io.netty.handler.codec.compression.JZlibDecoder Maven / Gradle / Ivy

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/*
 * Copyright 2012 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 com.jcraft.jzlib.Inflater;
import com.jcraft.jzlib.JZlib;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelHandlerContext;
import io.netty.util.internal.ObjectUtil;

import java.util.List;

public class JZlibDecoder extends ZlibDecoder {

    private final Inflater z = new Inflater();
    private byte[] dictionary;
    private volatile boolean finished;

    /**
     * Creates a new instance with the default wrapper ({@link ZlibWrapper#ZLIB}).
     *
     * @throws DecompressionException if failed to initialize zlib
     */
    public JZlibDecoder() {
        this(ZlibWrapper.ZLIB, 0);
    }

    /**
     * Creates a new instance with the default wrapper ({@link ZlibWrapper#ZLIB})
     * and specified maximum buffer allocation.
     *
     * @param maxAllocation
     *          Maximum size of the decompression buffer. Must be >= 0.
     *          If zero, maximum size is decided by the {@link ByteBufAllocator}.
     *
     * @throws DecompressionException if failed to initialize zlib
     */
    public JZlibDecoder(int maxAllocation) {
        this(ZlibWrapper.ZLIB, maxAllocation);
    }

    /**
     * Creates a new instance with the specified wrapper.
     *
     * @throws DecompressionException if failed to initialize zlib
     */
    public JZlibDecoder(ZlibWrapper wrapper) {
        this(wrapper, 0);
    }

    /**
     * Creates a new instance with the specified wrapper and maximum buffer allocation.
     *
     * @param maxAllocation
     *          Maximum size of the decompression buffer. Must be >= 0.
     *          If zero, maximum size is decided by the {@link ByteBufAllocator}.
     *
     * @throws DecompressionException if failed to initialize zlib
     */
    public JZlibDecoder(ZlibWrapper wrapper, int maxAllocation) {
        super(maxAllocation);

        ObjectUtil.checkNotNull(wrapper, "wrapper");

        int resultCode = z.init(ZlibUtil.convertWrapperType(wrapper));
        if (resultCode != JZlib.Z_OK) {
            ZlibUtil.fail(z, "initialization failure", resultCode);
        }
    }

    /**
     * Creates a new instance with the specified preset dictionary. The wrapper
     * is always {@link ZlibWrapper#ZLIB} because it is the only format that
     * supports the preset dictionary.
     *
     * @throws DecompressionException if failed to initialize zlib
     */
    public JZlibDecoder(byte[] dictionary) {
        this(dictionary, 0);
    }

    /**
     * Creates a new instance with the specified preset dictionary and maximum buffer allocation.
     * The wrapper is always {@link ZlibWrapper#ZLIB} because it is the only format that
     * supports the preset dictionary.
     *
     * @param maxAllocation
     *          Maximum size of the decompression buffer. Must be >= 0.
     *          If zero, maximum size is decided by the {@link ByteBufAllocator}.
     *
     * @throws DecompressionException if failed to initialize zlib
     */
    public JZlibDecoder(byte[] dictionary, int maxAllocation) {
        super(maxAllocation);
        this.dictionary = ObjectUtil.checkNotNull(dictionary, "dictionary");
        int resultCode;
        resultCode = z.inflateInit(JZlib.W_ZLIB);
        if (resultCode != JZlib.Z_OK) {
            ZlibUtil.fail(z, "initialization failure", resultCode);
        }
    }

    /**
     * Returns {@code true} if and only if the end of the compressed stream
     * has been reached.
     */
    @Override
    public boolean isClosed() {
        return finished;
    }

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List