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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.http.impl.client.cache;
28  
29  import java.io.ByteArrayOutputStream;
30  import java.io.IOException;
31  import java.io.InputStream;
32  
33  import org.apache.http.annotation.Contract;
34  import org.apache.http.annotation.ThreadingBehavior;
35  import org.apache.http.client.cache.InputLimit;
36  import org.apache.http.client.cache.Resource;
37  import org.apache.http.client.cache.ResourceFactory;
38  
39  /**
40   * Generates {@link Resource} instances stored entirely in heap.
41   *
42   * @since 4.1
43   */
44  @Contract(threading = ThreadingBehavior.IMMUTABLE)
45  public class HeapResourceFactory implements ResourceFactory {
46  
47      @Override
48      public Resource generate(
49              final String requestId,
50              final InputStream instream,
51              final InputLimit limit) throws IOException {
52          final ByteArrayOutputStream outstream = new ByteArrayOutputStream();
53          final byte[] buf = new byte[2048];
54          long total = 0;
55          int l;
56          while ((l = instream.read(buf)) != -1) {
57              outstream.write(buf, 0, l);
58              total += l;
59              if (limit != null && total > limit.getValue()) {
60                  limit.reached();
61                  break;
62              }
63          }
64          return createResource(outstream.toByteArray());
65      }
66  
67      @Override
68      public Resource copy(
69              final String requestId,
70              final Resource resource) throws IOException {
71          final byte[] body;
72          if (resource instanceof HeapResource) {
73              body = ((HeapResource) resource).getByteArray();
74          } else {
75              final ByteArrayOutputStream outstream = new ByteArrayOutputStream();
76              IOUtils.copyAndClose(resource.getInputStream(), outstream);
77              body = outstream.toByteArray();
78          }
79          return createResource(body);
80      }
81  
82      Resource createResource(final byte[] buf) {
83          return new HeapResource(buf);
84      }
85  
86  }