#ifndef __VARFHEAP_HPP
#define __VARFHEAP_HPP

#include "fileheap.hpp"

struct VarFileHeap_header;
struct VarFileHeap_directory;
class VarFileHeap : public FileHeap {
public:
        VarFileHeap(FileHeapStorage *s);
        VarFileHeap(FileHeapStorage *s, unsigned long bsize);
        ~VarFileHeap();
        
        recid Alloc(int rsize);
        int Free(recid r);
        int Read(recid r, void *data, int datalen);
        int Write(recid r, const void *data, int datalen);
        void Flush();
        
        int FindFirst(recid r[], int maxrecids, int *recids);
        int FindNext(recid from, recid r[], int maxrecids, int *recids);

        int cardinality();
        unsigned long count_approx();
        unsigned long count_exact();
private:
        VarFileHeap_header *header;
        int headerdirty;
        VarFileHeap_directory *dir;
        int dirdirty;
        unsigned long dirno;
        
        void makenewblock();
        void fetchdir(unsigned long bn);
        int finddir(recid r);
        int finddirentry(recid r);
        void syncdir();
        recid findfree(unsigned long size);
        unsigned long findfreeareaindir(unsigned long size);
        void insertdirentry(recid r, unsigned long offset, unsigned long size);
};

#endif