/* GLIB - Library of useful routines for C programming
* Copyright (C) 1991, 1992, 1996, 1997,1999,2004 Free Software Foundation, Inc.
* Copyright (C) 2000 Eazel, Inc.
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include "galloca.h"
#include "gmem.h"
#include "gqsort.h"
#include "gtestutils.h"
/* This file was originally from stdlib/msort.c in gnu libc, just changed
to build inside glib and to not fall back to an unstable quicksort
for large arrays. */
/* An alternative to qsort, with an identical interface.
This file is part of the GNU C Library.
Copyright (C) 1992,95-97,99,2000,01,02,04,07 Free Software Foundation, Inc.
Written by Mike Haertel, September 1988.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
struct msort_param
{
size_t s;
size_t var;
GCompareDataFunc cmp;
void *arg;
char *t;
};
static void msort_with_tmp (const struct msort_param *p, void *b, size_t n);
static void
msort_with_tmp (const struct msort_param *p, void *b, size_t n)
{
char *b1, *b2;
size_t n1, n2;
char *tmp = p->t;
const size_t s = p->s;
GCompareDataFunc cmp = p->cmp;
void *arg = p->arg;
if (n <= 1)
return;
n1 = n / 2;
n2 = n - n1;
b1 = b;
b2 = (char *) b + (n1 * p->s);
msort_with_tmp (p, b1, n1);
msort_with_tmp (p, b2, n2);
switch (p->var)
{
case 0:
while (n1 > 0 && n2 > 0)
{
if ((*cmp) (b1, b2, arg) <= 0)
{
*(guint32 *) tmp = *(guint32 *) b1;
b1 += sizeof (guint32);
--n1;
}
else
{
*(guint32 *) tmp = *(guint32 *) b2;
b2 += sizeof (guint32);
--n2;
}
tmp += sizeof (guint32);
}
break;
case 1:
while (n1 > 0 && n2 > 0)
{
if ((*cmp) (b1, b2, arg) <= 0)
{
*(guint64 *) tmp = *(guint64 *) b1;
b1 += sizeof (guint64);
--n1;
}
else
{
*(guint64 *) tmp = *(guint64 *) b2;
b2 += sizeof (guint64);
--n2;
}
tmp += sizeof (guint64);
}
break;
case 2:
while (n1 > 0 && n2 > 0)
{
unsigned long *tmpl = (unsigned long *) tmp;
unsigned long *bl;
tmp += s;
if ((*cmp) (b1, b2, arg) <= 0)
{
bl = (unsigned long *) b1;
b1 += s;
--n1;
}
else
{
bl = (unsigned long *) b2;
b2 += s;
--n2;
}
while (tmpl < (unsigned long *) tmp)
*tmpl++ = *bl++;
}
break;
case 3:
while (n1 > 0 && n2 > 0)
{
if ((*cmp) (*(const void **) b1, *(const void **) b2, arg) <= 0)
{
*(void **) tmp = *(void **) b1;
b1 += sizeof (void *);
--n1;
}
else
{
*(void **) tmp = *(void **) b2;
b2 += sizeof (void *);
--n2;
}
tmp += sizeof (void *);
}
break;
default:
while (n1 > 0 && n2 > 0)
{
if ((*cmp) (b1, b2, arg) <= 0)
{
memcpy (tmp, b1, s);
tmp += s;
b1 += s;
--n1;
}
else
{
memcpy (tmp, b2, s);
tmp += s;
b2 += s;
--n2;
}
}
break;
}
if (n1 > 0)
memcpy (tmp, b1, n1 * s);
memcpy (b, p->t, (n - n2) * s);
}
static void
msort_r (void *b, size_t n, size_t s, GCompareDataFunc cmp, void *arg)
{
size_t size = n * s;
char *tmp = NULL;
struct msort_param p;
/* For large object sizes use indirect sorting. */
if (s > 32)
size = 2 * n * sizeof (void *) + s;
if (size < 1024)
/* The temporary array is small, so put it on the stack. */
p.t = g_alloca (size);
else
{
/* It's large, so malloc it. */
tmp = g_malloc (size);
p.t = tmp;
}
p.s = s;
p.var = 4;
p.cmp = cmp;
p.arg = arg;
if (s > 32)
{
/* Indirect sorting. */
char *ip = (char *) b;
void **tp = (void **) (p.t + n * sizeof (void *));
void **t = tp;
void *tmp_storage = (void *) (tp + n);
char *kp;
size_t i;
while ((void *) t < tmp_storage)
{
*t++ = ip;
ip += s;
}
p.s = sizeof (void *);
p.var = 3;
msort_with_tmp (&p, p.t + n * sizeof (void *), n);
/* tp[0] .. tp[n - 1] is now sorted, copy around entries of
the original array. Knuth vol. 3 (2nd ed.) exercise 5.2-10. */
for (i = 0, ip = (char *) b; i < n; i++, ip += s)
if ((kp = tp[i]) != ip)
{
size_t j = i;
char *jp = ip;
memcpy (tmp_storage, ip, s);
do
{
size_t k = (kp - (char *) b) / s;
tp[j] = jp;
memcpy (jp, kp, s);
j = k;
jp = kp;
kp = tp[k];
}
while (kp != ip);
tp[j] = jp;
memcpy (jp, tmp_storage, s);
}
}
else
{
if ((s & (sizeof (guint32) - 1)) == 0
&& ((char *) b - (char *) 0) % ALIGNOF_GUINT32 == 0)
{
if (s == sizeof (guint32))
p.var = 0;
else if (s == sizeof (guint64)
&& ((char *) b - (char *) 0) % ALIGNOF_GUINT64 == 0)
p.var = 1;
else if ((s & (sizeof (unsigned long) - 1)) == 0
&& ((char *) b - (char *) 0)
% ALIGNOF_UNSIGNED_LONG == 0)
p.var = 2;
}
msort_with_tmp (&p, b, n);
}
g_free (tmp);
}
/**
* g_qsort_with_data:
* @pbase: (not nullable): start of array to sort
* @total_elems: elements in the array
* @size: size of each element
* @compare_func: function to compare elements
* @user_data: data to pass to @compare_func
*
* This is just like the standard C qsort() function, but
* the comparison routine accepts a user data argument.
*
* This is guaranteed to be a stable sort since version 2.32.
*/
void
g_qsort_with_data (gconstpointer pbase,
gint total_elems,
gsize size,
GCompareDataFunc compare_func,
gpointer user_data)
{
msort_r ((gpointer)pbase, total_elems, size, compare_func, user_data);
}