private void HandleFragment(IDirectBuffer buffer, int offset, int length, Header header, byte flags)
        {
            if ((flags & FrameDescriptor.BEGIN_FRAG_FLAG) == FrameDescriptor.BEGIN_FRAG_FLAG)
            {
                _builder.Reset().Append(buffer, offset, length);
            }
            else if (_builder.Limit() > 0)
            {
                _builder.Append(buffer, offset, length);

                if ((flags & FrameDescriptor.END_FRAG_FLAG) == FrameDescriptor.END_FRAG_FLAG)
                {
                    int msgLength = _builder.Limit();
                    _delegate.OnFragment(_builder.Buffer(), 0, msgLength, header);
                    _builder.Reset();
                }
            }
        }
        /// <summary>
        /// The implementation of <seealso cref="IControlledFragmentHandler"/> that reassembles and forwards whole messages.
        /// </summary>
        /// <param name="buffer"> containing the data. </param>
        /// <param name="offset"> at which the data begins. </param>
        /// <param name="length"> of the data in bytes. </param>
        /// <param name="header"> representing the meta data for the data. </param>
        /// <returns> <see cref="ControlledFragmentHandlerAction"/> to be taken after processing fragment.</returns>
        public ControlledFragmentHandlerAction OnFragment(IDirectBuffer buffer, int offset, int length, Header header)
        {
            var  action = ControlledFragmentHandlerAction.CONTINUE;
            byte flags  = header.Flags;

            if ((flags & FrameDescriptor.UNFRAGMENTED) == FrameDescriptor.UNFRAGMENTED)
            {
                action = _delegate.OnFragment(buffer, offset, length, header);
            }
            else
            {
                if ((flags & FrameDescriptor.BEGIN_FRAG_FLAG) == FrameDescriptor.BEGIN_FRAG_FLAG)
                {
                    _builder.Reset().Append(buffer, offset, length);
                }
                else
                {
                    int limit = _builder.Limit();
                    if (limit > 0)
                    {
                        _builder.Append(buffer, offset, length);

                        if ((flags & FrameDescriptor.END_FRAG_FLAG) == FrameDescriptor.END_FRAG_FLAG)
                        {
                            action = _delegate.OnFragment(_builder.Buffer(), 0, _builder.Limit(), header);

                            if (ControlledFragmentHandlerAction.ABORT == action)
                            {
                                _builder.Limit(limit);
                            }
                            else
                            {
                                _builder.Reset();
                            }
                        }
                    }
                }
            }

            return(action);
        }