me.ferrybig.p2pnetwork.codec.PacketRoutingHandler.java Source code

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Here is the source code for me.ferrybig.p2pnetwork.codec.PacketRoutingHandler.java

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package me.ferrybig.p2pnetwork.codec;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import java.util.function.Function;
import me.ferrybig.p2pnetwork.Address;
import me.ferrybig.p2pnetwork.RoutingMap;
import me.ferrybig.p2pnetwork.codec.packets.DestinationUnreachablePacket;
import me.ferrybig.p2pnetwork.codec.packets.Packet;
import me.ferrybig.p2pnetwork.codec.packets.RelayPacket;

/**
 *
 * @author Fernando
 */
public class PacketRoutingHandler extends SimpleChannelInboundHandler<RelayPacket> {

    private final Address ourself;
    private final RoutingMap routing;
    private final Function<RelayPacket, Boolean> router;

    public PacketRoutingHandler(Address ourself, RoutingMap routing, Function<RelayPacket, Boolean> router) {
        this.ourself = ourself;
        this.routing = routing;
        this.router = router;
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, RelayPacket msg) throws Exception {
        if (msg.getAddress().equals(ourself)) {
            ctx.fireChannelRead(msg.retain());
            return;
        }
        if (msg.getTtl() == 0) {
            DestinationUnreachablePacket result = new DestinationUnreachablePacket(
                    DestinationUnreachablePacket.Reason.TTL_EXPIRED, msg.getAddress());
            try {

                ByteBuf buf = ctx.alloc().buffer();
                buf.writeInt(PacketMap.getPacketId(result));
                result.write(buf);
                ctx.writeAndFlush(new RelayPacket(buf, ourself, msg.getFrom(), 127));
            } finally {
                result.release();
            }
            return;
        }
        msg.decrementTTL();
        if (!router.apply(msg)) {
            DestinationUnreachablePacket result = new DestinationUnreachablePacket(
                    DestinationUnreachablePacket.Reason.DESTINATION_HOST_UNREACHABLE, msg.getAddress());
            try {
                ByteBuf buf = ctx.alloc().buffer();
                result.write(buf);
                ctx.write(buf);
                ctx.writeAndFlush(new RelayPacket(buf));
            } finally {
                result.release();
            }
        }
    }

}