IndexId.java

/*
 * Copyright 2000-2017 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.util.indexing;

import gnu.trove.THashMap;
import org.jetbrains.annotations.ApiStatus;
import org.jetbrains.annotations.NotNull;

import java.util.Map;

@ApiStatus.Experimental
public class IndexId<K, V> {
  private static final Map<String, IndexId<?, ?>> ourInstances = new THashMap<String, IndexId<?, ?>>();

  @NotNull
  private final String myName;

  protected IndexId(@NotNull String name) {myName = name;}

  @NotNull
  public final String getName() {
    return myName;
  }

  public static <K, V> IndexId<K, V> create(String name) {
    @SuppressWarnings("unchecked")
    IndexId<K, V> id = (IndexId<K, V>)ourInstances.get(name);
    if (id == null) {
      ourInstances.put(name, id = new IndexId<K, V>(name));
    }
    return id;
  }
}