/*
* 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.sdk.values;
import java.util.Map;
import org.apache.beam.sdk.annotations.Internal;
import org.apache.beam.sdk.transforms.PTransform;
/**
* <b><i>For internal use. No backwards compatibility guarantees.</i></b>
*
* <p>A primitive value within Beam.
*/
@Internal
public interface PValue extends POutput, PInput {
/**
* Returns the name of this {@link PValue}.
*/
String getName();
/**
* {@inheritDoc}.
*
* <p>A {@link PValue} always expands into itself. Calling {@link #expand()} on a PValue is almost
* never appropriate.
*/
@Deprecated
Map<TupleTag<?>, PValue> expand();
/**
* After building, finalizes this {@code PValue} to make it ready for being used as an input to a
* {@link org.apache.beam.sdk.transforms.PTransform}.
*
* <p>Automatically invoked whenever {@code apply()} is invoked on this {@code PValue}. Users
* should not normally call this explicitly.
*
* @param upstreamInput the {@link PInput} the {@link PTransform} was applied to to produce this
* output
* @param upstreamTransform the {@link PTransform} that produced this {@link PValue}
*/
@Internal
void finishSpecifying(PInput upstreamInput, PTransform<?, ?> upstreamTransform);
}