INLINE bool TickCursorImpl::next()

in src/dxapi/native/tickdb/http/tickcursor_http.cpp [925:1002]
65 lines of code
17 McCabe index (conditional complexity)

INLINE bool TickCursorImpl::next(MessageHeader* const msg, bool nonBlocking)
{
    assert(!isInNext_ && "C++ - level TickCursor doesn't support concurrent calls");
    isInNext_ = true;
    try {
        assert(NULL != reader_);
        if (state >= CursorState::END) {
            if (isInterrupted_) {
                THROW_DBGLOG_EX(TickCursorInterruptedException, LOGHDR ".readNext(): interrupted", ID);
                msg->cursorState = state;
                readRemainderAndClose(true);
                return isInNext_ = false;
            }

            if (state > CursorState::END || (!mainState_->isExecutingSubscriptions() && 0 == reader_->nBytesAvailable() && 0 == activeInputStream_->nBytesAvailable())) {
                msg->cursorState = state;
                return isInNext_ = false;
            }

            msg->cursorState = setStateLocked(CursorState::STARTED);
        }

        if (nonBlocking) {
            if (isWithinMessageBlock_ && !readMessageDone_) {
                reader_->nextMessage();
                readMessageDone_ = true;
            }

            if (reader_->nBytesAvailableInStream() <= 0 && activeInputStream_->nBytesAvailable() <= 0) {
                return isInNext_ = false;
            }

            readMessageDone_ = false;
        }

        assert(state < CursorState::END);
        bool result = nonBlocking ? readNextMessageNonBlock(*msg) : readNextMessage(*msg);
        isInNext_ = false;
        return result;
    }

    catch (const IOStreamDisconnectException&) {
        DBGLOG(LOGHDR ".next(): Server disconnected", ID);
        msg->cursorState = setState(CursorState::END);
        doClose();
        isInNext_ = false;
        finalStats();
        return false;
    }

    catch (const IOStreamException& e) {
        DBGLOG(LOGHDR ".next(): I/O exception was unexpected: %s", ID, e.what());
        msg->cursorState = setState(CursorState::END);
        doClose();
        isInNext_ = false;
        throw;
    }

    catch (const std::exception& e) {
        DBGLOG(LOGHDR ".next(): std::exception: %s", ID, e.what());
        msg->cursorState = setState(CursorState::END);
        doClose();
        isInNext_ = false;
        throw;
    }

    catch (...) {
        msg->cursorState = setState(CursorState::END);
        isInNext_ = false;
        throw;
    }

    // Unreachable
    dx_assert(false, "This code should be unreachable!");
    msg->cursorState = setState(CursorState::END);
    isInNext_ = false;
    // No return
}