libgfaservices/shmqml/shmbitvar.cpp

#include "shmvar.h"
#include <QDebug>

#define GET_BOOL_VAL(p, m)				(!!(*p & m))
#define SET_BIT(p, m)					(*p |= m)
#define CLR_BIT(p, m)					(*p &= ~m)
#define STORE_BIT(p, m, b)				(b) ? SET_BIT(p, m) : CLR_BIT(p, m)

CShmBitVariable::CShmBitVariable(void *pData, size_t nOffset, int nBitNr, HSHM hShm, const char *pszName, QObject *pParent)
								: QObject(pParent), m_varName(pszName), m_nBitNr(nBitNr)
{
	if(!pData || !hShm || (nBitNr > 7))
	{
		Q_ASSERT_X(false, "CShmBitVariable::CShmBitVariable", "Invalid parameter!");
		return;
	}

	m_mask = (1 << nBitNr);
    m_pShmByte = (uint8_t*)pData + nOffset;
    m_cacheVal = GET_BOOL_VAL(m_pShmByte, m_mask);
    m_hShm = hShm;
    setObjectName(QStringLiteral("CShmBitVariable"));
}

CShmBitVariable::~CShmBitVariable(void)
{
}

void CShmBitVariable::valRaw(QVariant &v)
{
	bool bVal = GET_BOOL_VAL(m_pShmByte, m_mask);
	v.setValue(bVal);
}

QVariant CShmBitVariable::val(void)
{
	QVariant v;
	Lock();
	valRaw(v);
	Unlock();
    return v;
}

void CShmBitVariable::setVal(const QVariant &val)
{
	if(val.isValid() && !val.isNull())
	{
#if _TRACK_QT_WRITES
		char szDebugOut[256];
#endif	//	_TRACK_QT_WRITES

		if(val.canConvert<bool>())
		{
			Lock();
			bool bVal = GET_BOOL_VAL(m_pShmByte, m_mask);
			m_cacheVal = val.toBool();

			if(bVal != m_cacheVal)
			{
				STORE_BIT(m_pShmByte, m_mask, m_cacheVal);
				emitChanged(false);
#if _TRACK_QT_WRITES
				sprintf(szDebugOut, "CShmBitVariable::setVal: Bit %s : %c", m_varName.toStdString().c_str(), m_cacheVal ? '1' : '0');
    			qDebug() << szDebugOut;
#endif	//	_TRACK_QT_WRITES
			}
			Unlock();
		}
	}
}

unsigned int CShmBitVariable::vt(void) const
{
	return VT_bool;
}

unsigned long long CShmBitVariable::CheckUpdateShm(bool fLock)
{
	CHECK_UPDATE_SHM_RETVAL rv = {1, 0};

	if(fLock)
		Lock();
		
	bool bVal = GET_BOOL_VAL(m_pShmByte, m_mask);

	if(m_cacheVal != bVal)
	{
	    m_cacheVal = bVal;
		emitChanged(false);
		rv.nUpdated = 1;
	}

	if(fLock)
		Unlock();

	return rv.nRetval;
}

void CShmBitVariable::Lock(void)
{
	::GfaIpcLockSHM(m_hShm);
//	qDebug() << "CShmBitVariable::Lock";
}

void CShmBitVariable::Unlock(void)
{
//	qDebug() << "CShmBitVariable::Unlock";
	::GfaIpcUnlockSHM(m_hShm);
}

void CShmBitVariable::emitChanged(bool fLock)
{
//    qDebug() << "val changed!";
	if(fLock)
	    emit valChanged(val());
	else
	{
	    QVariant v;
	    valRaw(v);
	    emit valChanged(v);
	}
}