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1104 lines
28 KiB
C
1104 lines
28 KiB
C
/*
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* NTDLL bitmap functions
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*
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* Copyright 2002 Jon Griffiths
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
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*
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* NOTES
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* Bitmaps are an efficient type for manipulating large arrays of bits. They
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* are commonly used by device drivers (e.g. For holding dirty/free blocks),
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* but are also available to applications that need this functionality.
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*
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* Bits are set LSB to MSB in each consecutive byte, making this implementation
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* binary compatible with Win32.
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*
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* Note that to avoid unexpected behaviour, the size of a bitmap should be set
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* to a multiple of 32.
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*/
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#include <stdarg.h>
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#include <stdlib.h>
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#include <string.h>
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#include "windef.h"
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#include "winternl.h"
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#include "wine/debug.h"
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WINE_DEFAULT_DEBUG_CHANNEL(ntdll);
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/* Bits set from LSB to MSB; used as mask for runs < 8 bits */
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static const BYTE NTDLL_maskBits[8] = { 0, 1, 3, 7, 15, 31, 63, 127 };
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/* Number of set bits for each value of a nibble; used for counting */
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static const BYTE NTDLL_nibbleBitCount[16] = {
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0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4
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};
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/* First set bit in a nibble; used for determining least significant bit */
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static const BYTE NTDLL_leastSignificant[16] = {
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0, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0
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};
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/* Last set bit in a nibble; used for determining most significant bit */
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static const signed char NTDLL_mostSignificant[16] = {
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-1, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3
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};
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/*************************************************************************
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* RtlInitializeBitMap [NTDLL.@]
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*
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* Initialise a new bitmap.
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*
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* PARAMS
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* lpBits [I] Bitmap pointer
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* lpBuff [I] Memory for the bitmap
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* ulSize [I] Size of lpBuff in bits
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*
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* RETURNS
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* Nothing.
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*
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* NOTES
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* lpBuff must be aligned on a ULONG suitable boundary, to a multiple of 32 bytes
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* in size (irrespective of ulSize given).
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*/
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VOID WINAPI RtlInitializeBitMap(PRTL_BITMAP lpBits, PULONG lpBuff, ULONG ulSize)
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{
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TRACE("(%p,%p,%d)\n", lpBits,lpBuff,ulSize);
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lpBits->SizeOfBitMap = ulSize;
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lpBits->Buffer = lpBuff;
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}
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/*************************************************************************
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* RtlSetAllBits [NTDLL.@]
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*
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* Set all bits in a bitmap.
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*
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* PARAMS
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* lpBits [I] Bitmap pointer
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*
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* RETURNS
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* Nothing.
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*/
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VOID WINAPI RtlSetAllBits(PRTL_BITMAP lpBits)
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{
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TRACE("(%p)\n", lpBits);
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memset(lpBits->Buffer, 0xff, ((lpBits->SizeOfBitMap + 31) & ~31) >> 3);
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}
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/*************************************************************************
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* RtlClearAllBits [NTDLL.@]
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*
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* Clear all bits in a bitmap.
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*
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* PARAMS
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* lpBit [I] Bitmap pointer
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*
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* RETURNS
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* Nothing.
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*/
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VOID WINAPI RtlClearAllBits(PRTL_BITMAP lpBits)
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{
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TRACE("(%p)\n", lpBits);
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memset(lpBits->Buffer, 0, ((lpBits->SizeOfBitMap + 31) & ~31) >> 3);
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}
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/*************************************************************************
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* RtlSetBits [NTDLL.@]
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*
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* Set a range of bits in a bitmap.
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*
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* PARAMS
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* lpBits [I] Bitmap pointer
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* ulStart [I] First bit to set
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* ulCount [I] Number of consecutive bits to set
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*
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* RETURNS
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* Nothing.
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*/
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VOID WINAPI RtlSetBits(PRTL_BITMAP lpBits, ULONG ulStart, ULONG ulCount)
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{
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LPBYTE lpOut;
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TRACE("(%p,%d,%d)\n", lpBits, ulStart, ulCount);
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if (!lpBits || !ulCount ||
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ulStart >= lpBits->SizeOfBitMap ||
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ulCount > lpBits->SizeOfBitMap - ulStart)
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return;
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/* FIXME: It might be more efficient/cleaner to manipulate four bytes
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* at a time. But beware of the pointer arithmetics...
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*/
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lpOut = ((BYTE*)lpBits->Buffer) + (ulStart >> 3u);
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/* Set bits in first byte, if ulStart isn't a byte boundary */
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if (ulStart & 7)
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{
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if (ulCount > 7)
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{
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/* Set from start bit to the end of the byte */
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*lpOut++ |= 0xff << (ulStart & 7);
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ulCount -= (8 - (ulStart & 7));
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}
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else
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{
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/* Set from the start bit, possibly into the next byte also */
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USHORT initialWord = NTDLL_maskBits[ulCount] << (ulStart & 7);
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*lpOut++ |= (initialWord & 0xff);
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*lpOut |= (initialWord >> 8);
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return;
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}
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}
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/* Set bits up to complete byte count */
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if (ulCount >> 3)
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{
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memset(lpOut, 0xff, ulCount >> 3);
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lpOut = lpOut + (ulCount >> 3);
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}
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/* Set remaining bits, if any */
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if (ulCount & 0x7)
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*lpOut |= NTDLL_maskBits[ulCount & 0x7];
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}
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/*************************************************************************
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* RtlClearBits [NTDLL.@]
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*
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* Clear bits in a bitmap.
