| /* |
| * 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 com.intellij.openapi.vfs.newvfs.impl; |
| |
| import com.intellij.util.ConcurrencyUtil; |
| import com.intellij.util.containers.ConcurrentWeakHashMap; |
| import com.intellij.util.keyFMap.KeyFMap; |
| import com.intellij.util.keyFMap.OneElementFMap; |
| import org.jetbrains.annotations.NotNull; |
| |
| import java.nio.charset.Charset; |
| |
| /** |
| * @author peter |
| */ |
| class UserDataInterner { |
| private static final ConcurrentWeakHashMap<OneElementFMap, OneElementFMap> ourCache = new ConcurrentWeakHashMap<OneElementFMap, OneElementFMap>(); |
| |
| static KeyFMap internUserData(@NotNull KeyFMap map) { |
| if (map instanceof OneElementFMap && shouldIntern((OneElementFMap)map)) { |
| return ConcurrencyUtil.cacheOrGet(ourCache, (OneElementFMap)map, (OneElementFMap)map); |
| } |
| return map; |
| } |
| |
| private static boolean shouldIntern(OneElementFMap map) { |
| Object value = map.getValue(); |
| return value instanceof Enum || value instanceof Boolean || value instanceof Charset; |
| } |
| } |