/*
* 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.beam.runners.core;
import org.apache.beam.sdk.state.TimeDomain;
import org.apache.beam.sdk.transforms.DoFn;
import org.apache.beam.sdk.transforms.windowing.BoundedWindow;
import org.apache.beam.sdk.util.WindowedValue;
import org.joda.time.Instant;
/**
* An wrapper interface that represents the execution of a {@link DoFn}.
*/
public interface DoFnRunner<InputT, OutputT> {
/**
* Prepares and calls a {@link DoFn DoFn's} {@link DoFn.StartBundle @StartBundle} method.
*/
void startBundle();
/**
* Calls a {@link DoFn DoFn's} {@link DoFn.ProcessElement @ProcessElement} method with a
* {@link DoFn.ProcessContext} containing the provided element.
*/
void processElement(WindowedValue<InputT> elem);
/**
* Calls a {@link DoFn DoFn's} {@link DoFn.OnTimer @OnTimer} method for the given timer
* in the given window.
*/
void onTimer(String timerId, BoundedWindow window, Instant timestamp, TimeDomain timeDomain);
/**
* Calls a {@link DoFn DoFn's} {@link DoFn.FinishBundle @FinishBundle} method and performs
* additional tasks, such as flushing in-memory states.
*/
void finishBundle();
}