windows-nt/Source/XPSP1/NT/shell/osshell/dskquota/ui/dynarray.cpp

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///////////////////////////////////////////////////////////////////////////////
/* File: dynarray.cpp
Description: Wrapper classes around the DPA_xxxxx and DSA_xxxxx functions
provided by the common control's library. The classes add value by
providing multi-threaded protection, iterators and automatic cleanup
semantics.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
09/03/96 Added exception handling. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
#include "pch.h" // PCH
#pragma hdrstop
#include "dynarray.h"
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::PointerList
Description: Constructor.
Arguments:
cItemGrow - Number of items to grow list when expansion is required.
Default value is 0 which causes DPA to use 8.
Returns: Nothing.
Exception: Throws OutOfMemory.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
09/03/96 Initial creation. BrianAu
02/21/97 Added cItemGrow argument. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
PointerList::PointerList(
INT cItemGrow
)
: m_hdpa(NULL)
{
InitializeCriticalSection(&m_cs);
if (NULL == (m_hdpa = DPA_CreateEx(cItemGrow, NULL)))
{
DeleteCriticalSection(&m_cs);
throw CAllocException();
}
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::~PointerList
Description: Destructor. Destroys the DPA and closes the mutex handle.
Arguments: None.
Returns: Nothing.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
PointerList::~PointerList(
VOID
)
{
Lock();
if (NULL != m_hdpa)
DPA_Destroy(m_hdpa);
ReleaseLock();
DeleteCriticalSection(&m_cs);
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::Count
Description: Returns the number of elements in the list.
Arguments: None.
Returns: Count of elements in list.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
UINT
PointerList::Count(
VOID
)
{
UINT n = 0;
AutoLockCs lock(m_cs); // Get lock on container. Will automatically release.
DBGASSERT((NULL != m_hdpa));
n = DPA_GetPtrCount(m_hdpa);
return n;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::Insert
Description: Inserts a pointer into the pointer list at a given index.
If the index is beyond the upper bounds of the array, the array
is extended by one and the item is appended to the list.
Arguments:
pvItem - Pointer value to add to list.
index - List index where pointer is to be inserted. All following
items are shifted to one index higher. The list automatically
grows to accomodate as required.
Returns: Nothing.
Exceptions: OutOfMemory.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
09/03/96 Added exception handling. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
VOID
PointerList::Insert(
LPVOID pvItem,
UINT index
)
{
DBGASSERT((NULL != pvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will automatically release.
DBGASSERT((NULL != m_hdpa));
if (DPA_InsertPtr(m_hdpa, index, pvItem) < 0)
{
throw CAllocException();
}
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::Replace
Description: Replaces a pointer in the pointer list at a given index.
If the index is beyond the upper bounds of the array, the array
is extended by one and the item is appended to the list.
Arguments:
pvItem - Pointer value to add to list.
index - List index where pointer is to be replaced.
Returns:
TRUE - Success.
FALSE - Invalid index or empty container.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
PointerList::Replace(
LPVOID pvItem,
UINT index
)
{
DBGASSERT((NULL != pvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will automatically release.
DBGASSERT((NULL != m_hdpa));
return DPA_SetPtr(m_hdpa, index, pvItem);
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::Append
Description: Appends a pointer to the end of the list.
Arguments:
pvItem - Pointer value to add to list.
Returns: Nothing.
Exceptions: OutOfMemory.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
09/03/96 Added exception handling. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
VOID
PointerList::Append(
LPVOID pvItem
)
{
DBGASSERT((NULL != pvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will automatically release.
//
// Yes, this is correct. We're "inserting" an item to append something
// to the list. This saves a ( count - 1 ) calculation.
//
DBGASSERT((NULL != m_hdpa));
Insert(pvItem, DPA_GetPtrCount(m_hdpa));
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::Remove
Description: Removes a pointer from the list at a given index.
Arguments:
ppvItem - Address of variable to contain removed pointer value.
index - List index where pointer is to be removed. All following
items are shifted to one index lower.
Returns:
TRUE - Success.
FASLE - Index is invalid (or container is empty).
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
PointerList::Remove(
LPVOID *ppvItem,
UINT index
)
{
DBGASSERT((NULL != ppvItem));
DBGASSERT((NULL != m_hdpa));
AutoLockCs lock(m_cs); // Get lock on container. Will automatically release.
*ppvItem = DPA_DeletePtr(m_hdpa, index);
if (NULL == *ppvItem)
return FALSE;
return TRUE;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::RemoveLast
Description: Removes the last pointer from the list.
Arguments:
ppvItem - Address of variable to contain removed pointer value.
All following items are shifted to one index lower.
Returns:
TRUE - Success.
