/*-------------------------------------------------------------------------
 *
 * lselect.h--
 *    definitions for the replacement selection algorithm.
 *
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 * $Id: lselect.h,v 1.4 1997/08/06 03:42:07 momjian Exp $
 * 
 *-------------------------------------------------------------------------
 */
#ifndef	LSELECT_H
#define	LSELECT_H

#include <stdio.h>
#include "access/htup.h"

struct	leftist {
    short	lt_dist; 	/* distance to leaf/empty node */
    short	lt_devnum; 	/* device number of tuple */
    HeapTuple	lt_tuple;
    struct	leftist	*lt_left;
    struct	leftist	*lt_right;
};

/* replaces global variables in lselect.c to make it reentrant */
typedef struct {
    TupleDesc tupDesc;
    int nKeys;
    ScanKey scanKeys;
    int sortMem; /* needed for psort */
} LeftistContextData;
typedef LeftistContextData *LeftistContext;

extern struct leftist *lmerge(struct leftist *pt, struct leftist *qt,
    LeftistContext context);
extern HeapTuple gettuple(struct leftist **treep, short *devnum,
    LeftistContext context);
extern void puttuple(struct leftist **treep, HeapTuple newtuple, short devnum,
    LeftistContext context);
extern int tuplecmp(HeapTuple ltup, HeapTuple rtup, LeftistContext context);

#ifdef EBUG
extern void checktree(struct leftist *tree, LeftistContext context);
extern int checktreer(struct leftist *tree, int level, LeftistContext context);
#endif /* EBUG */

#endif 	/* LSELECT_H */
