gaoyunhaii commented on a change in pull request #5: URL: https://github.com/apache/flink-ml/pull/5#discussion_r720813368
########## File path: flink-ml-iteration/src/main/java/org/apache/flink/ml/iteration/IterationBodyResult.java ########## @@ -0,0 +1,74 @@ +/* + * 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.ml.iteration; + +import org.apache.flink.streaming.api.datastream.DataStream; + +import javax.annotation.Nullable; + +/** The result of an iteration, specifying the feedbacks and the outputs. */ +public class IterationBodyResult { + + /** + * A list of feedback variable streams. These streams will only be used during the iteration + * execution and will not be returned to the caller of the iteration body. It is assumed that + * the method which executes the iteration body will feed the records of the feedback variable + * streams back to the corresponding input variable streams. + */ + private final DataStreamList feedbackVariableStreams; + + /** + * A list of output streams. These streams will be returned to the caller of the methods that + * execute the iteration body. + */ + private final DataStreamList outputStreams; + + /** + * An optional termination criteria stream. If this stream is not null, it will be used together + * with the feedback variable streams to determine when the iteration should terminate. + */ + private final @Nullable DataStream<?> terminationCriteria; Review comment: The current flink coding style should not tend to use Optional as the class field: https://flink.apache.org/contributing/code-style-and-quality-java.html#java-optional. In general, optional should be used for the return value of the public api if it does not cause performance issue. -- 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]