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*
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* PARAMS
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* lpBits [I] Bitmap pointer
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* ulStart [I] First bit to set
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* ulCount [I] Number of consecutive bits to clear
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*
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* RETURNS
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* Nothing.
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*/
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VOID WINAPI RtlClearBits(PRTL_BITMAP lpBits, ULONG ulStart, ULONG ulCount)
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{
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LPBYTE lpOut;
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TRACE("(%p,%d,%d)\n", lpBits, ulStart, ulCount);
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if (!lpBits || !ulCount ||
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ulStart >= lpBits->SizeOfBitMap ||
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ulCount > lpBits->SizeOfBitMap - ulStart)
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return;
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/* FIXME: It might be more efficient/cleaner to manipulate four bytes
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* at a time. But beware of the pointer arithmetics...
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*/
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lpOut = ((BYTE*)lpBits->Buffer) + (ulStart >> 3u);
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/* Clear bits in first byte, if ulStart isn't a byte boundary */
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if (ulStart & 7)
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{
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if (ulCount > 7)
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{
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/* Clear from start bit to the end of the byte */
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*lpOut++ &= ~(0xff << (ulStart & 7));
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ulCount -= (8 - (ulStart & 7));
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}
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else
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{
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/* Clear from the start bit, possibly into the next byte also */
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USHORT initialWord = ~(NTDLL_maskBits[ulCount] << (ulStart & 7));
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*lpOut++ &= (initialWord & 0xff);
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*lpOut &= (initialWord >> 8);
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return;
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}
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}
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/* Clear bits (in blocks of 8) on whole byte boundaries */
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if (ulCount >> 3)
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{
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memset(lpOut, 0, ulCount >> 3);
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lpOut = lpOut + (ulCount >> 3);
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}
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/* Clear remaining bits, if any */
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if (ulCount & 0x7)
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*lpOut &= ~NTDLL_maskBits[ulCount & 0x7];
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}
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/*************************************************************************
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* RtlAreBitsSet [NTDLL.@]
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*
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* Determine if part of a bitmap is set.
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*
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* PARAMS
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* lpBits [I] Bitmap pointer
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* ulStart [I] First bit to check from
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* ulCount [I] Number of consecutive bits to check
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*
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* RETURNS
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* TRUE, If ulCount bits from ulStart are set.
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* FALSE, Otherwise.
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*/
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BOOLEAN WINAPI RtlAreBitsSet(PCRTL_BITMAP lpBits, ULONG ulStart, ULONG ulCount)
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{
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LPBYTE lpOut;
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ULONG ulRemainder;
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TRACE("(%p,%d,%d)\n", lpBits, ulStart, ulCount);
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if (!lpBits || !ulCount ||
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ulStart >= lpBits->SizeOfBitMap ||
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ulCount > lpBits->SizeOfBitMap - ulStart)
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return FALSE;
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/* FIXME: It might be more efficient/cleaner to manipulate four bytes
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* at a time. But beware of the pointer arithmetics...
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*/
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lpOut = ((BYTE*)lpBits->Buffer) + (ulStart >> 3u);
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/* Check bits in first byte, if ulStart isn't a byte boundary */
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if (ulStart & 7)
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{
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if (ulCount > 7)
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{
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/* Check from start bit to the end of the byte */
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if ((*lpOut &
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((0xff << (ulStart & 7))) & 0xff) != ((0xff << (ulStart & 7) & 0xff)))
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return FALSE;
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lpOut++;
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ulCount -= (8 - (ulStart & 7));
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}
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else
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{
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/* Check from the start bit, possibly into the next byte also */
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USHORT initialWord = NTDLL_maskBits[ulCount] << (ulStart & 7);
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if ((*lpOut & (initialWord & 0xff)) != (initialWord & 0xff))
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return FALSE;
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if ((initialWord & 0xff00) &&
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((lpOut[1] & (initialWord >> 8)) != (initialWord >> 8)))
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return FALSE;
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return TRUE;
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}
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}
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/* Check bits in blocks of 8 bytes */
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ulRemainder = ulCount & 7;
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ulCount >>= 3;
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while (ulCount--)
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{
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if (*lpOut++ != 0xff)
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return FALSE;
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}
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/* Check remaining bits, if any */
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if (ulRemainder &&
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(*lpOut & NTDLL_maskBits[ulRemainder]) != NTDLL_maskBits[ulRemainder])
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return FALSE;
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return TRUE;
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}
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/*************************************************************************
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* RtlAreBitsClear [NTDLL.@]
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*
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* Determine if part of a bitmap is clear.
