NettyCompressionDecoder.java

package net.minecraft.network;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;
import io.netty.handler.codec.DecoderException;
import java.util.List;
import java.util.zip.DataFormatException;
import java.util.zip.Inflater;

public class NettyCompressionDecoder extends ByteToMessageDecoder
{
    private final Inflater inflater;
    private int treshold;
    private static final String __OBFID = "CL_00002314";

    public NettyCompressionDecoder(int treshold)
    {
        this.treshold = treshold;
        this.inflater = new Inflater();
    }

    protected void decode(ChannelHandlerContext p_decode_1_, ByteBuf p_decode_2_, List p_decode_3_) throws DataFormatException
    {
        if (p_decode_2_.readableBytes() != 0)
        {
            PacketBuffer var4 = new PacketBuffer(p_decode_2_);
            int var5 = var4.readVarIntFromBuffer();

            if (var5 == 0)
            {
                p_decode_3_.add(var4.readBytes(var4.readableBytes()));
            }
            else
            {
                if (var5 < this.treshold)
                {
                    throw new DecoderException("Badly compressed packet - size of " + var5 + " is below server threshold of " + this.treshold);
                }

                if (var5 > 2097152)
                {
                    throw new DecoderException("Badly compressed packet - size of " + var5 + " is larger than protocol maximum of " + 2097152);
                }

                byte[] var6 = new byte[var4.readableBytes()];
                var4.readBytes(var6);
                this.inflater.setInput(var6);
                byte[] var7 = new byte[var5];
                this.inflater.inflate(var7);
                p_decode_3_.add(Unpooled.wrappedBuffer(var7));
                this.inflater.reset();
            }
        }
    }

    public void setCompressionTreshold(int treshold)
    {
        this.treshold = treshold;
    }
}