|  | // Copyright 2014 Google Inc. 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.collect.ImmutableSet; | 
|  |  | 
|  | import java.util.Set; | 
|  |  | 
|  | /** | 
|  | * Tracks nothing. Should be used by evaluators that don't do dirty node garbage collection. | 
|  | */ | 
|  | public class NullDirtyKeyTrackerImpl implements DirtyKeyTracker { | 
|  |  | 
|  | @Override | 
|  | public void dirty(SkyKey skyKey) { | 
|  | } | 
|  |  | 
|  | @Override | 
|  | public void notDirty(SkyKey skyKey) { | 
|  | } | 
|  |  | 
|  | @Override | 
|  | public Set<SkyKey> getDirtyKeys() { | 
|  | return ImmutableSet.of(); | 
|  | } | 
|  | } |