int CMsgBufVSE::nHandleBufferOverrun(INT nSize)
{
int nResult = CALL_SUCCESS;
if (m_nIndexRead < m_nIndexWrite)
{
if ((m_nIndexRead + m_nBufferSize) <= (m_nIndexWrite + nSize))
{
nResult = WARN_BUFFER_OVERRUN;
nAdvanceReadIndex();
nHandleBufferOverrun(nSize);
}
}
else if (m_nIndexRead > m_nIndexWrite)
{
if ((m_nIndexRead) <= (m_nIndexWrite + nSize))
{
nResult = WARN_BUFFER_OVERRUN;
nAdvanceReadIndex();
nHandleBufferOverrun(nSize);
}
}
else
{
if (m_nMsgCount != 0)
{
nResult = WARN_BUFFER_OVERRUN;
nAdvanceReadIndex();
nHandleBufferOverrun(nSize);
}
}
return nResult;
}
/**********************************************************************************
Function Name : ReadEntry
Input : INDEX, bSetNextIndexStartPos.
Output : CALL_SUCCESS for success.
ERR_READ_MEMORY_SHORT when caller specifies size of the msg
less than required size.
ERR_INVALID_INDEX for invalid index.
Functionality : Interface function. Reads the entry from the given index and
user will have an option set the next entry start pos.
Member of : CMsgBufVVSE
Friend of : -
Authors : Pradeep Kadoor
Date Created : 22/06/2009
Modifications : -
************************************************************************************/
HRESULT CMsgBufVVSE::ReadEntry(int& nType, BYTE* pbyMsg, int& nSize, int nEntry, BOOL bSetNextIndexStartPos)
{
// Lock the buffer
EnterCriticalSection(&m_CritSectionForGB);
HRESULT Result = CALL_SUCCESS;
if ((nEntry < 0) || ((nEntry + m_nTmpMsgCount) > m_nMsgCount))
{
Result = ERR_INVALID_INDEX;
}
else
{
int nTmpIndex = m_nReadIndexTmp;
for (int i = 0; i < nEntry; i++)
{
nAdvanceReadIndex(nTmpIndex);
}
Result = ReadBuffer(nType, pbyMsg, nSize, nTmpIndex);
if ((Result == CALL_SUCCESS) && (bSetNextIndexStartPos == TRUE))
{
m_nReadIndexTmp = nTmpIndex;
m_nTmpMsgCount += nEntry;
}
}
// Unlock the buffer
LeaveCriticalSection(&m_CritSectionForGB);
return Result;
}
/**********************************************************************************
Function Name : nHandleStartIndex()
Input(s) : -
Output : CALL_SUCCESS for success. CALL_FAILURE for failure.
Functionality : If buffer overrun criteria is met, start index
is advanced until it solves buffer overrun.
Member of : CMsgBufVVSE
Friend of : -
Authors : Pradeep Kadoor
Date Created : 22/06/2009
Modifications : -
************************************************************************************/
int CMsgBufVVSE::nHandleStartIndex(int nSize)
{
int nResult = CALL_SUCCESS;
if (m_nStartIndex < m_nIndexWrite)
{
if ((m_nStartIndex + m_nBufferSize) <= (m_nIndexWrite + nSize))
{
TRACE("<start>%d<read>%d<write>%d<count>%d<tmpCount>%d\n",m_nStartIndex, m_nReadIndexTmp, m_nIndexWrite, m_nMsgCount, m_nTmpMsgCount);
nAdvanceReadIndex(m_nStartIndex);
m_nMsgCount--;
m_nReadIndexTmp = m_nStartIndex;
m_nTmpMsgCount = 0;
TRACE("<start>%d<read>%d<write>%d<count>%d<tmpCount>%d\n",m_nStartIndex, m_nReadIndexTmp, m_nIndexWrite, m_nMsgCount, m_nTmpMsgCount);
nHandleStartIndex(nSize);
}
}
else if (m_nStartIndex > m_nIndexWrite)
{
if ((m_nStartIndex) <= (m_nIndexWrite + nSize))
{
TRACE("<start>%d<read>%d<write>%d<count>%d<tmpCount>%d\n",m_nStartIndex, m_nReadIndexTmp, m_nIndexWrite, m_nMsgCount, m_nTmpMsgCount);
nAdvanceReadIndex(m_nStartIndex);
m_nMsgCount--;
m_nReadIndexTmp = m_nStartIndex;
m_nTmpMsgCount = 0;
TRACE("<start>%d<read>%d<write>%d<count>%d<tmpCount>%d\n",m_nStartIndex, m_nReadIndexTmp, m_nIndexWrite, m_nMsgCount, m_nTmpMsgCount);
nHandleStartIndex(nSize);
}
}
else
{
if (m_nMsgCount != 0)
{
ASSERT(FALSE);
}
}
TRACE("handled<start>%d<read>%d<write>%d<count>%d<tmpCount>%d\n",m_nStartIndex, m_nReadIndexTmp, m_nIndexWrite, m_nMsgCount, m_nTmpMsgCount);
return nResult;
}
/**********************************************************************************
Function Name : AdvanceToNextMsg()
Output : CALL_SUCCESS for success. CALL_FAILURE for failure.
if allocated memory by the caller is not enough.
Functionality : Interface function. Current msg is skipped.
Caller can use this function when wishes to skip the
current msg due to memory constraint.
Member of : CMsgBufVSE
Friend of : -
Authors : Pradeep Kadoor
Date Created : 22/06/2009
Modifications : -
************************************************************************************/
HRESULT CMsgBufVSE::AdvanceToNextMsg()
{
HRESULT Result = CALL_SUCCESS;
if (m_nMsgCount == 0)
{
Result = EMPTY_APP_BUFFER;
}
else
{
nAdvanceReadIndex();//Helper function to advance the read index
//to the next msg.
}
return Result;
}
/**********************************************************************************
Function Name : nSetStartPos
Input : Entry Number - nIndex
Output : CALL_SUCCESS for success.
ERR_INVALID_INDEX for invalid index.
Functionality : Interface function. Sets the start pos to the 'nIndex'th entry.
Member of : CMsgBufVVSE
Friend of : -
Authors : Pradeep Kadoor
Date Created : 10/11/2009
Modifications : -
************************************************************************************/
HRESULT CMsgBufVVSE::SetStartPos(int nEntry)
{
HRESULT Result = CALL_SUCCESS;
if (nEntry < 0 || nEntry > m_nMsgCount)
{
Result = ERR_INVALID_INDEX;
}
else
{
m_nReadIndexTmp = m_nStartIndex;
for (int i = 0; i < nEntry; i++)
{
nAdvanceReadIndex(m_nReadIndexTmp);
m_nTmpMsgCount++;
}
}
return Result;
}