Class WsFrameBase

java/org/apache/tomcat/websocket/WsFrameBase.java:43–1099

Takes the ServletInputStream, processes the WebSocket frames it contains and extracts the messages. WebSocket Pings received will be responded to automatically without any action required by the application.

 * received will be responded to automatically without any action required by the application.
 */
public abstract class WsFrameBase {

    private static final StringManager sm = StringManager.getManager(WsFrameBase.class);

    // Connection level attributes
    /**
     * The WebSocket session for this frame.
     */
    protected final WsSession wsSession;
    /**
     * The input buffer for reading data.
     */
    protected final ByteBuffer inputBuffer;
    private final Transformation transformation;

    // Attributes for control messages
    // They can appear in the middle of other messages so need separate attributes
    private final ByteBuffer controlBufferBinary = ByteBuffer.allocate(125);
    private final CharBuffer controlBufferText = CharBuffer.allocate(125);

    // Attributes of the current message
    private final CharsetDecoder utf8DecoderControl = StandardCharsets.UTF_8.newDecoder()
            .onMalformedInput(CodingErrorAction.REPORT).onUnmappableCharacter(CodingErrorAction.REPORT);
    private final CharsetDecoder utf8DecoderMessage = StandardCharsets.UTF_8.newDecoder()
            .onMalformedInput(CodingErrorAction.REPORT).onUnmappableCharacter(CodingErrorAction.REPORT);
    private boolean continuationExpected = false;
    private boolean textMessage = false;
    private ByteBuffer messageBufferBinary;
    private CharBuffer messageBufferText;
    // Cache the message handler in force when the message starts so it is used
    // consistently for the entire message
    private MessageHandler binaryMsgHandler = null;
    private MessageHandler textMsgHandler = null;

    // Attributes of the current frame
    private boolean fin = false;
    private int rsv = 0;
    private byte opCode = 0;
    private final byte[] mask = new byte[4];
    private int maskIndex = 0;
    private long payloadLength = 0;
    private volatile long payloadWritten = 0;

    // Attributes tracking state
    private volatile State state = State.NEW_FRAME;
    private volatile boolean open = true;

    private static final AtomicReferenceFieldUpdater<WsFrameBase,ReadState> READ_STATE_UPDATER =
            AtomicReferenceFieldUpdater.newUpdater(WsFrameBase.class, ReadState.class, "readState");
    private volatile ReadState readState = ReadState.WAITING;

    /**
     * Constructs a new WsFrameBase.
     *
     * @param wsSession        The WebSocket session
     * @param transformation   The transformation to apply
     */
    public WsFrameBase(WsSession wsSession, Transformation transformation) {