NioChannelOption Class — netty Architecture

Source Code

transport/src/main/java/io/netty/channel/socket/nio/NioChannelOption.java lines 35–115

public final class NioChannelOption<T> extends ChannelOption<T> {

    private final SocketOption<T> option;

    @SuppressWarnings("deprecation")
    private NioChannelOption(SocketOption<T> option) {
        super(option.name());
        this.option = option;
    }

    /**
     * Returns a {@link ChannelOption} for the given {@link java.net.SocketOption}.
     */
    public static <T> ChannelOption<T> of(SocketOption<T> option) {
        return new NioChannelOption<T>(option);
    }

    // Internal helper methods to remove code duplication between Nio*Channel implementations.
    static <T> boolean setOption(Channel jdkChannel, NioChannelOption<T> option, T value) {
        NetworkChannel channel = (NetworkChannel) jdkChannel;
        if (!channel.supportedOptions().contains(option.option)) {
            return false;
        }
        if (channel instanceof ServerSocketChannel && option.option == StandardSocketOptions.IP_TOS) {
            // Skip IP_TOS as a workaround for a JDK bug:
            // See https://mail.openjdk.java.net/pipermail/nio-dev/2018-August/005365.html
            return false;
        }
        try {
            channel.setOption(option.option, value);
            return true;
        } catch (IOException e) {
            throw new ChannelException(e);
        }
    }

    static <T> T getOption(Channel jdkChannel, NioChannelOption<T> option) {
        NetworkChannel channel = (NetworkChannel) jdkChannel;

        if (!channel.supportedOptions().contains(option.option)) {
            return null;
        }
        if (channel instanceof ServerSocketChannel && option.option == StandardSocketOptions.IP_TOS) {
            // Skip IP_TOS as a workaround for a JDK bug:
            // See https://mail.openjdk.java.net/pipermail/nio-dev/2018-August/005365.html
            return null;
        }
        try {
            return channel.getOption(option.option);
        } catch (IOException e) {
            throw new ChannelException(e);
        }
    }

    @SuppressWarnings("unchecked")
    static ChannelOption<?>[] getOptions(Channel jdkChannel) {
        NetworkChannel channel = (NetworkChannel) jdkChannel;
        Set<SocketOption<?>> supportedOpts = channel.supportedOptions();

        if (channel instanceof ServerSocketChannel) {
            List<ChannelOption<?>> extraOpts = new ArrayList<ChannelOption<?>>(supportedOpts.size());
            for (SocketOption<?> opt : supportedOpts) {
                if (opt == StandardSocketOptions.IP_TOS) {
                    // Skip IP_TOS as a workaround for a JDK bug:
                    // See https://mail.openjdk.java.net/pipermail/nio-dev/2018-August/005365.html
                    continue;
                }
                extraOpts.add(new NioChannelOption(opt));
            }
            return extraOpts.toArray(new ChannelOption[0]);
        } else {
            ChannelOption<?>[] extraOpts = new ChannelOption[supportedOpts.size()];

            int i = 0;
            for (SocketOption<?> opt : supportedOpts) {
                extraOpts[i++] = new NioChannelOption(opt);
            }
            return extraOpts;
        }
    }
}