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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License.
18   *
19   */
20  package org.apache.mina.codec.delimited.serialization;
21  
22  import java.nio.ByteBuffer;
23  
24  import org.apache.mina.codec.ProtocolEncoderException;
25  import org.apache.mina.codec.delimited.ByteBufferEncoder;
26  import org.apache.thrift.TBase;
27  import org.apache.thrift.TException;
28  import org.apache.thrift.TSerializer;
29  import org.apache.thrift.protocol.TBinaryProtocol;
30  
31  /**
32   * Encode Thrift message into {@link ByteBuffer}
33   * 
34   * @param <INPUT> the base type for message to encode
35   * 
36   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
37   */
38  public class ThriftMessageEncoder<INPUT extends TBase<?, ?>> extends ByteBufferEncoder<INPUT> {
39      private final TSerializer serializer = new TSerializer(new TBinaryProtocol.Factory());
40  
41      private INPUT lastMessage;
42  
43      private byte[] lastBuffer;
44  
45      public static <L extends TBase<?, ?>> ThriftMessageEncoder<L> newInstance(Class<L> clazz) {
46          return new ThriftMessageEncoder<L>();
47      }
48  
49      private byte[] prepareBuffer(INPUT message) throws TException {
50          if (message != lastMessage) { // NOSONAR, comparing the messages, not their content
51              lastBuffer = serializer.serialize(message);
52              this.lastMessage = message;
53          }
54          return lastBuffer;
55      }
56  
57      /**
58       * {@inheritDoc}
59       */
60      @Override
61      public int getEncodedSize(INPUT message) {
62          try {
63              return prepareBuffer(message).length;
64          } catch (TException e) {
65              return 0;
66          }
67      }
68  
69      /**
70       * {@inheritDoc}
71       */
72      @Override
73      public void writeTo(INPUT message, ByteBuffer buffer) {
74          try {
75              buffer.put(prepareBuffer(message));
76          } catch (TException e) {
77              throw new ProtocolEncoderException(e);
78          }
79      }
80  }