channelRead() — netty Function Reference

Source Code

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdySessionHandler.java lines 88–411

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        if (msg instanceof SpdyDataFrame) {

            /*
             * SPDY Data frame processing requirements:
             *
             * If an endpoint receives a data frame for a Stream-ID which is not open
             * and the endpoint has not sent a GOAWAY frame, it must issue a stream error
             * with the error code INVALID_STREAM for the Stream-ID.
             *
             * If an endpoint which created the stream receives a data frame before receiving
             * a SYN_REPLY on that stream, it is a protocol error, and the recipient must
             * issue a stream error with the getStatus code PROTOCOL_ERROR for the Stream-ID.
             *
             * If an endpoint receives multiple data frames for invalid Stream-IDs,
             * it may close the session.
             *
             * If an endpoint refuses a stream it must ignore any data frames for that stream.
             *
             * If an endpoint receives a data frame after the stream is half-closed from the
             * sender, it must send a RST_STREAM frame with the getStatus STREAM_ALREADY_CLOSED.
             *
             * If an endpoint receives a data frame after the stream is closed, it must send
             * a RST_STREAM frame with the getStatus PROTOCOL_ERROR.
             */
            SpdyDataFrame spdyDataFrame = (SpdyDataFrame) msg;
            int streamId = spdyDataFrame.streamId();

            int deltaWindowSize = -1 * spdyDataFrame.content().readableBytes();
            int newSessionWindowSize =
                spdySession.updateReceiveWindowSize(SPDY_SESSION_STREAM_ID, deltaWindowSize);

            // Check if session window size is reduced beyond allowable lower bound
            if (newSessionWindowSize < 0) {
                issueSessionError(ctx, SpdySessionStatus.PROTOCOL_ERROR);
                return;
            }

            // Send a WINDOW_UPDATE frame if less than half the session window size remains
            if (newSessionWindowSize <= initialSessionReceiveWindowSize / 2) {
                int sessionDeltaWindowSize = initialSessionReceiveWindowSize - newSessionWindowSize;
                spdySession.updateReceiveWindowSize(SPDY_SESSION_STREAM_ID, sessionDeltaWindowSize);
                SpdyWindowUpdateFrame spdyWindowUpdateFrame =
                    new DefaultSpdyWindowUpdateFrame(SPDY_SESSION_STREAM_ID, sessionDeltaWindowSize);
                ctx.writeAndFlush(spdyWindowUpdateFrame);
            }

            // Check if we received a data frame for a Stream-ID which is not open

            if (!spdySession.isActiveStream(streamId)) {
                spdyDataFrame.release();
                if (streamId <= lastGoodStreamId) {
                    issueStreamError(ctx, streamId, SpdyStreamStatus.PROTOCOL_ERROR);
                } else if (!sentGoAwayFrame) {
                    issueStreamError(ctx, streamId, SpdyStreamStatus.INVALID_STREAM);
                }
                return;
            }

            // Check if we received a data frame for a stream which is half-closed

            if (spdySession.isRemoteSideClosed(streamId)) {
                spdyDataFrame.release();
                issueStreamError(ctx, streamId, SpdyStreamStatus.STREAM_ALREADY_CLOSED);
                return;
            }

            // Check if we received a data frame before receiving a SYN_REPLY
            if (!isRemoteInitiatedId(streamId) && !spdySession.hasReceivedReply(streamId)) {
                spdyDataFrame.release();
                issueStreamError(ctx, streamId, SpdyStreamStatus.PROTOCOL_ERROR);
                return;
            }

            /*
             * SPDY Data frame flow control processing requirements:
             *
             * Recipient should not send a WINDOW_UPDATE frame as it consumes the last data frame.
             */