Class Http2UpgradeHandler

java/org/apache/coyote/http2/Http2UpgradeHandler.java:72–2183

This represents an HTTP/2 connection from a client to Tomcat. It is designed on the basis that there will never be more than one thread performing I/O at a time. For reading, this implementation is blocking within frames and non-blocking between frames. Note: You will need to nest

 * </ul>
 */
class Http2UpgradeHandler extends AbstractStream implements InternalHttpUpgradeHandler, Input, Output {

    /**
     * Logger for this class.
     */
    protected static final Log log = LogFactory.getLog(Http2UpgradeHandler.class);

    /**
     * String manager for error messages.
     */
    protected static final StringManager sm = StringManager.getManager(Http2UpgradeHandler.class);

    private static final Integer STREAM_ID_ZERO = Integer.valueOf(0);

    /**
     * Flag indicating the end of a stream.
     */
    protected static final int FLAG_END_OF_STREAM = 1;

    /**
     * Flag indicating the end of headers.
     */
    protected static final int FLAG_END_OF_HEADERS = 4;

    /**
     * PING frame with zero payload length and zero stream ID.
     */
    protected static final byte[] PING = { 0x00, 0x00, 0x08, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00 };

    /**
     * PING ACK frame with zero payload length and zero stream ID.
     */
    protected static final byte[] PING_ACK = { 0x00, 0x00, 0x08, 0x06, 0x01, 0x00, 0x00, 0x00, 0x00 };

    /**
     * SETTINGS ACK frame with zero payload length and zero stream ID.
     */
    protected static final byte[] SETTINGS_ACK = { 0x00, 0x00, 0x00, 0x04, 0x01, 0x00, 0x00, 0x00, 0x00 };

    /**
     * GOAWAY frame header with zero stream ID.
     */
    protected static final byte[] GOAWAY = { 0x07, 0x00, 0x00, 0x00, 0x00, 0x00 };

    private static final String HTTP2_SETTINGS_HEADER = "HTTP2-Settings";

    /**
     * Default header sink for HPACK decoding.
     */
    protected static final HeaderSink HEADER_SINK = new HeaderSink();

    /**
     * Helper for user data logging with rate limiting.
     */
    protected static final UserDataHelper userDataHelper = new UserDataHelper(log);

    /**
     * Unique identifier for this connection.