CPolicyCache Class Reference

Collaboration diagram for CPolicyCache:

Public Member Functions
	~CPolicyCache ()
BOOL	Initialize (const SHPOLICY_ITEM *pItems, UINT cItems)
HRESULT	GetValue (_In_ REFGUID rpolid, _Out_opt_ PVOID pvValue, _Out_opt_ PDWORD pcbValue)

Protected Member Functions
void	_ValidateCachedResults ()
HRESULT	_GetValue (_In_ LPCWSTR pszSubKey, _In_ LPCWSTR pszValueName, _In_ const SHPOLICY_CONSTRAINT *pConstraint, _Out_opt_ PDWORD pdwType, _Out_opt_ PVOID pvData, _Inout_opt_ PDWORD pcbData)

Static Protected Member Functions
static void	_CacheResult (const SHPOLICY_CONSTRAINT *pConstraint, PVOID pvValue, PDWORD pcbValue, PSHPOLICY_RESULT pResult)

Protected Attributes
LPCWSTR	m_pszRootKey
HANDLE	m_hGlobalCounter
LONG	m_nCounterValue
DWORD	m_cItems
const SHPOLICY_ITEM *	m_pItems
PSHPOLICY_RESULT	m_pResults

Detailed Description

Definition at line 77 of file policy.cpp.

Constructor & Destructor Documentation

~CPolicyCache()

CPolicyCache::~CPolicyCache ( )

inline

Definition at line 80 of file policy.cpp.

    {
        LocalFree(m_pResults);
 
        if (m_hGlobalCounter)
            CloseHandle(m_hGlobalCounter);
    }

Member Function Documentation

_CacheResult()

void CPolicyCache::_CacheResult ( const SHPOLICY_CONSTRAINT *  pConstraint, PVOID  pvValue, PDWORD  pcbValue, PSHPOLICY_RESULT  pResult  )

staticprotected

Definition at line 223 of file policy.cpp.

{
    UNREFERENCED_PARAMETER(pcbValue); // Reserved for future use
 
    // Use caching only when dealing with DWORD value
    if (pConstraint->wFlags == SRRF_RT_DWORD)
    {
        pResult->dwValue = *(PDWORD)pvValue;
        pResult->state = POLICY_STATE_CACHED;
    }
}

Referenced by GetValue().

_GetValue()

HRESULT CPolicyCache::_GetValue ( _In_ LPCWSTR  pszSubKey, _In_ LPCWSTR  pszValueName, _In_ const SHPOLICY_CONSTRAINT *  pConstraint, _Out_opt_ PDWORD  pdwType, _Out_opt_ PVOID  pvData, _Inout_opt_ PDWORD  pcbData  )

protected

Definition at line 183 of file policy.cpp.

{
    CStringW szFullKey = CStringW(m_pszRootKey) + L"\\" + pszSubKey;
 
    DWORD cbDataSaved = pcbData ? *pcbData : 0;
    WORD wFlags = pConstraint->wFlags;
 
    LSTATUS error = RegGetValueW(HKEY_LOCAL_MACHINE, szFullKey, pszValueName, wFlags, pdwType,
                                 pvData, pcbData);
    if (error == ERROR_FILE_NOT_FOUND)
    {
        if (pcbData)
            *pcbData = cbDataSaved;
        error = RegGetValueW(HKEY_CURRENT_USER, szFullKey, pszValueName, wFlags, pdwType,
                             pvData, pcbData);
    }
 
    if (error)
        return HRESULT_FROM_WIN32(error);
 
    if (!pvData)
        return S_OK;
 
    if (pConstraint->wFlags == SRRF_RT_DWORD && pConstraint->wMinSize == sizeof(DWORD))
    {
        DWORD dwValue = *(PDWORD)pvData;
        if (dwValue < pConstraint->dwMin || pConstraint->dwMax < dwValue)
            return E_DATATYPE_MISMATCH;
    }
 
    return S_OK;
}

Referenced by GetValue().

_ValidateCachedResults()

void CPolicyCache::_ValidateCachedResults ( )

inlineprotected

Definition at line 117 of file policy.cpp.

