windows-nt/Source/XPSP1/NT/enduser/stuff/itircl/common/util/dynarray.c

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2020-09-26 03:20:57 -05:00
/*************************************************************************
* *
* DYNARRAY.C *
* *
* Copyright (C) Microsoft Corporation 1994-1995 *
* All Rights reserved. *
* *
* This library implements a robust dynamic array scheme. It replaces the *
* old DRG structure and should probably also replace the MR. *
* The total size of the array is NOT limited to 64K since it uses *
* Binh's threaded block memory manager to add new elements. Therefore it *
* should work correctly on both 16- and 32-bit platforms for any number *
* of elements. *
* * *
* Items in the array are assumed to be of a fixed size, which is defined *
* when the array is first initialized. To speed up the common operation *
* of forward enumeration, the next element function/macro is provided. *
* * *
* There are two types of lists possible: normal, and single-block *
* Use single-block for better space and possible more efficient time *
* usage when you know that your entire array will fit within a block. *
* Allocations beyond the one block limit will return NULL. *
* * *
* The first member of any element in the array MUST be an LPVOID. * *
* UNIMPLEMENTED: Insert into, delete *
**************************************************************************
* *
**************************************************************************
* *
* Written By : KevynCT *
* Current Owner: KevynCT *
* *
**************************************************************************/
#include <mvopsys.h>
#include <orkin.h>
#include <mem.h>
#include <_mvutil.h>
#include <dynarray.h>
#ifdef _DEBUG
static BYTE NEAR s_aszModule[] = __FILE__;
#endif
#define DYN_ARRAY_IS_SINGLEBLOCK(lpdl) ((lpdl)->dwFlags & DYN_ARRAY_SINGLEBLOCK)
#define DYN_ARRAY_SINGLEBLOCK_NEXT(lpdl, lpFoo) (((LPBYTE)lpFoo) + ((lpdl)->cbFoo))
#define DYN_ARRAY_SIZEOF_NEXT(lpdl) ( DYN_ARRAY_IS_SINGLE_BLOCK(lpdl) ? 0: sizeof(LPVOID))
#define NEXT_POINTER(lpFoo) (*(LPVOID FAR *)(lpFoo))
/// These are macros defined in the include file
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func DWORD | DynArrayGetNumElts |
* Return the number of elements currently in the list
*
* @parm LPDL | lpdl |
* Pointer to DynArray struct
*
* @rdesc None
*
* @comm
*
* Probably a macro
*************************************************************************/
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func LPVOID | DynArrayGetFirstElt |
* Return a pointer to the head of the list
*
* @parm LPDL | lpdl |
* Pointer to DynArray struct
*
* @rdesc
*
* @comm
*
* Probably a macro
*************************************************************************/
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func LPVOID | DynArrayGetCurElt |
* Returns the "current" element in the list
*
* @parm LPDL | lpdl |
* Pointer to DynArray struct
*
* @rdesc A valid pointer, or NULL if no current element has been set
*
* @comm
* Any operation ending in "Elt" will set the current elt pointer
* Probably a macro
*************************************************************************/
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func VOID | DynArraySetCurElt |
* Set the "current" element in the list
*
* @parm LPDL | lpdl |
* Pointer to DynArray struct
* LPVOID | lpvo |
* Pointer to a valid list element returned by one of the other
* element functions.
*
* @rdesc None
*
* @comm
* Probably a macro
*
*************************************************************************/
#ifdef SINGLE_BLOCK
BOOL PASCAL FAR DynArraySingleBlockInit(LPDL lpdl, DWORD BlockSize, WORD wElemSize, DWORD dwFlags)
{
if (lpdl && BlockSize && wElemSize)
{
MEMSET(lpdl, 0, sizeof(DL));
// single-block linked list
if (lpdl->lpBlockHead = BlockInitiate (BlockSize, wElemSize, 1, 0))
{
lpdl->lpFooHead = BlockGetElement(lpdl->lpBlockHead);
lpdl->lpFooFree = lpdl->lpFooHead;
lpdl->cbFoo = wElemSize;
lpdl->cFooPerBlock = BLOCKMGR_BLOCKSIZE(lpdl->lpBlockHead) / wElemSize;
lpdl->dwFlags = dwFlags | DYN_ARRAY_SINGLEBLOCK;
return TRUE;
}
}
return FALSE;
}
#endif
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func BOOL PASCAL FAR | DynArrayInit |
* Initializes the given DynArray struct to prepare the DynArray for use.
