DeflateFrameServerExtensionHandshaker Class — netty Architecture

Source Code

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/extensions/compression/DeflateFrameServerExtensionHandshaker.java lines 33–172

public final class DeflateFrameServerExtensionHandshaker implements WebSocketServerExtensionHandshaker {

    public static final int DEFAULT_COMPRESSION_LEVEL = 6;

    static final String X_WEBKIT_DEFLATE_FRAME_EXTENSION = "x-webkit-deflate-frame";
    static final String DEFLATE_FRAME_EXTENSION = "deflate-frame";

    private final int compressionLevel;
    private final WebSocketExtensionFilterProvider extensionFilterProvider;
    private final int maxAllocation;

    /**
     * Constructor with default configuration.
     * @deprecated
     *            Use {@link DeflateFrameServerExtensionHandshaker#DeflateFrameServerExtensionHandshaker(int, int)}
     *            with {@link DeflateFrameServerExtensionHandshaker#DEFAULT_COMPRESSION_LEVEL}.
     */
    @Deprecated
    public DeflateFrameServerExtensionHandshaker() {
        this(DEFAULT_COMPRESSION_LEVEL, 0);
    }

    /**
     * Constructor with custom configuration.
     *
     * @param compressionLevel
     *            Compression level between 0 and 9 (default is 6).
     * @deprecated
     *            Use {@link DeflateFrameServerExtensionHandshaker#DeflateFrameServerExtensionHandshaker(int, int)}.
     */
    @Deprecated
    public DeflateFrameServerExtensionHandshaker(int compressionLevel) {
        this(compressionLevel, 0);
    }

    /**
     * Constructor with custom configuration.
     *
     * @param compressionLevel
     *            Compression level between 0 and 9 (default is 6).
     * @param maxAllocation
     *            Maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is not limited.
     */
    public DeflateFrameServerExtensionHandshaker(int compressionLevel, int maxAllocation) {
        this(compressionLevel, WebSocketExtensionFilterProvider.DEFAULT, maxAllocation);
    }

    /**
     * Constructor with custom configuration.
     *
     * @param compressionLevel
     *            Compression level between 0 and 9 (default is 6).
     * @param extensionFilterProvider
     *            provides server extension filters for per frame deflate encoder and decoder.
     * @deprecated
     *            Use {@link DeflateFrameServerExtensionHandshaker#DeflateFrameServerExtensionHandshaker(int,
     *            WebSocketExtensionFilterProvider, int)}.
     */
    @Deprecated
    public DeflateFrameServerExtensionHandshaker(int compressionLevel,
                                                 WebSocketExtensionFilterProvider extensionFilterProvider) {
        this(compressionLevel, extensionFilterProvider, 0);
    }

    /**
     * Constructor with custom configuration.
     *
     * @param compressionLevel
     *            Compression level between 0 and 9 (default is 6).
     * @param extensionFilterProvider
     *            provides server extension filters for per frame deflate encoder and decoder.
     * @param maxAllocation
     *            Maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is not limited.
     */
    public DeflateFrameServerExtensionHandshaker(int compressionLevel,
            WebSocketExtensionFilterProvider extensionFilterProvider,
            int maxAllocation) {
        if (compressionLevel < 0 || compressionLevel > 9) {
            throw new IllegalArgumentException(
                    "compressionLevel: " + compressionLevel + " (expected: 0-9)");
        }