Leaked source code of windows server 2003
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7.9 KiB

//+---------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1991 - 1997.
//
// File: PROPBKP.HXX
//
// Contents: Property Store backup
//
// History: 30-May-97 KrishnaN Created
//
//----------------------------------------------------------------------------
#pragma once
#include <twidhash.hxx>
#include <thash.hxx>
#include <driveinf.hxx>
const WCHAR PROP_BKP_FILE[] = L"\\propstor.bkp"; // propstore backup
const WCHAR PROP_BKP_FILE1[] = L"\\propstor.bk1"; // primary store backup
const WCHAR PROP_BKP_FILE2[] = L"\\propstor.bk2"; // secondary store backup
//+-------------------------------------------------------------------------
//
// Class: CPropStoreBackupStream
//
// Purpose: Encapsulates a property store backup stream. It essentially
// opens a physical file and provides read/write/reset on that
// file.
//
// Interface:
//
// History: 30-May-97 KrishnaN Created
// 29-Oct-98 KLam Added disk space to leave to constructor
// Added _cMegToLeaveOnDisk private member
// Added _xDriveInfo private member
//
// Notes: The physical file is always opened with a fixed size. Append only
// implies that a logical page is added to the stream. It does not
// imply that the file is physically extended.
//
//--------------------------------------------------------------------------
//
// The number of pages used that can be backed up in the backup is configurable
// through the registry per catalog. This enables the admin to control the
// overall size of the catalog. The larger the number of pages, the less number
// of intermediate property store commits.
//
#define roundup(a, b) ((a%b) ? (a/b + 1) : (a/b))
const ULONG invalidSector = 0xFFFFFFFF;
const ULONG invalidPage = 0xFFFFFFFF;
class CPageHashTable
{
public:
CPageHashTable(ULONG cHashInit) : _hashTable(cHashInit, TRUE)
{
}
ULONG AddEntry(ULONG ulEntry, ULONG ulValue)
{
CWidValueHashEntry entry((WORKID)ulEntry, ulValue);
return _hashTable.AddEntry(entry);
}
BOOL LookUp(ULONG ulEntry, ULONG &ulValue)
{
CWidValueHashEntry entry((WORKID)ulEntry, 0);
if (!_hashTable.LookUpWorkId(entry))
return FALSE;
ulValue = entry.Value();
return TRUE;
}
void DeleteAllEntries()
{
_hashTable.DeleteAllEntries();
}
private:
TWidHashTable<CWidValueHashEntry> _hashTable;
};
class CPropStoreBackupStream
{
public:
~CPropStoreBackupStream();
//
// File operations
//
// Open a new or existing file
void OpenForBackup ( const WCHAR* wcsPath,
ULONG modeShare,
ULONG modeCreate,
ULONG ulMaxPages);
// Open an existing file
void OpenForRecovery ( const WCHAR* wcsPath,
ULONG modeShare);
// Close the file
void Close();
// Reset the file
void Reset(ULONG cMaxPages);
// Checks if the file is open
BOOL IsOpen() const { return (INVALID_HANDLE_VALUE != _hFile); }
// Checks if the file is open for recovery
BOOL IsOpenForRecovery() const { return _fOpenForRecovery; }
//
// Page read/write operations
//
// Read the i-th page. The page buffer is assumed to be at least the page size
// recorded in the backup file header.
BOOL ReadPage(ULONG ulPage, ULONG *pulLoc, void *pbPage);
// Get the page's location in prop store so that the caller can get the right
// buffer from the property store.
ULONG GetPageLocation(ULONG ulPage);
// Append a page at the end of the stream. The page buffer is assumed
// to be the size of the operating system page.
BOOL CommitPage(ULONG slot, void const *pbPage);
BOOL CommitPages(ULONG cPages,
ULONG const *pSlots,
void const * const * ppvPages);
BOOL CommitField(ULONG ulPage,
ULONG ulOffset,
ULONG cSize,
void const *pvBuffer);
//
// Query backup file properties
//
ULONG SectorSize() const { return _header.ulSectorSize; }
ULONG PageSize() const { return _header.ulPageSize; }
ULONG MaxPages() const { return _header.cMaxPages; }
ULONG Pages() const { return _cPages; }
ULONG GetSizeInBytes() const { return _cFileSizeInBytes; }
private:
friend CiStorage;
CPropStoreBackupStream( ULONG cbDiskSpaceToLeave );
void Init();
BOOL CommitSector(ULONG ulSector, void const *pbBuffer);
BOOL WriteToFile(ULONG ulStartLoc, ULONG ulNumBytes, void const *pbBuffer);
void ReadFromFile(ULONG ulStartLoc, ULONG ulNumBytes, void *pbBuffer);
inline void ReadSector(ULONG ulSector, PBYTE pbBuffer);
ULONG CountPages();
BOOL IsCorrupt();
void GetSystemParams();
HANDLE _hFile; // physical file
ULONG _cPages; // pages currently backed up
ULONG _cFileSizeInBytes; // physical file size
PBYTE _pSector; // current sector used for I/O in dir section
PBYTE _pBigBuffer; // a large buffer to hold the current sector.
ULONG _ulCurrentSector; // current sector in memory.
BOOL _fOpenForRecovery; // Is file open for recovery?
ULONG _cMegToLeaveOnDisk ; // megabytes not to write to
XPtr<CDriveInfo> _xDriveInfo; // Maintains information about the volume
//
// The following structure will be the backup file's header.
// The backup file, along with other property store files, can
// be moved across processor architectures, so the page and sector
// sizes used at backup write time should be recorded here.
//
struct SHeader
{
ULONG ulSectorSize; // sector size at create time
ULONG ulPageSize; // page size at create time
ULONG cMaxPages; // max pages in backup
ULONG ulDataOffset; // starting point of data pages in file
} _header;
#if CIDBG
ULONG _cPagesBackedUp, _cPagesCommited, _cFlushes, _cFieldsCommited; // some stats
#endif // CIDBG
//
// Computes the offset of the page descriptor in the backup file. This accounts
// for the space occupied by the header and space that might be wasted at the end
// of sectors to achieve alignment.
//
inline ULONG ComputePageDescriptorOffset(ULONG ulSectorSize, ULONG nPage)
{
ULONG cSlots = (roundup(sizeof(SHeader), sizeof(ULONG)) + nPage);
ULONG cSlotsPerSector = ulSectorSize / sizeof(ULONG);
ULONG cSectors = cSlots / cSlotsPerSector;
// space for cSectors PLUS space for the slots overfolowing into the next sector
return cSectors*ulSectorSize + (cSlots % cSlotsPerSector)*sizeof(ULONG);
}
inline ULONG ComputeFirstSectorOfPage(ULONG ulPageLoc)
{
return (_header.ulDataOffset + ulPageLoc*_header.ulPageSize) / _header.ulSectorSize;
}
// Verify that a ULONG is a power of 2. Such a number will have only one 1-bit. So keep
// right shifting until you get the first one bit in the LSB position. The next right
// shift after that should leave a 0.
inline BOOL IsPowerOf2(ULONG ulValue)
{
BOOL fPowerOf2 = (1 & ulValue);
for (short i = 1; i < sizeof(ULONG)*8 && !fPowerOf2; i++)
{
ulValue = ulValue >> 1;
fPowerOf2 = (1 & ulValue);
}
ulValue = ulValue >> 1;
return (fPowerOf2 ? !ulValue : FALSE);
}
CPageHashTable _pageTable;
};