comphead commented on code in PR #2346: URL: https://github.com/apache/datafusion-comet/pull/2346#discussion_r2331760084
########## common/src/main/java/org/apache/comet/vector/CometSelectionVector.java: ########## @@ -0,0 +1,279 @@ +/* + * 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.vector; + +import org.apache.arrow.memory.BufferAllocator; +import org.apache.arrow.vector.IntVector; +import org.apache.arrow.vector.dictionary.DictionaryProvider; +import org.apache.spark.sql.vectorized.ColumnVector; +import org.apache.spark.sql.vectorized.ColumnarArray; +import org.apache.spark.sql.vectorized.ColumnarMap; +import org.apache.spark.unsafe.types.UTF8String; + +/** + * A zero-copy selection vector that extends CometVector. This implementation stores the original + * data vector and selection indices as separate CometVectors, providing zero copy access to the the + * underlying data. + * + * <p>If the original vector has values [v0, v1, v2, v3, v4, v5, v6, v7] and the selection indices + * are [0, 1, 3, 4, 5, 7], then this selection vector will logically represent [v0, v1, v3, v4, v5, + * v7] without actually copying the data. + * + * <p>Most of the implementations of CometVector methods are implemented for completeness. We don't + * use this class except to transfer the original data and the selection indices to the native code. + */ +public class CometSelectionVector extends CometVector { + /** The original vector containing all values */ + private final CometVector values; + + /** + * The valid indices in the values vector. This array is converted into an Arrow vector so we can + * transfer the data to native in one JNI call. This is used to represent the rowid mapping used + * by Iceberg + */ + private final int[] selectionIndices; + + /** + * The indices vector containing selection indices. This is currently allocated by the JVM side + * unlike the values vector which is allocated on the native side + */ + private final CometVector indices; + + /** + * Number of selected elements. The indices array may have a length greater than this but only + * numValues elements in the array are valid + */ + private final int numValues; Review Comment: is it the same as `selectionIndices.length`? -- 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
