| // SPDX-License-Identifier: MIT |
| /* |
| * Stupid implementation of pointer -> pointer map. |
| * |
| * Copyright (c) 2017 Luc Van Oostenryck. |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| |
| #include "ptrmap.h" |
| #include "allocate.h" |
| #include <stddef.h> |
| |
| #define MAP_NR 7 |
| |
| struct ptrpair { |
| void *key; |
| void *val; |
| }; |
| struct ptrmap { |
| struct ptrmap *next; |
| int nr; |
| struct ptrpair pairs[MAP_NR]; |
| }; |
| |
| DECLARE_ALLOCATOR(ptrmap); |
| ALLOCATOR(ptrmap, "ptrmap"); |
| |
| void __ptrmap_add(struct ptrmap **mapp, void *key, void *val) |
| { |
| struct ptrmap *head = *mapp; |
| struct ptrmap *newmap; |
| struct ptrmap *map; |
| struct ptrpair *pair; |
| int nr; |
| |
| if ((map = head)) { |
| struct ptrmap *next = map->next; |
| if (next) // head is full |
| map = next; |
| if ((nr = map->nr) < MAP_NR) |
| goto oldmap; |
| } |
| |
| // need a new block |
| newmap = __alloc_ptrmap(0); |
| if (!head) { |
| *mapp = newmap; |
| } else { |
| newmap->next = head->next; |
| head->next = newmap; |
| } |
| map = newmap; |
| nr = 0; |
| |
| oldmap: |
| pair = &map->pairs[nr]; |
| pair->key = key; |
| pair->val = val; |
| map->nr = ++nr; |
| } |
| |
| void *__ptrmap_lookup(struct ptrmap *map, void *key) |
| { |
| for (; map; map = map->next) { |
| int i, n = map->nr; |
| for (i = 0; i < n; i++) { |
| struct ptrpair *pair = &map->pairs[i]; |
| if (pair->key == key) |
| return pair->val; |
| } |
| } |
| return NULL; |
| } |
| |
| void __ptrmap_update(struct ptrmap **mapp, void *key, void *val) |
| { |
| struct ptrmap *map = *mapp; |
| |
| for (; map; map = map->next) { |
| int i, n = map->nr; |
| for (i = 0; i < n; i++) { |
| struct ptrpair *pair = &map->pairs[i]; |
| if (pair->key == key) { |
| if (pair->val != val) |
| pair->val = val; |
| return; |
| } |
| } |
| } |
| |
| __ptrmap_add(mapp, key, val); |
| } |