windows-nt/Source/XPSP1/NT/admin/wmi/wbem/adapters/oledb/bitarray.cpp
2020-09-26 16:20:57 +08:00

382 lines
10 KiB
C++

////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Microsoft WMIOLE DB Provider
// (C) Copyright 1999 Microsoft Corporation. All Rights Reserved.
//
// This contains an implementation of a bit array class currently used by the Internal Buffer to
// mark released or unreleased rows.
//
////////////////////////////////////////////////////////////////////////////////////////////////////////
#include "headers.h"
#include "bitarray.h"
////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Constructor for this class
//
////////////////////////////////////////////////////////////////////////////////////////////////////////
CBitArray::CBitArray ( void )
{
m_rgbBit = NULL;
m_cPageMax = 0;
m_cPageCurrent = 0;
m_cslotCurrent = 0;
}
////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Destructor for this class
//
////////////////////////////////////////////////////////////////////////////////////////////////////////
CBitArray:: ~CBitArray (void )
{
if (m_rgbBit){
if (m_cPageCurrent){
VirtualFree((VOID *) m_rgbBit, m_cPageCurrent *m_cbPage, MEM_DECOMMIT );
}
VirtualFree((VOID *) m_rgbBit, 0, MEM_RELEASE );
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Allocate and Initialize the array of bits
//
// HRESULT indicating routines status
// S_OK | Initialization succeeded
// E_OUTOFMEMORY | Not enough memory to allocate bit array
//
////////////////////////////////////////////////////////////////////////////////////////////////////////
STDMETHODIMP CBitArray::FInit( HSLOT cslotMax, //IN Maximum number of slot
ULONG cbPage //IN Count of bytes per page
)
{
LONG_PTR cPage;
BYTE ib;
HRESULT hr = S_OK;
cPage = (cslotMax / 8 + 1) / cbPage + 1;
m_rgbBit = (BYTE *) VirtualAlloc( NULL, cbPage *cPage, MEM_RESERVE, PAGE_READWRITE );
if (m_rgbBit == NULL){
hr = E_OUTOFMEMORY;
}
else{
m_cPageMax = cPage;
m_cbPage = cbPage;
for (ib =0; ib < 8; ib++){
m_rgbBitMask[ib] = (1 << ib);
}
}
return hr;
}
////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Set a range of bit slots
//
// HRESULT indicating routines status
// S_OK Initialization succeeded
// E_OUTOFMEMORY Not enough memory to allocate bit array
//
////////////////////////////////////////////////////////////////////////////////////////////////////////
STDMETHODIMP CBitArray::SetSlots ( HSLOT islotFirst, //IN First slot in range to set
HSLOT islotLast //IN Last slot in range to set
)
{
HSLOT islot;
HRESULT hr = S_OK;
if (islotLast >= m_cslotCurrent){
ULONG_PTR cPageAdd;
cPageAdd = ((islotLast - m_cslotCurrent + 1) / 8 + 1) / m_cbPage + 1;
if ((cPageAdd + m_cPageCurrent) > (ULONG_PTR)m_cPageMax || VirtualAlloc( m_rgbBit + m_cPageCurrent*m_cbPage, cPageAdd *m_cbPage, MEM_COMMIT, PAGE_READWRITE ) == NULL){
hr = E_OUTOFMEMORY;
}
else{
memset( m_rgbBit + m_cPageCurrent*m_cbPage, 0x00, cPageAdd *m_cbPage );
m_cPageCurrent += cPageAdd;
m_cslotCurrent += cPageAdd *m_cbPage *8;
}
}
if( hr == S_OK ){
//=======================================================================================================
// Only do this top section if we have at least 2 byte's worth of bits to set. Although no real speedup
// until we have 3 byte's worth. Note really ought to be ((ilast-ifirst+1) >= 2*8).
// (Note could use CHAR_BIT, num bits in a char.) Also optimized end cases, so nothing is done
// if the start or end is byte aligned. Need this copied into ResetSlots.