*
* @parm LPDL | lpdl |
* Pointer to uninitialized DynArray struct
*
* DWORD | BlockSize |
* The size of each block in bytes
*
* WORD | cMaxBlock |
* The maximum number of blocks to be allowed
*
* WORD | wElemSize |
* The fixed size of each element of the array
*
* DWORD | dwFlags |
* Specifies attributes of the list
*
* @rdesc TRUE if successful, NULL otherwise
*
* @comm
*
*
*************************************************************************/
BOOL PASCAL FAR DynArrayInit(LPDL lpdl, DWORD BlockSize, WORD cMaxBlock, WORD wElemSize, DWORD dwFlags)
{
if (lpdl && BlockSize && wElemSize && cMaxBlock)
{
MEMSET(lpdl, 0, sizeof(DL));
if (lpdl->lpBlockHead = BlockInitiate (BlockSize, wElemSize, cMaxBlock, 0))
{
lpdl->lpFooHead = NULL;
lpdl->lpFooFree = lpdl->lpFooHead;
lpdl->cbFoo = wElemSize;
lpdl->cFooPerBlock = (WORD) BLOCKMGR_BLOCKSIZE(lpdl->lpBlockHead) / wElemSize;
lpdl->dwFlags = dwFlags;
return TRUE;
}
}
return FALSE;
}
#ifdef SINGLE_BLOCK
LPVOID PASCAL FAR DynArraySingleBlockAppendElt(lpdl)
{
Assert(lpdl);
Assert(lpdl->lpFooFree);
Assert(lpdl->dwFlags & DYN_ARRAY_SINGLEBLOCK);
lpdl->lpFooCache = lpdl->lpFooFree;
lpdl->lpFooFree = BlockGetElement(lpdl->lpBlockHead);
lpdl->cFoo++;
return lpFoo->lpFooCache;
}
#endif
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func LPVOID PASCAL FAR | DynArrayAppendElt |
* Appends a new element to the end of the list
*
* @parm LPDL | lpdl |
* Pointer to DynArray struct
*
* @rdesc Returns a pointer to the newly created elt, or NULL on failure
*
* @comm
*
*
*************************************************************************/
LPVOID PASCAL FAR DynArrayAppendElt(LPDL lpdl)
{
LPVOID lpFooNext;
Assert(lpdl);
// Assert(lpdl->lpFooFree);
// lpFooFree is always non-NULL and points to the next free element in the list. if this will be the last element in
// a block, then lpFooFree->lpNext will be NULL, and we will need to allocate the next block and link it into the list
if (lpFooNext = BlockGetElement(lpdl->lpBlockHead))
{
if (!lpdl->lpFooHead)
{
lpdl->lpFooHead = lpFooNext;
lpdl->lpFooFree = lpFooNext;
}
else
{
NEXT_POINTER(lpdl->lpFooFree) = lpFooNext;
}
lpdl->lpFooFree = lpFooNext;
lpdl->lpFooCache = lpdl->lpFooFree;
lpdl->cFoo++;
NEXT_POINTER(lpdl->lpFooFree) = NULL;
return lpdl->lpFooCache;
}
return NULL;
}
#ifdef SINGLE_BLOCK
INLINE LPVOID PASCAL FAR DynArraySingleBlockGetOrdinalElt(LPDL lpdl, DWORD dwEltIndex)
{
LPVOID lpv;
Assert(lpdl);
Assert(lpdl->dwFlags & DYN_ARRAY_SINGLEBLOCK);
if (dwEltIndex < lpdl->cFoo)
{
return (((LPBYTE)lpdl->lpFooHead) + (dwEltIndex % lpdl->cFooPerBlock) * lpdl->cbFoo);
}
return NULL;
}
#endif
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func LPVOID PASCAL FAR | DynArrayGetOrdinalElt |
* Retrieve pointer to the start of i-th element in the list (starting at zero)
*
* @parm LPDL | lpdl |
* Pointer to DynArray struct
* DWORD | dwEltIndex |
* Index of element to retrieve
*
* @rdesc Pointer to elt if successful, NULL otherwise
*
* @comm
* Finds N-th element in the linked list. Zero is first element
* Use this only if the list was NOT created insertable, i.e. append-only
*
*************************************************************************/
LPVOID PASCAL FAR DynArrayGetOrdinalElt(LPDL lpdl, DWORD dwEltIndex)
{
LPBYTE lpb;
Assert(lpdl);
if (dwEltIndex < lpdl->cFoo)
{
// the faster way: calc the block number and the offset within the block, and go directly there.
