andygrove commented on code in PR #363: URL: https://github.com/apache/datafusion-comet/pull/363#discussion_r1586506620
########## common/src/main/java/org/apache/comet/parquet/PositionColumnReader.java: ########## @@ -0,0 +1,47 @@ +/* + * 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. + */ + +package org.apache.comet.parquet; + +import org.apache.parquet.column.ColumnDescriptor; +import org.apache.spark.sql.types.DataTypes; + +/** A column reader for reading position column */ +public class PositionColumnReader extends MetadataColumnReader { + /** The current position value of the column that are used to initialize this column reader. */ + private long position; + + public PositionColumnReader(ColumnDescriptor descriptor) { + this(descriptor, 0L); + } + + PositionColumnReader(ColumnDescriptor descriptor, long position) { + super(DataTypes.LongType, descriptor, false); + this.position = position; + } + + @Override + public void readBatch(int total) { + Native.resetBatch(nativeHandle); + Native.setPosition(nativeHandle, position, total); + position += total; + + super.readBatch(total); Review Comment: I'm not familiar with this area of code, but this looks odd to me and maybe just needs a comment to explain. My understanding: - we set the position to `position` - we then increase the `position` by `total` - then we do the read, but shouldn't this be from the original position? -- 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: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
