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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#ifndef __COMMON_SORT_UTILS_H__
#define __COMMON_SORT_UTILS_H__
#include <stdbool.h>
#include "common/compat.h"
/*
* Example:
struct entry {
int id;
long size;
};
static int cmp_entry_id(const struct entry *a, const struct entry *b)
{
return (a->id < b->id ? -1 :
a->id > b->id ? 1 : 0);
}
static int cmp_entry_size(const struct entry *a, const struct entry *b)
{
return (a->size < b->size ? -1 :
a->size > b->size ? 1 : 0);
}
void test() {
// User data
struct entry entries[SIZE];
// Comparator structure
struct compare comp = { 0 };
// Keys, item comparators, help text definitions
struct sortdef sortit[] = {
{ .name = "id", .comp = (sort_cmp_t)cmp_entry_id,
.desc = "sort by id" },
{ .name = "size", .comp = (sort_cmp_t)cmp_entry_size,
.desc = "sort by entry size" },
SORTDEF_END
};
// List of keys to use for sort (e.g. from command line options)
const char *sortby[] = { "size", "id" };
compare_init(&comp, sortit);
for (i = 0; i < sizeof(sortby) / sizeof(sortby[0]); i++) {
ret = compare_add_sort_key(&comp, sortby[i]);
if (ret < 0) {
printf("ERROR adding sort key %s\n", sortby[i]);
break;
}
}
qsort_r(entries, SIZE, sizeof(struct entry), (sort_r_cmp_t)compare_cmp_multi,
&comp);
}
*/
#define SORTDEF_END { .name = NULL, .comp = NULL }
#define SORT_MAX_KEYS 32
typedef int (*sort_cmp_t)(const void *a, const void *b);
typedef int (*sort_r_cmp_t)(const void *a, const void *b, void *data);
#define SORTDEF_END { .name = NULL, .comp = NULL }
struct sortdef {
const char *name;
const char *desc;
sort_cmp_t comp;
/* User defined identifier of this sort key. */
int id;
};
struct compare {
sort_cmp_t comp[SORT_MAX_KEYS];
unsigned long invert_map;
int count;
const struct sortdef *sortdef;
};
int compare_init(struct compare *comp, const struct sortdef *sortdef);
int compare_cmp_multi(const void *a, const void *b, const struct compare *comp);
int compare_add_sort_key(struct compare *comp, const char *key);
int compare_parse_key_to_id(const struct compare *comp, const char **next);
int compare_add_sort_id(struct compare *comp, int id);
int compare_key_id(const struct compare *comp, const char *key);
const char *compare_id_name(const struct compare *comp, int id);
bool compare_has_id(const struct compare *comp, int id);
int compare_setup_sort(struct compare *comp, const struct sortdef *sdef, const char *def);
#endif
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