//if((islotLast -islotFirst) > 2*sizeof(BYTE))
//=======================================================================================================
if (islotLast - islotFirst > 2 * 8){
HSLOT ibFirst, ibLast;
int iFixFirst, iFixLast;
ibFirst = islotFirst / 8;
ibLast = islotLast / 8;
iFixFirst = (islotFirst % 8 != 0); // set to 1 if first byte not totally set
iFixLast = (islotLast % 8 != 7); // set to 1 if last byte not totally set
if (iFixFirst){
for (islot = islotFirst; (islot / 8) == ibFirst; islot++){
m_rgbBit[islot / 8] |= m_rgbBitMask[islot % 8];
}
}
memset( &m_rgbBit[ibFirst + iFixFirst], 0xff, ibLast - ibFirst + 1 - iFixFirst - iFixLast );
if (iFixLast){
for (islot = islotLast; (islot / 8) == ibLast; islot--){
m_rgbBit[islot / 8] |= m_rgbBitMask[islot % 8];
}
}
}
else{
for (islot = islotFirst; islot <= islotLast; islot++){
m_rgbBit[islot / 8] |= m_rgbBitMask[islot % 8];
}
}
}
return hr;
}
////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Clear all bit slots
//
////////////////////////////////////////////////////////////////////////////////////////////////////////
VOID CBitArray::ResetAllSlots ( void )
{
memset( m_rgbBit, 0x00, m_cPageCurrent*m_cbPage );
}
////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Reset a range of slots
//
// HRESULT indicating routines status
// S_OK Reset Succeeded
//
////////////////////////////////////////////////////////////////////////////////////////////////////////
STDMETHODIMP CBitArray::ResetSlots( HSLOT islotFirst, //IN First slot in range to reset
HSLOT islotLast //IN Last slot in range to reset
)
{
HSLOT ibFirst, ibLast, islot;
if (islotFirst < m_cslotCurrent){
if (islotLast >= m_cslotCurrent){
islotLast = m_cslotCurrent - 1;
}
if ((islotLast - islotFirst) > 2*8){
ibFirst = islotFirst / 8;
ibLast = islotLast / 8;
for (islot = islotFirst; (islot / 8) == ibFirst; islot++){
m_rgbBit[islot / 8] &= ~m_rgbBitMask[islot % 8];
}
memset( &m_rgbBit[ibFirst + 1], 0x00, ibLast - ibFirst - 1 );
for (islot = islotLast; (islot / 8) == ibLast; islot--){
m_rgbBit[islot / 8] &= ~m_rgbBitMask[islot % 8];
}
}
else{
for (islot = islotFirst; islot <= islotLast; islot++){
m_rgbBit[islot / 8] &= ~m_rgbBitMask[islot % 8];
}
}
}
return S_OK;
}
////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Determines if any bits are set
//
// HRESULT indicating routines status
// S_OK Array is Empty
// S_FALSE Array contains set bits
//
////////////////////////////////////////////////////////////////////////////////////////////////////////
STDMETHODIMP CBitArray::ArrayEmpty ( void )
{
HRESULT hr = S_OK;
if (m_cPageCurrent){
ULONG_PTR idw, cdw, *rgdw;
cdw = m_cPageCurrent * (m_cbPage / sizeof( ULONG_PTR ));
rgdw = (ULONG_PTR *) m_rgbBit;
for (idw =0; idw < cdw; idw++){
if (rgdw[idw]){
hr = S_FALSE;
}
}
}
return hr;
}
////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Determine if a particular bit slot is set
//
// HRESULT indicating routines status
// S_OK Slot is set
// E_OUTOFMEMORY Slot is not set
//
////////////////////////////////////////////////////////////////////////////////////////////////////////
STDMETHODIMP CBitArray::IsSlotSet( HSLOT islot ) //IN Bit slot to check
{
HRESULT hr = S_OK;
if (islot >= m_cslotCurrent || (m_rgbBit[islot / 8] & m_rgbBitMask[islot % 8]) == 0x00){
hr = S_FALSE; // not set
}
return hr;
}
////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Find the first set slot within the bit array given a starting position
//
// HRESULT indicating routines status
// S_OK Initialization succeeded
// E_OUTOFMEMORY Not enough memory to allocate bit array
//
////////////////////////////////////////////////////////////////////////////////////////////////////////
STDMETHODIMP CBitArray::FindSet( HSLOT islotStart, //IN Starting slot to search from
HSLOT islotLimit, //IN Number of slots to check
HSLOT *pislot //OUT Index of first set slot
)
{
HSLOT ibStart, ibLimit, idwStart, idwLimit, ibEnd, ib, islot, islotEnd, idw, *pdw;
HRESULT hr = E_FAIL;
BOOL bRet = FALSE;
BOOL bFound = FALSE;
islot = islotLimit;
if (islotStart > islotLimit)
{
ibStart = islotStart / 8;
ibLimit = islotLimit / 8;
if ((ibStart - ibLimit) > 1)
{
islotEnd = ibStart*8;
for (islot = islotStart; islot >= islotEnd; islot--){
if (m_rgbBit[islot / 8] & m_rgbBitMask[islot % 8]){
*pislot = islot;
hr = S_OK;
bRet = TRUE;
break;
}
}
if(bRet == FALSE)
{
idwStart = islotStart / 32;
idwLimit = islotLimit / 32;
if (idwStart - idwLimit > 1)
{
ibEnd = idwStart*4;
for (ib = ibStart - 1; ib >= ibEnd; ib--)
{
if (m_rgbBit[ib]){
islot = ib*8 + 7;
bFound = TRUE;
break;
}
}
if( bFound == FALSE)
{
for (pdw = (HSLOT *) & m_rgbBit[ (idwStart - 1) *4], idw = idwStart - 1; idw > idwLimit; idw--, pdw--)
{
if (*pdw)
{
islot = idw*32 + 31;
bFound = TRUE;
break;
}
}
if(bFound == FALSE)
{
ib = (idwLimit*4 + 3);
}
}
}
else
{
ib = ibStart - 1;
}
if( bFound == FALSE)
{
for (; ib > ibLimit; ib--)
{
if (m_rgbBit[ib])
{
islot = ib*8 + 7;
bFound = TRUE;
break;
}
}
if(bFound == FALSE)
{
islot = (ibLimit*8 + 7);
}
}
}
}
else
{
islot = islotStart;
}
}
if(bFound == TRUE)
{
for (; islot >= islotLimit; islot--)
{
if (m_rgbBit[islot / 8] & m_rgbBitMask[islot % 8])
{
*pislot = islot;
hr = S_OK;
}
}
hr = S_FALSE; // not found
}
return hr;
}