PostgresTypeId::kVarchar:
      case PostgresTypeId::kText:
      case PostgresTypeId::kName:
      case PostgresTypeId::kEnum:
      case PostgresTypeId::kJson:
      case PostgresTypeId::kJsonb:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_STRING));
        break;
      case PostgresTypeId::kBytea:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_BINARY));
        break;

      // ---- Temporal --------------------
      case PostgresTypeId::kDate:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_DATE32));
        break;

      case PostgresTypeId::kTime:
        // We always return microsecond precision even if the type
        // specifies differently
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetTypeDateTime(schema, NANOARROW_TYPE_TIME64,
                                                           NANOARROW_TIME_UNIT_MICRO,
                                                           /*timezone=*/nullptr));
        break;

      case PostgresTypeId::kTimestamp:
        // We always return microsecond precision even if the type
        // specifies differently
        NANOARROW_RETURN_NOT_OK(
            ArrowSchemaSetTypeDateTime(schema, NANOARROW_TYPE_TIMESTAMP,
                                       NANOARROW_TIME_UNIT_MICRO, /*timezone=*/nullptr));
        break;

      case PostgresTypeId::kTimestamptz:
        NANOARROW_RETURN_NOT_OK(
            ArrowSchemaSetTypeDateTime(schema, NANOARROW_TYPE_TIMESTAMP,
                                       NANOARROW_TIME_UNIT_MICRO, /*timezone=*/"UTC"));
        break;

      case PostgresTypeId::kInterval:
        NANOARROW_RETURN_NOT_OK(
            ArrowSchemaSetType(schema, NANOARROW_TYPE_INTERVAL_MONTH_DAY_NANO));
        break;

      // ---- Nested --------------------
      case PostgresTypeId::kRecord:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetTypeStruct(schema, n_children()));
        for (int64_t i = 0; i < n_children(); i++) {
          NANOARROW_RETURN_NOT_OK(
              children_[i].SetSchema(schema->children[i], vendor_name));
        }
        break;

      case PostgresTypeId::kArray:
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_LIST));
        NANOARROW_RETURN_NOT_OK(children_[0].SetSchema(schema->children[0], vendor_name));
        break;

      case PostgresTypeId::kUserDefined:
      default:
        // For user-defined types or types we don't explicitly know how to deal with, we
        // can still return the bytes postgres gives us and attach the type name as
        // metadata
        NANOARROW_RETURN_NOT_OK(ArrowSchemaSetType(schema, NANOARROW_TYPE_BINARY));
        NANOARROW_RETURN_NOT_OK(AddPostgresTypeMetadata(schema, vendor_name));
        break;
    }

    NANOARROW_RETURN_NOT_OK(ArrowSchemaSetName(schema, field_name_.c_str()));
    return NANOARROW_OK;
  }