Http3ControlStreamOutboundHandler Class — netty Architecture

Source Code

codec-http3/src/main/java/io/netty/handler/codec/http3/Http3ControlStreamOutboundHandler.java lines 29–143

final class Http3ControlStreamOutboundHandler
        extends Http3FrameTypeDuplexValidationHandler<Http3ControlStreamFrame> {
    private final boolean server;
    private final ChannelHandler codec;
    private Long sentMaxPushId;
    private Long sendGoAwayId;
    private Http3SettingsFrame localSettings;

    Http3ControlStreamOutboundHandler(boolean server, Http3SettingsFrame localSettings, ChannelHandler codec) {
        super(Http3ControlStreamFrame.class);
        this.server = server;
        this.localSettings = ObjectUtil.checkNotNull(localSettings, "localSettings");
        this.codec = ObjectUtil.checkNotNull(codec, "codec");
    }

    /**
     * Returns the last id that was sent in a MAX_PUSH_ID frame or {@code null} if none was sent yet.
     *
     * @return the id.
     */
    @Nullable
    Long sentMaxPushId() {
        return sentMaxPushId;
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) {
        // We need to write 0x00 into the stream before doing anything else.
        // See https://tools.ietf.org/html/draft-ietf-quic-http-32#section-6.2.1
        // Just allocate 8 bytes which would be the max needed.
        ByteBuf buffer = ctx.alloc().buffer(8);
        Http3CodecUtils.writeVariableLengthInteger(buffer, Http3CodecUtils.HTTP3_CONTROL_STREAM_TYPE);
        ctx.write(buffer);
        // Add the encoder and decoder in the pipeline so we can handle Http3Frames. This needs to happen after
        // we did write the type via a ByteBuf.
        ctx.pipeline().addFirst(codec);

        assert localSettings != null;
        // If writing of the local settings fails let's just teardown the connection.
        closeOnFailure(ctx.writeAndFlush(localSettings));

        // Let the GC collect localSettings.
        localSettings = null;

        ctx.fireChannelActive();
    }

    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) {
        if (evt instanceof ChannelInputShutdownEvent) {
            // See https://tools.ietf.org/html/draft-ietf-quic-http-32#section-6.2.1
            Http3CodecUtils.criticalStreamClosed(ctx);
        }
        ctx.fireUserEventTriggered(evt);
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) {
        // See https://tools.ietf.org/html/draft-ietf-quic-http-32#section-6.2.1
        Http3CodecUtils.criticalStreamClosed(ctx);
        ctx.fireChannelInactive();
    }

    @Override
    void write(ChannelHandlerContext ctx, Http3ControlStreamFrame msg, ChannelPromise promise) {
        if (msg instanceof Http3MaxPushIdFrame && !handleHttp3MaxPushIdFrame(promise, (Http3MaxPushIdFrame) msg)) {
            ReferenceCountUtil.release(msg);
            return;
        } else if (msg instanceof Http3GoAwayFrame && !handleHttp3GoAwayFrame(promise, (Http3GoAwayFrame) msg)) {
            ReferenceCountUtil.release(msg);
            return;
        }

        ctx.write(msg, promise);
    }

    private boolean handleHttp3MaxPushIdFrame(ChannelPromise promise, Http3MaxPushIdFrame maxPushIdFrame) {
        long id = maxPushIdFrame.id();

        // See https://datatracker.ietf.org/doc/html/draft-ietf-quic-http-32#section-7.2.7
        if (sentMaxPushId != null && id < sentMaxPushId) {