zenfenan commented on a change in pull request #11474: URL: https://github.com/apache/flink/pull/11474#discussion_r411517277
########## File path: flink-formats/flink-orc/src/main/java/org/apache/flink/orc/vector/Vectorizer.java ########## @@ -0,0 +1,93 @@ +/* + * 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.flink.orc.vector; + +import org.apache.flink.annotation.PublicEvolving; + +import org.apache.hadoop.hive.ql.exec.vector.VectorizedRowBatch; +import org.apache.orc.TypeDescription; + +import java.io.IOException; +import java.io.Serializable; + +import static org.apache.flink.util.Preconditions.checkNotNull; + +/** + * This class provides an abstracted set of methods to handle the lifecycle of {@link VectorizedRowBatch}. + * + * <p>Developers have to extend this class and override the vectorize() method with the logic + * to transform the element to a {@link VectorizedRowBatch}. + * + * @param <T> The type of the element + */ +@PublicEvolving +public abstract class Vectorizer<T> implements Serializable { + + protected transient VectorizedRowBatch rowBatch; + + private final TypeDescription schema; + + public Vectorizer(final String schema) { + checkNotNull(schema); + this.schema = TypeDescription.fromString(schema); + this.rowBatch = this.schema.createRowBatch(); + } + + public void initBatch() { + this.rowBatch = this.schema.createRowBatch(); + } + + /** + * Provides the ORC schema. + * + * @return the ORC schema + */ + public TypeDescription getSchema() { + return this.schema; + } + + /** + * Provides the VectorizedRowBatch containing the + * ColumnVectors of the input elements. + * + * @return vectorized row batch + */ + public VectorizedRowBatch getRowBatch() { + return this.rowBatch; + } + + /** + * Calls reset on the VectorizedRowBatch instance. + */ + public void reset() { + if (this.rowBatch != null) { + this.rowBatch.reset(); + } + } + + /** + * Transforms the provided element to ColumnVectors and + * sets them in the exposed VectorizedRowBatch. + * + * @param element The input element + * @throws IOException if there is an error while transforming the input. + */ + public abstract void vectorize(T element) throws IOException; Review comment: Makes sense. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