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*
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* PARAMS
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* lpBits [I] Bitmap pointer
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* ulStart [I] First bit to check from
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* ulCount [I] Number of consecutive bits to check
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*
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* RETURNS
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* TRUE, If ulCount bits from ulStart are clear.
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* FALSE, Otherwise.
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*/
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BOOLEAN WINAPI RtlAreBitsClear(PCRTL_BITMAP lpBits, ULONG ulStart, ULONG ulCount)
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{
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LPBYTE lpOut;
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ULONG ulRemainder;
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TRACE("(%p,%d,%d)\n", lpBits, ulStart, ulCount);
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if (!lpBits || !ulCount ||
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ulStart >= lpBits->SizeOfBitMap ||
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ulCount > lpBits->SizeOfBitMap - ulStart)
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return FALSE;
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/* FIXME: It might be more efficient/cleaner to manipulate four bytes
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* at a time. But beware of the pointer arithmetics...
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*/
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lpOut = ((BYTE*)lpBits->Buffer) + (ulStart >> 3u);
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/* Check bits in first byte, if ulStart isn't a byte boundary */
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if (ulStart & 7)
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{
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if (ulCount > 7)
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{
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/* Check from start bit to the end of the byte */
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if (*lpOut & ((0xff << (ulStart & 7)) & 0xff))
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return FALSE;
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lpOut++;
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ulCount -= (8 - (ulStart & 7));
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}
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else
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{
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/* Check from the start bit, possibly into the next byte also */
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USHORT initialWord = NTDLL_maskBits[ulCount] << (ulStart & 7);
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if (*lpOut & (initialWord & 0xff))
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return FALSE;
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if ((initialWord & 0xff00) && (lpOut[1] & (initialWord >> 8)))
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return FALSE;
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return TRUE;
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}
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}
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/* Check bits in blocks of 8 bytes */
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ulRemainder = ulCount & 7;
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ulCount >>= 3;
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while (ulCount--)
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{
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if (*lpOut++)
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return FALSE;
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}
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/* Check remaining bits, if any */
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if (ulRemainder && *lpOut & NTDLL_maskBits[ulRemainder])
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return FALSE;
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return TRUE;
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}
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/*************************************************************************
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* RtlFindSetBits [NTDLL.@]
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*
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* Find a block of set bits in a bitmap.
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*
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* PARAMS
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* lpBits [I] Bitmap pointer
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* ulCount [I] Number of consecutive set bits to find
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* ulHint [I] Suggested starting position for set bits
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*
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* RETURNS
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* The bit at which the match was found, or -1 if no match was found.
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*/
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ULONG WINAPI RtlFindSetBits(PCRTL_BITMAP lpBits, ULONG ulCount, ULONG ulHint)
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{
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ULONG ulPos, ulEnd;
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TRACE("(%p,%d,%d)\n", lpBits, ulCount, ulHint);
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if (!lpBits || !ulCount || ulCount > lpBits->SizeOfBitMap)
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return ~0U;
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ulEnd = lpBits->SizeOfBitMap;
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if (ulHint + ulCount > lpBits->SizeOfBitMap)
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ulHint = 0;
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ulPos = ulHint;
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while (ulPos < ulEnd)
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{
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/* FIXME: This could be made a _lot_ more efficient */
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if (RtlAreBitsSet(lpBits, ulPos, ulCount))
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return ulPos;
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/* Start from the beginning if we hit the end and had a hint */
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if (ulPos == ulEnd - 1 && ulHint)
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{
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ulEnd = ulHint;
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ulPos = ulHint = 0;
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}
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else
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ulPos++;
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}
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return ~0U;
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}
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/*************************************************************************
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* RtlFindClearBits [NTDLL.@]
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*
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* Find a block of clear bits in a bitmap.
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*
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* PARAMS
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* lpBits [I] Bitmap pointer
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* ulCount [I] Number of consecutive clear bits to find
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* ulHint [I] Suggested starting position for clear bits
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*
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* RETURNS
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* The bit at which the match was found, or -1 if no match was found.
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*/
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ULONG WINAPI RtlFindClearBits(PCRTL_BITMAP lpBits, ULONG ulCount, ULONG ulHint)
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{
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ULONG ulPos, ulEnd;
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TRACE("(%p,%d,%d)\n", lpBits, ulCount, ulHint);
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if (!lpBits || !ulCount || ulCount > lpBits->SizeOfBitMap)
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return ~0U;
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ulEnd = lpBits->SizeOfBitMap;
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if (ulHint + ulCount > lpBits->SizeOfBitMap)
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ulHint = 0;
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ulPos = ulHint;
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while (ulPos < ulEnd)
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{
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/* FIXME: This could be made a _lot_ more efficient */
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if (RtlAreBitsClear(lpBits, ulPos, ulCount))
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return ulPos;
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/* Start from the beginning if we hit the end and started from ulHint */
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if (ulPos == ulEnd - 1 && ulHint)
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{
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ulEnd = ulHint;
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ulPos = ulHint = 0;
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}
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else
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ulPos++;
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}
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return ~0U;
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}
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|
|
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/*************************************************************************
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* RtlFindSetBitsAndClear [NTDLL.@]
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*
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* Find a block of set bits in a bitmap, and clear them if found.
