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1   /*
2    * Copyright 2013 The Netty Project
3    *
4    * The Netty Project licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the License. You may obtain a copy of the License at:
7    *
8    *   http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations
14   * under the License.
15   */
16  package org.jboss.netty.handler.codec.spdy;
17  
18  import org.jboss.netty.buffer.ChannelBuffer;
19  import org.jboss.netty.buffer.ChannelBuffers;
20  
21  import java.nio.ByteOrder;
22  import java.util.Set;
23  
24  import static org.jboss.netty.handler.codec.spdy.SpdyCodecUtil.*;
25  
26  public class SpdyHeaderBlockRawEncoder extends SpdyHeaderBlockEncoder {
27  
28      private final int version;
29  
30      public SpdyHeaderBlockRawEncoder(SpdyVersion spdyVersion) {
31          if (spdyVersion == null) {
32              throw new NullPointerException("spdyVersion");
33          }
34          version = spdyVersion.getVersion();
35      }
36  
37      private static void setLengthField(ChannelBuffer buffer, int writerIndex, int length) {
38          buffer.setInt(writerIndex, length);
39      }
40  
41      private static void writeLengthField(ChannelBuffer buffer, int length) {
42          buffer.writeInt(length);
43      }
44  
45      @Override
46      public ChannelBuffer encode(SpdyHeadersFrame headerFrame) throws Exception {
47          Set<String> names = headerFrame.headers().names();
48          int numHeaders = names.size();
49          if (numHeaders == 0) {
50              return ChannelBuffers.EMPTY_BUFFER;
51          }
52          if (numHeaders > SPDY_MAX_NV_LENGTH) {
53              throw new IllegalArgumentException(
54                      "header block contains too many headers");
55          }
56          ChannelBuffer headerBlock = ChannelBuffers.dynamicBuffer(
57                  ByteOrder.BIG_ENDIAN, 256);
58          writeLengthField(headerBlock, numHeaders);
59          for (String name: names) {
60              byte[] nameBytes = name.getBytes("UTF-8");
61              writeLengthField(headerBlock, nameBytes.length);
62              headerBlock.writeBytes(nameBytes);
63              int savedIndex = headerBlock.writerIndex();
64              int valueLength = 0;
65              writeLengthField(headerBlock, valueLength);
66              for (String value: headerFrame.headers().getAll(name)) {
67                  byte[] valueBytes = value.getBytes("UTF-8");
68                  if (valueBytes.length > 0) {
69                      headerBlock.writeBytes(valueBytes);
70                      headerBlock.writeByte(0);
71                      valueLength += valueBytes.length + 1;
72                  }
73              }
74              if (valueLength != 0) {
75                  valueLength --;
76              }
77              if (valueLength > SPDY_MAX_NV_LENGTH) {
78                  throw new IllegalArgumentException(
79                          "header exceeds allowable length: " + name);
80              }
81              if (valueLength > 0) {
82                  setLengthField(headerBlock, savedIndex, valueLength);
83                  headerBlock.writerIndex(headerBlock.writerIndex() - 1);
84              }
85          }
86          return headerBlock;
87      }
88  
89      @Override
90      void end() {
91      }
92  }