windows-nt/Source/XPSP1/NT/net/tcpip/driver/inc/bitmap.h
2020-09-26 16:20:57 +08:00

276 lines
6.3 KiB
C

/*++
Copyright (c) 1989 Microsoft Corporation
Module Name:
BitMap.h
Abstract:
RTL Bitmap definitions and prototypes.
Revision History:
Borrowed from ntoskrnl for compatibility on other platforms (Win9x).
--*/
#ifndef _TCPIP_BITMAP_H_
#define _TCPIP_BITMAP_H_
#if MILLEN
//
// BitMap routines. The following structure, routines, and macros are
// for manipulating bitmaps. The user is responsible for allocating a bitmap
// structure (which is really a header) and a buffer (which must be longword
// aligned and multiple longwords in size).
//
typedef struct _RTL_BITMAP {
ULONG SizeOfBitMap; // Number of bits in bit map
PULONG Buffer; // Pointer to the bit map itself
} RTL_BITMAP;
typedef RTL_BITMAP *PRTL_BITMAP;
//
// The following routine initializes a new bitmap. It does not alter the
// data currently in the bitmap. This routine must be called before
// any other bitmap routine/macro.
VOID
RtlInitializeBitMap (
PRTL_BITMAP BitMapHeader,
PULONG BitMapBuffer,
ULONG SizeOfBitMap
);
//
// The following three routines clear, set, and test the state of a
// single bit in a bitmap.
//
VOID
RtlClearBit (
PRTL_BITMAP BitMapHeader,
ULONG BitNumber
);
VOID
RtlSetBit (
PRTL_BITMAP BitMapHeader,
ULONG BitNumber
);
BOOLEAN
RtlTestBit (
PRTL_BITMAP BitMapHeader,
ULONG BitNumber
);
//
// The following two routines either clear or set all of the bits
// in a bitmap.
//
VOID
RtlClearAllBits (
PRTL_BITMAP BitMapHeader
);
VOID
RtlSetAllBits (
PRTL_BITMAP BitMapHeader
);
//
// The following two routines locate a contiguous region of either
// clear or set bits within the bitmap. The region will be at least
// as large as the number specified, and the search of the bitmap will
// begin at the specified hint index (which is a bit index within the
// bitmap, zero based). The return value is the bit index of the located
// region (zero based) or -1 (i.e., 0xffffffff) if such a region cannot
// be located
//
ULONG
RtlFindClearBits (
PRTL_BITMAP BitMapHeader,
ULONG NumberToFind,
ULONG HintIndex
);
ULONG
RtlFindSetBits (
PRTL_BITMAP BitMapHeader,
ULONG NumberToFind,
ULONG HintIndex
);
//
// The following two routines locate a contiguous region of either
// clear or set bits within the bitmap and either set or clear the bits
// within the located region. The region will be as large as the number
// specified, and the search for the region will begin at the specified
// hint index (which is a bit index within the bitmap, zero based). The
// return value is the bit index of the located region (zero based) or
// -1 (i.e., 0xffffffff) if such a region cannot be located. If a region
// cannot be located then the setting/clearing of the bitmap is not performed.
//
ULONG
RtlFindClearBitsAndSet (
PRTL_BITMAP BitMapHeader,
ULONG NumberToFind,
ULONG HintIndex
);
ULONG
RtlFindSetBitsAndClear (
PRTL_BITMAP BitMapHeader,
ULONG NumberToFind,
ULONG HintIndex
);
//
// The following two routines clear or set bits within a specified region
// of the bitmap. The starting index is zero based.
//
VOID
RtlClearBits (
PRTL_BITMAP BitMapHeader,
ULONG StartingIndex,
ULONG NumberToClear
);
VOID
RtlSetBits (
PRTL_BITMAP BitMapHeader,
ULONG StartingIndex,
ULONG NumberToSet
);
//
// The following routine locates a set of contiguous regions of clear
// bits within the bitmap. The caller specifies whether to return the
// longest runs or just the first found lcoated. The following structure is
// used to denote a contiguous run of bits. The two routines return an array
// of this structure, one for each run located.
//
typedef struct _RTL_BITMAP_RUN {
ULONG StartingIndex;
ULONG NumberOfBits;
} RTL_BITMAP_RUN;
typedef RTL_BITMAP_RUN *PRTL_BITMAP_RUN;
ULONG
RtlFindClearRuns (
PRTL_BITMAP BitMapHeader,
PRTL_BITMAP_RUN RunArray,
ULONG SizeOfRunArray,
BOOLEAN LocateLongestRuns
);
//
// The following routine locates the longest contiguous region of
// clear bits within the bitmap. The returned starting index value
// denotes the first contiguous region located satisfying our requirements
// The return value is the length (in bits) of the longest region found.
//
ULONG
RtlFindLongestRunClear (
PRTL_BITMAP BitMapHeader,
PULONG StartingIndex
);
//
// The following routine locates the first contiguous region of
// clear bits within the bitmap. The returned starting index value
// denotes the first contiguous region located satisfying our requirements
// The return value is the length (in bits) of the region found.
//
ULONG
RtlFindFirstRunClear (
PRTL_BITMAP BitMapHeader,
PULONG StartingIndex
);
//
// The following macro returns the value of the bit stored within the
// bitmap at the specified location. If the bit is set a value of 1 is
// returned otherwise a value of 0 is returned.
//
// ULONG
// RtlCheckBit (
// PRTL_BITMAP BitMapHeader,
// ULONG BitPosition
// );
//
//
// To implement CheckBit the macro retrieves the longword containing the
// bit in question, shifts the longword to get the bit in question into the
// low order bit position and masks out all other bits.
//
#define RtlCheckBit(BMH,BP) ((((BMH)->Buffer[(BP) / 32]) >> ((BP) % 32)) & 0x1)
//
// The following two procedures return to the caller the total number of
// clear or set bits within the specified bitmap.
//
ULONG
RtlNumberOfClearBits (
PRTL_BITMAP BitMapHeader
);
ULONG
RtlNumberOfSetBits (
PRTL_BITMAP BitMapHeader
);
//
// The following two procedures return to the caller a boolean value
// indicating if the specified range of bits are all clear or set.
//
BOOLEAN
RtlAreBitsClear (
PRTL_BITMAP BitMapHeader,
ULONG StartingIndex,
ULONG Length
);
BOOLEAN
RtlAreBitsSet (
PRTL_BITMAP BitMapHeader,
ULONG StartingIndex,
ULONG Length
);
ULONG
RtlFindNextForwardRunClear (
IN PRTL_BITMAP BitMapHeader,
IN ULONG FromIndex,
IN PULONG StartingRunIndex
);
ULONG
RtlFindLastBackwardRunClear (
IN PRTL_BITMAP BitMapHeader,
IN ULONG FromIndex,
IN PULONG StartingRunIndex
);
#endif // MILLEN
#endif // !_TCPIP_BITMAP_H_