AbstractHttp2StreamChannel Class — netty Architecture

Source Code

codec-http2/src/main/java/io/netty/handler/codec/http2/AbstractHttp2StreamChannel.java lines 65–1289

abstract class AbstractHttp2StreamChannel extends DefaultAttributeMap implements Http2StreamChannel {

    static final Http2FrameStreamVisitor WRITABLE_VISITOR = new Http2FrameStreamVisitor() {
        @Override
        public boolean visit(Http2FrameStream stream) {
            final AbstractHttp2StreamChannel childChannel = (AbstractHttp2StreamChannel)
                    ((DefaultHttp2FrameStream) stream).attachment;
            childChannel.trySetWritable();
            return true;
        }
    };

    static final Http2FrameStreamVisitor CHANNEL_INPUT_SHUTDOWN_READ_COMPLETE_VISITOR =
            new UserEventStreamVisitor(ChannelInputShutdownReadComplete.INSTANCE);

    static final Http2FrameStreamVisitor CHANNEL_OUTPUT_SHUTDOWN_EVENT_VISITOR =
            new UserEventStreamVisitor(ChannelOutputShutdownEvent.INSTANCE);

    static final Http2FrameStreamVisitor SSL_CLOSE_COMPLETION_EVENT_VISITOR =
            new UserEventStreamVisitor(SslCloseCompletionEvent.SUCCESS);

    private static final InternalLogger logger = InternalLoggerFactory.getInstance(AbstractHttp2StreamChannel.class);

    private static final ChannelMetadata METADATA = new ChannelMetadata(false, 16);

    /**
     * Number of bytes to consider non-payload messages. 9 is arbitrary, but also the minimum size of an HTTP/2 frame.
     * Primarily is non-zero.
     */
    private static final int MIN_HTTP2_FRAME_SIZE = 9;

    /**
     * {@link Http2FrameStreamVisitor} that fires the user event for every active stream pipeline.
     */
    private static final class UserEventStreamVisitor implements Http2FrameStreamVisitor {

        private final Object event;

        UserEventStreamVisitor(Object event) {
            this.event = checkNotNull(event, "event");
        }

        @Override
        public boolean visit(Http2FrameStream stream) {
            final AbstractHttp2StreamChannel childChannel = (AbstractHttp2StreamChannel)
                    ((DefaultHttp2FrameStream) stream).attachment;
            childChannel.pipeline().fireUserEventTriggered(event);
            return true;
        }
    }

    /**
     * Returns the flow-control size for DATA frames, and {@value MIN_HTTP2_FRAME_SIZE} for all other frames.
     */
    private static final class FlowControlledFrameSizeEstimator implements MessageSizeEstimator {

        static final FlowControlledFrameSizeEstimator INSTANCE = new FlowControlledFrameSizeEstimator();

        private static final Handle HANDLE_INSTANCE = new Handle() {
            @Override
            public int size(Object msg) {
                return msg instanceof Http2DataFrame ?
                        // Guard against overflow.
                        (int) min(Integer.MAX_VALUE, ((Http2DataFrame) msg).initialFlowControlledBytes() +
                                (long) MIN_HTTP2_FRAME_SIZE) : MIN_HTTP2_FRAME_SIZE;
            }
        };

        @Override
        public Handle newHandle() {
            return HANDLE_INSTANCE;
        }
    }

    private static final AtomicLongFieldUpdater<AbstractHttp2StreamChannel> TOTAL_PENDING_SIZE_UPDATER =
            AtomicLongFieldUpdater.newUpdater(AbstractHttp2StreamChannel.class, "totalPendingSize");

    private static final AtomicIntegerFieldUpdater<AbstractHttp2StreamChannel> UNWRITABLE_UPDATER =
            AtomicIntegerFieldUpdater.newUpdater(AbstractHttp2StreamChannel.class, "unwritable");

    private static void windowUpdateFrameWriteComplete(ChannelFuture future, Channel streamChannel) {