1 /*
2 * Copyright 2014 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License, version 2.0 (the
5 * "License"); you may not use this file except in compliance with the License. You may obtain a
6 * copy of the License at:
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software distributed under the License
11 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
12 * or implied. See the License for the specific language governing permissions and limitations under
13 * the License.
14 */
15 package io.netty5.handler.codec.http2;
16
17 import io.netty5.buffer.api.Buffer;
18 import io.netty5.util.internal.UnstableApi;
19
20 /**
21 * Decodes HPACK-encoded headers blocks into {@link Http2Headers}.
22 */
23 @UnstableApi
24 public interface Http2HeadersDecoder {
25 /**
26 * Configuration related elements for the {@link Http2HeadersDecoder} interface
27 */
28 interface Configuration {
29 /**
30 * Represents the value for
31 * <a href="https://tools.ietf.org/html/rfc7540#section-6.5.2">SETTINGS_HEADER_TABLE_SIZE</a>.
32 * This method should only be called by Netty (not users) as a result of a receiving a {@code SETTINGS} frame.
33 */
34 void maxHeaderTableSize(long max) throws Http2Exception;
35
36 /**
37 * Represents the value for
38 * <a href="https://tools.ietf.org/html/rfc7540#section-6.5.2">SETTINGS_HEADER_TABLE_SIZE</a>. The initial value
39 * returned by this method must be {@link Http2CodecUtil#DEFAULT_HEADER_TABLE_SIZE}.
40 */
41 long maxHeaderTableSize();
42
43 /**
44 * Configure the maximum allowed size in bytes of each set of headers.
45 * <p>
46 * This method should only be called by Netty (not users) as a result of a receiving a {@code SETTINGS} frame.
47 * @param max <a href="https://tools.ietf.org/html/rfc7540#section-6.5.2">SETTINGS_MAX_HEADER_LIST_SIZE</a>.
48 * If this limit is exceeded the implementation should attempt to keep the HPACK header tables up to date
49 * by processing data from the peer, but a {@code RST_STREAM} frame will be sent for the offending stream.
50 * @param goAwayMax Must be {@code >= max}. A {@code GO_AWAY} frame will be generated if this limit is exceeded
51 * for any particular stream.
52 * @throws Http2Exception if limits exceed the RFC's boundaries or {@code max > goAwayMax}.
53 */
54 void maxHeaderListSize(long max, long goAwayMax) throws Http2Exception;
55
56 /**
57 * Represents the value for
58 * <a href="https://tools.ietf.org/html/rfc7540#section-6.5.2">SETTINGS_MAX_HEADER_LIST_SIZE</a>.
59 */
60 long maxHeaderListSize();
61
62 /**
63 * Represents the upper bound in bytes for a set of headers before a {@code GO_AWAY} should be sent.
64 * This will be {@code <=}
65 * <a href="https://tools.ietf.org/html/rfc7540#section-6.5.2">SETTINGS_MAX_HEADER_LIST_SIZE</a>.
66 */
67 long maxHeaderListSizeGoAway();
68 }
69
70 /**
71 * Decodes the given headers block and returns the headers.
72 */
73 Http2Headers decodeHeaders(int streamId, Buffer headerBlock) throws Http2Exception;
74
75 /**
76 * Get the {@link Configuration} for this {@link Http2HeadersDecoder}
77 */
78 Configuration configuration();
79 }