tomighita commented on code in PR #2120: URL: https://github.com/apache/iceberg-rust/pull/2120#discussion_r2965675094
########## crates/iceberg/src/transaction/update_schema.rs: ########## @@ -0,0 +1,1200 @@ +// 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. + +use std::collections::{HashMap, HashSet}; +use std::sync::Arc; + +use async_trait::async_trait; + +use crate::spec::{ + ListType, Literal, MapType, NestedField, NestedFieldRef, Schema, StructType, Type, +}; +use crate::table::Table; +use crate::transaction::action::{ActionCommit, TransactionAction}; +use crate::{Error, ErrorKind, Result, TableRequirement, TableUpdate}; + +/// Sentinel parent ID representing the table root (top-level columns). +const TABLE_ROOT_ID: i32 = -1; + +/// A pending column addition, recording the parent path and the field to add. +struct PendingAdd { + /// `None` means a root-level addition; `Some("person")` or `Some("person.address")` + /// identifies the nested struct to add the column to. + parent: Option<String>, + /// The field to add. Uses placeholder ID `0` which is auto-assigned at commit time. + field: NestedFieldRef, +} + +/// Schema evolution API modeled after the Java `SchemaUpdate` implementation. +/// +/// This action accumulates schema modifications (column additions and deletions) +/// via builder methods. At commit time, it validates all operations against the +/// current table schema, auto-assigns field IDs from `table.metadata().last_column_id()`, +/// builds a new schema, and emits `AddSchema` + `SetCurrentSchema` updates with a +/// `CurrentSchemaIdMatch` requirement. +/// +/// # Example +/// +/// ```ignore +/// let tx = Transaction::new(&table); +/// let action = tx.update_schema() +/// .add_column("new_col", Type::Primitive(PrimitiveType::Int)) +/// .add_column_to("person", "email", Type::Primitive(PrimitiveType::String)) +/// .delete_column("old_col"); +/// let tx = action.apply(tx).unwrap(); +/// let table = tx.commit(&catalog).await.unwrap(); +/// ``` +pub struct UpdateSchemaAction { + additions: Vec<PendingAdd>, + deletes: Vec<String>, + auto_assign_ids: bool, +} + +impl UpdateSchemaAction { + /// Creates a new empty `UpdateSchemaAction`. + pub(crate) fn new() -> Self { + Self { + additions: Vec::new(), + deletes: Vec::new(), + auto_assign_ids: true, + } + } + + // --- Root-level additions --- + + /// Add a `NestedFieldRef` column to the table root. + pub fn add_field(self, field: NestedFieldRef) -> Self { Review Comment: done -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
