ALERROR CIntSet::AddElement (int iElement)
// AddElement
//
// Adds an element to the set
{
ALERROR error;
DWORD dwBucket = ((DWORD)iElement) / g_BitsPerBucket;
// Look for the bucket; if we don't find it, add a new one
CIntArray *pBucket;
if (error = m_Set.Lookup(dwBucket, (CObject **)&pBucket))
{
pBucket = new CIntArray;
if (pBucket == NULL)
return ERR_MEMORY;
if (error = m_Set.AddEntry(dwBucket, pBucket))
{
delete pBucket;
return error;
}
}
// Look for the bit in the bucket
DWORD dwBucketBit = ((DWORD)iElement) % g_BitsPerBucket;
DWORD dwOffset = dwBucketBit / 32;
// Make sure there is room in the bucket
if ((int)dwOffset >= pBucket->GetCount())
{
int iOldCount = pBucket->GetCount();
int iExpandBy = ((int)dwOffset + 1) - iOldCount;
if (error = pBucket->ExpandArray(-1, iExpandBy))
return error;
for (int i = iOldCount; i < pBucket->GetCount(); i++)
pBucket->ReplaceElement(i, 0);
}
// OR-in the new element
DWORD dwBit = dwBucketBit % 32;
DWORD dwNewValue = ((DWORD)pBucket->GetElement(dwOffset)) | (1 << dwBit);
pBucket->ReplaceElement(dwOffset, dwNewValue);
return NOERROR;
}
void CIntSet::RemoveElement (int iElement)
// RemoveElement
//
// Removes the given element in the set
{
DWORD dwBucket = ((DWORD)iElement) / g_BitsPerBucket;
// Look for the bucket
CIntArray *pBucket;
if (m_Set.Lookup(dwBucket, (CObject **)&pBucket) != NOERROR)
return;
DWORD dwBucketBit = ((DWORD)iElement) % g_BitsPerBucket;
DWORD dwOffset = dwBucketBit / 32;
if ((int)dwOffset >= pBucket->GetCount())
return;
DWORD dwBit = dwBucketBit % 32;
DWORD dwNewValue = ((DWORD)pBucket->GetElement(dwOffset)) & ~(1 << dwBit);
pBucket->ReplaceElement(dwOffset, dwNewValue);
}