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#ifndef _STGSTRMS_HXX
#define _STGSTRMS_HXX

#include <tools/stream.hxx>
#include <vector>

class StgIo;
class StgStrm;
class StgPage;
class StgDirEntry;

// The FAT class performs FAT operations on an underlying storage stream.
// This stream is either the physical FAT stream (bPhys == sal_True ) or a normal
// storage stream, which then holds the FAT for small data allocations.

class StgFAT
{                                       // FAT allocator
    StgStrm& rStrm;                     // underlying stream
    sal_Int32 nMaxPage;                     // highest page allocated so far
    short nPageSize;                    // physical page size
    short nEntries;                     // FAT entries per page
    short nOffset;                      // current offset within page
    sal_Int32 nLimit;                       // search limit recommendation
    sal_Bool  bPhys;                        // sal_True: physical FAT
    StgPage* GetPhysPage( sal_Int32 nPage );
    sal_Bool  MakeChain( sal_Int32 nStart, sal_Int32 nPages );
    sal_Bool  InitNew( sal_Int32 nPage1 );
public:
    StgFAT( StgStrm& rStrm, sal_Bool bMark );
    sal_Int32 FindBlock( sal_Int32& nPages );
    sal_Int32 GetNextPage( sal_Int32 nPg );
    sal_Int32 AllocPages( sal_Int32 nStart, sal_Int32 nPages );
    sal_Bool  FreePages( sal_Int32 nStart, sal_Bool bAll );
    sal_Int32 GetMaxPage() { return nMaxPage; }
    void  SetLimit( sal_Int32 n ) { nLimit = n; }
};

// The base stream class provides basic functionality for seeking
// and accessing the data on a physical basis. It uses the built-in
// FAT class for the page allocations.

class StgStrm {                         // base class for all streams
protected:
    StgIo& rIo;                         // I/O system
    StgFAT* pFat;                       // FAT stream for allocations
    StgDirEntry* pEntry;                // dir entry (for ownership)
    sal_Int32 nStart;                       // 1st data page
    sal_Int32 nSize;                        // stream size in bytes
    sal_Int32 nPos;                         // current byte position
    sal_Int32 nPage;                        // current logical page
    short nOffset;                      // offset into current page
    short nPageSize;                    // logical page size
    std::vector<sal_Int32> m_aPagesCache;
    void scanBuildPageChainCache(sal_Int32 *pOptionalCalcSize = NULL);
    sal_Bool  Copy( sal_Int32 nFrom, sal_Int32 nBytes );
    StgStrm( StgIo& );
public:
    virtual ~StgStrm();
    StgIo&  GetIo()     { return rIo;    }
    sal_Int32   GetPos()    { return nPos;   }
    sal_Int32   GetStart()  { return nStart; }
    sal_Int32   GetSize()   { return nSize;  }
    sal_Int32   GetPage()   { return nPage;  }
    short   GetPageSize() { return nPageSize; }
    sal_Int32   GetPages();
    short   GetOffset() { return nOffset;}
    void    SetEntry( StgDirEntry& );
    virtual sal_Bool SetSize( sal_Int32 );
    virtual sal_Bool Pos2Page( sal_Int32 nBytePos );
    virtual sal_Int32 Read( void*, sal_Int32 )        { return 0; }
    virtual sal_Int32 Write( const void*, sal_Int32 ) { return 0; }
    virtual StgPage* GetPhysPage( sal_Int32 nBytePos, sal_Bool bForce = sal_False );
    virtual sal_Bool IsSmallStrm() { return sal_False; }
};

// The FAT stream class provides physical access to the master FAT.
// Since this access is implemented as a StgStrm, we can use the
// FAT allocator.

class StgFATStrm : public StgStrm {     // the master FAT stream
    virtual sal_Bool Pos2Page( sal_Int32 nBytePos );
    sal_Bool  SetPage( short, sal_Int32 );
public:
    StgFATStrm( StgIo& );
    virtual ~StgFATStrm() {}
    using StgStrm::GetPage;
    sal_Int32 GetPage( short, sal_Bool, sal_uInt16 *pnMasterAlloc = 0);
    virtual sal_Bool SetSize( sal_Int32 );
    virtual StgPage* GetPhysPage( sal_Int32 nBytePos, sal_Bool bForce = sal_False );
};

// The stream has a size increment which normally is 1, but which can be
// set to any value is you want the size to be incremented by certain values.

class StgDataStrm : public StgStrm      // a physical data stream
{
    short nIncr;                        // size adjust increment
    void Init( sal_Int32 nBgn, sal_Int32 nLen );
public:
    StgDataStrm( StgIo&, sal_Int32 nBgn, sal_Int32 nLen=-1 );
	StgDataStrm( StgIo&, StgDirEntry& );
    void* GetPtr( sal_Int32 nPos, sal_Bool bForce, sal_Bool bDirty );
    void SetIncrement( short n ) { nIncr = n ; }
    virtual sal_Bool SetSize( sal_Int32 );
    virtual sal_Int32 Read( void*, sal_Int32 );
    virtual sal_Int32 Write( const void*, sal_Int32 );
};

// The small stream class provides access to streams with a size < 4096 bytes.
// This stream is a StgStream containing small pages. The FAT for this stream
// is also a StgStream. The start of the FAT is in the header at DataRootPage,
// the stream itself is pointed to by the root entry (it holds start & size).

class StgSmallStrm : public StgStrm     // a logical data stream
{
    StgStrm* pData;                     // the data stream
    void Init( sal_Int32 nBgn, sal_Int32 nLen );
public:
    StgSmallStrm( StgIo&, sal_Int32 nBgn, sal_Int32 nLen );
	StgSmallStrm( StgIo&, StgDirEntry& );
    virtual sal_Int32 Read( void*, sal_Int32 );
    virtual sal_Int32 Write( const void*, sal_Int32 );
    virtual sal_Bool IsSmallStrm() { return sal_True; }
};

class StgTmpStrm : public SvMemoryStream
{
    String aName;
    SvFileStream* pStrm;
    using SvMemoryStream::GetData;
    virtual sal_uLong GetData( void* pData, sal_uLong nSize );
    virtual sal_uLong PutData( const void* pData, sal_uLong nSize );
    virtual sal_uLong SeekPos( sal_uLong nPos );
    virtual void FlushData();

public:
    StgTmpStrm( sal_uLong=16 );
   ~StgTmpStrm();
    sal_Bool Copy( StgTmpStrm& );
    void SetSize( sal_uLong );
    sal_uLong GetSize() const;
};

#endif

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