windows-xp/Source/XPSP1/NT/base/win32/fusion/installer/id/idaux.cpp

#include <windows.h>
#include <shlwapi.h>
#include <idp.h>
#include <idaux.h>


ULONG
FusionpDbgPrintEx(
    ULONG Level,
    PCSTR Format,
    ...
    )
{
    return 0;
}


int
FusionpCompareStrings(
    PCWSTR psz1,
    SIZE_T cch1,
    PCWSTR psz2,
    SIZE_T cch2,
    bool fCaseInsensitive
    )
{
    if (fCaseInsensitive)
        return StrCmpI(psz1, psz2);
    else
        return StrCmp(psz1, psz2);    
}




BOOL
FusionpHashUnicodeString(
    PCWSTR String,
    SIZE_T cch,
    PULONG HashValue,
    DWORD dwCmpFlags
    )
{
    BOOL fSuccess = FALSE;
    FN_TRACE_WIN32(fSuccess);
    ULONG TmpHashValue = 0;

    if (HashValue != NULL)
        *HashValue = 0;

    //PARAMETER_CHECK((dwCmpFlags == 0) || (dwCmpFlags == (NORM_IGNORECASE|SORT_STRINGSORT))); // ?safe
    PARAMETER_CHECK((dwCmpFlags == 0) || (dwCmpFlags & NORM_IGNORECASE)); // ?safe
    PARAMETER_CHECK(HashValue != NULL);

    if (dwCmpFlags & NORM_IGNORECASE)
        dwCmpFlags  |= SORT_STRINGSORT;     

    //
    //  Note that if you change this implementation, you have to have the implementation inside
    //  ntdll change to match it.  Since that's hard and will affect everyone else in the world,
    //  DON'T CHANGE THIS ALGORITHM NO MATTER HOW GOOD OF AN IDEA IT SEEMS TO BE!  This isn't the
    //  most perfect hashing algorithm, but its stability is critical to being able to match
    //  previously persisted hash values.
    //

    if (dwCmpFlags & NORM_IGNORECASE)
    {
        while (cch-- != 0)
        {
            WCHAR Char = *String++;
            TmpHashValue = (TmpHashValue * 65599) + (WCHAR) ::CharUpperW((PWSTR) Char);
        }
    }
    else
    {
        while (cch-- != 0)
            TmpHashValue = (TmpHashValue * 65599) + *String++;
    }

    *HashValue = TmpHashValue;
    fSuccess = TRUE;
Exit:
    return fSuccess;
}