1 /*
2 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.net.http;
27
28 import java.io.IOException;
29 import java.nio.ByteBuffer;
30
31 class SettingsFrame extends Http2Frame {
32
33 int[] parameters;
34
35 public static final int TYPE = 0x4;
36
37 // Flags
38 public static final int ACK = 0x1;
39
40 @Override
41 String flagAsString(int flag) {
42 switch (flag) {
43 case ACK:
44 return "ACK";
45 }
46 return super.flagAsString(flag);
47 }
48
49 @Override
50 public String toString() {
51 StringBuilder sb = new StringBuilder();
52 sb.append(super.toString())
53 .append(" Settings: ");
54
55 for (int i = 0; i < MAX_PARAM; i++) {
56 if (parameters[i] != -1) {
57 sb.append(name(i))
58 .append("=")
59 .append(Integer.toString(parameters[i]))
60 .append(' ');
61 }
62 }
63 return sb.toString();
64 }
65
66 // Parameters
67 public static final int HEADER_TABLE_SIZE = 0x1;
68 public static final int ENABLE_PUSH = 0x2;
69 public static final int MAX_CONCURRENT_STREAMS = 0x3;
70 public static final int INITIAL_WINDOW_SIZE = 0x4;
71 public static final int MAX_FRAME_SIZE = 0x5;
72 public static final int MAX_HEADER_LIST_SIZE = 0x6;
73
74 private String name(int i) {
75 switch (i+1) {
76 case HEADER_TABLE_SIZE:
77 return "HEADER_TABLE_SIZE";
78 case ENABLE_PUSH:
79 return "ENABLE_PUSH";
80 case MAX_CONCURRENT_STREAMS:
81 return "MAX_CONCURRENT_STREAMS";
82 case INITIAL_WINDOW_SIZE:
83 return "INITIAL_WINDOW_SIZE";
84 case MAX_FRAME_SIZE:
85 return "MAX_FRAME_SIZE";
86 case MAX_HEADER_LIST_SIZE:
87 return "MAX_HEADER_LIST_SIZE";
88 }
89 return "unknown parameter";
90 }
91 public static final int MAX_PARAM = 0x6;
92
93 public SettingsFrame() {
94 type = TYPE;
95 parameters = new int [MAX_PARAM];
96 for (int i=0; i < parameters.length; i++) {
97 parameters[i] = -1;
98 }
99 }
100
101 public int getParameter(int paramID) {
102 if (paramID > MAX_PARAM) {
103 throw new IllegalArgumentException("illegal parameter");
104 }
105 return parameters[paramID-1];
106 }
107
108 public SettingsFrame setParameter(int paramID, int value) {
109 if (paramID > MAX_PARAM) {
110 throw new IllegalArgumentException("illegal parameter");
111 }
112 parameters[paramID-1] = value;
113 return this;
114 }
115
116 @Override
117 void readIncomingImpl(ByteBufferConsumer bc) throws IOException {
118 if (length % 6 != 0) {
119 throw new IOException("Protocol error: invalid settings frame");
120 }
121 int n = length / 6;
122 for (int i=0; i<n; i++) {
123 int id = bc.getShort();
124 int val = bc.getInt();
125 if (id > 0 || id <= MAX_PARAM) {
126 // a known parameter. Ignore otherwise
127 parameters[id-1] = val;
128 }
129 }
130 }
131
132 @Override
133 void computeLength() {
134 length = 0;
135 for (int i : parameters) {
136 if (i != -1) {
137 length += 6;
138 }
139 }
140 }
141
142 @Override
143 void writeOutgoing(ByteBufferGenerator bg) {
144 super.writeOutgoing(bg);
145 ByteBuffer buf = bg.getBuffer(length);
146 for (int i = 0; i < MAX_PARAM; i++) {
147 if (parameters[i] != -1) {
148 buf.putShort((short)(i+1));
149 buf.putInt(parameters[i]);
150 }
151 }
152 }
153
154 private static final int K = 1024;
155
156 public static SettingsFrame getDefaultSettings() {
157 SettingsFrame f = new SettingsFrame();
158 // TODO: check these values
159 f.setParameter(ENABLE_PUSH, 1);
160 f.setParameter(HEADER_TABLE_SIZE, 4 * K);
161 f.setParameter(MAX_CONCURRENT_STREAMS, 35);
162 f.setParameter(INITIAL_WINDOW_SIZE, 16 * K);
163 f.setParameter(MAX_FRAME_SIZE, 16 * K);
164 return f;
165 }
166 }