1 /*
2 * Copyright 2015 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
17 /*
18 * Copyright 2014 Twitter, Inc.
19 *
20 * Licensed under the Apache License, Version 2.0 (the "License");
21 * you may not use this file except in compliance with the License.
22 * You may obtain a copy of the License at
23 *
24 * http://www.apache.org/licenses/LICENSE-2.0
25 *
26 * Unless required by applicable law or agreed to in writing, software
27 * distributed under the License is distributed on an "AS IS" BASIS,
28 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
29 * See the License for the specific language governing permissions and
30 * limitations under the License.
31 */
32 package io.netty.handler.codec.http2;
33
34 import io.netty.handler.codec.UnsupportedValueConverter;
35 import io.netty.util.AsciiString;
36
37 import java.util.Arrays;
38 import java.util.List;
39
40 import static io.netty.handler.codec.http2.HpackUtil.equalsConstantTime;
41
42 final class HpackStaticTable {
43
44 // Appendix A: Static Table
45 // http://tools.ietf.org/html/rfc7541#appendix-A
46 private static final List<HpackHeaderField> STATIC_TABLE = Arrays.asList(
47 /* 1 */ newEmptyHeaderField(":authority"),
48 /* 2 */ newHeaderField(":method", "GET"),
49 /* 3 */ newHeaderField(":method", "POST"),
50 /* 4 */ newHeaderField(":path", "/"),
51 /* 5 */ newHeaderField(":path", "/index.html"),
52 /* 6 */ newHeaderField(":scheme", "http"),
53 /* 7 */ newHeaderField(":scheme", "https"),
54 /* 8 */ newHeaderField(":status", "200"),
55 /* 9 */ newHeaderField(":status", "204"),
56 /* 10 */ newHeaderField(":status", "206"),
57 /* 11 */ newHeaderField(":status", "304"),
58 /* 12 */ newHeaderField(":status", "400"),
59 /* 13 */ newHeaderField(":status", "404"),
60 /* 14 */ newHeaderField(":status", "500"),
61 /* 15 */ newEmptyHeaderField("accept-charset"),
62 /* 16 */ newHeaderField("accept-encoding", "gzip, deflate"),
63 /* 17 */ newEmptyHeaderField("accept-language"),
64 /* 18 */ newEmptyHeaderField("accept-ranges"),
65 /* 19 */ newEmptyHeaderField("accept"),
66 /* 20 */ newEmptyHeaderField("access-control-allow-origin"),
67 /* 21 */ newEmptyHeaderField("age"),
68 /* 22 */ newEmptyHeaderField("allow"),
69 /* 23 */ newEmptyHeaderField("authorization"),
70 /* 24 */ newEmptyHeaderField("cache-control"),
71 /* 25 */ newEmptyHeaderField("content-disposition"),
72 /* 26 */ newEmptyHeaderField("content-encoding"),
73 /* 27 */ newEmptyHeaderField("content-language"),
74 /* 28 */ newEmptyHeaderField("content-length"),
75 /* 29 */ newEmptyHeaderField("content-location"),
76 /* 30 */ newEmptyHeaderField("content-range"),
77 /* 31 */ newEmptyHeaderField("content-type"),
78 /* 32 */ newEmptyHeaderField("cookie"),
79 /* 33 */ newEmptyHeaderField("date"),
80 /* 34 */ newEmptyHeaderField("etag"),
81 /* 35 */ newEmptyHeaderField("expect"),
82 /* 36 */ newEmptyHeaderField("expires"),
83 /* 37 */ newEmptyHeaderField("from"),
84 /* 38 */ newEmptyHeaderField("host"),
85 /* 39 */ newEmptyHeaderField("if-match"),
86 /* 40 */ newEmptyHeaderField("if-modified-since"),
87 /* 41 */ newEmptyHeaderField("if-none-match"),
88 /* 42 */ newEmptyHeaderField("if-range"),
89 /* 43 */ newEmptyHeaderField("if-unmodified-since"),
90 /* 44 */ newEmptyHeaderField("last-modified"),
91 /* 45 */ newEmptyHeaderField("link"),
92 /* 46 */ newEmptyHeaderField("location"),
93 /* 47 */ newEmptyHeaderField("max-forwards"),
94 /* 48 */ newEmptyHeaderField("proxy-authenticate"),
95 /* 49 */ newEmptyHeaderField("proxy-authorization"),
96 /* 50 */ newEmptyHeaderField("range"),
97 /* 51 */ newEmptyHeaderField("referer"),
98 /* 52 */ newEmptyHeaderField("refresh"),
99 /* 53 */ newEmptyHeaderField("retry-after"),
100 /* 54 */ newEmptyHeaderField("server"),
101 /* 55 */ newEmptyHeaderField("set-cookie"),
102 /* 56 */ newEmptyHeaderField("strict-transport-security"),
103 /* 57 */ newEmptyHeaderField("transfer-encoding"),
104 /* 58 */ newEmptyHeaderField("user-agent"),
105 /* 59 */ newEmptyHeaderField("vary"),
106 /* 60 */ newEmptyHeaderField("via"),
107 /* 61 */ newEmptyHeaderField("www-authenticate")
108 );
109
110 private static HpackHeaderField newEmptyHeaderField(String name) {
111 return new HpackHeaderField(AsciiString.cached(name), AsciiString.EMPTY_STRING);
112 }
113
114 private static HpackHeaderField newHeaderField(String name, String value) {
115 return new HpackHeaderField(AsciiString.cached(name), AsciiString.cached(value));
116 }
117
118 private static final CharSequenceMap<Integer> STATIC_INDEX_BY_NAME = createMap();
119
120 /**
121 * The number of header fields in the static table.
122 */
123 static final int length = STATIC_TABLE.size();
124
125 /**
126 * Return the header field at the given index value.
127 */
128 static HpackHeaderField getEntry(int index) {
129 return STATIC_TABLE.get(index - 1);
130 }
131
132 /**
133 * Returns the lowest index value for the given header field name in the static table. Returns
134 * -1 if the header field name is not in the static table.
135 */
136 static int getIndex(CharSequence name) {
137 Integer index = STATIC_INDEX_BY_NAME.get(name);
138 if (index == null) {
139 return -1;
140 }
141 return index;
142 }
143
144 /**
145 * Returns the index value for the given header field in the static table. Returns -1 if the
146 * header field is not in the static table.
147 */
148 static int getIndex(CharSequence name, CharSequence value) {
149 int index = getIndex(name);
150 if (index == -1) {
151 return -1;
152 }
153
154 // Note this assumes all entries for a given header field are sequential.
155 while (index <= length) {
156 HpackHeaderField entry = getEntry(index);
157 if (equalsConstantTime(name, entry.name) == 0) {
158 break;
159 }
160 if (equalsConstantTime(value, entry.value) != 0) {
161 return index;
162 }
163 index++;
164 }
165
166 return -1;
167 }
168
169 // create a map CharSequenceMap header name to index value to allow quick lookup
170 private static CharSequenceMap<Integer> createMap() {
171 int length = STATIC_TABLE.size();
172 @SuppressWarnings("unchecked")
173 CharSequenceMap<Integer> ret = new CharSequenceMap<Integer>(true,
174 UnsupportedValueConverter.<Integer>instance(), length);
175 // Iterate through the static table in reverse order to
176 // save the smallest index for a given name in the map.
177 for (int index = length; index > 0; index--) {
178 HpackHeaderField entry = getEntry(index);
179 CharSequence name = entry.name;
180 ret.set(name, index);
181 }
182 return ret;
183 }
184
185 // singleton
186 private HpackStaticTable() {
187 }
188 }