Ben-Zvi commented on a change in pull request #1408: DRILL-6453: Resolve deadlock when reading from build and probe sides simultaneously in HashJoin URL: https://github.com/apache/drill/pull/1408#discussion_r208753091
########## File path: exec/java-exec/src/main/java/org/apache/drill/exec/physical/impl/join/BatchSizePredictor.java ########## @@ -0,0 +1,79 @@ +/* + * 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.drill.exec.physical.impl.join; + +import org.apache.drill.exec.record.RecordBatch; + +/** + * This class predicts the sizes of batches given an input batch. + * + * <h4>Invariants</h4> + * <ul> + * <li>The {@link BatchSizePredictor} assumes that a {@link RecordBatch} is in a state where it can return a valid record count.</li> + * </ul> + */ +public interface BatchSizePredictor { + /** + * Gets the batchSize computed in the call to {@link #updateStats()}. Returns 0 if {@link #hasData()} is false. + * @return Gets the batchSize computed in the call to {@link #updateStats()}. Returns 0 if {@link #hasData()} is false. + * @throws IllegalStateException if {@link #updateStats()} was never called. + */ + long getBatchSize(); + + /** + * Gets the number of records computed in the call to {@link #updateStats()}. Returns 0 if {@link #hasData()} is false. + * @return Gets the number of records computed in the call to {@link #updateStats()}. Returns 0 if {@link #hasData()} is false. + * @throws IllegalStateException if {@link #updateStats()} was never called. + */ + int getNumRecords(); + + /** + * True if the input batch had records in the last call to {@link #updateStats()}. False otherwise. + * @return True if the input batch had records in the last call to {@link #updateStats()}. False otherwise. + */ + boolean hasData(); Review comment: The name "hasData()" is slightly confusing, as it implies preset time. Is there a better name ? "hadDataLastTime" ? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
