JdkZlibDecoder Class — netty Architecture

Source Code

codec-compression/src/main/java/io/netty/handler/codec/compression/JdkZlibDecoder.java lines 32–544

public class JdkZlibDecoder extends ZlibDecoder {
    private static final int FHCRC = 0x02;
    private static final int FEXTRA = 0x04;
    private static final int FNAME = 0x08;
    private static final int FCOMMENT = 0x10;
    private static final int FRESERVED = 0xE0;

    private Inflater inflater;
    private final byte[] dictionary;

    // GZIP related
    private final ByteBufChecksum crc;
    private final boolean decompressConcatenated;

    private enum GzipState {
        HEADER_START,
        HEADER_END,
        FLG_READ,
        XLEN_READ,
        SKIP_FNAME,
        SKIP_COMMENT,
        PROCESS_FHCRC,
        FOOTER_START,
    }

    private GzipState gzipState = GzipState.HEADER_START;
    private int flags = -1;
    private int xlen = -1;
    private boolean needsRead;

    private volatile boolean finished;

    private boolean decideZlibOrNone;

    /**
     * Creates a new instance with the default wrapper ({@link ZlibWrapper#ZLIB}).
     *
     * @deprecated Use {@link JdkZlibDecoder#JdkZlibDecoder(int)}.
     */
    @Deprecated
    public JdkZlibDecoder() {
        this(ZlibWrapper.ZLIB, null, false, 0);
    }

    /**
     * Creates a new instance with the default wrapper ({@link ZlibWrapper#ZLIB})
     * and the 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}.
     */
    public JdkZlibDecoder(int maxAllocation) {
        this(ZlibWrapper.ZLIB, null, false, maxAllocation);
    }

    /**
     * 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.
     *
     * @deprecated Use {@link JdkZlibDecoder#JdkZlibDecoder(byte[], int)}.
     */
    @Deprecated
    public JdkZlibDecoder(byte[] dictionary) {
        this(ZlibWrapper.ZLIB, dictionary, false, 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}.
     */
    public JdkZlibDecoder(byte[] dictionary, int maxAllocation) {
        this(ZlibWrapper.ZLIB, dictionary, false, maxAllocation);
    }