xudong963 commented on code in PR #22398: URL: https://github.com/apache/datafusion/pull/22398#discussion_r3278931752
########## datafusion/datasource-parquet/src/decoder_projection.rs: ########## @@ -0,0 +1,130 @@ +// 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. + +//! Decoder-projection construction for the parquet scan. +//! +//! [`DecoderProjection`] owns the two halves of "project a decoded parquet +//! batch onto the scan's output schema": +//! +//! * the [`ProjectionMask`] installed on every parquet decoder run, and +//! * the per-batch transform ([`DecoderProjection::map`]) that applies the +//! projector and, when needed, rebuilds the batch with the user's +//! `output_schema` to recover metadata / nullability the file schema does +//! not carry. +//! +//! The opener constructs one [`DecoderProjection`] per file via +//! [`DecoderProjection::build`] and hands it to the push-decoder stream, Review Comment: ```suggestion ```rust //! [`DecoderProjection::try_new`] and hands it to the push-decoder stream, ``` ``` -- 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]
