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https://git.kernel.org/pub/scm/linux/kernel/git/kdave/btrfs-progs.git
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90 lines
2.4 KiB
C
90 lines
2.4 KiB
C
/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#ifndef __COMMON_SORT_UTILS_H__
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#define __COMMON_SORT_UTILS_H__
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/*
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* Example:
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struct entry {
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int id;
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long size;
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};
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static int cmp_entry_id(const struct entry *a, const struct entry *b)
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{
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return (a->id < b->id ? -1 :
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a->id > b->id ? 1 : 0);
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}
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static int cmp_entry_size(const struct entry *a, const struct entry *b)
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{
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return (a->size < b->size ? -1 :
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a->size > b->size ? 1 : 0);
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}
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void test() {
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// User data
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struct entry entries[SIZE];
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// Comparator structure
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struct compare comp = { 0 };
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// Keys, item comparators, help text defitions
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struct sortdef sortit[] = {
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{ .name = "id", .comp = (sort_cmp_t)cmp_entry_id,
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.desc = "sort by id" },
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{ .name = "size", .comp = (sort_cmp_t)cmp_entry_size,
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.desc = "sort by entry size" },
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{ .name = NULL, .comp = NULL }
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};
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// List of keys to use for sort (e.g. from command line options)
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const char *sortby[] = { "size", "id" };
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compare_init(&comp, sortit);
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for (i = 0; i < sizeof(sortby) / sizeof(sortby[0]); i++) {
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ret = compare_add_sort_key(&comp, sortby[i]);
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if (ret < 0) {
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printf("ERROR adding sort key %s\n", sortby[i]);
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break;
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}
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}
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qsort_r(entries, SIZE, sizeof(struct entry), (sort_r_cmp_t)compare_cmp_multi,
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&comp);
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}
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*/
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typedef int (*sort_cmp_t)(const void *a, const void *b);
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typedef int (*sort_r_cmp_t)(const void *a, const void *b, void *data);
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struct sortdef {
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const char *name;
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const char *desc;
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sort_cmp_t comp;
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};
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struct compare {
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sort_cmp_t comp[32];
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unsigned long invert_map;
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int count;
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const struct sortdef *sortdef;
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};
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int compare_init(struct compare *comp, const struct sortdef *sortdef);
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int compare_cmp_multi(const void *a, const void *b, const struct compare *comp);
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int compare_add_sort_key(struct compare *comp, const char *key);
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#endif
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