| /* |
| * Copyright 2000-2013 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.util; |
| |
| import com.intellij.util.containers.ConcurrentWeakValueIntObjectHashMap; |
| import com.intellij.util.containers.StripedLockIntObjectConcurrentHashMap; |
| import org.jetbrains.annotations.NonNls; |
| import org.jetbrains.annotations.NotNull; |
| import org.jetbrains.annotations.Nullable; |
| |
| import java.util.Map; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| /** |
| * Provides type-safe access to data. |
| * |
| * @author max |
| * @author Konstantin Bulenkov |
| */ |
| @SuppressWarnings({"EqualsWhichDoesntCheckParameterClass"}) |
| public class Key<T> { |
| private static final AtomicInteger ourKeysCounter = new AtomicInteger(); |
| private final int myIndex = ourKeysCounter.getAndIncrement(); |
| private final String myName; |
| private static final ConcurrentWeakValueIntObjectHashMap<Key> allKeys = new ConcurrentWeakValueIntObjectHashMap<Key>(); |
| |
| public Key(@NotNull @NonNls String name) { |
| myName = name; |
| allKeys.put(myIndex, this); |
| } |
| |
| public final int hashCode() { |
| return myIndex; |
| } |
| |
| @Override |
| public final boolean equals(Object obj) { |
| return obj == this; |
| } |
| |
| public String toString() { |
| return myName; |
| } |
| |
| public static <T> Key<T> create(@NotNull @NonNls String name) { |
| return new Key<T>(name); |
| } |
| |
| public T get(@Nullable UserDataHolder holder) { |
| return holder == null ? null : holder.getUserData(this); |
| } |
| |
| public T get(@Nullable Map<Key, ?> holder) { |
| //noinspection unchecked |
| return holder == null ? null : (T)holder.get(this); |
| } |
| |
| public T get(@Nullable UserDataHolder holder, T defaultValue) { |
| final T t = get(holder); |
| return t == null ? defaultValue : t; |
| } |
| |
| /** |
| * Returns <code>true</code> if and only if the <code>holder</code> has |
| * not null value by the key. |
| * |
| * @param holder user data holder object |
| * @return <code>true</code> if holder.getUserData(this) != null |
| * <code>false</code> otherwise. |
| */ |
| public boolean isIn(@Nullable UserDataHolder holder) { |
| return get(holder) != null; |
| } |
| |
| public void set(@Nullable UserDataHolder holder, @Nullable T value) { |
| if (holder != null) { |
| holder.putUserData(this, value); |
| } |
| } |
| |
| public void set(@Nullable Map<Key, Object> holder, T value) { |
| if (holder != null) { |
| holder.put(this, value); |
| } |
| } |
| |
| public static <T> Key<T> getKeyByIndex(int index) { |
| //noinspection unchecked |
| return (Key<T>)allKeys.get(index); |
| } |
| |
| @Nullable |
| public static <T> Key<T> findKeyByName(String name) { |
| for (StripedLockIntObjectConcurrentHashMap.IntEntry<Key> key : allKeys.entries()) { |
| if (name.equals(key.getValue().myName)) { |
| //noinspection unchecked |
| return key.getValue(); |
| } |
| } |
| return null; |
| } |
| } |