| /* |
| * Copyright 2000-2014 JetBrains s.r.o. |
| * |
| * 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 org.jetbrains.plugins.groovy.util; |
| |
| import com.intellij.openapi.util.Key; |
| import com.intellij.openapi.util.Pair; |
| import com.intellij.openapi.util.UserDataHolderEx; |
| import com.intellij.psi.PsiElement; |
| import org.jetbrains.annotations.NotNull; |
| import org.jetbrains.annotations.Nullable; |
| |
| /** |
| * @author Sergey Evdokimov |
| */ |
| public class LightCacheKey<T> { |
| |
| private final Key<Pair<Long, T>> key = Key.create(this.toString()); |
| |
| /** |
| * @return Cached value or null if cached value is not exists or outdated. |
| */ |
| @Nullable |
| public T getCachedValue(PsiElement holder) { |
| Pair<Long, T> userData = holder.getUserData(key); |
| |
| if (userData == null || getModificationCount(holder) != userData.first) { |
| return null; |
| } |
| |
| return userData.second; |
| } |
| |
| protected long getModificationCount(PsiElement holder) { |
| return holder.getManager().getModificationTracker().getModificationCount(); |
| } |
| |
| public T putCachedValue(PsiElement holder, @NotNull T value) { |
| long modificationCount = getModificationCount(holder); |
| |
| Pair<Long, T> pair = Pair.create(modificationCount, value); |
| |
| Pair<Long, T> puttedValue = ((UserDataHolderEx)holder).putUserDataIfAbsent(key, pair); |
| if (puttedValue == pair) { |
| return value; |
| } |
| |
| if (puttedValue.first == modificationCount) { |
| return puttedValue.second; |
| } |
| |
| if (((UserDataHolderEx)holder).replace(key, puttedValue, pair)) { |
| return value; |
| } |
| |
| Pair<Long, T> createdFromOtherThreadValue = holder.getUserData(key); |
| //noinspection ConstantConditions |
| assert createdFromOtherThreadValue.first == modificationCount; |
| |
| return createdFromOtherThreadValue.second; |
| } |
| |
| public static <T> LightCacheKey<T> create() { |
| return new LightCacheKey<T>(); |
| } |
| |
| public static <T> LightCacheKey<T> createByJavaModificationCount() { |
| return new LightCacheKey<T>() { |
| @Override |
| protected long getModificationCount(PsiElement holder) { |
| return holder.getManager().getModificationTracker().getJavaStructureModificationCount(); |
| } |
| }; |
| } |
| |
| public static <T> LightCacheKey<T> createByFileModificationCount() { |
| return new LightCacheKey<T>() { |
| @Override |
| protected long getModificationCount(PsiElement holder) { |
| return holder.getContainingFile().getModificationStamp(); |
| } |
| }; |
| } |
| |
| } |