void *String::internalAlloc(uint32 nNewLength)
{
void *pMemoryBlock;
if (m_pString)
{
pMemoryBlock = ((int32 *) m_pString) - 2;
if (nNewLength > getCapacity())
{
uint32 nCapacity = calcNewCapacity(nNewLength);
pMemoryBlock = xRealloc(pMemoryBlock, sizeof(XCHAR)*(nCapacity + 1));
m_pString = (XCHAR *) (((int32 *)pMemoryBlock) + 2);
setCapacity(nCapacity);
}
}
else
{
uint32 nCapacity = calcNewCapacity(nNewLength);
pMemoryBlock = xAlloc(sizeof(StringData) + sizeof(XCHAR)*(nCapacity + 1));
m_pString = (XCHAR *) (((int32 *)pMemoryBlock) + 2);
setCapacity(nCapacity);
*(((int32 *) m_pString) - 1) = 1;
}
m_pString[ nNewLength ] = 0;
return pMemoryBlock;
}
Btree<T>::Btree(const char* filename)
//
// Purpose: initializes the instances of a B-tree. The
// constructor allocates dynamic memory for the array that tracks
// the deleted nodes.
//
// Parameters:
//
// input: filename - the name of the supporting file.
//
{
root = BTREE_NIL;
numData = 0;
numNodes = 0;
numDelNodes = 0;
// create the array that tracks the deleted nodes
countDelNodeArray = BTREE_MIN_DEL_ARRAY;
delNodeArray = new unsigned[countDelNodeArray];
if (!delNodeArray)
xAlloc();
// assign BTREE_NIL to the elements of the array delNodeArray
for (unsigned i = 0; i < countDelNodeArray; i++)
*(delNodeArray + i) = BTREE_NIL;
errMsg[0] = '\0';
nodeSize = sizeof(Bstruct<T>);
// open the stream for binary I/O
f.open(filename, ios::binary | ios::in | ios::out);
if (!f.good())
xFileOpen();
}
XCHAR *String::getForModify()
{
if (!m_pString)
{
// In general, we optimise away small mallocs for empty strings
// but if you ask for the non-const bytes, they must be writable
// so we can't return "" here, like we do for the const version - jd
void *pMemoryBlock = xAlloc(sizeof(XCHAR));
m_pString = (XCHAR *)pMemoryBlock;
*m_pString = 0;
}
return m_pString;
}
