windows-nt/Source/XPSP1/NT/base/fs/utils/ulib/inc/bitvect.hxx

/*++

Copyright (c) 1991-2000 Microsoft Corporation

Module Name:

        bitvect.hxx

Abstract:

        This module contains the definition for the BITVECTOR class. BITVECTOR
        is a concrete class which implements a bit array.

Author:

        David J. Gilman (davegi) 13-Jan-1991

Environment:

        ULIB, User Mode

Notes:

        BITVECTOR is an implementation of a general purpose bit
        vector.  It is based around an abstract type called PT
        (Primitive Type) to increase it's portability.  BITVECTORs
        can be created of arbitrary size.  If required they will
        allocate memory to maintain the bits or will use a memory
        buffer supplied by the client.  This allows the client to
        superimpose a bit vector onto a predefined buffer (e.g. onto
        a SECBUF).

--*/
#if ! defined ( _BITVECTOR_ )

#define _BITVECTOR_

DECLARE_CLASS( BITVECTOR );

//
// BITVECTOR allocation increment - Primitive Type
//

DEFINE_TYPE( ULONG, PT );

//
// BIT values
//

enum BIT {
        SET     = 1,
        RESET   = 0
};

//
// Invalid bit count
//

extern CONST PT InvalidBitCount;

class BITVECTOR : public OBJECT {

        public:

        ULIB_EXPORT
                DECLARE_CONSTRUCTOR( BITVECTOR );

                DECLARE_CAST_MEMBER_FUNCTION( BITVECTOR );

                NONVIRTUAL
        ULIB_EXPORT
        ~BITVECTOR (
                        );

                NONVIRTUAL
        ULIB_EXPORT
        BOOLEAN
                Initialize (
                        IN PT   Size                    DEFAULT 0,
                        IN BIT  InitialValue    DEFAULT RESET,
                        IN PPT  Memory                  DEFAULT NULL
                        );

                NONVIRTUAL
                PCPT
                GetBuf (
                        ) CONST;

                NONVIRTUAL
                BOOLEAN
                IsBitSet (
                        IN PT   Index
                        ) CONST;

                NONVIRTUAL
                PT
                QueryCountSet (
                        ) CONST;

                NONVIRTUAL
        PT
                QuerySize (
                        ) CONST;

                NONVIRTUAL
                VOID
                ResetAll (
                        );

                NONVIRTUAL
                VOID
                ResetBit (
                        IN PT   Index
                        );

                NONVIRTUAL
        ULIB_EXPORT
        VOID
                ResetBit (
                        IN PT   Index,
                        IN PT   Count
                        );

                NONVIRTUAL
                VOID
                SetAll (
                        );

                NONVIRTUAL
                VOID
                SetBit (
                        IN PT   Index
                        );

                NONVIRTUAL
        ULIB_EXPORT
        VOID
                SetBit (
                        IN PT   Index,
                        IN PT   Count
                        );

                NONVIRTUAL
        ULIB_EXPORT
        PT
                SetSize (
                        IN PT   Size,
                        IN BIT  InitialValue    DEFAULT RESET
                        );

                NONVIRTUAL
                VOID
                ToggleBit (
                        IN PT   Index,
                        IN PT   Count   DEFAULT 1
                        );

        private:

                NONVIRTUAL
                VOID
                Construct (
                        );

        NONVIRTUAL
        ULIB_EXPORT
        PT
        ComputeCountSet (
                        ) CONST;

                NONVIRTUAL
                VOID
                Destroy (
                );

                VOID
                NONVIRTUAL
                InitAll (
                        IN PT   InitialValue
                        );

                // Note that these three member data items cannot
                // be static because they are used in INLINE functions
                // that are called from outside the DLL.

                PT              _BitsPerPT;
                PT              _IndexShiftCount;
                PT              _BitPositionMask;

                STATIC
                CONST
                BYTE    _BitsSetLookUp[ 256 ];

                PPT             _BitVector;
                PT              _PTCount;
                BOOLEAN _FreeBitVector;

};

INLINE
PCPT
BITVECTOR::GetBuf (
        ) CONST

/*++

Routine Description:

        Returns the underlying bit vector.

Arguments:

        None.

Return Value:

        PCPT - Returns a pointer to the underlying bitvector.

--*/

{
        return( _BitVector );
}

INLINE
PT
BITVECTOR::QuerySize (
        ) CONST

/*++

Routine Description:

        Returns the number of bits in this BITVECTOR.

Arguments:

        None.

Return Value:

        PT

--*/

{
        return( _PTCount * _BitsPerPT );
}

INLINE
VOID
BITVECTOR::InitAll (
        IN PT   InitialValue
        )

/*++

Routine Description:

        Initialize each element in the internal bit vector to the
        supplied bit pattern.

Arguments:

        InitialValue - Supplies the pattern for each element.

Return Value:

        None.

--*/

{
        DebugAssert( _BitVector != NULL );

        memset(( PVOID ) _BitVector,
        ( int ) InitialValue, ( size_t ) ( sizeof( PT ) * _PTCount ));
}

INLINE
VOID
BITVECTOR::SetAll (
        )

/*++

Routine Description:

        Set (to one) all of the bits in this BITVECTOR.

Arguments:

        None.

Return Value:

        None.

--*/

{
        InitAll(( PT ) ~0 );
}

INLINE
VOID
BITVECTOR::ResetAll (
        )

/*++

Routine Description:

        Reset (to zero) all of the bits in this BITVECTOR.

Arguments:

        None.

Return Value:

        None.

--*/

{
        InitAll(( PT ) 0 );
}

INLINE
BOOLEAN
BITVECTOR::IsBitSet (
        IN PT   Index
        ) CONST

/*++

Routine Description:

        Determine if the bit at the supplied index is set.

Arguments:

        Index - Supplies the index to the bit of interest.

Return Value:

        BOOLEAN - Returns TRUE if the bit of interest is set.

--*/

{
        DebugAssert( _BitVector != NULL );
        DebugAssert( Index < ( _PTCount * _BitsPerPT ));

        return (_BitVector[Index >> _IndexShiftCount] &
                (1 << (Index & _BitPositionMask))) ? TRUE : FALSE;
}

INLINE
VOID
BITVECTOR::SetBit (
        IN PT   Index
        )

/*++

Routine Description:

        Set the bit at the supplied index.

Arguments:

        Index - Supplies the index to the bit of interest.

Return Value:

    None.

--*/

{
        DebugAssert( _BitVector != NULL );
        DebugAssert( Index < ( _PTCount * _BitsPerPT ));

        _BitVector[Index >> _IndexShiftCount] |=
                (1 << (Index & _BitPositionMask));
}

INLINE
VOID
BITVECTOR::ResetBit (
        IN PT   Index
        )

/*++

Routine Description:

        Reset the bit at the supplied index.

Arguments:

        Index - Supplies the index to the bit of interest.

Return Value:

    None.

--*/

{
        DebugAssert( _BitVector != NULL );
        DebugAssert( Index < ( _PTCount * _BitsPerPT ));

        _BitVector[Index >> _IndexShiftCount] &=
                ~(1 << (Index & _BitPositionMask));
}

INLINE
PT
BITVECTOR::QueryCountSet (
        ) CONST

/*++

Routine Description:

        Determine the number of bits set in this BITVECTOR.

Arguments:

        None.

Return Value:

        PT - Returns the number of set bits.

--*/
{
        return ComputeCountSet();
}

#endif // _BITVECTOR_