JZlibEncoder Class — netty Architecture

Source Code

codec-compression/src/main/java/io/netty/handler/codec/compression/JZlibEncoder.java lines 37–401

public class JZlibEncoder extends ZlibEncoder {

    private final int wrapperOverhead;
    private final Deflater z = new Deflater();
    private volatile boolean finished;
    private volatile ChannelHandlerContext ctx;

    private static final int THREAD_POOL_DELAY_SECONDS = 10;

    /**
     * Creates a new zlib encoder with the default compression level ({@code 6}),
     * default window bits ({@code 15}), default memory level ({@code 8}),
     * and the default wrapper ({@link ZlibWrapper#ZLIB}).
     *
     * @throws CompressionException if failed to initialize zlib
     */
    public JZlibEncoder() {
        this(6);
    }

    /**
     * Creates a new zlib encoder with the specified {@code compressionLevel},
     * default window bits ({@code 15}), default memory level ({@code 8}),
     * and the default wrapper ({@link ZlibWrapper#ZLIB}).
     *
     * @param compressionLevel
     *        {@code 1} yields the fastest compression and {@code 9} yields the
     *        best compression.  {@code 0} means no compression.  The default
     *        compression level is {@code 6}.
     *
     * @throws CompressionException if failed to initialize zlib
     */
    public JZlibEncoder(int compressionLevel) {
        this(ZlibWrapper.ZLIB, compressionLevel);
    }

    /**
     * Creates a new zlib encoder with the default compression level ({@code 6}),
     * default window bits ({@code 15}), default memory level ({@code 8}),
     * and the specified wrapper.
     *
     * @throws CompressionException if failed to initialize zlib
     */
    public JZlibEncoder(ZlibWrapper wrapper) {
        this(wrapper, 6);
    }

    /**
     * Creates a new zlib encoder with the specified {@code compressionLevel},
     * default window bits ({@code 15}), default memory level ({@code 8}),
     * and the specified wrapper.
     *
     * @param compressionLevel
     *        {@code 1} yields the fastest compression and {@code 9} yields the
     *        best compression.  {@code 0} means no compression.  The default
     *        compression level is {@code 6}.
     *
     * @throws CompressionException if failed to initialize zlib
     */
    public JZlibEncoder(ZlibWrapper wrapper, int compressionLevel) {
        this(wrapper, compressionLevel, 15, 8);
    }

    /**
     * Creates a new zlib encoder with the specified {@code compressionLevel},
     * the specified {@code windowBits}, the specified {@code memLevel}, and
     * the specified wrapper.
     *
     * @param compressionLevel
     *        {@code 1} yields the fastest compression and {@code 9} yields the
     *        best compression.  {@code 0} means no compression.  The default
     *        compression level is {@code 6}.
     * @param windowBits
     *        The base two logarithm of the size of the history buffer.  The
     *        value should be in the range {@code 9} to {@code 15} inclusive.
     *        Larger values result in better compression at the expense of
     *        memory usage.  The default value is {@code 15}.
     * @param memLevel
     *        How much memory should be allocated for the internal compression
     *        state.  {@code 1} uses minimum memory and {@code 9} uses maximum
     *        memory.  Larger values result in better and faster compression