cmcarthur commented on code in PR #1176: URL: https://github.com/apache/iceberg-rust/pull/1176#discussion_r2031711629
########## crates/iceberg/src/transaction/add_field.rs: ########## @@ -0,0 +1,114 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +//! This module contains an AddFieldsAction for adding fields to a table. + +use crate::error::Result; +use crate::spec::NestedFieldRef; +use crate::transaction::Transaction; +use crate::{TableRequirement, TableUpdate}; + +/// Transaction action for easily adding fields to the table. +pub struct AddFieldsAction<'a> { + tx: Transaction<'a>, + fields: Vec<NestedFieldRef>, +} + +/// Transaction action for easily adding fields to the table. +impl<'a> AddFieldsAction<'a> { + /// Creates a new `AddFieldsAction` for the given transaction. + pub(crate) fn new(tx: Transaction<'a>, fields: Vec<NestedFieldRef>) -> Self { + Self { tx, fields } + } + + /// Finish building the action and apply it to the transaction. + pub fn apply(mut self) -> Result<Transaction<'a>> { + let base_schema = self.tx.table.metadata().current_schema(); + let schema_builder = <crate::spec::Schema as Clone>::clone(base_schema).into_builder(); + let schema = schema_builder.with_fields(self.fields).build()?; + let schema_id = schema.schema_id(); + + let updates = vec