1 //
2 // ========================================================================
3 // Copyright (c) 1995-2016 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.http2.frames;
20
21 import java.util.Objects;
22
23 public class PingFrame extends Frame
24 {
25 public static final int PING_LENGTH = 8;
26 private static final byte[] EMPTY_PAYLOAD = new byte[8];
27
28 private final byte[] payload;
29 private final boolean reply;
30
31 /**
32 * Creates a PING frame with an empty payload.
33 *
34 * @param reply whether this PING frame is a reply
35 */
36 public PingFrame(boolean reply)
37 {
38 this(EMPTY_PAYLOAD, reply);
39 }
40
41 /**
42 * Creates a PING frame with the given {@code long} {@code value} as payload.
43 *
44 * @param value the value to use as a payload for this PING frame
45 * @param reply whether this PING frame is a reply
46 */
47 public PingFrame(long value, boolean reply)
48 {
49 this(toBytes(value), reply);
50 }
51
52 /**
53 * Creates a PING frame with the given {@code payload}.
54 *
55 * @param payload the payload for this PING frame
56 * @param reply whether this PING frame is a reply
57 */
58 public PingFrame(byte[] payload, boolean reply)
59 {
60 super(FrameType.PING);
61 this.payload = Objects.requireNonNull(payload);
62 if (payload.length != PING_LENGTH)
63 throw new IllegalArgumentException("PING payload must be 8 bytes");
64 this.reply = reply;
65 }
66
67 public byte[] getPayload()
68 {
69 return payload;
70 }
71
72 public long getPayloadAsLong()
73 {
74 return toLong(payload);
75 }
76
77 public boolean isReply()
78 {
79 return reply;
80 }
81
82 private static byte[] toBytes(long value)
83 {
84 byte[] result = new byte[8];
85 for (int i = result.length - 1; i >= 0; --i)
86 {
87 result[i] = (byte)(value & 0xFF);
88 value >>= 8;
89 }
90 return result;
91 }
92
93 private static long toLong(byte[] payload)
94 {
95 long result = 0;
96 for (int i = 0; i < 8; ++i)
97 {
98 result <<= 8;
99 result |= (payload[i] & 0xFF);
100 }
101 return result;
102 }
103 }