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ASF GitHub Bot commented on FLINK-5886: --------------------------------------- Github user zentol commented on a diff in the pull request: https://github.com/apache/flink/pull/3838#discussion_r121900122 --- Diff: flink-libraries/flink-streaming-python/src/main/java/org/apache/flink/streaming/python/api/functions/PythonOutputSelector.java --- @@ -0,0 +1,62 @@ +/* + * 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.streaming.python.api.functions; + +import org.apache.flink.streaming.api.collector.selector.OutputSelector; +import org.apache.flink.streaming.python.util.serialization.SerializationUtils; +import org.python.core.PyObject; + +import java.io.IOException; + +/** + * The {@code PythonOutputSelector} is a thin wrapper layer over a Python UDF {@code OutputSelector}. + * It receives an {@code OutputSelector} as an input and keeps it internally in a serialized form. + * It is then delivered, as part of the job graph, up to the TaskManager, then it is opened and becomes + * a sort of mediator to the Python UDF {@code OutputSelector}. + * + * <p>This function is used internally by the Python thin wrapper layer over the streaming data + * functionality</p> + */ +public class PythonOutputSelector implements OutputSelector<PyObject> { + private static final long serialVersionUID = 909266346633598177L; + + private final byte[] serFun; + private transient OutputSelector<PyObject> fun; + + public PythonOutputSelector(OutputSelector<PyObject> fun) throws IOException { + this.serFun = SerializationUtils.serializeObject(fun); + } + + @Override + @SuppressWarnings("unchecked") + public Iterable<String> select(PyObject value) { + if (this.fun == null) { + try { + this.fun = (OutputSelector<PyObject>) SerializationUtils.deserializeObject(this.serFun); + } catch (IOException e) { + e.printStackTrace(); --- End diff -- we should fail here, and in case of a `ClassNotFoundException`. > Python API for streaming applications > ------------------------------------- > > Key: FLINK-5886 > URL: https://issues.apache.org/jira/browse/FLINK-5886 > Project: Flink > Issue Type: New Feature > Components: Python API > Reporter: Zohar Mizrahi > Assignee: Zohar Mizrahi > > A work in progress to provide python interface for Flink streaming APIs. The > core technology is based on jython and thus imposes two limitations: a. user > defined functions cannot use python extensions. b. the python version is 2.x > The branch is based on Flink release 1.2.0, as can be found here: > https://github.com/zohar-pm/flink/tree/python-streaming > In order to test it, someone can use IntelliJ IDE. Assuming IntelliJ was > setup properly (see: > https://ci.apache.org/projects/flink/flink-docs-release-1.3/internals/ide_setup.html), > one can run/debug {{org.apache.flink.python.api.PythonStreamBinderTest}}, > which in return will execute all the tests under > {{/Users/zohar/dev/pm-flink/flink-libraries/flink-python/src/test/python/org/apache/flink/python/api/streaming}} -- This message was sent by Atlassian JIRA (v6.4.14#64029)