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1   /*
2    * Copyright (c) 2001-2017, Zoltan Farkas All Rights Reserved.
3    *
4    * This library is free software; you can redistribute it and/or
5    * modify it under the terms of the GNU Lesser General Public
6    * License as published by the Free Software Foundation; either
7    * version 2.1 of the License, or (at your option) any later version.
8    *
9    * This library is distributed in the hope that it will be useful,
10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   * GNU General Public License for more details.
13   *
14   * You should have received a copy of the GNU Lesser General Public
15   * License along with this program; if not, write to the Free Software
16   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
17   *
18   * Additionally licensed with:
19   *
20   * Licensed under the Apache License, Version 2.0 (the "License");
21   * you may not use this file except in compliance with the License.
22   * You may obtain a copy of the License at
23   *
24   *      http://www.apache.org/licenses/LICENSE-2.0
25   *
26   * Unless required by applicable law or agreed to in writing, software
27   * distributed under the License is distributed on an "AS IS" BASIS,
28   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
29   * See the License for the specific language governing permissions and
30   * limitations under the License.
31   */
32  package org.spf4j.recyclable.impl;
33  
34  import java.util.function.Supplier;
35  import javax.annotation.Nonnull;
36  import org.spf4j.recyclable.NonValidatingRecyclingSupplier;
37  
38  /**
39   * @author Zoltan Farkas
40   */
41  public final class ThreadLocalRecyclingSupplier<T> implements NonValidatingRecyclingSupplier<T> {
42  
43    private final Supplier<T> supplier;
44  
45    private final ThreadLocal<T> threadLocal;
46  
47    public ThreadLocalRecyclingSupplier(final Supplier<T> supplier) {
48      this.supplier = supplier;
49      threadLocal = new ThreadLocal<T>() {
50        @Override
51        protected T initialValue() {
52          return supplier.get();
53        }
54      };
55    }
56  
57    @Override
58    @Nonnull
59    public T get() {
60      T obj = threadLocal.get();
61      if (obj == null) {
62        return supplier.get();
63      } else {
64        threadLocal.set(null);
65        return obj;
66      }
67    }
68  
69    @Override
70    public void recycle(final T object) {
71      threadLocal.set(object);
72    }
73  
74    @Override
75    public String toString() {
76      return "ThreadLocalRecyclingSupplier{" + "supplier=" + supplier + ", threadLocal=" + threadLocal + '}';
77    }
78  
79  }