FALSE - Container is emtpy.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
PointerList::RemoveLast(
LPVOID *ppvItem
)
{
DBGASSERT((NULL != ppvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will automatically release.
if (0 == Count())
return FALSE;
Remove(ppvItem, Count() - 1);
return TRUE;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::Retrieve
Description: Retrieve a pointer from the list at a given index.
The pointer value is merely retrieved and not removed from the list.
Arguments:
ppvItem - Address of variable to contain retrieved pointer value.
index - List index where pointer is to be retrieved.
Returns:
TRUE - Success.
FALSE - Invalid index or container is empty.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
PointerList::Retrieve(
LPVOID *ppvItem,
UINT index
)
{
DBGASSERT((NULL != ppvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will automatically release.
DBGASSERT((NULL != m_hdpa));
*ppvItem = DPA_GetPtr(m_hdpa, index);
if (NULL == *ppvItem)
return FALSE;
return TRUE;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::RetrieveLast
Description: Retrieves the last pointer from the list.
Arguments:
ppvItem - Address of variable to contain retrieved pointer value.
Returns:
TRUE - Success.
FALSE - Container is empty.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
09/03/96 Added exception handling. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
PointerList::RetrieveLast(
LPVOID *ppvItem
)
{
DBGASSERT((NULL != ppvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will automatically release.
if (0 == Count())
return FALSE;
Retrieve(ppvItem, Count() - 1);
return TRUE;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::FindIndex
Description: Returns the list index associated with a given pointer
value. If duplicates exist, the index of the first item is returned.
Arguments:
pvItem - Pointer value of item to be found.
pIndex - Address of index variable to hold resulting index.
Returns:
TRUE = Success
FALSE = Item not found in list.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
09/03/96 Changed returned value to BOOL. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
PointerList::FindIndex(
LPVOID pvItem,
INT *pIndex
)
{
INT i = -1;
DBGASSERT((NULL != pIndex));
DBGASSERT((NULL != pvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will automatically release.
DBGASSERT((NULL != m_hdpa));
i = *pIndex = DPA_GetPtrIndex(m_hdpa, pvItem);
if (-1 == i)
return FALSE;
return TRUE;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::Sort
Description: Sorts the list given a comparison function.
Arguments:
pfnCompare - Address of comparison callback.
lParam - 32-bit parameter passed to the callback.
Returns:
TRUE = Success
FALSE = Item not found in list.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
02/21/97 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
PointerList::Sort(
PFNDPACOMPARE pfnCompare,
LPARAM lParam
)
{
DBGASSERT((NULL != pfnCompare));
AutoLockCs lock(m_cs); // Get lock on container. Will automatically release.
DBGASSERT((NULL != m_hdpa));
DBGASSERT((NULL != pfnCompare));
return DPA_Sort(m_hdpa, pfnCompare, lParam);
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerList::Search
Description: Searches the list for a given item.
Arguments:
pvKey - Address of key item used for search.
pfnCompare - Address of comparison callback.
uOptions - Options controlling sort operation.
DPAS_SORTED = Array is already sorted.
Will use binary search.
DPAS_INSERTBEFORE = If no exact match is found, return index of
previous best match.
DPAS_INSERTAFTER = If no exact match is found, return index of
next best match.
iStart - Index of where to start search. 0 for start of list.
lParam - 32-bit parameter passed to the callback.
Returns: Index of found item or -1 if none found.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
02/21/97 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
INT
PointerList::Search(
LPVOID pvKey,
PFNDPACOMPARE pfnCompare,
UINT uOptions,
INT iStart,
LPARAM lParam
)
{
DBGASSERT((NULL != pfnCompare));
AutoLockCs lock(m_cs); // Get lock on container. Will automatically release.
DBGASSERT((NULL != m_hdpa));
DBGASSERT((NULL != pvKey));
DBGASSERT((NULL != pfnCompare));
return DPA_Search(m_hdpa, pvKey, iStart, pfnCompare, lParam, uOptions);
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerListIterator::operator =
Description: Assignment for PointerListIterator.
Arguments:
rhs - Reference to constant iterator that is the rhs of the assignment.
Returns:
Returns a reference to "this" iterator object following the assignment.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
02/27/97 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
PointerListIterator&
PointerListIterator::operator = (
const PointerListIterator& rhs
)
{
if (this != &rhs)
{
m_pList = rhs.m_pList;
m_Index = rhs.m_Index;
}
return *this;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: PointerListIterator::Advance
Description: Both the Next() and Prev() iterator functions call this
one function. It handles the actual iteration.
Arguments:
ppvOut - Address of pointer variable to contain the value of the
pointer at the "current" iterator location. The iterator is
advance (or retreated) after the pointer value is copied to the
destination.
bForward - TRUE = Advance toward end of list.
FALSE = Advance toward front of list.
