PerFrameDeflateDecoder Class — netty Architecture

Source Code

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/extensions/compression/PerFrameDeflateDecoder.java lines 28–79

class PerFrameDeflateDecoder extends DeflateDecoder {

    /**
     * Constructor
     *
     * @param noContext true to disable context takeover.
     * @param maxAllocation
     *          maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is not limited.
     */
    PerFrameDeflateDecoder(boolean noContext, int maxAllocation) {
        super(noContext, WebSocketExtensionFilter.NEVER_SKIP, maxAllocation);
    }

    /**
     * Constructor
     *
     * @param noContext true to disable context takeover.
     * @param extensionDecoderFilter extension decoder filter for per frame deflate decoder.
     * @param maxAllocation
     *            maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is not limited.
     */
    PerFrameDeflateDecoder(boolean noContext, WebSocketExtensionFilter extensionDecoderFilter, int maxAllocation) {
        super(noContext, extensionDecoderFilter, maxAllocation);
    }

    @Override
    public boolean acceptInboundMessage(Object msg) throws Exception {
        if (!super.acceptInboundMessage(msg)) {
            return false;
        }

        WebSocketFrame wsFrame = (WebSocketFrame) msg;
        if (extensionDecoderFilter().mustSkip(wsFrame)) {
            return false;
        }

        return (msg instanceof TextWebSocketFrame || msg instanceof BinaryWebSocketFrame ||
                msg instanceof ContinuationWebSocketFrame) &&
               (wsFrame.rsv() & WebSocketExtension.RSV1) > 0;
    }

    @Override
    protected int newRsv(WebSocketFrame msg) {
        return msg.rsv() ^ WebSocketExtension.RSV1;
    }

    @Override
    protected boolean appendFrameTail(WebSocketFrame msg) {
        return true;
    }

}