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*
|
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* PARAMS
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* lpBits [I] Bitmap pointer
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|
* ulCount [I] Number of consecutive set bits to find
|
|
* ulHint [I] Suggested starting position for set bits
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*
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* RETURNS
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* The bit at which the match was found, or -1 if no match was found.
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*/
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ULONG WINAPI RtlFindSetBitsAndClear(PRTL_BITMAP lpBits, ULONG ulCount, ULONG ulHint)
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{
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ULONG ulPos;
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TRACE("(%p,%d,%d)\n", lpBits, ulCount, ulHint);
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|
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ulPos = RtlFindSetBits(lpBits, ulCount, ulHint);
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if (ulPos != ~0U)
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RtlClearBits(lpBits, ulPos, ulCount);
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return ulPos;
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}
|
|
|
|
/*************************************************************************
|
|
* RtlFindClearBitsAndSet [NTDLL.@]
|
|
*
|
|
* Find a block of clear bits in a bitmap, and set them if found.
|
|
*
|
|
* PARAMS
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|
* lpBits [I] Bitmap pointer
|
|
* ulCount [I] Number of consecutive clear bits to find
|
|
* ulHint [I] Suggested starting position for clear bits
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*
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* RETURNS
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* The bit at which the match was found, or -1 if no match was found.
|
|
*/
|
|
ULONG WINAPI RtlFindClearBitsAndSet(PRTL_BITMAP lpBits, ULONG ulCount, ULONG ulHint)
|
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{
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ULONG ulPos;
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TRACE("(%p,%d,%d)\n", lpBits, ulCount, ulHint);
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|
|
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ulPos = RtlFindClearBits(lpBits, ulCount, ulHint);
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if (ulPos != ~0U)
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RtlSetBits(lpBits, ulPos, ulCount);
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return ulPos;
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}
|
|
|
|
/*************************************************************************
|
|
* RtlNumberOfSetBits [NTDLL.@]
|
|
*
|
|
* Find the number of set bits in a bitmap.
|
|
*
|
|
* PARAMS
|
|
* lpBits [I] Bitmap pointer
|
|
*
|
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* RETURNS
|
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* The number of set bits.
|
|
*/
|
|
ULONG WINAPI RtlNumberOfSetBits(PCRTL_BITMAP lpBits)
|
|
{
|
|
ULONG ulSet = 0;
|
|
|
|
TRACE("(%p)\n", lpBits);
|
|
|
|
if (lpBits)
|
|
{
|
|
LPBYTE lpOut = (BYTE *)lpBits->Buffer;
|
|
ULONG ulCount, ulRemainder;
|
|
BYTE bMasked;
|
|
|
|
ulCount = lpBits->SizeOfBitMap >> 3;
|
|
ulRemainder = lpBits->SizeOfBitMap & 0x7;
|
|
|
|
while (ulCount--)
|
|
{
|
|
ulSet += NTDLL_nibbleBitCount[*lpOut >> 4];
|
|
ulSet += NTDLL_nibbleBitCount[*lpOut & 0xf];
|
|
lpOut++;
|
|
}
|
|
|
|
if (ulRemainder)
|
|
{
|
|
bMasked = *lpOut & NTDLL_maskBits[ulRemainder];
|
|
ulSet += NTDLL_nibbleBitCount[bMasked >> 4];
|
|
ulSet += NTDLL_nibbleBitCount[bMasked & 0xf];
|
|
}
|
|
}
|
|
return ulSet;
|
|
}
|
|
|
|
/*************************************************************************
|
|
* RtlNumberOfClearBits [NTDLL.@]
|
|
*
|
|
* Find the number of clear bits in a bitmap.
|
|
*
|
|
* PARAMS
|
|
* lpBits [I] Bitmap pointer
|
|
*
|
|
* RETURNS
|
|
* The number of clear bits.
|
|
*/
|
|
ULONG WINAPI RtlNumberOfClearBits(PCRTL_BITMAP lpBits)
|
|
{
|
|
TRACE("(%p)\n", lpBits);
|
|
|
|
if (lpBits)
|
|
return lpBits->SizeOfBitMap - RtlNumberOfSetBits(lpBits);
|
|
return 0;
|
|
}
|
|
|
|
/*************************************************************************
|
|
* RtlFindMostSignificantBit [NTDLL.@]
|
|
*
|
|
* Find the most significant bit in a 64 bit integer.
|
|
*
|
|
* RETURNS
|
|
* The position of the most significant bit.
