org.spongepowered.clean.network.netty.PacketSplitter.java Source code

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Here is the source code for org.spongepowered.clean.network.netty.PacketSplitter.java

Source

/*
 * This file is part of SpongeClean, licensed under the MIT License (MIT).
 *
 * Copyright (c) The VoxelBox <http://thevoxelbox.com>
 * Copyright (c) contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package org.spongepowered.clean.network.netty;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;

import java.util.List;

public class PacketSplitter extends ByteToMessageDecoder {

    public PacketSplitter() {

    }

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        in.markReaderIndex();
        int numRead = 0;
        int length = 0;
        byte read;
        do {
            if (!in.isReadable()) {
                in.resetReaderIndex();
                return;
            }
            read = in.readByte();
            int value = (read & 0b01111111);
            length |= (value << (7 * numRead));

            numRead++;
            if (numRead > 5) {
                throw new RuntimeException("Error decoding packet, length not a varint!");
            }
        } while ((read & 0b10000000) != 0);
        if (in.readableBytes() >= length) {
            out.add(in.readBytes(length));
        } else {
            in.resetReaderIndex();
        }
    }

}