1 //
2 // ========================================================================
3 // Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
8 //
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
11 //
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
14 //
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
17 //
18
19 package org.eclipse.jetty.websocket.common.extensions.compress;
20
21 import java.nio.ByteBuffer;
22
23 import org.eclipse.jetty.websocket.api.extensions.Frame;
24 import org.eclipse.jetty.websocket.common.OpCode;
25
26 /**
27 * Implementation of the
28 * <a href="https://tools.ietf.org/id/draft-tyoshino-hybi-websocket-perframe-deflate.txt">deflate-frame</a>
29 * extension seen out in the wild.
30 */
31 public class DeflateFrameExtension extends CompressExtension
32 {
33 @Override
34 public String getName()
35 {
36 return "deflate-frame";
37 }
38
39 @Override
40 int getRsvUseMode()
41 {
42 return RSV_USE_ALWAYS;
43 }
44
45 @Override
46 int getTailDropMode()
47 {
48 return TAIL_DROP_ALWAYS;
49 }
50
51 @Override
52 public void incomingFrame(Frame frame)
53 {
54 // Incoming frames are always non concurrent because
55 // they are read and parsed with a single thread, and
56 // therefore there is no need for synchronization.
57
58 if (OpCode.isControlFrame(frame.getOpCode()) || !frame.isRsv1() || !frame.hasPayload())
59 {
60 nextIncomingFrame(frame);
61 return;
62 }
63
64 ByteBuffer payload = frame.getPayload();
65 int remaining = payload.remaining();
66 byte[] input = new byte[remaining + TAIL_BYTES.length];
67 payload.get(input, 0, remaining);
68 System.arraycopy(TAIL_BYTES, 0, input, remaining, TAIL_BYTES.length);
69
70 forwardIncoming(frame, decompress(input));
71 }
72 }