qsort.c File Reference

#include "c.h"

Include dependency graph for qsort.c:

Go to the source code of this file.

Defines
#define	swapcode(TYPE, parmi, parmj, n)
#define	SWAPINIT(a, es)
#define	swap(a, b)
#define	vecswap(a, b, n)   if ((n) > 0) swapfunc((a), (b), (size_t)(n), swaptype)
Functions
static char *	med3 (char *a, char *b, char *c, int(*cmp)(const void *, const void *))
static void	swapfunc (char *, char *, size_t, int)
void	pg_qsort (void *a, size_t n, size_t es, int(*cmp)(const void *, const void *))
int	pg_qsort_strcmp (const void *a, const void *b)

---

Define Documentation

#define swap	(		a,
			b
	)

Value:

if (swaptype == 0) {                    \
        long t = *(long *)(void *)(a);          \
        *(long *)(void *)(a) = *(long *)(void *)(b);    \
        *(long *)(void *)(b) = t;           \
    } else                          \
        swapfunc(a, b, es, swaptype)

Definition at line 84 of file qsort.c.

Referenced by lo_hton64(), lo_ntoh64(), pg_lltoa(), pg_ltoa(), pg_qsort(), pq_getmsgfloat4(), pq_getmsgfloat8(), pq_sendfloat4(), and pq_sendfloat8().

#define swapcode	(		TYPE,
			parmi,
			parmj,
			n
	)

Value:

do {        \
    size_t i = (n) / sizeof (TYPE);         \
    TYPE *pi = (TYPE *)(void *)(parmi);         \
    TYPE *pj = (TYPE *)(void *)(parmj);         \
    do {                        \
        TYPE    t = *pi;            \
        *pi++ = *pj;                \
        *pj++ = t;              \
        } while (--i > 0);              \
} while (0)

Definition at line 60 of file qsort.c.

Referenced by swapfunc().

#define SWAPINIT	(		a,
			es
	)

Value:

swaptype = ((char *)(a) - (char *)0) % sizeof(long) || \
    (es) % sizeof(long) ? 2 : (es) == sizeof(long)? 0 : 1;

Definition at line 72 of file qsort.c.

Referenced by pg_qsort().

#define vecswap	(		a,
			b,
			n
	)			if ((n) > 0) swapfunc((a), (b), (size_t)(n), swaptype)

Definition at line 92 of file qsort.c.

Referenced by pg_qsort().

---

Function Documentation

static char * med3	(	char *	a,
		char *	b,
		char *	c,
		int(*)(const void *, const void *)	cmp
	)			[static]

Definition at line 95 of file qsort.c.

References cmp().

Referenced by pg_qsort().

{
    return cmp(a, b) < 0 ?
        (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a))
        : (cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c));
}

void pg_qsort	(	void *	a,
		size_t	n,
		size_t	es,
		int(*)(const void *, const void *)	cmp
	)

Definition at line 103 of file qsort.c.

References cmp(), med3(), Min, qsort, swap, SWAPINIT, and vecswap.

Referenced by DropRelFileNodesAllBuffers().

{
    char       *pa,
               *pb,
               *pc,
               *pd,
               *pl,
               *pm,
               *pn;
    int         d,
                r,
                swaptype,
                presorted;

loop:SWAPINIT(a, es);
    if (n < 7)
    {
        for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es)
            for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
                 pl -= es)
                swap(pl, pl - es);
        return;
    }
    presorted = 1;
    for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es)
    {
        if (cmp(pm - es, pm) > 0)
        {
            presorted = 0;
            break;
        }
    }
    if (presorted)
        return;
    pm = (char *) a + (n / 2) * es;
    if (n > 7)
    {
        pl = (char *) a;
        pn = (char *) a + (n - 1) * es;
        if (n > 40)
        {
            d = (n / 8) * es;
            pl = med3(pl, pl + d, pl + 2 * d, cmp);
            pm = med3(pm - d, pm, pm + d, cmp);
            pn = med3(pn - 2 * d, pn - d, pn, cmp);
        }
        pm = med3(pl, pm, pn, cmp);
    }
    swap(a, pm);
    pa = pb = (char *) a + es;
    pc = pd = (char *) a + (n - 1) * es;
    for (;;)
    {
        while (pb <= pc && (r = cmp(pb, a)) <= 0)
        {
            if (r == 0)
            {
                swap(pa, pb);
                pa += es;
            }
            pb += es;
        }
        while (pb <= pc && (r = cmp(pc, a)) >= 0)
        {
            if (r == 0)
            {
                swap(pc, pd);
                pd -= es;
            }
            pc -= es;
        }
        if (pb > pc)
            break;
        swap(pb, pc);
        pb += es;
        pc -= es;
    }
    pn = (char *) a + n * es;
    r = Min(pa - (char *) a, pb - pa);
    vecswap(a, pb - r, r);
    r = Min(pd - pc, pn - pd - es);
    vecswap(pb, pn - r, r);
    if ((r = pb - pa) > es)
        qsort(a, r / es, es, cmp);
    if ((r = pd - pc) > es)
    {
        /* Iterate rather than recurse to save stack space */
        a = pn - r;
        n = r / es;
        goto loop;
    }
/*      qsort(pn - r, r / es, es, cmp);*/
}

int pg_qsort_strcmp	(	const void *	a,
		const void *	b
	)

Definition at line 201 of file qsort.c.

Referenced by BuildEventTriggerCache(), filter_event_trigger(), readstoplist(), and searchstoplist().

{
    return strcmp(*(char *const *) a, *(char *const *) b);
}

static void swapfunc	(	char *	a,
		char *	b,
		size_t	n,
		int	swaptype
	)			[static]

Definition at line 76 of file qsort.c.

References swapcode.

{
    if (swaptype <= 1)
        swapcode(long, a, b, n);
    else
        swapcode(char, a, b, n);
}