|
|
*/
|
|
CCHAR WINAPI RtlFindMostSignificantBit(ULONGLONG ulLong)
|
|
{
|
|
signed char ret = 32;
|
|
DWORD dw;
|
|
|
|
if (!(dw = (ulLong >> 32)))
|
|
{
|
|
ret = 0;
|
|
dw = (DWORD)ulLong;
|
|
}
|
|
if (dw & 0xffff0000)
|
|
{
|
|
dw >>= 16;
|
|
ret += 16;
|
|
}
|
|
if (dw & 0xff00)
|
|
{
|
|
dw >>= 8;
|
|
ret += 8;
|
|
}
|
|
if (dw & 0xf0)
|
|
{
|
|
dw >>= 4;
|
|
ret += 4;
|
|
}
|
|
return ret + NTDLL_mostSignificant[dw];
|
|
}
|
|
|
|
/*************************************************************************
|
|
* RtlFindLeastSignificantBit [NTDLL.@]
|
|
*
|
|
* Find the least significant bit in a 64 bit integer.
|
|
*
|
|
* RETURNS
|
|
* The position of the least significant bit.
|
|
*/
|
|
CCHAR WINAPI RtlFindLeastSignificantBit(ULONGLONG ulLong)
|
|
{
|
|
signed char ret = 0;
|
|
DWORD dw;
|
|
|
|
if (!(dw = (DWORD)ulLong))
|
|
{
|
|
ret = 32;
|
|
if (!(dw = ulLong >> 32)) return -1;
|
|
}
|
|
if (!(dw & 0xffff))
|
|
{
|
|
dw >>= 16;
|
|
ret += 16;
|
|
}
|
|
if (!(dw & 0xff))
|
|
{
|
|
dw >>= 8;
|
|
ret += 8;
|
|
}
|
|
if (!(dw & 0x0f))
|
|
{
|
|
dw >>= 4;
|
|
ret += 4;
|
|
}
|
|
return ret + NTDLL_leastSignificant[dw & 0x0f];
|
|
}
|
|
|
|
/*************************************************************************
|
|
* NTDLL_RunSortFn
|
|
*
|
|
* Internal helper: qsort comparison function for RTL_BITMAP_RUN arrays
|
|
*/
|
|
static int NTDLL_RunSortFn(const void *lhs, const void *rhs)
|
|
{
|
|
if (((const RTL_BITMAP_RUN*)lhs)->NumberOfBits > ((const RTL_BITMAP_RUN*)rhs)->NumberOfBits)
|
|
return -1;
|
|
return 1;
|
|
}
|
|
|
|
/*************************************************************************
|
|
* NTDLL_FindSetRun
|
|
*
|
|
* Internal helper: Find the next run of set bits in a bitmap.
|
|
*/
|
|
static ULONG NTDLL_FindSetRun(PCRTL_BITMAP lpBits, ULONG ulStart, PULONG lpSize)
|
|
{
|
|
LPBYTE lpOut;
|
|
ULONG ulFoundAt = 0, ulCount = 0;
|
|
|
|
/* FIXME: It might be more efficient/cleaner to manipulate four bytes
|
|
* at a time. But beware of the pointer arithmetics...
|
|
*/
|
|
lpOut = ((BYTE*)lpBits->Buffer) + (ulStart >> 3u);
|
|
|
|
while (1)
|
|
{
|
|
/* Check bits in first byte */
|
|
const BYTE bMask = (0xff << (ulStart & 7)) & 0xff;
|
|
const BYTE bFirst = *lpOut & bMask;
|
|
|
|
if (bFirst)
|
|
{
|
|
/* Have a set bit in first byte */
|
|
if (bFirst != bMask)
|
|
{
|
|
/* Not every bit is set */
|
|
ULONG ulOffset;
|
|
|
|
if (bFirst & 0x0f)
|
|
ulOffset = NTDLL_leastSignificant[bFirst & 0x0f];
|
|
else
|
|
ulOffset = 4 + NTDLL_leastSignificant[bFirst >> 4];
|
|
ulStart += ulOffset;
|
|
ulFoundAt = ulStart;
|
|
for (;ulOffset < 8; ulOffset++)
|
|
{
|
|
if (!(bFirst & (1 << ulOffset)))
|
|
{
|
|
*lpSize = ulCount;
|
|
return ulFoundAt; /* Set from start, but not until the end */
|
|
}
|
|
ulCount++;
|
|
ulStart++;
|
|
}
|
|
/* Set to the end - go on to count further bits */
|
|
lpOut++;
|
|
break;
|
|
}
|
|
/* every bit from start until the end of the byte is set */
|
|
ulFoundAt = ulStart;
|
|
ulCount = 8 - (ulStart & 7);
|
|
ulStart = (ulStart & ~7u) + 8;
|
|
lpOut++;
|
|
break;
|
|
}
|
|
ulStart = (ulStart & ~7u) + 8;
|
|
lpOut++;
|
|
if (ulStart >= lpBits->SizeOfBitMap)
|
|
return ~0U;
|
|
}
|
|
|
|
/* Count blocks of 8 set bits */
|
|
while (*lpOut == 0xff)
|
|
{
|
|
ulCount += 8;
|
|
ulStart += 8;
|
|
if (ulStart >= lpBits->SizeOfBitMap)
|
|
{
|
|
*lpSize = ulCount - (ulStart - lpBits->SizeOfBitMap);
|
|
return ulFoundAt;
|
|
}
|
|
lpOut++;
|
|
}
|
|
|
|
/* Count remaining contiguous bits, if any */
|
|
if (*lpOut & 1)
|
|
{
|
|
ULONG ulOffset = 0;
|
|
|
|
for (;ulOffset < 7u; ulOffset++)
|
|
{
|
|
if (!(*lpOut & (1 << ulOffset)))
|
|
break;
|
|
ulCount++;
|
|
}
|
|
}
|
|
*lpSize = ulCount;
|
|
return ulFoundAt;
|
|
}
|
|
|
|
/*************************************************************************
|
|
* NTDLL_FindClearRun
|
|
*
|
|
* Internal helper: Find the next run of set bits in a bitmap.
