/*
**	'application' avltree stuff
*/

#define AVL_DEFAULTKEYLEN (4 * sizeof(int))	/* size of default key */

typedef void		*AVL_RECPOS;

typedef struct {
	AVL_RECPOS	recptr;
	unsigned int	count;
	char		key[AVL_DEFAULTKEYLEN]; 
			   /* actually can be of any length */
} rectype;

typedef rectype		AVL_IX_REC;


typedef struct {
	void		*root;
	int		keylength; /* zero for null-terminated strings */
	int		dup_keys;
} AVL_IX_DESC;

/*  return codes  */
#define AVL_IX_OK	1
#define AVL_IX_FAIL	0
#define AVL_EOIX	(-2)

/*  'dup' args of avl_create_index()  */
#define AVL_NO_DUP_KEYS	0	/* repeated key causes an error message */
#define AVL_DUP_KEYS_OK	1	/* repeated key & rec cause an error message */
#define AVL_COUNT_DUPS	2	/* complete dups allowed, count repetitions */

extern void	avl_create_index(AVL_IX_DESC *pix, int dup, int keylength);
extern void	avl_destroy_index(AVL_IX_DESC *pix);
extern int	avl_find_key(AVL_IX_REC *pe, AVL_IX_DESC *pix);
extern int	avl_locate_key(AVL_IX_REC *pe, AVL_IX_DESC *pix);
extern int	avl_add_key(AVL_IX_REC *pe, AVL_IX_DESC *pix);
extern int	avl_delete_key(AVL_IX_REC *pe, AVL_IX_DESC *pix);
extern void	avl_first_key(AVL_IX_DESC *pix);
extern void	avl_last_key(AVL_IX_DESC *pix);
extern int	avl_next_key(AVL_IX_REC *pe, AVL_IX_DESC *pix);
extern int	avl_prev_key(AVL_IX_REC *pe, AVL_IX_DESC *pix);
extern int	avl_find_exact(AVL_IX_REC *pe, AVL_IX_DESC *pix);