/*
* 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.apex.translation;
import org.apache.beam.runners.apex.translation.operators.ApexProcessFnOperator;
import org.apache.beam.sdk.transforms.windowing.BoundedWindow;
import org.apache.beam.sdk.transforms.windowing.Window;
import org.apache.beam.sdk.transforms.windowing.WindowFn;
import org.apache.beam.sdk.values.PCollection;
/**
* {@link Window} is translated to {@link ApexProcessFnOperator#assignWindows}.
*/
class WindowAssignTranslator<T> implements TransformTranslator<Window.Assign<T>> {
private static final long serialVersionUID = 1L;
@Override
public void translate(Window.Assign<T> transform, TranslationContext context) {
PCollection<T> output = context.getOutput();
PCollection<T> input = context.getInput();
if (transform.getWindowFn() == null) {
// no work to do
context.addAlias(output, input);
} else {
@SuppressWarnings("unchecked")
WindowFn<T, BoundedWindow> windowFn = (WindowFn<T, BoundedWindow>) transform.getWindowFn();
ApexProcessFnOperator<T> operator = ApexProcessFnOperator.assignWindows(windowFn,
context.getPipelineOptions());
context.addOperator(operator, operator.outputPort);
context.addStream(context.getInput(), operator.inputPort);
}
}
}