|
|
*/
|
|
static ULONG NTDLL_FindClearRun(PCRTL_BITMAP lpBits, ULONG ulStart, PULONG lpSize)
|
|
{
|
|
LPBYTE lpOut;
|
|
ULONG ulFoundAt = 0, ulCount = 0;
|
|
|
|
/* FIXME: It might be more efficient/cleaner to manipulate four bytes
|
|
* at a time. But beware of the pointer arithmetics...
|
|
*/
|
|
lpOut = ((BYTE*)lpBits->Buffer) + (ulStart >> 3u);
|
|
|
|
while (1)
|
|
{
|
|
/* Check bits in first byte */
|
|
const BYTE bMask = (0xff << (ulStart & 7)) & 0xff;
|
|
const BYTE bFirst = (~*lpOut) & bMask;
|
|
|
|
if (bFirst)
|
|
{
|
|
/* Have a clear bit in first byte */
|
|
if (bFirst != bMask)
|
|
{
|
|
/* Not every bit is clear */
|
|
ULONG ulOffset;
|
|
|
|
if (bFirst & 0x0f)
|
|
ulOffset = NTDLL_leastSignificant[bFirst & 0x0f];
|
|
else
|
|
ulOffset = 4 + NTDLL_leastSignificant[bFirst >> 4];
|
|
ulStart += ulOffset;
|
|
ulFoundAt = ulStart;
|
|
for (;ulOffset < 8; ulOffset++)
|
|
{
|
|
if (!(bFirst & (1 << ulOffset)))
|
|
{
|
|
*lpSize = ulCount;
|
|
return ulFoundAt; /* Clear from start, but not until the end */
|
|
}
|
|
ulCount++;
|
|
ulStart++;
|
|
}
|
|
/* Clear to the end - go on to count further bits */
|
|
lpOut++;
|
|
break;
|
|
}
|
|
/* Every bit from start until the end of the byte is clear */
|
|
ulFoundAt = ulStart;
|
|
ulCount = 8 - (ulStart & 7);
|
|
ulStart = (ulStart & ~7u) + 8;
|
|
lpOut++;
|
|
break;
|
|
}
|
|
ulStart = (ulStart & ~7u) + 8;
|
|
lpOut++;
|
|
if (ulStart >= lpBits->SizeOfBitMap)
|
|
return ~0U;
|
|
}
|
|
|
|
/* Count blocks of 8 clear bits */
|
|
while (!*lpOut)
|
|
{
|
|
ulCount += 8;
|
|
ulStart += 8;
|
|
if (ulStart >= lpBits->SizeOfBitMap)
|
|
{
|
|
*lpSize = ulCount - (ulStart - lpBits->SizeOfBitMap);
|
|
return ulFoundAt;
|
|
}
|
|
lpOut++;
|
|
}
|
|
|
|
/* Count remaining contiguous bits, if any */
|
|
if (!(*lpOut & 1))
|
|
{
|
|
ULONG ulOffset = 0;
|
|
|
|
for (;ulOffset < 7u; ulOffset++)
|
|
{
|
|
if (*lpOut & (1 << ulOffset))
|
|
break;
|
|
ulCount++;
|
|
}
|
|
}
|
|
*lpSize = ulCount;
|
|
return ulFoundAt;
|
|
}
|
|
|
|
/*************************************************************************
|
|
* RtlFindNextForwardRunSet [NTDLL.@]
|
|
*
|
|
* Find the next run of set bits in a bitmap.
|
|
*
|
|
* PARAMS
|
|
* lpBits [I] Bitmap pointer
|
|
* ulStart [I] Bit position to start searching from
|
|
* lpPos [O] Start of run
|
|
*
|
|
* RETURNS
|
|
* Success: The length of the next set run in the bitmap. lpPos is set to
|
|
* the start of the run.
|
|
* Failure: 0, if no run is found or any parameters are invalid.