Returns:
NO_ERROR - Iterator advanced. Returned pointer is valid.
E_FAIL - Iterator already at begining or end of list. Returned
pointer will be NULL.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/14/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
HRESULT
PointerListIterator::Advance(
LPVOID *ppvOut,
BOOL bForward
)
{
LPVOID pv = NULL;
HRESULT hResult = NO_ERROR;
DBGASSERT((NULL != ppvOut));
m_pList->Lock();
if (0 < m_pList->Count() && m_Index != EndOfList)
{
//
// Get pointer value at index "m_Index".
//
DBGASSERT((NULL != m_pList->m_hdpa));
pv = DPA_GetPtr(m_pList->m_hdpa, m_Index);
if (bForward)
{
//
// Advance iterator index.
//
if ((UINT)(++m_Index) == m_pList->Count())
m_Index = EndOfList;
}
else
{
//
// Retreat iterator index.
//
m_Index--; // Will be -1 (EndOfList) if currently 0.
}
}
else
hResult = E_FAIL;
m_pList->ReleaseLock();
*ppvOut = pv; // Return pointer value.
return hResult;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureList::StructureList
Description: Constructor.
Arguments:
cbItem - Size of each item in bytes.
cItemGrow - Number of items to grow array at each expansion.
Returns: Nothing.
Exceptions: OutOfMemory
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
09/06/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
StructureList::StructureList(
INT cbItem,
INT cItemGrow
)
{
InitializeCriticalSection(&m_cs);
if (NULL == (m_hdsa = DSA_Create(cbItem, cItemGrow)))
{
DeleteCriticalSection(&m_cs);
throw CAllocException();
}
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureList::~StructureList
Description: Destructor. Destroys the DSA and closes the mutex handle.
Arguments: None.
Returns: Nothing.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/24/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
StructureList::~StructureList(void)
{
Lock();
if (NULL != m_hdsa)
DSA_Destroy(m_hdsa);
ReleaseLock();
DeleteCriticalSection(&m_cs);
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureListIterator::operator =
Description: Assignment for StructureListIterator.
Arguments:
rhs - Reference to constant iterator that is the rhs of the assignment.
Returns:
Returns a reference to "this" iterator object following the assignment.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
02/27/97 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
StructureListIterator&
StructureListIterator::operator = (
const StructureListIterator& rhs
)
{
if (this != &rhs)
{
m_pList = rhs.m_pList;
m_Index = rhs.m_Index;
}
return *this;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureList::Count
Description: Returns the number of elements in the list.
Arguments: None.
Returns: Count of elements in list.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/24/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
UINT StructureList::Count(VOID)
{
UINT n = 0;
AutoLockCs lock(m_cs); // Get lock on container. Will auto-release.
DBGASSERT((NULL != m_hdsa));
n = DSA_GetItemCount(m_hdsa);
return n;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureList::Insert
Description: Insert an item into the Structure list at a given index.
If the index is beyond the upper bounds of the array, the array
is extended by one and the item is appended to the list.
Arguments:
pvItem - Address of item to add to list.
index - List index where item is to be inserted. All following
items are shifted to one index higher. The list automatically
grows to accomodate as required.
Returns: Nothing.
Exceptions: OutOfMemory.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/24/96 Initial creation. BrianAu
09/06/96 Added exception handling. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
VOID
StructureList::Insert(
LPVOID pvItem,
UINT index
)
{
DBGASSERT((NULL != pvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will auto-release.
DBGASSERT((NULL != m_hdsa));
if (DSA_InsertItem(m_hdsa, index, pvItem) < 0)
{
throw CAllocException();
}
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureList::Replace
Description: Replaces an item in the Structure list at a given index.
If the index is beyond the upper bounds of the array, the array
is extended by one and the item is appended to the list.
Arguments:
pvItem - Address of item to replace existing item.
index - List index where item is to be replaced.
Returns:
TRUE - Success.
FALSE - Invalid index or empty container.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/24/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
StructureList::Replace(
LPVOID pvItem,
UINT index
)
{
DBGASSERT((NULL != pvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will auto-release.
DBGASSERT((NULL != m_hdsa));
return DSA_SetItem(m_hdsa, index, pvItem);
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureList::Append
Description: Appends an item to the end of the list.
Arguments:
pvItem - Address of item to add to list.
Returns: Nothing.
Exceptions: OutOfMemory.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/24/96 Initial creation. BrianAu
09/06/96 Added exception handling. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
VOID
StructureList::Append(
LPVOID pvItem
)
{
DBGASSERT((NULL != pvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will auto-release.
//
// Yes, this is correct. We're "inserting" an item to append something
// to the list. This saves a ( count - 1 ) calculation.
