FastLzFrameDecoder.java — netty Source File

Source Code

/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.handler.codec.compression;

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

import java.util.List;
import java.util.zip.Adler32;
import java.util.zip.Checksum;

import static io.netty.handler.codec.compression.FastLz.BLOCK_TYPE_COMPRESSED;
import static io.netty.handler.codec.compression.FastLz.BLOCK_WITH_CHECKSUM;
import static io.netty.handler.codec.compression.FastLz.MAGIC_NUMBER;
import static io.netty.handler.codec.compression.FastLz.decompress;

/**
 * Uncompresses a {@link ByteBuf} encoded by {@link FastLzFrameEncoder} using the FastLZ algorithm.
 *
 * See <a href="https://github.com/netty/netty/issues/2750">FastLZ format</a>.
 */
public class FastLzFrameDecoder extends ByteToMessageDecoder {
    /**
     * Current state of decompression.
     */
    private enum State {
        INIT_BLOCK,
        INIT_BLOCK_PARAMS,
        DECOMPRESS_DATA,
        CORRUPTED
    }

    private State currentState = State.INIT_BLOCK;

    /**
     * Underlying checksum calculator in use.
     */
    private final ByteBufChecksum checksum;

    /**
     * Length of current received chunk of data.
     */
    private int chunkLength;

    /**
     * Original of current received chunk of data.
// ... (149 more lines)