channelRead() — netty Function Reference

Source Code

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/extensions/WebSocketServerExtensionHandler.java lines 69–89

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        // JDK type checks vs non-implemented interfaces costs O(N), where
        // N is the number of interfaces already implemented by the concrete type that's being tested.
        // The only requirement for this call is to make HttpRequest(s) implementors to call onHttpRequestChannelRead
        // and super.channelRead the others, but due to the O(n) cost we perform few fast-path for commonly met
        // singleton and/or concrete types, to save performing such slow type checks.
        if (msg != LastHttpContent.EMPTY_LAST_CONTENT) {
            if (msg instanceof DefaultHttpRequest) {
                // fast-path
                onHttpRequestChannelRead(ctx, (DefaultHttpRequest) msg);
            } else if (msg instanceof HttpRequest) {
                // slow path
                onHttpRequestChannelRead(ctx, (HttpRequest) msg);
            } else {
                super.channelRead(ctx, msg);
            }
        } else {
            super.channelRead(ctx, msg);
        }
    }