/*
 * Copyright 2001-2010, Haiku Inc. All rights reserved.
 * This file may be used under the terms of the MIT License.
 *
 * Authors:
 *              Janito V. Ferreira Filho
 */
#ifndef BITMAPBLOCK_H
#define BITMAPBLOCK_H


#include "CachedBlock.h"


class BitmapBlock : public CachedBlock {
public:
                                                        BitmapBlock(Volume* volume, uint32 numBits);
                                                        ~BitmapBlock();

                        bool                    SetTo(off_t block);
                        bool                    SetToWritable(Transaction& transaction,
                                                                off_t block, bool empty = false);

                        bool                    CheckMarked(uint32 start, uint32 length);
                        bool                    CheckUnmarked(uint32 start, uint32 length);

                        bool                    Mark(uint32 start, uint32 length,
                                                                bool force = false);
                        bool                    Unmark(uint32 start, uint32 length,
                                                                bool force = false);

                        void                    FindNextMarked(uint32& pos);
                        void                    FindNextUnmarked(uint32& pos);

                        void                    FindPreviousMarked(uint32& pos);

                        void                    FindLargestUnmarkedRange(uint32& start,
                                                                uint32& length);

                        uint32                  NumBits() const { return fNumBits; }
                        uint32                  Checksum(uint32 unitsPerGroup) const;

private:
                        bool                    _Check(uint32 start, uint32 length, bool marked);
                        void                    _FindNext(uint32& pos, bool marked);
                        bool                    _Update(uint32 start, uint32 length, bool mark,
                                                                bool force);

                        Volume*                 fVolume;
                        uint32*                 fData;
                        const uint32*   fReadOnlyData;

                        uint32                  fNumBits;
                        uint32                  fMaxIndex;
};


inline bool
BitmapBlock::CheckUnmarked(uint32 start, uint32 length)
{
        return _Check(start, length, false);
}


inline bool
BitmapBlock::CheckMarked(uint32 start, uint32 length)
{
        return _Check(start, length, true);
}


inline bool
BitmapBlock::Mark(uint32 start, uint32 length, bool force)
{
        return _Update(start, length, true, force);
}


inline bool
BitmapBlock::Unmark(uint32 start, uint32 length, bool force)
{
        return _Update(start, length, false, force);
}


inline void
BitmapBlock::FindNextMarked(uint32& pos)
{
        _FindNext(pos, true);
}


inline void
BitmapBlock::FindNextUnmarked(uint32& pos)
{
        _FindNext(pos, false);
}


#endif  // BITMAPBLOCK_H