Http2FrameCodec Class — netty Architecture

Source Code

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2FrameCodec.java lines 144–788

public class Http2FrameCodec extends Http2ConnectionHandler {

    private static final InternalLogger LOG = InternalLoggerFactory.getInstance(Http2FrameCodec.class);

    private static final Class<?>[] SUPPORTED_MESSAGES = new Class[] {
            Http2DataFrame.class, Http2HeadersFrame.class, Http2WindowUpdateFrame.class, Http2ResetFrame.class,
            Http2PingFrame.class, Http2SettingsFrame.class, Http2SettingsAckFrame.class, Http2GoAwayFrame.class,
            Http2PushPromiseFrame.class, Http2PriorityFrame.class, Http2UnknownFrame.class };

    protected final PropertyKey streamKey;
    private final PropertyKey upgradeKey;

    private final Integer initialFlowControlWindowSize;

    ChannelHandlerContext ctx;

    /**
     * Number of buffered streams if the {@link StreamBufferingEncoder} is used.
     **/
    private int numBufferedStreams;
    private final IntObjectMap<DefaultHttp2FrameStream> frameStreamToInitializeMap =
            new IntObjectHashMap<DefaultHttp2FrameStream>(8);

    protected Http2FrameCodec(Http2ConnectionEncoder encoder, Http2ConnectionDecoder decoder,
                              Http2Settings initialSettings, boolean decoupleCloseAndGoAway, boolean flushPreface) {
        super(decoder, encoder, initialSettings, decoupleCloseAndGoAway, flushPreface);

        decoder.frameListener(new FrameListener());
        connection().addListener(new ConnectionListener());
        connection().remote().flowController().listener(new Http2RemoteFlowControllerListener());
        streamKey = connection().newKey();
        upgradeKey = connection().newKey();
        initialFlowControlWindowSize = initialSettings.initialWindowSize();
    }

    /**
     * Creates a new outbound/local stream.
     */
    DefaultHttp2FrameStream newStream() {
        return new DefaultHttp2FrameStream();
    }

    /**
     * Iterates over all active HTTP/2 streams.
     *
     * <p>This method must not be called outside of the event loop.
     */
    final void forEachActiveStream(final Http2FrameStreamVisitor streamVisitor) throws Http2Exception {
        assert ctx.executor().inEventLoop();
        if (connection().numActiveStreams() > 0) {
            connection().forEachActiveStream(new Http2StreamVisitor() {
                @Override
                public boolean visit(Http2Stream stream) {
                    try {
                        return streamVisitor.visit((Http2FrameStream) stream.getProperty(streamKey));
                    } catch (Throwable cause) {
                        onError(ctx, false, cause);
                        return false;
                    }
                }
            });
        }
    }

    /**
     * Retrieve the number of streams currently in the process of being initialized.
     * <p>
     * This is package-private for testing only.
     */
    int numInitializingStreams() {
        return frameStreamToInitializeMap.size();
    }

    @Override
    public final void handlerAdded(ChannelHandlerContext ctx) throws Exception {
        this.ctx = ctx;
        super.handlerAdded(ctx);
        handlerAdded0(ctx);
        // Must be after Http2ConnectionHandler does its initialization in handlerAdded above.
        // The server will not send a connection preface so we are good to send a window update.
        Http2Connection connection = connection();