PacketImpl.java

package com.gmail.woodyc40.common.protocol.impl;

import com.esotericsoftware.reflectasm.FieldAccess;
import com.gmail.woodyc40.common.protocol.ByteAppender;
import com.gmail.woodyc40.common.protocol.Packet;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import net.tridentsdk.server.TridentServer;
import net.tridentsdk.server.netty.packet.PacketData;
import net.tridentsdk.server.netty.packet.PacketDirection;
import net.tridentsdk.server.netty.protocol.Protocol;

import java.util.concurrent.atomic.AtomicInteger;

/**
 * Implements {@link com.gmail.woodyc40.common.protocol.Packet}
 *
 * @author Pierre C
 */
public class PacketImpl implements Packet {
    /** The Trident packet */
    private final net.tridentsdk.server.netty.packet.Packet packet;
    /** The field getter and setter */
    private final FieldAccess access;
    /** The write index */
    private final AtomicInteger writeIdx = new AtomicInteger();
    /** The read index */
    private final AtomicInteger readIdx = new AtomicInteger();

    /**
     * Constructs a new packet wrapper with the data provided
     *
     * @param data the data
     */
    private PacketImpl(PacketData data) {
        this.packet = TridentServer
                .instance()
                .protocol()
                .getPacket(data.getId(), Protocol.ClientStage.PLAY, PacketDirection.IN);
        this.access = FieldAccess.get(packet.getClass());
        this.packet.decode(data.getData());

        data.getData().resetReaderIndex();
    }

    /**
     * Constructs a new packet wrapper with the packet provided
     *
     * @param packet the packet
     */
    PacketImpl(net.tridentsdk.server.netty.packet.Packet packet) {
        this.packet = packet;
        this.access = FieldAccess.get(packet.getClass());
    }

    /**
     * Constructs a new packet wrapper with the data provided
     *
     * @param msg the data
     * @return the new packet wrapper
     */
    public static PacketImpl in(Object msg) {
        return new PacketImpl((PacketData) msg);
    }

    /**
     * Constructs a new packet wrapper with the packet provided
     *
     * @param msg the packet
     * @return the new packet wrapper
     */
    public static PacketImpl out(Object msg) {
        return new PacketImpl((net.tridentsdk.server.netty.packet.Packet) msg);
    }

    @Override public void write(int idx, Object o) {
        access.set(packet, idx, o);
    }

    @Override public void write(Object o) {
        access.set(packet, writeIdx.getAndIncrement(), o);
    }

    @Override public int writeIndex() {
        return writeIdx.get();
    }

    @Override public void setWriteIndex(int index) {
        writeIdx.set(id());
    }

    @Override public Object read(int idx) {
        return access.get(packet, idx);
    }

    @Override public Object read() {
        return access.get(packet, readIdx.getAndIncrement());
    }

    @Override public int readIndex() {
        return readIdx.get();
    }

    @Override public void setReadIndex(int index) {
        readIdx.set(index);
    }

    @Override public int id() {
        return this.packet.id();
    }

    @Override public void encode(ByteAppender appender) {
        appender.segment();

        ByteBuf b = Unpooled.directBuffer();
        this.packet.encode(b);
        appender.append(b);
        b.release();
    }

    @Override public void decode(ByteBuf buf) {
        packet.decode(buf);
    }

    @Override public Object asTridentForm() {
        return this.packet;
    }
}