/*
 * 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 DATASTREAM_H
#define DATASTREAM_H


#include "ext2.h"
#include "Transaction.h"


class Volume;


class DataStream
{
public:
                                        DataStream(Volume* volume, ext2_data_stream* stream,
                                                off_t size);
                                        ~DataStream();

        status_t                FindBlock(off_t offset, fsblock_t& block,
                                                uint32 *_count = NULL);
        status_t                Enlarge(Transaction& transaction, off_t& numBlocks);
        status_t                Shrink(Transaction& transaction, off_t& numBlocks);

private:
        uint32                  _BlocksNeeded(off_t end);

        status_t                _GetBlock(Transaction& transaction, uint32& block);
        status_t                _PrepareBlock(Transaction& transaction, uint32* pos,
                                                uint32& blockNum, bool& clear);

        status_t                _AddBlocks(Transaction& transaction, uint32* block,
                                                off_t count);
        status_t                _AddBlocks(Transaction& transaction, uint32* block,
                                                off_t start, off_t end, int recursion);

        status_t                _AddForDirectBlocks(Transaction& transaction,
                                                uint32 numBlocks);
        status_t                _AddForIndirectBlock(Transaction& transaction,
                                                uint32 numBlocks);
        status_t                _AddForDoubleIndirectBlock(Transaction& transaction,
                                                uint32 numBlocks);
        status_t                _AddForTripleIndirectBlock(Transaction& transaction,
                                                uint32 numBlocks);

        status_t                _PerformFree(Transaction& transaction);
        status_t                _MarkBlockForRemoval(Transaction& transaction,
                                                uint32* block);

        status_t                _FreeBlocks(Transaction& transaction, uint32* block,
                                                uint32 count);
        status_t                _FreeBlocks(Transaction& transaction, uint32* block,
                                                off_t start, off_t end, bool freeParent,
                                                int recursion);

        status_t                _RemoveFromDirectBlocks(Transaction& transaction,
                                                uint32 numBlocks);
        status_t                _RemoveFromIndirectBlock(Transaction& transaction,
                                                uint32 numBlocks);
        status_t                _RemoveFromDoubleIndirectBlock(Transaction& transaction,
                                                uint32 numBlocks);
        status_t                _RemoveFromTripleIndirectBlock(Transaction& transaction,
                                                uint32 numBlocks);


        const uint32    kBlockSize;
        const uint32    kIndirectsPerBlock;
        const uint32    kIndirectsPerBlock2;
        const uint32    kIndirectsPerBlock3;

        const uint32    kMaxDirect;
        const uint32    kMaxIndirect;
        const uint32    kMaxDoubleIndirect;

        Volume*                 fVolume;
        ext2_data_stream* fStream;
        uint32                  fFirstBlock;

        uint32                  fAllocated;
        fsblock_t               fAllocatedPos;
        uint32                  fWaiting;

        uint32                  fFreeStart;
        uint32                  fFreeCount;

        off_t                   fNumBlocks;
        uint32                  fRemovedBlocks;
        off_t                   fSize;
};

#endif  // DATASTREAM_H