if (lpb = BlockGetOrdinalBlock(lpdl->lpBlockHead, (WORD)(dwEltIndex / lpdl->cFooPerBlock)))
return (lpdl->lpFooCache = (lpb + (dwEltIndex % lpdl->cFooPerBlock) * lpdl->cbFoo));
}
return NULL;
}
#if 0
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func LPVOID PASCAL FAR | DynArrayInsertableGetElt |
* Retrieve pointer to the start of i-th element in the list (starting at zero)
*
* @parm LPDL | lpdl |
* Pointer to DynArray struct
* DWORD | dwEltIndex |
* Index of element to retrieve
*
* @rdesc Pointer to elt if successful, NULL otherwise
*
* @comm
* Finds N-th element in the linked list. Zero is first element
* Use this only if the list was NOT created insertable, i.e. append-only
*
*************************************************************************/
LPVOID PASCAL FAR DynInsertableListGetElt(LPDL lpdl, DWORD dwEltIndex)
{
LPVOID lpv;
Assert(lpdl);
// need to find it the long way since pointers may no longer be contiguous within a block after an insertion.
for (lpv = lpdl->lpFooHead; dwEltIndex && lpv; lpv = NEXT_POINTER(lpThis), dwEltIndex--)
;
if (lpv) lpdl->lpFooCache = lpv;
return lpv;
}
#endif
#ifdef SINGLE_BLOCK
INLINE LPVOID PASCAL FAR DynArraySingleBlockNextElt(LPDL lpdl)
{
Assert(lpdl);
Assert(lpdl->lpFooCache);
Assert(lpdl->dwFlags & DYN_ARRAY_SINGLEBLOCK);
return (lpdl->lpFooCache = DYN_ARRAY_SINGLEBLOCK_NEXT(lpdl, lpdl->lpFooCache));
}
#endif
#if 0
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func LPVOID PASCAL FAR | DynArrayNextElt |
* Get next element in list after the current one.
*
* @parm LPDL | lpdl |
* Pointer to DynArray struct
*
* @rdesc Pointer to elt if successful, NULL otherwise
*
* @comm
* Responsibility of caller to know when current element is NULL
* This function will execute quickly.
*
*************************************************************************/
_inline LPVOID PASCAL FAR DynArrayNextElt(LPDL lpdl)
{
Assert(lpdl);
Assert(lpdl->lpFooCache);
return (lpdl->lpFooCache = NEXT_POINTER(lpdl->lpFooCache));
}
#endif
#if 1
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func LPVOID PASCAL FAR | DynArrayClearElt |
* Zero-inits the current element, but does not harm NEXT link of the elt.
*
* @parm LPDL | lpdl |
* Pointer to DynArray struct
*
* @rdesc Pointer to current element if there is one, NULL otherwise.
*
* @comm
*
*
*************************************************************************/
LPVOID PASCAL FAR DynArrayClearElt(LPDL lpdl)
{
Assert(lpdl);
if (lpdl->lpFooCache)
{
MEMSET((LPBYTE)(lpdl->lpFooCache) + sizeof(LPVOID), 0, lpdl->cbFoo - sizeof(LPVOID));
return lpdl->lpFooCache;
}
return NULL;
}
#endif
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func VOID PASCAL FAR | DynArrayFree |
* Free any memory that was allocated for the given dynlist over the
* course of its life.
*
* @parm LPDL | lpdl |
* Pointer to uninitialized DynArray struct
*
* @rdesc None
*
* @comm
*
*
*************************************************************************/
VOID PASCAL FAR DynArrayFree(LPDL lpdl)
{
Assert(lpdl);
BlockFree(lpdl->lpBlockHead);
MEMSET(lpdl, 0, sizeof(DL));
}
/*************************************************************************
* @doc INTERNAL RETRIEVAL
*
* @func VOID PASCAL FAR | DynArrayReset |
* Pretend we never added any elements to this list, but don't free mem.
*
* @parm LPDL | lpdl |
* Pointer to uninitialized DynArray struct
*
* @rdesc None
*
* @comm
*
*
*************************************************************************/
VOID PASCAL FAR DynArrayReset(LPDL lpdl)
{
Assert(lpdl);
BlockReset(lpdl->lpBlockHead);
lpdl->lpFooHead = NULL;
lpdl->lpFooFree = lpdl->lpFooHead;
lpdl->cFoo = 0;
}
// UNIMPLEMENTED: DELETE and INSERT