    {
        LONG Value = SHGlobalCounterGetValue(m_hGlobalCounter);
        if (m_nCounterValue != Value)
        {
            m_nCounterValue = Value;
            ZeroMemory(m_pResults, m_cItems * sizeof(SHPOLICY_RESULT));
        }
    }

Referenced by GetValue().

GetValue()

HRESULT CPolicyCache::GetValue	(	_In_ REFGUID	rpolid,
		_Out_opt_ PVOID	pvValue,
		_Out_opt_ PDWORD	pcbValue
	)

Definition at line 143 of file policy.cpp.

{
    _ValidateCachedResults();
 
    if (m_cItems == 0)
        return E_UNEXPECTED;
 
    UINT iItem;
    for (iItem = 0; iItem < m_cItems; ++iItem)
    {
        if (IsEqualGUID(m_pItems[iItem].rpolid, rpolid))
            break;
    }
 
    if (iItem >= m_cItems)
        return E_UNEXPECTED;
 
    const SHPOLICY_ITEM *pItem = &m_pItems[iItem];
    PSHPOLICY_RESULT pResult = &m_pResults[iItem];
 
    if (pResult->state == POLICY_STATE_NOT_FOUND)
        return HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND);
 
    // Use caching only when dealing with DWORD value
    if (pvValue && pcbValue && *pcbValue == sizeof(DWORD) && pResult->state == POLICY_STATE_CACHED)
    {
        *(PDWORD)pvValue = pResult->dwValue;
        return S_OK;
    }
 
    HRESULT hr = _GetValue(pItem->pszKeyName, pItem->pszValueName, pItem->pConstraint, NULL,
                           pvValue, pcbValue);
    if (hr == HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND))
        pResult->state = POLICY_STATE_NOT_FOUND;
    else if (SUCCEEDED(hr) && pvValue)
        _CacheResult(pItem->pConstraint, pvValue, pcbValue, pResult);
 
    return hr;
}

Referenced by SHWindowsPolicyGetValue().

Initialize()

BOOL CPolicyCache::Initialize ( const SHPOLICY_ITEM *  pItems, UINT  cItems  )

inline

Definition at line 88 of file policy.cpp.

    {
        m_nCounterValue = MINLONG;
        m_pszRootKey = L"Software\\Microsoft\\Windows\\CurrentVersion\\Policies";
        m_pItems = pItems;
        m_cItems = cItems;
        m_pResults = (PSHPOLICY_RESULT)LocalAlloc(LPTR, cItems * sizeof(SHPOLICY_RESULT));
        if (!m_pResults)
            return FALSE;
        m_hGlobalCounter = SHGlobalCounterCreate(GUID_Restrictions);
        if (!m_hGlobalCounter)
        {
            LocalFree(m_pResults);
            m_pResults = NULL;
            return FALSE;
        }
        return TRUE;
    }

Referenced by SHPolicyCache_Create().

Member Data Documentation

m_cItems

DWORD CPolicyCache::m_cItems

protected

Definition at line 113 of file policy.cpp.

Referenced by _ValidateCachedResults(), GetValue(), and Initialize().

m_hGlobalCounter

HANDLE CPolicyCache::m_hGlobalCounter

protected

Definition at line 111 of file policy.cpp.

Referenced by _ValidateCachedResults(), Initialize(), and ~CPolicyCache().

m_nCounterValue

LONG CPolicyCache::m_nCounterValue

protected

Definition at line 112 of file policy.cpp.

Referenced by _ValidateCachedResults(), and Initialize().

m_pItems

const SHPOLICY_ITEM* CPolicyCache::m_pItems

protected

Definition at line 114 of file policy.cpp.

Referenced by GetValue(), and Initialize().

m_pResults

PSHPOLICY_RESULT CPolicyCache::m_pResults

protected

Definition at line 115 of file policy.cpp.

Referenced by _ValidateCachedResults(), GetValue(), Initialize(), and ~CPolicyCache().

m_pszRootKey

LPCWSTR CPolicyCache::m_pszRootKey

protected

Definition at line 110 of file policy.cpp.

Referenced by _GetValue(), and Initialize().

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The documentation for this class was generated from the following file:

• dll/win32/shlwapi/policy.cpp