becketqin commented on a change in pull request #9184: [FLINK-13339][ml] Add an implementation of pipeline's api URL: https://github.com/apache/flink/pull/9184#discussion_r329106466
########## File path: flink-ml-parent/flink-ml-lib/src/main/java/org/apache/flink/ml/operator/stream/StreamOperator.java ########## @@ -0,0 +1,130 @@ +/* + * 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.operator.stream; + +import org.apache.flink.ml.api.misc.param.Params; +import org.apache.flink.ml.operator.AlgoOperator; +import org.apache.flink.ml.operator.stream.source.TableSourceStreamOp; +import org.apache.flink.table.api.Table; +import org.apache.flink.util.Preconditions; + +/** + * Base class of stream algorithm operators. + * + * <p>This class is extended to support the data transmission between the StreamOperators. + */ +public abstract class StreamOperator<T extends StreamOperator<T>> extends AlgoOperator<T> { + + public StreamOperator() { + super(); + } + + /** + * The constructor of StreamOperator with {@link Params}. + * + * @param params the initial Params. + */ + public StreamOperator(Params params) { + super(params); + } + + /** + * Link to another {@link StreamOperator}. + * + * <p>Link the <code>next</code> to StreamOperator using this as its input. + * + * <p>For example: + * + * <pre> + * {@code + * StreamOperator a = ...; + * StreamOperator b = ...; + * + * StreamOperator c = a.link(b) + * } + * </pre> + * + * <p>the <code>c</code> in upper code is the linked + * <code>b</code> which use <code>a</code> as input. + * + * @param next the linked StreamOperator + * @param <S> type of StreamOpearator returned + * @return the linked next + * @see #linkFrom(StreamOperator[]) + */ + public <S extends StreamOperator<?>> S link(S next) { + next.linkFrom(this); + return next; + } + + /** + * Link from others {@link StreamOperator}. + * + * <p>Link this object to StreamOperator using the StreamOperators as its input. + * + * <p>For example: + * + * <pre> + * {@code + * StreamOperator a = ...; + * StreamOperator b = ...; + * StreamOperator c = ...; + * + * StreamOperator d = c.linkFrom(a, b) + * } + * </pre> + * + * <p>the <code>d</code> in upper code is the linked + * <code>c</code> which use a and b as its inputs. + * + * <p>note: It is not recommended to linkFrom itself or linkFrom the same group inputs twice. + * + * @param inputs the linked inputs + * @return the linked this object + */ + public abstract T linkFrom(StreamOperator<?>... inputs); + + /** + * create a new StreamOperator from table. + * + * @param table the input table + * @return the new StreamOperator + */ + public static StreamOperator<?> sourceFrom(Table table) { + return new TableSourceStreamOp(table); + } + + protected void checkOpSize(int size, StreamOperator<?>... inputs) { Review comment: Why these methods are not static here just like they are in BatchOperator? Also, it seems that these methods can be merged with the methods in BatchOperator by changing the parameter type to AlgoOperator. ---------------------------------------------------------------- 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 With regards, Apache Git Services
