void ClientConnection::s_onProtocolMessage()

in eventstream_rpc/source/EventStreamClient.cpp [795:878]
68 lines of code
12 McCabe index (conditional complexity)

        void ClientConnection::s_onProtocolMessage(
            struct aws_event_stream_rpc_client_connection *connection,
            const struct aws_event_stream_rpc_message_args *messageArgs,
            void *userData) noexcept
        {
            AWS_PRECONDITION(messageArgs != nullptr);
            (void)connection;

            /* The `userData` pointer is used to pass `this` of a `ClientConnection` object. */
            auto *thisConnection = static_cast<ClientConnection *>(userData);
            Crt::List<EventStreamHeader> pingHeaders;

            switch (messageArgs->message_type)
            {
                case AWS_EVENT_STREAM_RPC_MESSAGE_TYPE_CONNECT_ACK:
                    thisConnection->m_stateMutex.lock();
                    if (thisConnection->m_clientState == WAITING_FOR_CONNECT_ACK)
                    {
                        if (messageArgs->message_flags & AWS_EVENT_STREAM_RPC_MESSAGE_FLAG_CONNECTION_ACCEPTED)
                        {
                            thisConnection->m_clientState = CONNECTED;
                            thisConnection->m_onConnectCalled = true;
                            thisConnection->m_connectAckedPromise.set_value({EVENT_STREAM_RPC_SUCCESS, 0});
                            thisConnection->m_lifecycleHandler->OnConnectCallback();
                        }
                        else
                        {
                            thisConnection->m_closeReason = {EVENT_STREAM_RPC_CONNECTION_ACCESS_DENIED, 0};
                            thisConnection->Close();
                        }
                    }
                    else
                    {
                        /* Unexpected CONNECT_ACK received. */
                    }
                    thisConnection->m_stateMutex.unlock();

                    break;

                case AWS_EVENT_STREAM_RPC_MESSAGE_TYPE_PING:

                    for (size_t i = 0; i < messageArgs->headers_count; ++i)
                    {
                        pingHeaders.emplace_back(
                            EventStreamHeader(messageArgs->headers[i], thisConnection->m_allocator));
                    }

                    if (messageArgs->payload)
                    {
                        thisConnection->m_lifecycleHandler->OnPingCallback(pingHeaders, *messageArgs->payload);
                    }
                    else
                    {
                        thisConnection->m_lifecycleHandler->OnPingCallback(pingHeaders, Crt::Optional<Crt::ByteBuf>());
                    }

                    break;

                case AWS_EVENT_STREAM_RPC_MESSAGE_TYPE_PING_RESPONSE:
                    return;
                    break;

                case AWS_EVENT_STREAM_RPC_MESSAGE_TYPE_PROTOCOL_ERROR:
                case AWS_EVENT_STREAM_RPC_MESSAGE_TYPE_INTERNAL_ERROR:

                    if (thisConnection->m_lifecycleHandler->OnErrorCallback(
                            {EVENT_STREAM_RPC_CRT_ERROR, AWS_ERROR_EVENT_STREAM_RPC_PROTOCOL_ERROR}))
                    {
                        thisConnection->Close();
                    }

                    break;

                default:

                    if (thisConnection->m_lifecycleHandler->OnErrorCallback(
                            {EVENT_STREAM_RPC_UNKNOWN_PROTOCOL_MESSAGE, 0}))
                    {
                        thisConnection->Close();
                    }

                    break;
            }
        }