|
|
*/
|
|
ULONG WINAPI RtlFindNextForwardRunSet(PCRTL_BITMAP lpBits, ULONG ulStart, PULONG lpPos)
|
|
{
|
|
ULONG ulSize = 0;
|
|
|
|
TRACE("(%p,%d,%p)\n", lpBits, ulStart, lpPos);
|
|
|
|
if (lpBits && ulStart < lpBits->SizeOfBitMap && lpPos)
|
|
*lpPos = NTDLL_FindSetRun(lpBits, ulStart, &ulSize);
|
|
|
|
return ulSize;
|
|
}
|
|
|
|
/*************************************************************************
|
|
* RtlFindNextForwardRunClear [NTDLL.@]
|
|
*
|
|
* Find the next run of clear bits in a bitmap.
|
|
*
|
|
* PARAMS
|
|
* lpBits [I] Bitmap pointer
|
|
* ulStart [I] Bit position to start searching from
|
|
* lpPos [O] Start of run
|
|
*
|
|
* RETURNS
|
|
* Success: The length of the next clear run in the bitmap. lpPos is set to
|
|
* the start of the run.
|
|
* Failure: 0, if no run is found or any parameters are invalid.
|
|
*/
|
|
ULONG WINAPI RtlFindNextForwardRunClear(PCRTL_BITMAP lpBits, ULONG ulStart, PULONG lpPos)
|
|
{
|
|
ULONG ulSize = 0;
|
|
|
|
TRACE("(%p,%d,%p)\n", lpBits, ulStart, lpPos);
|
|
|
|
if (lpBits && ulStart < lpBits->SizeOfBitMap && lpPos)
|
|
*lpPos = NTDLL_FindClearRun(lpBits, ulStart, &ulSize);
|
|
|
|
return ulSize;
|
|
}
|
|
|
|
/*************************************************************************
|
|
* RtlFindLastBackwardRunSet [NTDLL.@]
|
|
*
|
|
* Find a previous run of set bits in a bitmap.
|
|
*
|
|
* PARAMS
|
|
* lpBits [I] Bitmap pointer
|
|
* ulStart [I] Bit position to start searching from
|
|
* lpPos [O] Start of run
|
|
*
|
|
* RETURNS
|
|
* Success: The length of the previous set run in the bitmap. lpPos is set to
|
|
* the start of the run.
|
|
* Failure: 0, if no run is found or any parameters are invalid.
|
|
*/
|
|
ULONG WINAPI RtlFindLastBackwardRunSet(PCRTL_BITMAP lpBits, ULONG ulStart, PULONG lpPos)
|
|
{
|
|
FIXME("(%p,%d,%p)-stub!\n", lpBits, ulStart, lpPos);
|
|
return 0;
|
|
}
|
|
|
|
/*************************************************************************
|
|
* RtlFindLastBackwardRunClear [NTDLL.@]
|
|
*
|
|
* Find a previous run of clear bits in a bitmap.
|
|
*
|
|
* PARAMS
|
|
* lpBits [I] Bitmap pointer
|
|
* ulStart [I] Bit position to start searching from
|
|
* lpPos [O] Start of run
|
|
*
|
|
* RETURNS
|
|
* Success: The length of the previous clear run in the bitmap. lpPos is set
|
|
* to the start of the run.
|
|
* Failure: 0, if no run is found or any parameters are invalid.
|
|
*/
|
|
ULONG WINAPI RtlFindLastBackwardRunClear(PCRTL_BITMAP lpBits, ULONG ulStart, PULONG lpPos)
|
|
{
|
|
FIXME("(%p,%d,%p)-stub!\n", lpBits, ulStart, lpPos);
|
|
return 0;
|
|
}
|
|
|
|
/*************************************************************************
|
|
* NTDLL_FindRuns
|
|
*
|
|
* Internal implementation of RtlFindSetRuns/RtlFindClearRuns.
|
|
*/
|
|
static ULONG NTDLL_FindRuns(PCRTL_BITMAP lpBits, PRTL_BITMAP_RUN lpSeries,
|
|
ULONG ulCount, BOOLEAN bLongest,
|
|
ULONG (*fn)(PCRTL_BITMAP,ULONG,PULONG))
|
|
{
|
|
BOOL bNeedSort = ulCount > 1 ? TRUE : FALSE;
|
|
ULONG ulPos = 0, ulRuns = 0;
|
|
|
|
TRACE("(%p,%p,%d,%d)\n", lpBits, lpSeries, ulCount, bLongest);
|
|
|
|
if (!ulCount)
|
|
return ~0U;
|
|
|
|
while (ulPos < lpBits->SizeOfBitMap)
|
|
{
|
|
/* Find next set/clear run */
|
|
ULONG ulSize, ulNextPos = fn(lpBits, ulPos, &ulSize);
|
|
|
|
if (ulNextPos == ~0U)
|
|
break;
|
|
|
|
if (bLongest && ulRuns == ulCount)
|
|
{
|
|
/* Sort runs with shortest at end, if they are out of order */
|
|
if (bNeedSort)
|
|
qsort(lpSeries, ulRuns, sizeof(RTL_BITMAP_RUN), NTDLL_RunSortFn);
|
|
|
|
/* Replace last run if this one is bigger */
|
|
if (ulSize > lpSeries[ulRuns - 1].NumberOfBits)
|
|
{
|
|
lpSeries[ulRuns - 1].StartingIndex = ulNextPos;
|
|
lpSeries[ulRuns - 1].NumberOfBits = ulSize;
|
|
|
|
/* We need to re-sort the array, _if_ we didn't leave it sorted */
|
|
if (ulRuns > 1 && ulSize > lpSeries[ulRuns - 2].NumberOfBits)
|
|
bNeedSort = TRUE;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Append to found runs */
|
|
lpSeries[ulRuns].StartingIndex = ulNextPos;
|
|
lpSeries[ulRuns].NumberOfBits = ulSize;
|
|
ulRuns++;
|
|
|
|
if (!bLongest && ulRuns == ulCount)
|
|
break;
|
|
}
|
|
ulPos = ulNextPos + ulSize;
|
|
}
|
|
return ulRuns;
|
|
}
|
|
|
|
/*************************************************************************
|
|
* RtlFindSetRuns [NTDLL.@]
|
|
*
|
|
* Find a series of set runs in a bitmap.
