AbstractQPackStreamInitializer Class — netty Architecture

Source Code

codec-http3/src/main/java/io/netty/handler/codec/http3/Http3ControlStreamInboundHandler.java lines 226–268

    private abstract static class AbstractQPackStreamInitializer extends ChannelInboundHandlerAdapter {
        private final int streamType;
        protected final QpackAttributes attributes;

        AbstractQPackStreamInitializer(int streamType, QpackAttributes attributes) {
            this.streamType = streamType;
            this.attributes = attributes;
        }

        @Override
        public final void channelActive(ChannelHandlerContext ctx) {
            // We need to write the streamType 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, streamType);
            closeOnFailure(ctx.writeAndFlush(buffer));
            streamAvailable(ctx);
            ctx.fireChannelActive();
        }

        @Override
        public final void userEventTriggered(ChannelHandlerContext ctx, Object evt) {
            streamClosed(ctx);
            if (evt instanceof ChannelInputShutdownEvent) {
                // See https://quicwg.org/base-drafts/draft-ietf-quic-qpack.html#section-4.2
                criticalStreamClosed(ctx);
            }
            ctx.fireUserEventTriggered(evt);
        }

        @Override
        public void channelInactive(ChannelHandlerContext ctx) {
            streamClosed(ctx);
            // See https://quicwg.org/base-drafts/draft-ietf-quic-qpack.html#section-4.2
            criticalStreamClosed(ctx);
            ctx.fireChannelInactive();
        }

        protected abstract void streamAvailable(ChannelHandlerContext ctx);

        protected abstract void streamClosed(ChannelHandlerContext ctx);
    }