public ProtocolHandler parse()

in broker-plugins/amqp-1-0-protocol/src/main/java/org/apache/qpid/server/protocol/v1_0/framing/FrameHandler.java [60:238]
159 lines of code
23 McCabe index (conditional complexity)

    public ProtocolHandler parse(QpidByteBuffer in)
    {
        try
        {
            LOGGER.debug("RECV {} bytes", in.remaining());
            Error frameParsingError = null;
            int size;

            int remaining;
            List<ChannelFrameBody> channelFrameBodies = new ArrayList<>();
            while ((remaining = in.remaining()) >=8 && frameParsingError == null)
            {

                size = in.getInt();

                if (size < 8)
                {
                    frameParsingError = createFramingError(
                            "specified frame size %d smaller than minimum frame header size %d",
                            size,
                            8);
                    break;
                }

                if(size > _connectionHandler.getMaxFrameSize())
                {
                    frameParsingError = createFramingError(
                            "specified frame size %d larger than maximum frame header size %d",
                            size,
                            _connectionHandler.getMaxFrameSize());
                    break;
                }

                if(remaining < size)
                {
                    in.position(in.position()-4);
                    break;
                }
                int dataOffset = (in.get() << 2) & 0x3FF;

                if (dataOffset < 8)
                {
                    frameParsingError = createFramingError(
                            "specified frame data offset %d smaller than minimum frame header size %d",
                            dataOffset,
                            8);
                    break;
                }

                if (dataOffset > size)
                {
                    frameParsingError = createFramingError(
                            "specified frame data offset %d larger than the frame size %d",
                            dataOffset,
                            size);
                    break;
                }


                byte type = in.get();

                switch(type)
                {
                    case 0:
                        if(_isSasl)
                        {
                            frameParsingError = createFramingError("received an AMQP frame type when expecting an SASL frame");
                        }
                        break;
                    case 1:
                        if(!_isSasl)
                        {
                            frameParsingError = createFramingError("received a SASL frame type when expecting an AMQP frame");
                        }
                        break;
                    default:
                        frameParsingError = createFramingError("unknown frame type: %d", type);
                }

                if(frameParsingError != null)
                {
                    break;
                }

                int channel = in.getUnsignedShort();

                if (dataOffset != 8)
                {
                    in.position(in.position() + dataOffset - 8);
                }

                try (QpidByteBuffer dup = in.slice())
                {
                    dup.limit(size - dataOffset);
                    in.position(in.position() + size - dataOffset);

                    final boolean hasFrameBody = dup.hasRemaining();
                    Object frameBody;
                    if (hasFrameBody)
                    {
                        frameBody = _valueHandler.parse(dup);
                        if (dup.hasRemaining())
                        {
                            if (frameBody instanceof Transfer)
                            {
                                try (QpidByteBuffer payload = dup.slice())
                                {
                                    ((Transfer) frameBody).setPayload(payload);
                                }
                            }
                            else
                            {
                                frameParsingError = createFramingError(
                                        "Frame length %d larger than contained frame body %s.",
                                        size,
                                        frameBody);
                                break;
                            }
                        }
                    }
                    else
                    {
                        frameBody = null;
                        if(_isSasl)
                        {
                            frameParsingError = createFramingError(
                                    "Empty (heartbeat) frames are not permitted during SASL negotiation");
                            break;
                        }
                    }

                    channelFrameBodies.add(new ChannelFrameBody()
                    {
                        @Override
                        public int getChannel()
                        {
                            return channel;
                        }

                        @Override
                        public Object getFrameBody()
                        {
                            return frameBody;
                        }
                    });

                    if (_isSasl)
                    {
                        break;
                    }
                }
                catch (AmqpErrorException ex)
                {
                    frameParsingError = ex.getError();
                }
            }

            if (frameParsingError != null)
            {
                _connectionHandler.handleError(frameParsingError);
                _errored = true;
            }
            else
            {
                _connectionHandler.receive(channelFrameBodies);
            }
        }
        catch (RuntimeException e)
        {
            if (e instanceof ServerScopedRuntimeException)
            {
                throw e;
            }
            LOGGER.warn("Unexpected exception handling frame", e);
            // This exception is unexpected. The up layer should handle error condition gracefully
            _connectionHandler.handleError(this.createError(AmqpError.INTERNAL_ERROR, e.toString()));
        }
        return this;
    }