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1   /*
2    * Copyright 2016 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  package io.netty.handler.codec.http2;
17  
18  import io.netty.channel.ChannelHandlerContext;
19  import io.netty.channel.ChannelInboundHandlerAdapter;
20  import io.netty.handler.codec.http.FullHttpMessage;
21  import io.netty.handler.codec.http.HttpHeaders;
22  import io.netty.handler.codec.http.HttpScheme;
23  import io.netty.util.internal.UnstableApi;
24  
25  /**
26   * Translates HTTP/1.x object reads into HTTP/2 frames.
27   */
28  @UnstableApi
29  public class InboundHttpToHttp2Adapter extends ChannelInboundHandlerAdapter {
30      private final Http2Connection connection;
31      private final Http2FrameListener listener;
32  
33      public InboundHttpToHttp2Adapter(Http2Connection connection, Http2FrameListener listener) {
34          this.connection = connection;
35          this.listener = listener;
36      }
37  
38      private static int getStreamId(Http2Connection connection, HttpHeaders httpHeaders) {
39          return httpHeaders.getInt(HttpConversionUtil.ExtensionHeaderNames.STREAM_ID.text(),
40                                    connection.remote().incrementAndGetNextStreamId());
41      }
42  
43      @Override
44      public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
45          if (msg instanceof FullHttpMessage) {
46              handle(ctx, connection, listener, (FullHttpMessage) msg);
47          } else {
48              super.channelRead(ctx, msg);
49          }
50      }
51  
52      // note that this may behave strangely when used for the initial upgrade
53      // message when using h2c, since that message is ineligible for flow
54      // control, but there is not yet an API for signaling that.
55      static void handle(ChannelHandlerContext ctx, Http2Connection connection,
56                                Http2FrameListener listener, FullHttpMessage message) throws Http2Exception {
57          try {
58              int streamId = getStreamId(connection, message.headers());
59              Http2Stream stream = connection.stream(streamId);
60              if (stream == null) {
61                  stream = connection.remote().createStream(streamId, false);
62              }
63              message.headers().set(HttpConversionUtil.ExtensionHeaderNames.SCHEME.text(), HttpScheme.HTTP.name());
64              Http2Headers messageHeaders = HttpConversionUtil.toHttp2Headers(message, true);
65              boolean hasContent = message.content().isReadable();
66              boolean hasTrailers = !message.trailingHeaders().isEmpty();
67              listener.onHeadersRead(
68                      ctx, streamId, messageHeaders, 0, !(hasContent || hasTrailers));
69              if (hasContent) {
70                  listener.onDataRead(ctx, streamId, message.content(), 0, !hasTrailers);
71              }
72              if (hasTrailers) {
73                  Http2Headers headers = HttpConversionUtil.toHttp2Headers(message.trailingHeaders(), true);
74                  listener.onHeadersRead(ctx, streamId, headers, 0, true);
75              }
76              stream.closeRemoteSide();
77          } finally {
78              message.release();
79          }
80      }
81  }