1 // SPDX-License-Identifier: MIT
2 /*
3 * Stupid implementation of pointer -> pointer map.
4 *
5 * Copyright (c) 2017 Luc Van Oostenryck.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25
26 #include "ptrmap.h"
27 #include "allocate.h"
28 #include <stddef.h>
29
30 #define MAP_NR 7
31
32 struct ptrpair {
33 void *key;
34 void *val;
35 };
36 struct ptrmap {
37 struct ptrmap *next;
38 int nr;
39 struct ptrpair pairs[MAP_NR];
40 };
41
42 DECLARE_ALLOCATOR(ptrmap);
43 ALLOCATOR(ptrmap, "ptrmap");
44
__ptrmap_add(struct ptrmap ** mapp,void * key,void * val)45 void __ptrmap_add(struct ptrmap **mapp, void *key, void *val)
46 {
47 struct ptrmap *head = *mapp;
48 struct ptrmap *newmap;
49 struct ptrmap *map;
50 struct ptrpair *pair;
51 int nr;
52
53 if ((map = head)) {
54 struct ptrmap *next = map->next;
55 if (next) // head is full
56 map = next;
57 if ((nr = map->nr) < MAP_NR)
58 goto oldmap;
59 }
60
61 // need a new block
62 newmap = __alloc_ptrmap(0);
63 if (!head) {
64 *mapp = newmap;
65 } else {
66 newmap->next = head->next;
67 head->next = newmap;
68 }
69 map = newmap;
70 nr = 0;
71
72 oldmap:
73 pair = &map->pairs[nr];
74 pair->key = key;
75 pair->val = val;
76 map->nr = ++nr;
77 }
78
__ptrmap_lookup(struct ptrmap * map,void * key)79 void *__ptrmap_lookup(struct ptrmap *map, void *key)
80 {
81 for (; map; map = map->next) {
82 int i, n = map->nr;
83 for (i = 0; i < n; i++) {
84 struct ptrpair *pair = &map->pairs[i];
85 if (pair->key == key)
86 return pair->val;
87 }
88 }
89 return NULL;
90 }
91
__ptrmap_update(struct ptrmap ** mapp,void * key,void * val)92 void __ptrmap_update(struct ptrmap **mapp, void *key, void *val)
93 {
94 struct ptrmap *map = *mapp;
95
96 for (; map; map = map->next) {
97 int i, n = map->nr;
98 for (i = 0; i < n; i++) {
99 struct ptrpair *pair = &map->pairs[i];
100 if (pair->key == key) {
101 if (pair->val != val)
102 pair->val = val;
103 return;
104 }
105 }
106 }
107
108 __ptrmap_add(mapp, key, val);
109 }
110