#define EOIX            (-2)
#define IX_FAIL         (-1)
#define IX_OK           0
#define FREE_LEVEL      (-1)
#define LEFTN           (-1)
#define RIGHTN          1
#define BIN_MODE        0
#define ASC_MODE        1

#define NULLREC         (-1L)

#define MAXKEY          100
#define IXB_SIZE        1024
#define IXB_SPACE       IXB_SIZE - sizeof(int)*2 - sizeof(long)
#define MAX_LEVELS      4

typedef long RECPOS ;

typedef struct 
{
	RECPOS rptr ;
	unsigned char key[MAXKEY];
    /* DATA TYPE */     
} ENTRY;        

typedef struct 
{
	RECPOS  brec ;
	int     bend;
	int     lvl;
	unsigned char entries[IXB_SPACE];
} BLOCK;

typedef struct 
{
	int nl;    
	int order;        /* relative field file was indexed on */	
	RECPOS rb;
	RECPOS ff;              
	ENTRY  dume;
} IX_DISK;      

typedef struct
{
	FILE *ixfile ;
	struct 
	{
		RECPOS cblock;
		int coffset;
	} pos[MAX_LEVELS];
	int (*pcomp) () ;
	int (*psize) () ;
	BLOCK cache[MAX_LEVELS];
	IX_DISK dx;
} IX_DESC;   
      

/* macros */

#define CURR 1
#define NOT_CURR 0

#define CALL(pfun)      (* (pfun))
#define call(pfun)      (* (pfun))

#define ENT_ADR(pb,off) ((ENTRY *) ((char *) (& (pb)->entries)+off))

#define ENT_SIZE(pe) (*(pci->psize)) (pe)

#define CB(l)   (pci->pos[l].cblock)
#define CO(l)   (pci->pos[l].coffset)

/* prototypes */          
int    make_index(char *fn,int dupok,int file_no);
int    first_key(ENTRY *pe,IX_DESC *pix);
int    last_key(ENTRY *pe,IX_DESC *pix);
int    next_key(ENTRY *pe,IX_DESC *pix);    
int    prev_key(ENTRY *pe,IX_DESC *pix);
int    find_key(ENTRY *pe,IX_DESC *pix);
int    add_key(ENTRY *pe,IX_DESC *pix);
int    locate_key(ENTRY *pe,IX_DESC *pix);
int    delete_key(ENTRY *pe,IX_DESC *pix);

BLOCK  *neighbor(int l,int direction);
int    copy_current(int l,ENTRY *pe);
int    prev_entry(BLOCK *pb,int off);
int    next_entry(BLOCK *pb,int off);
void   copy_entry(ENTRY *to,ENTRY *from);
int    scan_blk(BLOCK *pb,int n);
int    last_entry(BLOCK *pb);
FILE  *creat_if(char fn[]);
int    read_if(RECPOS start,char buf[],int nrd);
int    write_if(RECPOS start,char buf[],int nwrt);
int    close_if();
FILE  *open_if(char fn[]);
void   make_free(RECPOS fstart,RECPOS filesize);
RECPOS get_free();
void   write_free(RECPOS r,BLOCK *pb);
void   init_bio();
int    retrieve_block(int l,RECPOS r,BLOCK *pb,int current);
void   update_block(BLOCK *pb);
int    get_block(int l,BLOCK *pb);
void   put_free(BLOCK *pb);
int    read_block(RECPOS r,BLOCK *pb);
int    write_block(RECPOS r,BLOCK *pb);
void   init_cache();
int    chk_cache(int l, RECPOS r);
int    get_cache(int l,RECPOS r,BLOCK *to);
void   put_cache(int l, BLOCK *pb);
void   scrub_cache(RECPOS r);
int    openix(char name[],IX_DESC *pix,int (*cfun) (),int (*sfun) ());
void   closeix(IX_DESC *pix);
int    creatix(char name[],long filesize,ENTRY *pdum,int ndum,int field_no);
RECPOS wrt_dum(ENTRY *pdum, int ndum);
void   removeix(char name[]);
int    go_first(IX_DESC *pix);
void   first_ix(int l,RECPOS r,BLOCK *pb);
int    go_last(IX_DESC *pix);
void   final_ix(int l, RECPOS r, BLOCK *pb);
int    get_next(ENTRY *pe,IX_DESC *pix);
RECPOS next_ix(int l,BLOCK *pb);
int    get_previous(ENTRY *pe,IX_DESC *pix);
RECPOS last_ix(int l,BLOCK *pb);
void   get_current(ENTRY *pe,IX_DESC *pix);
int    find_block(ENTRY *pe,BLOCK *pb,int *poff,int (*comp_fun) ());
void   ins_block(BLOCK *pb,ENTRY *pe,int off);
void   del_block(BLOCK *pb,int off);
void   moveup(BLOCK *pb,int off,int n);
void   movedown(BLOCK *pb,int off,int n);
void   combine(BLOCK *pl,BLOCK *pr);
int    find_ix(ENTRY *pe,IX_DESC *pix);
int    find_level(int l,ENTRY *pe,RECPOS r);
int    insert_ix(ENTRY *pe,IX_DESC *pix);
int    ins_level(int l,ENTRY *pe,BLOCK *pb);
int    split(int l,ENTRY *pe,BLOCK *pb);
int    delete_ix(IX_DESC *pix);
int    del_level(int l,BLOCK *pb);
int    compress(int l,BLOCK *pb);
int    fix_last(int l,RECPOS r, ENTRY *pe);
int    replace_entry(int l,ENTRY *pe);
int    find_exact(ENTRY *pe,IX_DESC *pix);
int    find_ins(ENTRY *pe, IX_DESC *pix);
int    find_del(ENTRY *pe,IX_DESC *pix);

#if !MSDOS
void   memmove(char *to,char *from,unsigned int count);
#endif