src/main/java/com/google/devtools/build/skyframe/ValueOrUntypedException.java

// Copyright 2014 The Bazel Authors. All rights reserved.
//
// Licensed 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 com.google.devtools.build.skyframe;

import com.google.common.annotations.VisibleForTesting;

import javax.annotation.Nullable;

/**
 * Wrapper for a value or the untyped exception thrown when trying to compute it.
 *
 * <p>This is an implementation detail of {@link ParallelEvaluator} and
 * {@link ValueOrExceptionUtils}. It's an abstract class (as opposed to an interface) to avoid
 * exposing the methods outside the package.
 */
@VisibleForTesting
public abstract class ValueOrUntypedException {

  /** Returns the stored value, if there was one. */
  @Nullable
  abstract SkyValue getValue();

  /** Returns the stored exception, if there was one. */
  @Nullable
  abstract Exception getException();
}