//
DBGASSERT((NULL != m_hdsa));
Insert(pvItem, DSA_GetItemCount(m_hdsa));
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureList::Remove
Description: Removes an item from the list at a given index.
Arguments:
pvItem - Address of buffer to receive removed item. Assumes buffer
is sized properly.
index - List index where item is to be removed. All following
items are shifted to one index lower.
Returns:
TRUE - Success.
FALSE - Invalid index or container is empty.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/24/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
StructureList::Remove(
LPVOID pvItem,
UINT index
)
{
DBGASSERT((NULL != pvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will auto-release.
DBGASSERT((NULL != m_hdsa));
if (!DSA_GetItem(m_hdsa, index, pvItem) ||
!DSA_DeleteItem(m_hdsa, index))
{
return FALSE;
}
return TRUE;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureList::Retrieve
Description: Retrieve an item from the list at a given index.
The item value is merely copied and not removed from the list.
Arguments:
pvItem - Address of buffer to receive removed item. Assumes buffer
is sized properly.
index - List index where item is to be retrieved.
Returns:
TRUE - Success.
FALSE - Invalid index or empty container.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/24/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
StructureList::Retrieve(
LPVOID pvItem,
UINT index
)
{
DBGASSERT((NULL != pvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will auto-release.
DBGASSERT((NULL != m_hdsa));
if (!DSA_GetItem(m_hdsa, index, pvItem))
{
return FALSE;
}
return TRUE;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureList::RemoveLast
Description: Removes the last item from the list.
Arguments:
pvItem - Address of buffer to receive removed item. Assumes buffer
is sized properly.
Returns:
TRUE - Success.
FALSE - Empty container.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/24/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
StructureList::RemoveLast(
LPVOID pvItem
)
{
DBGASSERT((NULL != pvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will auto-release.
DBGASSERT((NULL != m_hdsa));
if (0 == DSA_GetItemCount(m_hdsa))
return FALSE;
Remove(pvItem, DSA_GetItemCount(m_hdsa) - 1);
return TRUE;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureList::RetrieveLast
Description: Retrieves the last pointer from the list.
Arguments:
pvItem - Address of buffer to receive removed item. Assumes buffer
is sized properly.
Returns:
TRUE - Success.
FALSE - Empty container.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/24/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
BOOL
StructureList::RetrieveLast(
LPVOID pvItem
)
{
DBGASSERT((NULL != pvItem));
AutoLockCs lock(m_cs); // Get lock on container. Will auto-release.
DBGASSERT((NULL != m_hdsa));
if (0 == DSA_GetItemCount(m_hdsa))
return FALSE;
Retrieve(pvItem, DSA_GetItemCount(m_hdsa) - 1);
return TRUE;
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureList::Clear
Description: Removes all items from the list.
Arguments: None.
Returns: Nothing.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/26/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
VOID
StructureList::Clear(
VOID
)
{
AutoLockCs lock(m_cs); // Get lock on container. Will auto-release.
DBGASSERT((NULL != m_hdsa));
DSA_DeleteAllItems(m_hdsa);
}
///////////////////////////////////////////////////////////////////////////////
/* Function: StructureListIterator::Advance
Description: Both the Next() and Prev() iterator functions call this
one function. It handles the actual iteration.
Arguments:
ppvOut - Address of pointer variable to receive the address of the
item at the "current" iterator location. The iterator is
advance (or retreated) after the pointer value is copied to the
destination.
bForward - TRUE = Advance toward end of list.
FALSE = Advance toward front of list.
Returns:
NO_ERROR - Iterator advanced. Returned pointer is valid.
E_FAIL - Iterator already at begining or end of list. Returned
pointer will be NULL.
Revision History:
Date Description Programmer
-------- --------------------------------------------------- ----------
06/24/96 Initial creation. BrianAu
*/
///////////////////////////////////////////////////////////////////////////////
HRESULT
StructureListIterator::Advance(
LPVOID *ppvOut,
BOOL bForward
)
{
LPVOID pv = NULL;
HRESULT hResult = NO_ERROR;
DBGASSERT((NULL != ppvOut));
m_pList->Lock();
if (0 < m_pList->Count() && m_Index != EndOfList)
{
//
// Get address of item at index "m_Index".
//
DBGASSERT((NULL != m_pList->m_hdsa));
pv = DSA_GetItemPtr(m_pList->m_hdsa, m_Index);
if (bForward)
{
//
// Advance iterator index.
//
if ((UINT)(++m_Index) == m_pList->Count())
m_Index = EndOfList;
}
else
{
//
// Retreat iterator index.
//
m_Index--; // Will be -1 (EndOfList) if currently 0.
}
}
else
hResult = E_FAIL;
m_pList->ReleaseLock();
*ppvOut = pv; // Return pointer value.
return hResult;
}