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1   /*
2    * ====================================================================
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *   http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing,
14   * software distributed under the License is distributed on an
15   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16   * KIND, either express or implied.  See the License for the
17   * specific language governing permissions and limitations
18   * under the License.
19   * ====================================================================
20   *
21   * This software consists of voluntary contributions made by many
22   * individuals on behalf of the Apache Software Foundation.  For more
23   * information on the Apache Software Foundation, please see
24   * <http://www.apache.org/>.
25   *
26   */
27  package org.apache.hc.client5.http.impl.cache;
28  
29  import java.util.concurrent.atomic.AtomicReference;
30  
31  import org.apache.hc.client5.http.cache.Resource;
32  import org.apache.hc.client5.http.cache.ResourceIOException;
33  import org.apache.hc.core5.annotation.Contract;
34  import org.apache.hc.core5.annotation.ThreadingBehavior;
35  
36  /**
37   * Cache resource backed by a byte array on the heap.
38   *
39   * @since 4.1
40   */
41  @Contract(threading = ThreadingBehavior.IMMUTABLE)
42  public class HeapResource extends Resource {
43  
44      private static final long serialVersionUID = -2078599905620463394L;
45  
46      private final AtomicReference<byte[]> arrayRef;
47  
48      public HeapResource(final byte[] b) {
49          super();
50          this.arrayRef = new AtomicReference<>(b);
51      }
52  
53      @Override
54      public byte[] get() throws ResourceIOException {
55          final byte[] byteArray = this.arrayRef.get();
56          if (byteArray != null) {
57              return byteArray;
58          }
59          throw new ResourceIOException("Resource already disposed");
60      }
61  
62      @Override
63      public long length() {
64          final byte[] byteArray = this.arrayRef.get();
65          if (byteArray != null) {
66              return byteArray.length;
67          } else {
68              return -1;
69          }
70      }
71  
72      @Override
73      public void dispose() {
74          this.arrayRef.set(null);
75      }
76  
77  }