EchoHandler Class — netty Architecture

Source Code

codec-native-quic/src/test/java/io/netty/handler/codec/quic/QuicChannelEchoTest.java lines 365–439

    private class EchoHandler extends SimpleChannelInboundHandler<ByteBuf> {
        private final boolean server;
        private final boolean autoRead;
        private final ByteBufAllocator allocator;
        volatile Channel channel;
        final AtomicReference<Throwable> exception = new AtomicReference<>();
        volatile int counter;

        EchoHandler(boolean server, boolean autoRead, ByteBufAllocator allocator) {
            this.server = server;
            this.autoRead = autoRead;
            this.allocator = allocator;
        }

        @Override
        public void channelRegistered(ChannelHandlerContext ctx) {
            ctx.channel().config().setAutoRead(autoRead);
            setAllocator(ctx.channel(), allocator);
            ctx.fireChannelRegistered();
        }

        @Override
        public void channelActive(ChannelHandlerContext ctx) {
            channel = ctx.channel();
            QuicStreamChannel channel = (QuicStreamChannel)  ctx.channel();
            assertEquals(QuicStreamType.BIDIRECTIONAL, channel.type());
            if (channel.isLocalCreated()) {
                // Server starts with 1, client with 0
                assertEquals(server ? 1 : 0, channel.streamId());
            } else {
                // Server starts with 1, client with 0
                assertEquals(server ? 0 : 1, channel.streamId());
            }
            if (!autoRead) {
                ctx.read();
            }
        }

        @Override
        protected void channelRead0(ChannelHandlerContext ctx, ByteBuf in) {
            byte[] actual = new byte[in.readableBytes()];
            in.readBytes(actual);

            int lastIdx = counter;
            for (int i = 0; i < actual.length; i ++) {
                assertEquals(data[i + lastIdx], actual[i]);
            }

            if (!((QuicStreamChannel) ctx.channel()).isLocalCreated()) {
                channel.write(Unpooled.wrappedBuffer(actual));
            }

            counter += actual.length;
        }

        @Override
        public void channelReadComplete(ChannelHandlerContext ctx) {
            try {
                ctx.flush();
            } finally {
                if (!autoRead) {
                    ctx.read();
                }
            }
        }

        @Override
        public void exceptionCaught(ChannelHandlerContext ctx,
                                    Throwable cause) {
            if (exception.compareAndSet(null, cause)) {
                cause.printStackTrace();
                ctx.close();
            }
        }
    }