|
|
*
|
|
* PARAMS
|
|
* lpBits [I] Bitmap pointer
|
|
* lpSeries [O] Array for each run found
|
|
* ulCount [I] Number of runs to find
|
|
* bLongest [I] Whether to find the very longest runs or not
|
|
*
|
|
* RETURNS
|
|
* The number of set runs found.
|
|
*/
|
|
ULONG WINAPI RtlFindSetRuns(PCRTL_BITMAP lpBits, PRTL_BITMAP_RUN lpSeries,
|
|
ULONG ulCount, BOOLEAN bLongest)
|
|
{
|
|
TRACE("(%p,%p,%d,%d)\n", lpBits, lpSeries, ulCount, bLongest);
|
|
|
|
return NTDLL_FindRuns(lpBits, lpSeries, ulCount, bLongest, NTDLL_FindSetRun);
|
|
}
|
|
|
|
/*************************************************************************
|
|
* RtlFindClearRuns [NTDLL.@]
|
|
*
|
|
* Find a series of clear runs in a bitmap.
|
|
*
|
|
* PARAMS
|
|
* lpBits [I] Bitmap pointer
|
|
* ulSeries [O] Array for each run found
|
|
* ulCount [I] Number of runs to find
|
|
* bLongest [I] Whether to find the very longest runs or not
|
|
*
|
|
* RETURNS
|
|
* The number of clear runs found.
|
|
*/
|
|
ULONG WINAPI RtlFindClearRuns(PCRTL_BITMAP lpBits, PRTL_BITMAP_RUN lpSeries,
|
|
ULONG ulCount, BOOLEAN bLongest)
|
|
{
|
|
TRACE("(%p,%p,%d,%d)\n", lpBits, lpSeries, ulCount, bLongest);
|
|
|
|
return NTDLL_FindRuns(lpBits, lpSeries, ulCount, bLongest, NTDLL_FindClearRun);
|
|
}
|
|
|
|
/*************************************************************************
|
|
* RtlFindLongestRunSet [NTDLL.@]
|
|
*
|
|
* Find the longest set run in a bitmap.
|
|
*
|
|
* PARAMS
|
|
* lpBits [I] Bitmap pointer
|
|
* pulStart [O] Destination for start of run
|
|
*
|
|
* RETURNS
|
|
* The length of the run found, or 0 if no run is found.
|
|
*/
|
|
ULONG WINAPI RtlFindLongestRunSet(PCRTL_BITMAP lpBits, PULONG pulStart)
|
|
{
|
|
RTL_BITMAP_RUN br;
|
|
|
|
TRACE("(%p,%p)\n", lpBits, pulStart);
|
|
|
|
if (RtlFindSetRuns(lpBits, &br, 1, TRUE) == 1)
|
|
{
|
|
if (pulStart)
|
|
*pulStart = br.StartingIndex;
|
|
return br.NumberOfBits;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*************************************************************************
|
|
* RtlFindLongestRunClear [NTDLL.@]
|
|
*
|
|
* Find the longest clear run in a bitmap.
|
|
*
|
|
* PARAMS
|
|
* lpBits [I] Bitmap pointer
|
|
* pulStart [O] Destination for start of run
|
|
*
|
|
* RETURNS
|
|
* The length of the run found, or 0 if no run is found.
|
|
*/
|
|
ULONG WINAPI RtlFindLongestRunClear(PCRTL_BITMAP lpBits, PULONG pulStart)
|
|
{
|
|
RTL_BITMAP_RUN br;
|
|
|
|
TRACE("(%p,%p)\n", lpBits, pulStart);
|
|
|
|
if (RtlFindClearRuns(lpBits, &br, 1, TRUE) == 1)
|
|
{
|
|
if (pulStart)
|
|
*pulStart = br.StartingIndex;
|
|
return br.NumberOfBits;
|
|
}
|
|
return 0;
|
|
}
|